Through analyzing a large number of overseas exploration cases in the past 30 years of CNPC“going out”,the current exploration status,distribution characteristics and exploration models of lithostratigraphic reservoirs were systematically summarized,and the exploration potential of global lithostratigraphic reservoirs and outlook for lithostratigraphic reservoirs of CNPC overseas were pointed out. The results show that:（1）The exploration of global lithostratigraphic reservoirs has gone through four stages,and is currently in a mature stage of development. The large-scale deep-water sediments and reefs have become the main areas for discovering giant lithostratigraphic oil and gas fields.（2）Lithostratigraphic reservoirs newly discovered by CNPC overseas exploration and global lithostratigraphic reservoirs are mainly distributed in composite traps,mainly developed in foreland,rift and passive continental margin basins,The former has the largest reserves found in rift basins,followed by foreland basin,while the latter has the largest reserves in foreland basin,rift basins was the second.（3）CNPC overseas has implemented the same deployment and integrated exploration strategy for structural and lithostratigraphic oil and gas reservoirs,forming three distinctive exploration models:Stereoscopic exploration for multiple lithostratigraphic reservoirs,discovered high abundance lithologic reservoirs in lower combination,high buried hill reservoirs and low buried hill-lithologic complex reservoirs in Bongor Basin of Chad,and channel,fan delta,subaqueous fan and buried hill reservoirs in South Turgai Basin of Kazakhstan;High resolution 3D seismic exploration for complex lithologic bodies,discovered large gentle slope reef-beach complex gas reservoirs in Amu Darya Basin of Turkmenistan,giant lacustrine reef-beach oil fields in Santos Basin of Brazil,and deep-water turbidite sandstone biogas reservoirs in Rakhine sub-basin of Myanmar;Geology and engineering integration exploration for thin layer low amplitude structural-lithologic complex,discovered low amplitude structural-lithologic complex oil reservoirs in Oriente Basin of South America and thin layer reef-beach oil reservoirs in the Oman sub-basin of Middle East.（4）The exploration of global lithostratigraphic reservoirs will expand from mature exploration areas to frontier areas with low exploration levels,and from onshore to deep-water and ultra deep-water areas. The deep-water sedimentary bodies,subaqueous fans,and reefs in passive continental margin basins will be the hotspots of lithostratigraphic reservoir exploration. Subaqueous fans and burial hills in rift basins,composite traps related to reefs in foreland and passive continental margin basins will be the main targets of lithostratigraphic reservoirs exploration for CNPC overseas,which have favorable prospects for exploration.

Using high quality 3D seismic and logging data,Paleocene-Oligocene deep-water depositional system in Rovuma Basin and Upper Cretaceous deep-water depositional system in Zambezi Depression were studied,and the hydrocarbon accumulation conditions of both deep-water depositional systems were compared. The results show that:（1）Channel and lobe sands are large-scale favorable reservoirs in Paleocene-Oligocene deepwater depositional system in Rovuma Basin,and the reconstruction of contour current is the key factor for the formation of high-quality reservoirs.（2）Typical deep-water deposits,such as channels,lobes,block transport deposits,are developed in Upper Cretaceous in Zambezi Depression,while large scale drifts possibly are highquality reservoirs.（3）A large amount of hydrocarbon was potentially accumulated in Upper Cretaceous deepwater sands in Zambezi Depression,which was generated from Lower Cretaceous shale of restricted marine environment. Reservoirs were capped by widely distributed HST shale,and lithologic traps could be assumed by up dip pinch-out. With good conditions for hydrocarbon accumulation,it is a favorable area for next oil and gas exploration.

A seismic data processing method was proposed to address the severe high-frequency energy absorption and attenuation of seismic reflection waves by surface sand dunes,which results in low resolution,weak energy,and narrow frequency bandwidth in seismic data from desert areas. The method combines three approaches:nearsurface pre-stack Q compensation with micro-logging constraints,pre-stack depth Q migration,and post-stack compressive sensing frequency extrapolation based on well constraints. The method was tested on data from Agedem area in Niger. The results show that:（1）After applying the micro-logging constrained Q compensation method,the seismic data from Agedem area in Niger showed higher signal-to-noise ratio,improved resolution,smoother continuous reflection axes,enhanced effective information energy,and clearer depiction of small structures. The frequency bandwidth was expanded from 35 Hz to 70 Hz,and the main frequency increased from 30 Hz to 45 Hz.（2）The Q pre-stack depth migration eliminated the attenuation and dispersion caused by non-elastic factors and formation absorption during seismic wave propagation,ensuring imaging accuracy.（3）The results of compressive sensing frequency extrapolation method based on well-constrained data showed better matching with synthetic well records than that of unconstrained extrapolation processing,resulting in improved fidelity. It further enhanced weak signal energy and recovered the energy loss caused by severe absorption attenuation. The positioning accuracy of the 20-40 ms interval in Agedem area of Niger was improved,and the problem of false horizons at 180 ms after unconstrained processing was resolved.（4）The combined method achieved favorable results in Agedem area of Niger. The processed seismic data exhibited clear fault structures,crisp fault section waves,and easily identifiable small fault segments. After calibration with well logging data of well DB1,the correlation coefficient for the entire well section exceeded 0.92.

Through core observation,seismic interpretation,reservoir inversion,crude oil geochemical analysis,oil-source correlation,and oil and gas migration tracing analysis,the accumulation rules of typical structurallithologic composite reservoirs in block W of the slope zone of Oriente Basin in South America were analyzed,and the further favorable exploration directions were pointed out. The results show that:（1）the structurallithologic composite reservoirs in block W of the slope zone of Oriente Basin are generally characterized by westsouthwest dipping monoclinic structures,with local nose uplifts. The target layer of the oil reservoirs is M1ss member of Cretaceous Napo Formation. The sand bodies are NW-SE trending,with a large reservoir thickness and good physical properties.（2）Reservoir distribution is controlled by the sandbars in estuaries,the NW-SE extends shale belt and stable west-southwest dipping nose uplifts background joint control the trap formation and the spatial distribution of effective oil migration pathway controls reservoir formation.（3）There are three stages for structural-lithologic reservoir formation,including the early conventional crude oil filling stage,the middle stage for crude oil degradation,and late stage of conventional crude oil mixing.（4）The southwest part of the two shale belts in southern area of block W is favorable for structural-lithologic traps.

Based on seismic,drilling and thin section data,seismic wave impedance reservoir inversion technology was used to study the characteristics and hydrocarbon accumulation rules of Carboniferous subsalt carbonate reservoirs in the eastern margin of Pre-Caspian Basin,and the next risk exploration direction was pointed out.The results show that:（1）Carboniferous subsalt carbonate reservoirs in the eastern margin of Pre-Caspian Basin can be divided into limestones,dolomites,dolomitic limestones,calcareous dolomites,silicified siliceous rocks. The reservoir porosity is 4%-12%,and the permeability is generally less than 1 mD,belonging to lowmedium porosity and low permeability vug-pore reservoirs.（2）Lithologic reservoirs are mainly developed in Aknol structural belt in the study area,without uniform oil-water contact. The oil layers are distributed in thin layers,with poor correlation and continuity. High-quality reservoirs are mostly high growth rate beach bodies in the upper part of high-frequency third-order sequence cycles and karst reservoirs near unconformity surfaces.（3）The seismic wave impedance reservoir inversion technology based on the initial model constrained by horizon and logging was used to predict thin carbonate reservoirs,which can more clearly show the horizontal and vertical distribution characteristics of KT-Ⅰ and KT-Ⅱ reservoir groups. The favorable reservoirs in the study area are mainly developed in G1 and G4 sublayers at the top of KT-Ⅱ reservoir group.

Passive continental margin basins have low exploration degree and high potential,and Senegal Basin is one of the exploration hotspots of passive continental margin basins in recent years. Based on plate tectonic evolution,the evolution process of Senegal Basin was restored using seismic and geologic data,and the exploration prospects of lithologic reservoirs were analyzed. The results show that:（1）The Senegal Basin can be divided into three evolution stages,incluing intra-continental rift during the Middle Triassic rift,inter-continental rift during the Late Triassic to Early Jurassic transition,and passive continental margin during the Middle Jurassic to the present drift. Controlled by paleostructure and paleoclimate,the rift sediments are thin and buried deeply,mainly in continental red beds stratigraphic sequence. Evaporite facies develop widely in intercontinental rift. The drifting sequence deposits with large thickness and deep-water sedimentary system are important reservoirs in discovered oil and gas fields.（2）The Lower Cretaceous Albian delta sand bodies were mainly developed in the deep-water area of the Middle sub-basin,and the Lower Cretaceous fault-lithologic reservoirs were formed by lateral or vertical migration of oil and gas. The Upper Cretaceous Cenomanian-Maastrichtian turbidity fan sand bodies were developed in the ultra-deep water area,and the oil and gas migrated upward to form Upper Cretaceous submarine fan lithologic reservoirs. Miocene turbidite fan sand bodies were mainly developed in Mauritania and Casamance salt basins,salt diapirs have important effects on oil and gas migration and sealing,forming salt structure related oil and gas reservoirs.（3）Combined with the discovered law of oil and gas accumulation,the Upper Cretaceous submarine fan reservoirs may be developed in Mauritania and Casamance subbasins without drilled wells,while the reef-shoal reservoirs may be developed in the carbonate platform of the entire basin shelf,and they are the next key exploration areas.

In order to standardize overseas oil reserves evaluation,a method for classifying and categorizing overseas lithologic reservoir reserves,determining lithologic boundary,o il bearing area and effective thickness was proposed. The results show that:（1）Reserves classified as P generally require a development plan approved by the company or the government of the resources country. P1 reserves are calculated based on wells with commercial production or commercial test flow rates,and their area is usually determined by the drainage area of the production wells and the range limited by the known gas bottom or the known oil top and oil bottom. The reserves within half the distance from the P1 reserves boundary to lithologic boundary are P2 reserves,and the reserves within the range from P2 reserves boundary to lithologic boundary are P3 reserves. If there is no oil water contact within the trap or cannot be determined yet,P3 reserves should be determined based on the spill point of the trap. If there are significant changes in lithologies or reservoir physical properties,P2 reserves can be determined by extrapolating one development well spacing based on P1 reserves,and P3 reserves can be determined by extrapolating one development well spacing based on P2 reserves.（2）When the distance from a class P reserve well to the pinchout line of a permeable reservoir is no more than 3-4 times the development well spacing,for medium to high porosity and permeability reservoirs,the pinchout line can be directly determined as the lithologic boundary,while for low porosity and permeability reservoirs,the minimum effective thickness contour line that can meet the class P reserve standard is determined as the lithologic boundary. The oil and gas bearing area should be comprehensively delineated by lithology boundaries,oil（gas）water contact,tight layer sealing zones,etc,the wells within the area should meet the class P reserve standard. For oil and gas reservoirs with identified fluid interfaces,the fluid interfaces used to delineate oil and gas bearing area should be confirmed by drilling and coring data or testing data. For oil and gas reservoirs with unidentified fluid interfaces,the oil and gas bearing area should be determined by extrapolating the lowest confirmed bottom boundary of the oil and gas producing layer or the effective thickness value through testing.（3）The determination of the effective thickness of P1 reserves should have reliable formation testing data or sufficient logging data and have demonstrated its production capacity. The determination of the effective thickness of P2 reserves usually lacks conclusive testing data and has not confirmed its production capacity. Due to the uncertainty in rock physical interpretation,there is significant uncertainty in the effective thickness of P3 reserves.（4）It is recommended to use the volumetric method for evaluating lithologic reservoir reserves. The application example in TP oilfield in Ecuador has confirmed the effectiveness of the classification and categorization of lithologic reservoir reserves and reserves evaluation method.

By using methods such as core and thin section analysis,nuclear magnetic resonance and micro-CT testing,isochronous tracing under sequence framework and paleogeomorphic restoration,a systematic analysis was conducted on the sedimentary characteristics,sequence,sedimentary evolution characteristics and diagenesis of high porosity and permeability limestone reservoirs of Cretaceous Cenomanian in the western United Arab Emirates,and the controlling factors of high porosity and permeability reservoirs were studied from the aspects of structure,sedimentation and diagenesis. The results show that:（1）The high porosity and permeability limestone reservoirs of Cenomanian in the western United Arab Emirates are mainly developed in Mishrif Formation,with the lithologies mainly consisting of sparite rudist limestone,sparite bioclastic limestone,and micrite bioclastic limestone. The reservoirs space is mainly composed of biological cavities,moldic pores and intergranular dissolved pores. The Mishrif Formation is generally characterized by carbonate ramp sedimentation,three types of subfacies including inner ramp,middle ramp and outer ramp,and six types of microfacies including rudistid reefs,high-energy shoals,front/back shoals and inter-shoals,lagoons can be identified. High porosity and permeability reservoirs are mainly developed in rudistid reefs and high-energy shoals. The porosity and permeability of limestone reservoirs in rudistid reefs are 20%-34% and 150-2 000 mD,respectively,while the porosity and permeability of limestone reservoirs in high-energy shoals are 25%-33% and 40-370 mD,respectively.（2）From bottom to top,the Mishrif Formation in the study area can be divided into three third-order sequences SQ1-SQ3 and seven systems tracts. The SQ1-SQ2 sequences are mainly composed of highstand systems tract,with rudistid reefs and high-energy shoals broadly developed. The SQ3 sequence is composed of highstand systems tract and transgressive systems tract,with high-energy shoals well developed in high parts of ancient landform and beeter properties.（3）The pore development of the high porosity and permeability reservoirs of Mishrif Formation in the study area is afffacted by multi-stage of diagenesis,including constructive diagenesis dominated by contemporaneous atmospheric freshwater dissolution and maintenance diagenesis related to hydrocarbon filling.（4）The high porosity and permeability reservoirs of Mishrif Formation in the study area are controlled by multiple geological factors such as sedimentary facies,sequence framework,paleogeomorphology and diagenetic effects,and the sedimentary facies was setted as the main factors. The distribution and evolution of sedimentary facies in Mishrif Formation was controlled by HST during SQ1 and SQ2,while influenced by the inherited paleogeomorphology during the SQ3.

Based on seismic data,drilling and logging data,the seismic reflection characteristics and the distribution rules of carbonate dissolution valleys filled with mudstones of Cretaceous in block A of Oman Basin were studied by using seismic forward modeling and attributes,and the hydrocarbon accumulation model was determined. The results show that:（1）A dissolution valleys system filled with mudstones is developed in the west and middle of block A,Oman Basin,which is characterized by concave features,discontinuous reflection and weak amplitude. The dissolution valleys with depth greater than 3 m and width greater than 10 m could be identified using available seismic data.（2）By optimizing seismic attribute,it is found that Euler curvature could suppress the influence of dense faults and the effect of dissolution valleys identification is better than coherence and regular curvature attributes.（3）Combination traps of dissolution valleys filled with mudstones are identified whose total area is 80.66 km² by the new identification technology. In addition,good oil and gas shows was revealed by a new well,confirming the reliability of this technology.

Referring to the domestic exploration theory and technology of lithologic oil and gas reservoirs in fault basins,sequence stratigraphy analysis method was used to carry out multi-scale sequence stratigraphy division,geochemical analysis of source rocks,research on hydrocarbon accumulation rules,favorable zone division and potential evaluation of Fula Sag in Muglad Basin of Central African Rift System. The results show that:（1）Five third-order sequences can be identified based on the sea level changes,and the flooding surface is the most favorable vertical location for lithologic reservoirs.（2）There are three major provenance systems in AG Formation in the study area. Fula-west steep slope belt is short-axis with rapid deposition and narrow distribution of facies zones. Braided river delta system is continuously developed with wide distribution in the northeastern part of the study area,and braided river delta system is limited developed in the southeastern part at the later period. The delta front and beach bar in shore-shallow lacustrine are the most favorable sedimentary facies for lithologic reservoirs.（3）Grey-dark mudstones developed in AG2 member（SQ4 sequence）of AG Formation are mainly deposited in shallow lake to semi-deep lake environment. The kerogen is type Ⅰ-Ⅱ₁,the average total organic carbon（TOC）content is 3.41%,and the hydrocarbon generation potential（S₁+ S₂）is greater than 8 mg/g,which are good-excellent source rocks and the material basis for the forming of structural-lithologic reservoirs.（4）The AG Formation can be divided into seven lithologic reservoirs zones,among which the northern Fula-Moga slope zone has favorable conditions for hydrocarbon accumulation and great exploration potential.

Based on drilling,logging and 3D seismic data,core analysis,well correlation,oil and gas migration and accumulation simulation,seismic inversion and multi-information superposition methods were used to analyze the main controlling factors of structural-lithologic reservoirs above source kitchen in Melut and Muglad rift basins in South Sudan from three aspects:oil source conditions,reservoir and cap-rock assemblage and migration systems,and hydrocarbon accumulation models were discussed. The results show that:（1）The Melut and Muglad basins both developed high-quality source rocks in the I stage rifting period of the Early Cretaceous with large thickness,wide area,good organic matter type and moderate maturity,providing good oil source conditions. The Paleogene Yabus Formation and Neogene Jimidi Formation in Melut Basin,and Cretaceous Aradeiba Formation in Muglad Basin developed delta facies and fluvial deposits,and the microfacies sand bodies of river channels and underwater distributary channels had moderate sand content and sandstone thickness,and sealing zones in floodplains and underwater distributary bays are locally developed.The sand-mud interlayer reservoir and cap assemblage formed on multiple sources,and the reservoir and cap-rock assemblage and its vertical sedimentary evolution controlled the formation of large-scale structural-lithologic traps. The boundary-controlled basin faults and the depression-controlling faults in the slope area of the basin margin were the main vertical migration channels of oil and gas connecting the main source rock and the target layer above source kitchen. The multi-stage unconformities and sand-rich strata above source kitchen formed multiple lateral dominant migration paths（transport ridges）. The coupling of the source faults and transport ridges controlled the favorable zones of the structural-lithologic reservoirs above the source kitchen in Melut and Muglad basins.（2）The Yabus Formation,Jimidi Formation in Melut Basin and Aradeiba Formation in Muglad Basin have the petroleum geological conditions for the formation of scale structural-lithologic reservoirs above source kitchen,and the accumula-tion models are vertical migration of fault,vertical migration of fault and lateral migration of unconformity plane,and vertical migration of fault and lateral migration of connected sandbodies.

Guided by the classic model of sequence stratigraphy,using core,welllog,mudlog and seismic data,the characteristics of the third-order and fourth-order sequence boundaries of Middle Eocene in the deep-water area of Rovuma Basin in East Africa were summarized. Corresponding to channel-lobe complexes in deep-water depo-sits,sedimentary subfacies and microfacies were divided. Based on this,the evolution laws of deep-water deposits and the influence of sedimentary microfacies on reservoirs were explored. The results show that:（1）The top boundary of the third-order sequence of Middle Eocene in Rovuma Basin is located at the top of the condensed section and occasional carbonate debris flow,and the bottom boundary is located at the bottom of the gravity flow that migrates southward in stages. The fourth-order sequence is determined by the top boundary of the bathyal deposit and the sedimentary interface with good continuity on the seismic section,but can only be interpreted within the distribution range of the channel-lobe complexes.（2）Two sedimentary facies,including channel complex and lobe complex,have been identified in deep-water deposits in the study area. The two sedimentary facies can be subdivided into four subfacies:composite channel,lobe,crevasse splay,and overbank/drift deposits. There are nine microfacies,including channel axis/edge filling,internal natural levee,mass transport deposits（MTD）,channel bottom lag deposit,lobe element main body/edge,crevasse splay,and overbank/drift deposits. Both crevasse splay and overbank/drift deposits are distributed in the northern part of the composite channel,and the crevasse splay affected by bottom flow is in a northward divergent vein shape.（3）The evolution of deep-water depo-sits of Middle Eocene in the study area can be divided into four stages,namely SQ1-SQ4 in sequence,showing a process of progradational deposition and retrograde deposition as a whole. Affected by the interaction between gravity flow and bottom current,the channel-lobe complexes gradually migrated southward.（4）The development of reservoirs in the research area is mainly controlled by sedimentary microfacies. The main body of the lobe element and the axis of the channel developed high-quality reservoirs. The reservoirs are the most developed and the physical properties are the best in the main body of the lobe element,with a porosity of 13.00%-21.00% and a permeability of 5.0-118.0 mD. The reservoir properties at the axis of the channel are secondary,with a poro-sity of 13.00%-19.00% and a permeability of 0.8-23.0 m D. The reservoir properties of overbank/drift deposits are poor,and the reservoirs in the crevasse splay are not developed.

Based on core,thin section,and well logging data,the lithologies,reservoir space,and physical properties of Jurassic Oxfordian reservoir in the eastern right bank of Amu Darya in Central Asia were analyzed.3D seismic data were used to carry out semi-quantitative prediction of reservoir distribution and thickness through methods such as forward seismic modeling,waveform clustering,frequency-division RGB fusion and ensemble learning. The results show that:（1）The lithologies of Jurassic Oxfordian reservoir in the eastern right bank of Amu Darya are mainly bioclastic limestone,grainstone and micritic limestone,and the reservoirs are characterized by fractured-vuggy type. The reservoir space is dominated by biological framework pores,intragranular pores and fractures,and fractures provide a channel for later dissolution fluids. The average thickness of the reservoir is 41.6 m,and the average porosity is 4.65%.（2）The reservoirs in the study area are mostly developed in the XVhp layer,and can be divided into top-type,bottom-type,and dual-type according to their distribution position in the XVhp layer. The top-type reservoirs are mainly distributed in the central and eastern parts of the study area,the bottom-type reservoirs are concentrated in the west,while the dual-type reservoirs are extensively developed in the northwest. The reservoirs in the western and northeastern parts of the study area are well developed,with a thickness of 45-75 m,mostly distributed along fault zones. The reservoirs in the southeastern part are poorly developed,with a thickness less than 30 m,and are further away from faults.（3）When using ensemble learning method to calculate the reservoir thickness in the study area,the stacking method in the heterogeneous ensemble approach was used for model computation. Outliers were eliminated using a boxplotbased method,and the predictive performance of the models was evaluated through cross-validation. The calculated reservoir thickness showed a high degree of agreement with the thickness observed in 11 wells drilled in the study area,and the correlation coefficient is 0.74.

Beach sand body is one of the essential reservoir types in continental basins in China. Based on core testing， drilling，logging and 3D seismic data，the sedimentary characteristics of the beach sand bodies of Jurassic Badaowan Formation in Shawan Sag of Junggar Basin were systematically analyzed，and their distribution，depositional model and exploration potential were discussed. The results show that： （1）The beach sand bodies of Badaowan Formation in Shawan Sag comprise beach ridges and troughs. The beach ridges are rich in sand，mainly composed of sandy conglomerate，pebbly sandstone and sandstone，with massive bedding，wave cross-bedding and local soft sedimentary deformation bedding being developed，showing multi-phase beach ridge superposition. The beach trough is poor in sand and dominated by thin siltstone，with reversed grain sequence in vertical. The single beach ridge comprises three sedimentary sequences， and each sequence has grain size probability curves in three-stage.（2）The beach ridges in the study area show a reflection characteristic of strong amplitude lenticular discontinuity on seismic section，and the stratal slices show beach ridges distributed in rows and belts along the lake shoreline. Beach sand bodies are distributed in strips along the lake shorelines in the recessed area between the two big delta fan bodies in the west ring belt， and beach ridges and troughs are distributed alternately. The single beach ridge has small area， with large number，up to 12. Appearing in groups and belts，the area of beach ridge sand body group is up to 145 km².（3）The ridged trough beach sand bodies at the bottom of Badaowan Formation in the study area have excellent exploration and development potential，with a considerable thickness of sand bodies， good physical properties，and a wide distribution area. The trough can be used as a lateral barrier layer to form suitable reservoirs and traps. The high-quality source rocks of the alkaline lake of Permian Fengcheng Formation provide oil and gas sources， and the unconformity surface and faults are favorable oil and gas transport systems.

Based on cores,analytical tests,well logging and seismic data,the stages,lithology and lithofacies,geophysical characteristics and volcanic edifices of igneous rocks in Santos Basin of Brazil were studied by means of combination of geology and geophysics,and the development characteristics of igneous rocks in Eastern oilfield was analyzed. The results show that:（1）The Santos Basin developed five stages of magmatic activities,namely Valanginian-Hauterivian eruptive rocks,Barremian-Early Aptian eruptive rocks,Aptian eruptive rocks,Campanian intrusive rocks,and Eocene intrusive rocks and eruptive rocks. There are two eruption models,incluing subaerial eruption and subaqueous eruption,two types of volcanic edifices,including fissure type and central type,and six types of rock facies,including volcanic channel facies,volcanic neck facies,overflow facies,cataclastic facies,subvolcanic facies and volcanic sedimentary facies.（2）The distribution prediction of igneous rocks in Eastern oilfield has been realized according to the prediction method of region determination by volcanic edifice,source determination by volcanic channel,facies determination by seismic reflection characteristics,qualitative determination by multiple attributes and quantitative determination by pre-stack inversion. Intrusive rocks are mainly distributed in the central part of the study area,and eruptive rocks are mainly distributed in the northwest and east part of the study area. The results were confirmed by drilling and the coincidence rate reached 95%.（3）Hydrocarbon accumulation in basins with igneous rocks is closely related to the formation and evolution of igneous rocks. Igneous rocks have both constructive and destructive effects on hydrocarbon accumulation,and they are of great significance for oil and gas exploration.

Lithologic reservoirs are developed in the lower member of Miocene Gumai Formation in South Sumatra Basin. Based on logging,mud logging and seismic data,combined with regional setting,the hydrocarbon accumulation conditions and main controlling factors of the lower member of Miocene Gumai Formation in block J of South Sumatra Basin were studied,and the favorable zones were predicted. The results show that:（1）Oil and gas in block J of South Sumatra Basin mainly come from the eastern Betara hydrocarbon generation sag,and there are three sets of source rock developed,namely,the source rocks in the lower member of Talang Akar Formation,the source rocks in the upper member of Talang Akar Formation,and the source rocks in Gumai Formation. Among them,the marine continental transitional source rocks developed in the lower member of Talang Akar Formation are the best,mainly type Ⅰ or Ⅱ kerogen,containing a large number of coal seams. The TOC content is mainly 0.5%-2.0%,hydrogen index（HI）is mainly 100-350 mg/g,and the average oxygen index（OI）is 30 mg/g.（2）The lower member of Gumai Formation in block J developed a set of sedimentary systems from east to west,including proximal delta front,distal delta front,and prodelta. The proximal delta front in the eastern part of the block is mainly composed of thick sandstone,while the distal delta front in the western part is mainly composed of mudstone with thin sandstone. Massive medium to fine sandstones are the main reservoir rocks,with widely developed argillaceous bands,which are underwater distributary channels and overbank in the delta front.（3）The lithologic reservoirs of Gumai Formation in block J are controlled by mudstone seal and major faults. Oil and gas are mostly concentrated in distal delta front with high shale content and good sealing conditions in the western part of the block.（4）The lithologic reservoirs in the lower member of Gumai Formation in block J have a hydrocarbon accumulation model of“lower generation and upper storage,composite transport,and caprock controlled reservoir”. The W and P regions in the central part are favorable areas for lithologic reservoir exploration.

A new effective permeability calculation method was proposed for the granitic buried-hill reservoirs in Bongor Basin of Chad based on drilling,logging,and oil testing data. Apparent effective permeability was derived from well testing results,serving as labeled data for the sample dataset. The method relies primarily on domain knowledge and mechanism-driven models,and is supplemented by machine learning to establish feature logs. The dual-prediction model XGBoost+KNN was employed to calculate apparent effective permeability,with SHAP values used for model interpretability analysis. The results show that:（1）Permeability indicator logs,namely apparent acoustic impedance and porosity,were utilized to select 26 effective testing intervals from19 wells,based on their intersection with production index. The well testing results were converted into apparent permeability values,ranging from 0.01 to 1 601.50 m D,resulting in a dataset comprising 51 348 depth data points and 14 input logs. The sample dataset adequately covers the main buried hill zones and incorporates input log response characteristics from diverse lithologies,reservoir qualities,and well testing production performance,thus achieving sufficient representativeness.（2）The XGBoost model effectively uses various logs,inclu-ding the apparent acoustic impedance log,normalized depth log representing the vertical zoning characteristics of buried-hill reservoirs,density log,window average of natural gamma ray log,acoustic log,neutron log,window average of neutron-density porosity difference log,deep and shallow resistivity log,and window standard deviation of natural gamma ray log. The model’s predictions exhibit consistency with qualitative understanding of buried-hill reservoir quality and demonstrate higher accuracy compared to the KNN model.（3）The granitic buried-hill reservoirs of Bongor Basin,Chad,with effective permeability greater than 1.00 m D,are classified as effective reservoirs,while those exceeding 50.00 mD are considered good reservoirs. The calculated results using the proposed method are consistent with the well testing results.

Based on literature research and geological analysis，the research progress，application prospect and development trend of distributive fluvial system（DFS）theory were reviewed. The results show that：（1）There are five important problems should be claimed in current DFS research，including to excavate the scientific connotation of DFS through case analysis and explore its application value；DFS is a multi-channel coexisting depositional system which cannot be thought as a new pattern of channel；channels network and channels transition，as well as their evolution，are important issues in DFS study；it is urgent to build and to perfect the depositional model； predictable reservoir modelling is the way to realize the basin-scale reservoir prediction.（2）DFS are prospected to be widely developed in petroliferous basins and the researches are of great theoretical significance and application value for promoting the theoretical sedimentary innovation and oil and gas resources exploration.（3）The current study should be focused on DFS sedimentary database construction，DFS facies identification model construction，the research of quantitative DFS channel network prediction and their evolution and hierarchical DFS reservoir geological model integration. Future trend in DFS research should combine sedimentology with geomorphology，geography and Earth Information Science and technology，with the help of big data and intelligent technology， to realize quantitative depositional system prediction and reservoir characterization.

The exploration potential of Ma 5₅ sub-member of Ordovician Majiagou Formation in Sulige area of Ordos Basin is huge. Through core observation，thin section identification，scanning electron microscope and geochemical testing，combined with geophysical technologies，the sedimentary characteristics of Ma 5₅ sub-member of Ordovician Majiagou Formation in Sulige area were studied，and its petroleum geological significance was discussed. The results show that： （1）The Ma 5₅ sub-member of Ordovician Majiagou Formation in Sulige area belongs to carbonate platform facies which inclines to the east under the background of overall transgression and late regressions. Open platform and restricted platform subfacies are developed，which can be subdivided into dolomite flat，carbonate flat，and intraplatform shoal，dolomite-carbonate flat and carbonate-dolomite flat according to the composition.（2）In the plane，the sedimentary environment is typical banded distribution，the salinity of the sedimentary water in the western region is relatively high，with restricted platform characteristics，while the salinity of the sedimentary water in the eastern region is low and has the characteristics of open platform.（3）The low-lying areas within the restricted platform and the open platform in the study area，where high-density and Mg-rich seawater converges，are favorable areas for dolomite development.（4）The restricted/open dolomite flat，intraplatform shoal and gypsum-bearing dolomite flat microfacies mainly develop various kinds of dolomite reservoirs. The western and northern areas with contiguous dolomites are potential replacement areas for oil and gas exploration.

It is important to carry out fine characterization of different levels of reservoir architecture units in the composite sand bodies for the optimization of the development plan of the lower Minghuazhen Formation in Penglai 19-3 oilfield in Bohai Sea. The cores，logging and 3D seismic data were used to characterize fifth to thirdorder architecture units based on multi-attribute intelligent fusion in the second sublayer of Ⅳ oil group of lower Minghuazhen Formation in the third region of Penglai 19-3 oilfield. The results show that：（1）It can be divided into different levels of reservoir architecture units such as single meander belts， single point bar sand body and single lateral deposit in Penglai 19-3 oilfield.（2）Through the optimization of seismic attributes， the maximum amplitude， reflection intensity and relative impedance are more sensitive to reservoir response. The neural network multi-attribute fusion based on parameter supervision further improves the accuracy and reliability of reservoir prediction.（3）A single meander belt with fifth-order configuration unit is developed in the study area， which is narrow in the middle and wide at both ends in the north-south direction. The fourth-order architecture unit of single point bar is distributed in a string of beads， and the point bars are cut and transformed with each other. The lateral deposit is positive rhythm， and the dip angle of the lateral deposit is 2°-5°.（4）The geometric shape， scale and structure of the configuration units of different genetic types are relevant， which is of great significance for adjusting the well location， improving the injection-production well pattern and improving the efficiency of oilfield development.

Shawan Sag and Mahu Sag in Junggar Basin have similar tectonic，sedimentary and reservoir-forming backgrounds. Based on the study of lithofacies paleogeographic pattern and source-sink system of Shawan Sag， it was proposed that a large-scale far-source depositional system from the northwest direction was developed in the center of the sag， namely Liushugou river system，and the sedimentary evolution characteristics and hydrocarbon accumulation conditions of Shawan Sag were analyzed about this water system. The results show that：（1）Liushugou river in Shawan Sag originated from Zaire Mountain and formed a large fluvial delta depositional system in the central Shawan Sag after flowing through Zhongguai uplift. The large-scale reservoirs such as meandering river point sand bar， delta front underwater distributary channel，estuary bar and sheet sand are formed in the sag.（2）The Liushugou River developed inheritantly from Permian to Jurassic，experienced the processes of Permian transgression，early regression and mid-late transgression of Triassic， and lake water body shock development successively of Jurassic， forming scale source rocks of Middle-Lower Permian. Large delta fans of Permian-Early Triassic， multi-stage channel superimposed reservoirs of Jurassic，and regional cap rocks of late Late Permian and late Early Triassic， formed multi-sets of vertically advantageous assemblages of source-reservoir-cap rock. The unconformities and fault systems formed by multi-stage tectonic movements have constructed a favorable transport system for oil and gas migration and adjustment in Shawan Sag.（3）The discovery of Liushugou river system has changed the traditional understanding that there is no large remote river system in Shawan Sag and only near-source fan delta developed. The center of Shawan Sag and the lower part of slope are new areas for searching for large-scale oil and gas reservoirs.

Based on data of core facies，logging facies and rock fragment analysis，the microstructure，reservoir unit types and oil-water connectivity of Paleogene Shahejie Formation in Langgu Sag of Bohai Bay Basin were studied using a point-line-surface representation method. The results show that：（1）The Paleogene Shahejie Formation in Langgu Sag mainly has two types of reservoir units，namley，structural reservoir units and “fault sand configuration” reservoir units. There are six，five，three and two reservoir units in No. 1 to No. 4 sublayers of Es₄-Ⅰ sand group in An 11 well area，respectively. There are five reservoir units in both No. 3 and No. 7 sublayers of Es₃-Ⅱ sand group in An 22 well area，while the number of reservoir units in other sublayers varies.（2）The reservoir units of the upper Es₄-Ⅰ sand group in An 11 well area have high connectivity of sand bodies and fluids， while the reservoir units of middle Es₃ in An 22 well area have complex types，complex distribution，high sand body connectivity and relatively low fluid connectivity.（3）After implementing the reservoir units as development units，the daily crude oil production of each sublayer in An 11 and An 22 well area has increased. Fine characterization of reservoir units is favorable for indentifing the rolling evaluation objectives in exploration and development，and it also can determine accurate reservoir thickness，reservoir boundaries and reservoir distribution range for the calibration of dynamic reserves and economically recoverable reserves during the development process.

Through thin section observation，fluid inclusion analysis，rock geochemical testing and basin numerical simulation，the development characteristics of veins of Lower Cambrian Qiongzhusi Formation in Wangcang area at Micang Mountain front，Sichuan Basin，were studied，and the fluid activity stages and fluid properties in the sedimentary period were distinguished. The results show that： （1）There are two stages of calcite veins and one stage of quartz veins developed in Qiongzhusi Formation in Wangcang area，and the quartz veins were formed later than the calcite veins. The first stage of calcite veins was formed in the Early Silurian，and the vein forming fluids were mainly inner formation water，which were affected by a small amount of atmospheric fresh water and seawater，and filled veins together with liquid hydrocarbon fluids. The homogenization temperature ranged from 83.1 ℃ to 136.2 ℃，and the salinity was 0.4%-12.2%. The second stage of calcite veins was formed in the Early Jurassic. The vein forming fluids were inner formation water，which filled calcite veins together with liquid hydrocarbon and high density methane in gas phase. The homogenization temperature ranged from 140.2 ℃ to 185.4 ℃， and the salinity was 5.7%-17.3%. The quartz veins were formed in the Early Cretaceous，and the vein forming fluids were siliceous fluids in Qiongzhusi Formation，which filled the quartz veins with methane. The homogenization temperature was 162.1 ℃，and the salinity was 13.8%.（2）The δ¹⁸O_PDB values of calcite vein samples from Qiongzhusi Formation in the study area range from -14.95‰ to -9.17‰，and the measured average δ¹⁸O_PDB value of most calcite veins is smaller than that of global seawater of the Early Cambrian. The negative migration characteristics are controlled by temperature and δ¹⁸O abundance of the vein forming fluids. Rare earth elements are enriched in calcite veins and wall rocks，both of which have Eu positive anomaly and Ce no anomaly，and the fluids came from inner formation water.（3）Qiongzhusi Formation in the study area was affected less by external fluids， and the development of joints and fractures did not connect with the upper and lower strata，which was conducive to the accumulation and closed preservation of shale gas in Qiongzhusi Formation in the piedmont zones.

Through microscopic thin section identification，X-ray diffraction analysis，major and trace elements test of shale samples from Permian Wujiaping Formation in eastern Sichuan Basin，the pyrite characteristics and anoxic events in shales of Permian Wujiaping Formation in eastern Sichuan Basin were studied. The results show that：（1）The shale mineral composition of Wujiaping Formation in eastern Sichuan Basin is relatively complex，rich in clay minerals，and pyrite is developed. The lithofacies are mainly divided into calcareous siliceous mixed shale，siliceous shale and clay shale.（2）The sensitive parameters of oxidation-reduction environment including U/Th，Ni/Co and V/Cr indicate that the sedimentary environment of Wujiaping Formation shale in the study area is generally suboxic environment，presenting the characteristics of transition from oxidation environment to anoxic environment from bottom to top vertically.（3）The grain size of framboidal pyrite in the study area is 5.18-10.75 μm，and it gradually decreases from bottom to top. This change in grain size can be regarded as its response to the Late Permian oceanic anoxic event.（4）The anoxic event caused by the eruption of the Emeishan basalt involves the late stage of Maokou Formation，and the stage of Wujiaping Formation and Dalong/Changxing Formation. Since the eruption of the Emeishan basalt，CO₂ has been continuously dissolved in the water，plankton has increased greatly，and the oxygen content in the water has continued to decline. By the stage of Dalong/Changxing Formation， the water in eastern Sichuan Basin has been completely in an anoxic or even sulfide environment.

On the basis of field outcrops， drilling and seismic data， through the methods of regional unconformity identification，apatite fission track age analysis and buried hydrocarbon generation history recovery，the main tectonic events of Meso-Cenozoic in Zhangpenggou area in the eastern Junggar Basin and their effects on hydrocarbon accumulation were studied. The results show that： （1）There are four stages of regional unconformity in the Meso-Cenozoic era in Zhangpenggou area，namely，the unconformity between Jurassic Badaowan Formation and Triassic Xiaoquangou Formation（J₁b/T_2-3xq），the unconformity between Cretaceous Tugulu Group and Jurassic Shishugou Group（K₁tg/J_2-3sh），the unconformity between Neogene Shawan Formation and Cretaceous Tugulu Group（N₁s/K₁tg）and the unconformity between Quaternary and Neogene Shawan Formation（Q/N₁s），which respectively correspond to four tectonic uplift events，namely，the Late Triassic to Early Jurassic compressional uplift，Late Jurassic to Early Cretaceous compressional uplift，Late Cretaceous to Paleocene uplift and tilting， and Miocene to present continuous uplift and denudation. Each tectonic event has obvious regional tectonic background and geological response such as folds and faults.（2）The uplift of the Late Triassic to Early Jurassic in the study area resulted in a decrease in the rate of hydrocarbon generation of the source rocks and the thermal evolution of hydrocarbon. The fault generated by the Late Jurassic-Early Cretaceous compressional uplift event became an effective channel for hydrocarbon transmission，which matched well with the hydrocarbon filling period，and was a key structural event for hydrocarbon accumulation. Late Cretaceous to Paleocene uplift and tilting，and Miocene to present continuous uplift play a role in the reconstruction and destruction of later oil reservoirs. The formation of Kelameili fault has a controlling effect on hydrocarbon accumulation in the study area.（3）The oil source in the study area mainly comes from Middle Permian Pingdiquan Formation，and the reservoir accumulation model is near-source lateral migration self-generation and self-storage type. Hydrocarbon accmulated in lithologic shielding area and high structural parts of the anticline wing. The faults and unconformities generated by tectonic movement control the plane hydrocarbon distribution. The Permian Pingdiquan Formation near faults and unconformities is a favorable area for hydrocarbon exploration.

Kongqueting area in Xihu Sag of the East China Sea Basin is highly explored and rich in oil and gas. Through the data of cast thin section，scanning electron microscope and X-diffraction，the diagenesis of Pinghu Formation and its influence on pore evolution in Kongqueting area of Xihu Sag were analyzed. The results show that：（1）The Pinghu Formation in Kongqueting area of the East China Sea Basin is mainly delta-bay sedimentary environment. The lower and upper parts of the lower member of Pinghu Formation are mainly tidal flat sedimentary environment，and the middle and upper members of Pinghu Formation transit from tidal flat to delta sedimentary environment.（2）The reservoir rocks of Pinghu Formation in Kongqueting area are mainly feldspathic lithic sandstone，with medium composition maturity and high structural maturity. It is a low porosity and low permeability reservoir，with an average porosity of 10.44% and an average permeability of 25.65 mD.（3）The study area has experienced a variety of diagenesis. Compaction reduces reservoir physical properties，cementation makes the reservoir physical properties poor，but to a certain extent，the cements can resist compaction and protect the primary intergranular pores，and dissolution is an important factor to improve reservoir physical properties.（4）The reservoir in the study area is mainly in the late diagenetic A2 stage. Two secondary pore development zones were formed at 3 000-3 500 m and 4 000-4 400 m. The relatively high quality reservoirs are conducive to hydrocarbon accumulation.

Taking a homogeneous radial gas reservoir with edge water as an example，based on the material balance theory of water drive gas reservoirs，the relationship between the average water saturation of the formation and the exit-end water saturation was derived. Water storage volume coefficient was introduced to establish the relationhsips of average water saturation with dynamic reserves and water influx of gas reservoirs，so as to calculate the dynamic reserves and water influx of gas reservoirs. This method was applied to the sixth layer of Quaternary Sebei Formation in Tainan gas field of Qaidam Basin，the dynamic geological reserves were verified using the apparent geological reserves method，and the calculation results of water influx were verified using numerical simulation method. The results show that：（1）In homogeneous radial gas reservoir with edge water，the average water saturation of the formation is linearly positively correlated with the exit-end water saturation.（2）When calculating the dynamic reserves of gas reservoirs through average saturation，the data that tends to stabilize in the middle and later stages of development should be selected. At this time，the pressure drop of the formation affects the reservoir boundary，which can reflect the real dynamic reserves of the entire work area. However，the results calculated by early data are relatively small.（3）The dynamic geological reserves of the sixth layer of Quaternary Sebei Formation in Tainan gas field of Qaidam Basin calculated by average saturation are 8.1×10⁸ m³，with an error of 1% compared with the dynamic geological reserves calculated by apparent geological reserves method. The error between the water influx calculated by average saturation and the water influx calculated by numerical simulation method is about 10%.

Through the dissection of typical subtle oil and gas reservoirs in the southern slope of Kuqa Depression，the structure， sedimentological conditions， trap development types and models of subtle traps were sorted out，and the exploration direction was pointed out. The results show that：（1）Three types of subtle traps are mainly developed in the southern slope belt of Kuqa Depression，including stratigraphic overlap trap，sandstone updip pinchout lithologic trap and fault lithologic compound trap.（2）Two types of traps are developed in Xinhe and adjacent areas： sandstone updip pinchout traps formed by structural tilting after sedimentation and large-scale fan delta stratigraphic overlap trap developed under the control of ancient uplift， and sandstone updip pinch out trap is the main exploration target in the next step.（3）At the top of Bashijiqike Formation， a lacustrine transgressive systems tract was developed， and lacustrine transgressive mudstone separated multidirectional source systems， which can form large-scale lithologic traps. The Triassic source rock has reached mature to high mature evolution stage in Xinhe area. The “dual source hydrocarbon supply” system provides sufficient oil and gas sources for subtle oil and gas reservoirs in this area， which has great exploration potential.

The extra-deep fault-controlled fractured-vuggy reservoirs distributed along strike-slip fault zones in Shunbei area of Tarim Basin have obvious subsection differences. Through interpretation of 3D seismic data， combined with data of drilling，logging and production test，the characteristics of the strike-slip segments of Shunbei No. 1 fault zone and the differences and causes of internal reservoir structure in different geometric segments were studied，and favorable reservoirs were selected. The results show that： （1）Shunbei No. 1 fault zone is formed by the oblique superposition of eight geometric segments，each of which forms a set of independent reservoir units. The internal fracture cave structure of a single reservoir unit is basically the same，but the internal fracture cave structure of adjacent reservoir units is obviously different，and the oil and gas reservoirs are not connected with each other.（2）The internal fracture cavity structure of the geometric segments is controlled by the activity intensity of strike-slip structure，according to which，internal and external fracture structures，double hole fracture structures，large-scale homogeneous reservoirs and other internal reservoir structure can be divided. Among them，large-scale homogeneous reservoirs develop multiple sets of fracture cavity bodies，with large size， large number and strong internal connectivity， which is conducive to oil and gas enrichment.

Based on drilling，logging，logging and seismic data，combined with rock and mineral characteristics，paleontological fossils and geochemical characteristics，the sedimentary facies characteristics and distribution rules of Carboniferous Yanghugou Formation in the western margin of Ordos Basin were systematically studied. The results show that：（1）The Yanghugou Formation in the western margin of Ordos Basin is mainly composed of mudstone，carbonaceous mudstone and coal seams，intercalated with argillaceous siltstone and sandstone. It was formed in a marine and continental transitional sedimentary environment，and the paleoclimate during the deposition was warm and humid. The salinity of the lake basin of Jingyuan-Yanghugou Formation gradually increased，the paleoclimate transited from the early warm and humid climate to dry and hot climate，the sedimentary environment transited from the early oxidation environment to the middle and late oxidation-reduction environment，the relative paleo water depth transited from shallow to deep，and to the late depositional period of Yanghugou Formation，rapid water regression occurred.（2）The Yanghugou Formation in the study area is mainly composed of mixed sediments，developed with delta，barrier coast and shore shallow sea sedimentary system，which belongs to a typical marine-continental transitional facies. Lagoon-barrier island sedimentary facies belt were developed in Weizhou-Shigouyi area，which can be divided into two regional transgression and regression cycles. The lower transgressive cycle was dominated by bay-tidal flat deposition，and the upper regressive cycle was dominated by delta deposition.（3）The sedimentary water body of Yanghugou Formation was relatively shallow，delta was developed around，and internal barrier sand bar was relatively developed，forming a favorable sedimentary facies zone. Vertically，the regional transgression regression cycle change of bay-tidal flat-barrier island-lagoon-swamp facies was developed in Jingyuan-Yanghugou Formation.

The 2D and 3D physical simulation experiments and numerical simulation studies were carried out on the reservoirs of Jurassic Qigu Formation in F well area of Fengcheng oilfield，Xinjiang，revealing the evolution law and production mechanism in the compound development of steam chamber. The results show that：（1）Under the action of steam overlay and pressure relief traction at the recovery point，the main body of the leading edge of the steam chamber advanced to the horizontal section，and the shape of the leading edge of the steam chamber evolved from “spout” type to “bell” type，and finally became “cap” type. The three-dimensional shape of the steam chamber first presented an “isolated island” type around the vertical well，then connected into a “corridor bridge” type，and finally converged into a large cavity.（2）According to the evolution law of steam chamber， the whole simulation experiment process was divided into injection-production connection stage，steam chamber formation stage，steam chamber lateral expansion stage and steam chamber decline stage. The recovery rate of the whole production cycle can reach 55.6%，the oil-steam ratio is 0.17，and good experimental results have been obtained.（3）The physical simulation experiment and numerical simulation results reveal the oil displacement mechanism of steam displacement in the early stage and gravity drainage in the middle and later stage of compound development，characterizing the evolution law of steam chamber，which provide technical support for the efficient development of similar reservoirs.

Through systematic sampling and geochemical characteristics analysis of three field profiles of Upper Permian Dalong Formation in northern Sichuan Basin，the sedimentary environment of source rocks was analyzed from four aspects of sedimentary background，hydrothermal activity and upwelling，paleoclimate and paleosalinity， and water environment，and the organic matter accumulation model and exploration potential were discussed. The results show that：（1）The Permian Dalong Formation in northern Sichuan Basin has argillaceous and siliceous source rocks with an effective thickness of 10-40 m，a high abundance of organic matters（the average content of organic carbon is 4.58%）， good types of organic matters（type Ⅱ₂ organic matter is dominant）， and great hydrocarbon generation potential（the average pyrolysis hydrocarbon generation potential is 5.90 mg/g）. The Changjianggou profile and Xibeixiang profile in Guangyuan area at the margin of Sichuan Basin are in mature stage，with R_o values of 0.72% and 1.06%，respectively. The average T_max value of Daliangxiang profile in the eastern part of the basin is 604 ℃，reaching an over mature stage. The gas generation of Dalong Formation in Guangyuan-Liangping trough reaches 432.38×10¹² m³，with conventional natural gas resource of 1.70×10¹² m³ and shale gas resource in trillions of cubic meters，which is a set of marine high-quality source rocks with large gas potential.（2）The high-quality source rocks of Dalong Formation in the study area were formed in a continental margin environment with semi-limited cycle of water hypoxia，and experienced two stages of the evolution of water environment，including embryonic stage and expansion stage of the trough development. In the early stage，there was anoxic-local anaerobic-anoxic unvulcanized and sulphide environment，and organic matter was not developed. In the middle and late stages，there was an oxygen-poor-anoxic-main anaerobic-anoxic environment. Organic matter enrichment was closely related to hydrothermal activity and upwelling. The acid gas from volcanic eruptions and the semi enclosed water environment jointly formed a long-term and large-scale anaerobic hydrodesulfurization environment，which was conducive to the enrichment and preservation of organic matters. It shows a high TOC value in the slope shelf areas such as Xibeixiang and Changjianggou. The TOC value is the greatest in the weak sulfuration environment，followed by the moderate sulfuration environment，and the TOC value is the smallest in a strong retention vulcanization environment.（3）Shale gas of Dalong Formation and high-quality reservoir gas from Changxing-Feixianguan Formation in Guangyuan-Liangping trough are the main exploration directions.

With the decarbonization of energy worldwide，natural hydrogen，as a primary energy，has gained widespread interest for its carbon-free emission and renewability. However，natural hydrogen has not yet to be explored in China. Through the review of the main geological settings and genesis of natural hydrogen with a high content（greater than 10%）discovered worldwide，the beneficial geological factors for natural hydrogen accumulation were systematically summarized，and the exploration prospects of natural hydrogen in China were evaluated based on the exploration and development status of natural hydrogen abroad. The results show that：（1）Global high content natural hydrogen is mainly developed in ophiolite belts，rift valley，and Precambrian iron-rich strata，mainly inorganic genesis，and the serpentinization process of iron-rich minerals is the most critical source of natural hydrogen，followed by degassing in the deep earth and water radiolysis.（2）High-quality hydrogen sources and good migration channels are the prerequisites for hydrogen enrichment，and the sealing ability of the cap rocks is a key element for the formation of natural hydrogen reservoirs. When natural hydrogen is used as associated gas，the traditional cap rocks can seal it，but may be difficult to form effective sealing when its content is high. The rift valley environment，ophiolite development areas，and the fracture-developed Precambrian iron-rich strata are the favorable areas for the exploration of hydrogen-rich gas reservoirs.（3）Many countries and regions abroad have formulated plans to explore，develop，and utilize natural hydrogen. Mali has realized commercial exploita‐tion of natural hydrogen，and the United States and Australia have also successfully drilled natural hydrogen ex‐ploration wells.（4）The areas with high hydrogen content in China are highly compatible with hydrogen-rich geological conditions，and the prospects of natural hydrogen exploration are good. The Tan-Lu fault zone and the peripheral rift basin areas，the Altyn fault zone and the basin areas on both sides，and the Sanjiang orogenic beltLongmenshan fault zone and peripheral basin areas have great natural hydrogen exploration potential. China should carry out the survey work of natural hydrogen as soon as possible，strengthen the research on hydrogen reservoir accumulation process and potential evaluation，and carry out research on exploration technology，ex‐traction and separation technology，and storage and transportation technology，to prepare technological reserves for large-scale development and utilization of natural hydrogen.

By reviewing the development history，main research progress，and development direction of artificial intelligence technology in the field of geophysical exploration（geophysical exploration）both domestically and internationally，the advantages and challenges of intelligent geophysical exploration were summarized，and solutions were proposed. The results show that：（1）Geophysical technology was integrated with artificial intelligence technology in the second wave of artificial intelligence development. Thanks to the exponential growth of data volume in the field of geophysical exploration，the rapid development of hardware computing power，and the emergence of new deep learning frameworks，intelligent geophysical technology has developed from early machine learning to current deep learning，and has achieved a large number of research results in seismic data processing and interpretation.（2）At present，intelligent geophysical technology is widely used in the construction of tag sets，denoising，fault detection，layer and sequence interpretation，seismic facies classification and anomaly detection，lithology identification and reservoir development，and seismic inversion imaging，greatly improving work efficiency，reducing work costs，overcoming the subjectivity and unreliability of manual interaction and experience，and helping to break the bottleneck of traditional geophysical technology.（3）The development of intelligent geophysical technology faces challenges such as a lack of publicly available label datasets，a lack of intelligent frameworks to solve problems in the field of geophysics，and the lack of an intelligent development platform suitable for sharing in the field of geophysics. These challenges can be addressed by addressing data infrastructure，building intelligent platforms，conducting basic research on network architecture，and combining it with application scenarios. In addition，the development direction of intelligent geophysical technology also includes the following aspects：research on intelligent seismic imaging methods，reservoir imaging methods，oil and gas big data mining，intelligent risk assessment and intelligent decision-making，and research and development of supercomputing software equipment.

Based on the current situation of geothermal development in China，the characteristics of geothermal resource occurrence and distribution，and the comparison of different geothermal development methods，the potential for the development and utilization of geothermal resources in oilfields was analyzed，and the develop‐ment trends of China’s geothermal industry，especially oilfield geothermal，were discussed. The results show that：（1）China has abundant geothermal resources，mainly consisting of medium to low temperature geothermal resources. Shallow geothermal resources are distributed nationwide. Medium to low temperature geothermal resources are distributed in sedimentary basins，southeastern coastal areas，and uplift mountainous areas，forming a large area of thermal reservoirs containing geothermal water at different depths，which are hydrothermal geothermal resources. High temperature geothermal resources are concentrated in southern Xizang，western Sichuan，western Yunnan and Taiwan. China’s shallow geothermal energy resources（shallower than 200 m） have an annual mining output of 7×10⁸ tons of standard coal.（2）Due to the environmental and efficiency issues in the development and utilization of shallow geothermal energy，the efficiency issues of direct heat exchange in deep wells，and the technical bottlenecks in the development and utilization of dry hot rocks，medium to deep hydrothermal geothermal resources will be the most important and practical field for the development and utilization of geothermal resources in China today.（3）A series of key technologies have been developed in the geothermal development of oilfields，including geothermal resource exploration and evaluation，sandstone formation reinjection，renovation of abandoned wells into geothermal wells，and high-temperature drilling and completion， all of which have been successfully applied in large-scale geothermal development projects. Oilfields have abundant produced water resources that can be directly utilized，and a large number of abandoned or inefficient oil wells can be transformed into geothermal wells through technological transformation for geothermal resource development，thereby reducing geothermal development costs and improving the economic efficiency of geothermal projects.（4）In addition to being used for energy consumption replacement and clean heating in oilfields， oilfield geothermal energy has great potential for development in the fields of medium-low temperature geothermal power generation，the production of associated resources such as helium，heat storage in depleted hydrocarbon reservoirs，and carbon dioxide sequestration. The comprehensive development and utilization of geothermal energy is the main direction for the future development of geothermal energy in oilfields.

Based on the geochemical and other experimental analysis results of drilling cores，combined withproduction testing data，the geological characteristics and enrichment conditions of shale oil of Jurassic LianggaoshanFormation in Yilong-Pingchang area of Sichuan Basin were studied，and favorable exploration areas weredivided. The results show that：（1）The Lianggaoshan Formation in Yilong-Pingchang area is a sediment during the third lacustrine basin expansion stage of Jurassic，which has undergone the sedimentary environment changes of shore lake to shallow lake in the lower member of Lianggaoshan Formation，deep lake to semi-deep lake and shallow lake in the middle and lower part of the upper member of Lianggaoshan Formation，and delta front and shallow lake in upper part of the upper member of Lianggaoshan Formation.（2）The shales of Lianggaoshan Formation can be divided into felsic shales，calcareous shales and clay shales，with a high abundance of organic matter，TOC values ranging from 0.50% to 3.39% and an average of 1.30%. The organic matters are mainly type Ⅱ₁ and type Ⅱ₂，with a high degree of thermal evolution and vitrinite reflectance（R_o）ranging from 1.00% to1.90%，and indicating a high mature to over mature stage.（3）The shales of Lianggaoshan Formation have good physical properties，and the reservoir space types such as inorganic pores，organic pores and structural fractures are developed. The porosity ranges from 0.48% to 7.17%，with an average value of 3.61%. The oil-bearing capacity is good and mainly composed of light components，which is scattered and punctate in the whole，and locally concentrated in clumps. The lower part of the upper member of Lianggaoshan Formation is more developed with organic-rich shale，which is the focus of exploration at present.（4）The weak subsidence environment during the transitional period of foreland basin，widespread distribution of deep lacustrine sediments，the high degree of thermal evolution and widespread development of micro-fractures are favorable for shale oil and gas enrichment in Lianggaoshan Formation. The central and southern regions of the study area are shale oil and gas potential zones，with shale reservoir thickness generally greater than 15m，TOC value greater than 1.50%，porosity greater than 4.00%，Ro greater than 1.30%. Lianggaoshan Formation has 26.75×10⁸t of shaleoilresources and 1.72×10¹²m³ of shale gas resources，which is expected to become themain layer for increasing oil production in Sichuan Basin.

Baased on cores，well-log and seismic data，combined with seismic interpretation，balanced crosssection and inclusion detection techniques，the structural evolution history of the high-steep structural zones in eastern Sichuan Basin was restored，and the natural gas sources，migration，accumulation and preservation conditions in Pingqiao，Jiannan and Zilichang structures were analyzed. The results show that：（1）Single reverse fault on the eastern flank of Pingqiao faulted anticlinal trap in eastern Sichuan Basin caused a lateral conjunction between Longmaxi source rocks on the footwall and Xixiangchi reservoir on the hanging wall，which enables the migration of gas through the fault zone to the reservoir on the hanging wall and，with good transport conditions. The cap rocks of the trap are not damaged by faulting，and the preservation conditions are good，which is condu‐cive to gas accumulation.（2）Although multiple parallel reverse faults in the flank of Jiannan faulted anticlinal trap result in source-reservoir conjunction，the combination of multiple faults reduces the gas lateral migration ability，causing natural gas to fail to accumulate on a large scale.（3）The Zilichang faulted anticlinal trap has good source-reservoir assemblages and transport conditions，but the sealing ability of the cap rocks is poor， mostly reduced by faults. Drilling indicates that the reservoir is water-bearing.（4）The main controlling factors for the natural gas accumulation of Cambrian Xixiangchi Group in the high-steep structural zones of eastern Sichuan Basin are source-reservoir assemblages controlled by fault or fault combination，lateral transport conditions，and the sealing ability of of cap rocks.

Through rock mechanics experiment, acoustic emission experiment, comprehensive interpretation of seismic data, the finite element numerical simulation method was used to numerically simulate the paleotectonic stress field of marine shales of Ordovician Wufeng Formation to Silurian Longmaxi Formation in southern Fuling area. Combined with the measured results of cores, the development characteristics of structural fractures were predicted. The results show that:(1) The distribution of tectonic stress and fractures in southern Fuling area during the main formation period of fractures(the Late Yanshanian) was influenced by faults, rock mechanical properties, and tectonic stress. In areas where faults are widely developed, stress concentration can easily occur and cause large stress gradients.(2) Coulomb-Moore fracture criterion was used to predict the development of structural fractures in the study area, and the shear fracture index R was introduced to quantitatively characterize the strength of fracture development. The larger the value, the higher the degree of fracture development. Narrow and steep fault anticlines and fractures are developed near faults, mainly with high angle shear fractures, while the development of fractures is weakest in the wide and gentle synclines. The stress in the siliceous shales at the bottom of the Wufeng Formation Longmaxi Formation in the study area is concentrated, and the fractures are the most developed.(3) There are three favorable zones for the preservation of marine shale gas in the southern Fuling area:The Fenglai syncline, which is far away from the major faults and has not suffered significant damage during the main structural deformation period, is located in the low stress area with good preservation conditions, and is classified as class Ⅰ favorable zone;The Baima syncline, with small faults developed, stress values at a moderate level and moderate preservation conditions, is classified as class Ⅱ favorable zone;The Shimen-Jinping fault anti-cline, which has undergone strong transformation and is prone to large-scale shear fractures, making the preservation conditions damaged, is classified as class Ⅲ unfavorable zone.

By means of core observation, thin section identification, electron backscattering, secondary imaging and energy spectrum analysis, the micron pores and micron fractures in shale oil reservoirs of Cretaceous Qing‐ shankou Formation in Gulong sag of Songliao Basin were studied. The results show that:（1）The lithologies of shale oil reservoirs in Gulong sag are fine-grained clastic rocks dominated by shale, and the mineral composition is mainly clay and felsic, showing the characteristics of mudstone or shale in structure, and the whole reservoir is felsic shale. Micron pores and micron fractures are developed in reservoirs with various types.（2）The diameter of micron pores in the study area is generally 1-2 μm, and the maximum can reach 70 μm, and they are nearly round, oblate, polygonal and irregular. According to the genesis, they can be divided into six types:compaction stress shielding pores, diagenetic authigenic pores, dissolved pores, hydrocarbon generation and expulsion expansion pores, organic matter pores and diatom residual pores. Compaction stress shielding pores are mostly developed on both sides of rigid minerals. Diagenetic authigenic pores are often developed in authigenic minerals such as dolo‐ mite, chlorite and illite, mainly intergranular pores. Dissolved pores are mostly developed in carbonate minerals, and secondary mycelial floccules can be seen inside. Hydrocarbon generation and expulsion expansion pores are mostly produced in vertical or nearly vertical rows, which is related to the secondary hydrocarbon generation and expulsion formed by light oil. Organic matter pores develop in organic matter and are related to residual cells of plants and filling of light oil and natural gas. Diatom residual pores mainly develop in the interior and edge of dia‐ toms, with large sizes ranging from several microns to tens of microns.（3）The micron fractures in the study area are mainly bedding, with a width of 1-10 μm and a maximum of 100 μm, and a length of several microns to tens of microns. They can be divided into four types:diagenetic shrinkage fractures, dissolved fractures, hydrocarbon generation and expulsion expansion fractures and structural/shear fractures. The diagenetic shrinkage fractures are mainly tensile fractures, with curved fractures and uneven fracture wall. The width of dissolved fractures can reach 60-70 μm, authigenic clay can be seen in the fractures, and authigenic minerals such as pyrite, apatite and dolomite can be found on both sides of the fracture. Both sides of hydrocarbon generation and expulsion expan‐ sion fractures are jagged and uneven, bypassing rigid minerals. Structural/shear micron fractures are generally straight, accompanied by other fractures related to shear.（4）The connectivity between pores and fractures of dif‐ ferent scales in the study area is good, forming a three-level reservoir and transport system of“nano-pores + nanofractures, micron-pores + micron-fractures, millimeter-pores + millimeter-fractures”.