Lithologic Reservoirs

Fault block developed well in Dagang Oilfield, so the geology is complex. The research on the petrofacies and paleogeography in fault block region is significant for finding non-structural reservoir. A great number of lithostratigraphy traps formed in Qikou Sag due to the special petrofacies and paleogeography. Based on the petrofacies and paleogeography conditions, combined with the factors for lithologic trap forming, the probability of obtaining high productivitywell in Binhai slope region in Qikou Sag is discussed.

Analysis on petroleum exploration potential in Bijialing- Lingnan slope belt in Liaohe seabeach

PAN Wei

2010, Vol.22(Z1): 7–9 Abstract ( 547 ) PDF (475 KB) ( 438 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.002

Bijialing-Lingnan slope belt in Liaohe seabeach has good oil source- reservoir- cap conditions, but the exploration degree is low. In order to improve the lithologic reservoir exploration in this area, the sand body trace is carried out through detailed inversion ofwell-log and seismic data, and the area and thickness of the sand body are predicted. The stratigraphic-lithologic traps in slope belt and burial hill are forecasted, the exploration potential in this area is analyzed, and then the favorable traps are proposed.

Study on lithologic reservoir description method of Gutao Formation： A case study from Laohekou Oilfield

PANG Limin， ZHANG Xuefang， SONG Yanfang

2010, Vol.22(Z1): 10–13 Abstract ( 560 ) PDF (548 KB) ( 602 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.003

The Laohekou Oilfield is a type of subtle lithologic reservoir found at a single gentle anticline, where the strata are flat and the fault is few. Based on high quality of seismic data, the method of signal reconfiguration in wavelet domain is used to analyze the petrophysics and forward model characteristics of fluvial facies reservoir in isochronous stratigraphic framework. The time slice technique and 3D visualization technique are applied to carry out sand body trace and interpretation. According to absorption coefficient features of sand body, the post-stack seismic data are used to conduct oil and gas identification. A set ofmethods for lithologic reservoir description ofGuantao Formation is concluded.

Analysis on controlling factors of Cretaceous lithologic reservoirs in Yaxi area of Jiuquan Basin

LI Tao， YANG Kerong， HAN Xiaosong， JIANG Yongxiang

2010, Vol.22(Z1): 14–17 Abstract ( 520 ) PDF (456 KB) ( 828 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.004

Fan-delta depositional system in Cretaceous developed in steep coast in Yaxi area, which provides a good condition for the forming of lithologic reservoirs. The lithologic reservoirs in the study area include two types，and they distributed respectively in the high position and low position of nose structure in Yaxi area. The forming and distribution of lithologic reservoirs are controlled by the tectonic setting, sedimentary facies belt, transportation systemand lithologic features. The nose structure provides direction for petroleum migration, and constitutes the background for the forming of lithologic reservoirs. The“T- S” transportation system offers transportation conditions for lithologic reservoirs. The development position of different types of channel sand body determines the distribution of different lithologic reservoirs. The differences of reservoir lithology determine the enrichment degree of reservoirs.

Microcosmic characteristics of sandy conglomerate reservoir in Wangzhuang area

QU Weiguang

2010, Vol.22(Z1): 18–21 Abstract ( 406 ) PDF (448 KB) ( 647 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.005

Based on core observation, thin section analysis, property analysis and scanning electronic microscope, the rock type, diagenesis, reservoir spaces, physical property of the sandy conglomerate reservoir of the forth member of Shahejie Formation in wangzhuang area are studied. Accorded to the difference of the physical properties, the reservoir in this area can be divided into four types, among which type Ⅰ,Ⅱand Ⅲ reservoir facies belts are the favorable exploration area.

Pore structure type and characteristics of Chang 3 reservoir in the outskirt area of Hua 152 well field in Chenghao-Huachi Oilfield

ZHU Xiaoyan， ZHAO Yonggang， TIAN Suiliang， LI Xiaobao， ZHANG Baojin

2010, Vol.22(Z1): 22–26 Abstract ( 464 ) PDF (672 KB) ( 498 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.006

The Outskirt area ofHua 152 well field is important oil producing region and major expansion well field, and Chang 3 reservoir is its principal producing formation. The research on the pore characteristics of Chang 3 reservoir is significant for the reservoir evaluation, the cognition of reservoir forming and reservoir distribution prediction. Based on thin section observation, scanning electronic microscope and pore throat image analysis, it is believed that residual primary intergranular pore is the main pore type in Chang 3 reservoir, followed by all kinds of secondary dissolution pores. Lamellar throat is the main type of throat, and secondly it is constriction pore and tubular throat. The pore features of the sandstone are related to the sedimentary environment. Medium to fine throat chiefly distributes in the sandstone reservoir of subaqueous distributary channel, and mediumthroat mainly distributes in the sandstone reservoir of river mouth bar. By means of mercury intrusion method, capillary pressure characteristics of Chang 3 reservoir are analyzed, and it is found out that there are complicated unimodal model and simply bimodal model of pore throat distribution. Capillary pressure curve can be approximately divided into typesⅠ, Ⅱ and Ⅲ. Pore throat sorting degree of Chang 3 reservoir is better on the whole, there is large difference among volume of pore throats. In brief, standstone pore structure and its distribution characteristics demonstrate that Chang 3 reservoir of the study area has fairly accumulation capability and is favorable for reservoir formation.

Application of property modeling to reservoir description of Lotus oil layer in Gao 2 block of Gaosheng Oilfield

SUN Yinsen，GUO Shaobin，SHAO Yanlin

2010, Vol.22(Z1): 27–30 Abstract ( 487 ) PDF (568 KB) ( 888 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.007

In viewof the present situation of the fine reservoir description in China, it is proposed that using stochastic modeling to study the reservoir properties based on log interpretation and combined with variation function analysis in geologic statistics. Through the strata frame work provided fromstructural model and the digitization of the sedimentary microfacies maps of the sublayers in the study area, the sedimentary microfacies model is established. The physical property model controlled by microfacies models is built up, which makes the quantitative application of sedimentary microfacies study in the field exploration research and the combination with the reservoir parameters distribution realized. It provides accurate data set for reservoir numerical modeling and provides basis for the development adjustment and full use of the remaining oil.

Study on sedimentary microfacies of the eighth member of Shihezi Formation in southern Sulige

WANG Shicheng， GUO Yabin， YANG Zhi， REN Li， LIU Hongjiu

2010, Vol.22(Z1): 31–36 Abstract ( 456 ) PDF (943 KB) ( 620 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.008

Based on core description and analysis, combined with log and seismic data, the sedimentarymicrofacies of the eighth member of Shihezi Formation in southern Sulige is studied. The research result is favorable to ascertain the distribution of single sand body and facies belt. It provides basis for further exploration deployment and submitting oil and gas reserves.

Carbonate reservoir characteristics of Upper Carboniferous Dapu Formation in Dushan area, southern Guizhou

FAN Yu， CHEN Hongde， LIN Liangbiao， ZHU Zhijun， LONG Ke， DAN Yong

2010, Vol.22(Z1): 37–43 Abstract ( 569 ) PDF (927 KB) ( 477 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.009

The huge-thick carbonate rock developed in Upper Carboniferous in southern Guizhou, and it is characterized bywide distribution, integrated strata and huge sediment thickness. But its exploration degree is low. So doing a good job in the research of carbonate reservoir characteristics has significances to the evaluation of resource potentiality and prospect ofmarine strata in southern Guizhou. Based on field actual measurement data, cast slice, scanning electronic microscope and reservoir property test, the reservoir characteristics of different lithologies of Upper Carboniferous Dapu Formation are analyzed. The lithologies of Dapu Formation mainly are lastic limestone, microcry-stalline limestone, dolomitic limestone, limy dolomite and dolomite. The main reservoir space type is secondary pore, and the primary pore does not develop. The reservoir pore structure is complicated, belonging to low-porosity and low-permeability reservoirs. The controlling factors of reservoir development mainly contain lithology, diagenesis and structural fracture, except for sedimentary facies. The zone of concealed structural fracture and burial dolomitization may become the further important exploration areas.

Main controlling factors of fracture development and distribution in Shiwu Oilfield

SONG Wenyan， QIN Qirong， SU Peidong， WANG Zhiping， GAN Xueqi

2010, Vol.22(Z1): 44–48 Abstract ( 425 ) PDF (561 KB) ( 691 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.010

Based on core observation, dip log and imaging log analysis, the fracture characteristics of Shiwu Oilfield are studied. The result shows that the main controlling factors of fracture development and distribution in Shiwu Oilfield are tectonic stress, tectonic position, lithology, rock thickness and burial depth, which provides basis for further oil and gas exploration.

Analysis on reservoir characteristics of lower part of Lower Ganchaigou Formation and its influencing factors in Qie 12 structure

SUN Kang， LI Guoyan， WANG Bo， WANG Peng， LI Yuankui

2010, Vol.22(Z1): 49–53 Abstract ( 386 ) PDF (584 KB) ( 492 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.011

Based on core analysis （including physical properties, cast thin section and mercury penetration）, the characteristics of petrology, physical property and pore of Lower Ganchaigou Formation in Qie 12 structure of Kunbei fault zone are analyzed. Combined with the structure and sedimentary features, the influencing factors of reservoir properties are analyzed. The result shows that the reservoir rocks are of low textural maturity and compositional maturity, poor sorting, high content of shale and clayminerals, the reservoir property is poor, and that the pore throat is small with poor sorting and pore connectivity. It is concluded that sedimentary environment, clay mineral, clay matrix and tectonic movement are the main factors influencing the reservoir properties.

Characteristics and controlling factors of Ordovician carbonate reservoir in Tuofutai area

ZHU He， MENG Wanbin， ZENG Haiyan， YANG Yongjian

2010, Vol.22(Z1): 54–59 Abstract ( 431 ) PDF (802 KB) ( 574 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.012

Based on well drilling and logging, as well as core observation, the reservoir rocks in the study area are mainly cryptite in open platform facies, followed by granular limestone. Combined with well logging interpretation and statistical data of fractures and cavity of core samples， it is concluded that the main reservoir space types are dissolved cavity and low angle dissolved fracture that is semi-filled and unfilled. The thick Upper Ordovician un-karstic strata made the Ordovician reservoir obstructed from the karst alteration. The paleokarst reservoir developed mainly below Caledonian parallel unconformity, and the reservoir quality is much poorer compared with the reservoirs in the main region of Tahe Oilfield where Upper Ordovician is absent. It is well developed when closer to the host of Tahe oilfield. The paleokarst reservoir developed at the top of the Ordovician Yijianfang Formation and the reservoir development decreased with the increase of burial depth. The reservoir development is controlled by sedimentary facies, Caledonian karstification, fault and fracture. It is concluded that Ordovician Yijianfang Formation may be the main reservoir space.

Reservoir characteristics and controlling factors of Paleogene in Qianxi area in northern margin of Qaidam Basin

YANG Yongjian， LIU Jiaduo， MENG Wanbin， ZHU He

2010, Vol.22(Z1): 60–65 Abstract ( 419 ) PDF (619 KB) ( 494 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.013

Based on the drilling, logging data and core test analysis, it is concluded that the reservoir component of Paleogene in Qianxi area mainly are lithic arkose and feldspathic litharenite with lowmaturity, and the reservoir spaces mainly are secondary dissolved pore including intergranular dissolved pore, intragranular dissolved pore and casting pore. The average porosity of the reservoir is 10.1%, and the average permeability is 21.64 mD. The Paleogene reservoir is low porosity and low permeability reservoir with strong heterogeneity. The reservoir is influenced by sedimentary facies and diagenesis. Sedimentary facies plays a role in macro control of the reservoir development, and the reservoir developed in braided channel has relative good properties. Diagenesis plays a decisive role in the reservoir development. Compaction and cementation destruct the capacity of the reservoir, while denudation and cataclasis improve the performance of the reservoir.

Research and application of frequency division imaging interpretation technology in TB area

CHANG Shaoying， SU Pibo， MA Hongxia， XIONG Ran

2010, Vol.22(Z1): 66–68 Abstract ( 477 ) PDF (554 KB) ( 781 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.014

Frequency division interpretation technology improves and enhances the resolution of the anomalous geological body by scanning the three-dimensional seismic data on the full spectrum in the frequency domain. Seismic data interpretation in the frequency domain can carry out reservoir studies. It has become an important geophysical exploration technology at present. It has unique advantages in thin reservoir identification, thickness calculation of thin reservoir and showing the heterogeneity inside reservoir. The principle of frequency division imaging technology is described and the characteristics in actual work are expounded.

Application of pre-stack inversion technology to tracing sand body: A case study from Huagang Formation in Pinghu Oil and Gas Field

WANG Wei， ZHANG Xin， CUI Xiaoduo， ZHANG Xiaozhen

2010, Vol.22(Z1): 69–73 Abstract ( 533 ) PDF (712 KB) ( 602 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.015

Pinghu Oil and Gas Field is a medium-sized Oil and Gas Field, which is controlled by structure and lithology, with active bottom/edge water. The main oil-bearing layer is Paleogene Huagang Formation. At present, the oil field has entered late stage of the development, with 97% moisture content and recovery of 40%. By using pre-stack inversion technology of reservoir prediction, parameters such as Poisson ratio and Lame coefficient are optimized. Based on structural interpretation, reservoir inversion and sand body tracing, the structural characteristics, distribution and contact of sublayers of the sand body are further implemented, which could provide guidance for the development of the oilfield.

Fine sand body contrast of Lower Crataceous Heidimiao reservoir under the constrained seismic inversion in southern Aonan Oilfield

LI Mintong， LI Zhongquan， MA Chengdou， DUAN Xinguo， LI Hongkui

2010, Vol.22(Z1): 74–79 Abstract ( 442 ) PDF (993 KB) ( 463 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.016

The exploration in recent years has proved that Heidimiao reservoir in southern Putaohua structure has a good exploration prospect. The research on sand bodies in Heidimiao reservoir is few. The facies change in terrestrial formation is fast, which causes great lateral variation of sand bodies, so it is difficult to carry out fine contrast between sand bodies. TakingMao 701 block in Aonan Oilfield as a research example, based on the sandstone classification, fine sand body contrast ofHeidimiao reservoir is carried out by constrained seismic inversion. The result of seismic inversion and drilling practice result show that the first part of Heidimiao reservoir vertically developed well, there are many vertical sand body layers which superimpose with large gross thickness, and the sand bodies can be executed tracing contrast on the horizontal; while the sand body of the second part of Heidimiao reservoir is basically undeveloped. It is helpful to exactly predict the favorable accumulation zone and provide an important geological basis for instructing the oil and gas exploration ofHeidimiao reservoir in Aonan Oilfield.

Application of elastic wave impedance inversion technique

LI Guofu， SU Yun， HUANG Qian

2010, Vol.22(Z1): 80–84 Abstract ( 595 ) PDF (864 KB) ( 721 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.017

The elastic wave impedance inversion is a “bright point” in the seismic inversion technique in recent years, and alsoa “hot point” in the inversion research. Elastic wave impedance inversion is a seismic inversion technique which combines conventional acoustic impedance inversion with AVO inversion. It uses different offset gathers data and S- wave、P- wave and density data to carry out joint inversion of elastic parameters related to lithologies and oil/gasbearing ability, and determine the reservoir properties and oil-bearing ability. The basic principle and method of the pre-stack elastic wave impedance inversion are briefly expounded, and the application case is given.

Study on CO₂ storage potential in saline aquifer and its influencing factors

WANG Tao

2010, Vol.22(Z1): 85–88 Abstract ( 476 ) PDF (306 KB) ( 771 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.018

Huge number of greenhouse gas emission of carbon dioxide leads to global warming, which has put much pressure on both human being’s survival and social economy development. If the storage place and storage way are proper, the storage volume will be very huge. The saline aquifer in deep sedimentary basin is unsuitable for exploration, but it can be used to storage CO2. Based on the mechanism of CO2 storage in saline aquifer, the calculation formula for CO2 storage is obtained, and then the strata and fluid for CO2 storage in saline aquifer are analyzed by numerical simulation,and the influencing factors are systematically evaluated.

Reservoir dynamic variation characteristics after water flooding and its influencing factors

XU Chunmei， ZHANG Rong， MA Liping， LUO Bilin

2010, Vol.22(Z1): 89–92 Abstract ( 510 ) PDF (244 KB) ( 742 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.019

Water flooding in reservoirs and oilfields shows that the hydrodynamic geologic processes including transportation and deposition are strong and durative, and they change the reservoir properties much. The dynamic variation characteristics in water flooding process are analyzed in the aspects ofmacroparameters, micropara-meters and filtering parameters; the influencing factors for dynamic variation after water flooding are expounded in the aspects of reservoir space, fluid property and development conditions; the mechanism of dynamic variation is analyzed, which is significant for understanding the dynamic variation lawof water flooding reservoir, describing the high and extra-high water cut reservoir properties, and predicting the remaining oil distribution.

Application of horizontal well development technology in N1 section of Beizhong block

XING Ertao， ZHANG Yunfeng

2010, Vol.22(Z1): 93–95 Abstract ( 428 ) PDF (278 KB) ( 496 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.020

The reservoir of N1 section in Beizhong block is characterized by thin reservoir and poor physical properties. The experimental study of horizontal wells is carried out in order to raise the individual well production, to improve the used level of the reservoir, and to increase the contact area of the bore hole with oil layer. The geologic features of N1 section are analyzed, and the practicability of horizontal well development is discussed. Combined with the typical Xi 3- Ping 1 well, the development and production of horizontal well in N1 section are analyzed. The result shows that the output of a horizontal well is 3 to 4 times higher than the vertical well around, which provides foundation for the further development of horizontal wells.

Integrated evaluation of deliverability in low permeability lithologic gas reservoirs in Santanghu Basin

ZHANG Yunjie， WU Yunli

2010, Vol.22(Z1): 96–99 Abstract ( 412 ) PDF (373 KB) ( 403 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.021

It is necessary to carry out reasonable deliverability study for a single well, since deliverability test of gas well in lowpermeability lithologic reservoirs is difficult and seldom and the capacity analysis data are little utilized. The sensitivities of characteristic parameters of single-point deliverability equation to permeability, effective thickness and skin coefficient are analyzed. The result shows that the common experience productivity formula is invalid for the gas reservoirs with different properties, complex boundary and strong heterogeneity. The modified isochronal test and the single-point method are integrated to determine the reasonable deliverability: the deliverability in Qigu Group in Niu 101-Ma 1 block is 1.5×104m3/d, and it is 1.0×104m3/d in Toutunhe Group.

Method to improve producing degree of thermal recovery horizontal wells and its application

WANG Feiyu

2010, Vol.22(Z1): 100–103 Abstract ( 473 ) PDF (368 KB) ( 562 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.022

The application of horizontal wells in Liaohe Oilfield has moved frompilot phase into large-scale application stage. According to numerical simulation and theoretical studies，under the similar reservoir parameters, it shows good linear relationship between the producing effect of horizontal wells and production horizontal well length. However, the advantage of horizontal well length is not obvious in the actual production, and the use of horizontal inequality becomes increasingly prominent. Unreasonable steam injection intensity, uneven horizontal steam absorption and well interference are the main influencing factors for the horizontal well producing effect. Based on the numerical reservoir simulation and reservoir engineering calculation, combined with field practice, the techniques such as increasing steam injection intensity, even steam injection and modular handling are proposed, the uses of which enhance the producing degree of horizontal wells. The field application results are obvious.

Application and correction of one point method in Tainan Gasfield

CAO Jihua， LIU Junfeng， LI Wei

2010, Vol.22(Z1): 104–106 Abstract ( 381 ) PDF (213 KB) ( 594 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.Z1.023

Absolute open flowof natural gas well is not only the important indicator to reflect potential productivity, but also the foundation to determine reasonable production rate. One point method deliverability testing is a quick and effective method to determine gas well productivity. Based on one point method systematic well testing theoretical model, the systematic well testing data of Tainan Gasfield are analyzed, and the one point method empiric equation suitable for unconsolidated gas reservoir is obtained. After Error correction of the empiric equation, this method can be used tomonitor productivity changes.