Lithologic Reservoirs

At recent two decades, the numerous famous oil-gas geologists in Russia,Ukraine,Azerbaijan radically renewed the theories and thought of outgassiug of the earth and of oil-gas genesis which were not known in China. These newtheories and thought are more advanced than theWest.

Analysis of internal structure and reservoir-forming conditions of palaeo-buried hill, Western Liaohe Sag

ZHENG Rongcai， HU Cheng， DONG Xia

2009, Vol.21(4): 10–18 Abstract ( 573 ) PDF (979 KB) ( 538 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.002

Structural belt of buried hill is a building unit which shows great concentration of hydrocarbon in eastern-China faulted basin, but the research of the relationship between buried hill and hydrocarbon trap is still weak. Taking the buried hill belt of western Liaohe Sag as a research target, this paper expounds the internal structure of buried hill and the control action of accumulation from various aspects, including structural framework and active phases of inner buried hill, formation lithology and attitude, morphological unit classification and distribution framework, trapping types and hydrocarbon source conditions，hydrocarbon migration and accumulation conditions. The hydrocarbon trap is divided into palaeogeomorphology reservoir and stratigraphic hydrocarbon reservoir of inner buried hill. It establishes the “new source and old reservoir” hydrocarbon accumulation that the hydrocarbon migrates fromtop to bottom, then parallel migrates fromlowtomediumburied hill along unconformable face, at last fills in buried hill and forms the reservoir. The hydrocarbon accumulation model provides references for deep exploration activity of buried belt in Liaohe Sag.

First discovery of the sandy debris flow from the Triassic Yanchang Formation, Ordos Basin

LI Xiangbo，LIU Huaqing，WANYAN Rong，WEI Lihua，LIAO Jianbo，MA Yuhu

2009, Vol.21(4): 19–21 Abstract ( 557 ) PDF (401 KB) ( 684 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.003

Based on the large amount of the core data, field observations and analysis as well as seismic sequence interpretation, three kinds of sediment-gravity flows ( the sandy debris flow, the classic turbidite and the slumps ) were identified from the Chang 6 member of the Triassic Yanchang Formation in the deepwater area at the center of the ancient Ordos Basin lake, of which the sandy debris flow is dominant, whereas the classic turbidite is limited in distribution. The identification of sandy debris flow indicates previous study about deepwater sedimentation of the Yanchang Formation might overrate the turbidite sedimentation. Further study suggests that the distribution and the reservoir character of the deep water sediment-gravity flows sand bodies such as sandy debris floware mainly controlled by the slope break. In general, the upper slope is better than the lower slope and the ramp is favorable than steep slope and consequently, sandy debris flow is the best oil prone, classic turbidite A section is moderate oil bearing and the slump is poor.

Reservoir accumulation conditions and patterns of buried hill in Erlian Basin

JIANG Shuanqi， CHEN Yanjun， ZHAO Zhigang， GAO Shuang， LI Hongen， LI Xiaohong

2009, Vol.21(4): 22–27 Abstract ( 561 ) PDF (612 KB) ( 670 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.004

There are some features of shallowbury, high production, fine benefit for buried-hill reservoirs. The article analyses the geology of buried-hill reservoirs in Erlian Basin and summarizes five reservoir types. The weathering crust reservoir of carbonate rocks in Carboniferous is the representative. The article indicates that the main system of hydrocarbon migration of buried-hill is fault, its reservoir physical properties are mainly controlled by fault and weathering eluviations. This study provides the guidance to exploration of Erlian Basin and other buried hill reservoirs of similar geologic condition.

Sequence stratigraphic framework and sequence components of the Yitong Basin

LI Bencai，SUN Kai，BAI Hongbin,WANG Hongwei

2009, Vol.21(4): 28–31 Abstract ( 463 ) PDF (530 KB) ( 386 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.005

On account of the difficult questions of a strip of double-fault-style rift basin-Yitong Basin stratigraphic correlation, this article, studies the features of the secondary and tertiary sequence boundary and sets up a sequence stratigraphic framework on the basis of the analysis of the regional structure, stratigraphy, sediment characteristics.Authors believe that Tf surface ultimately belongs to the secondary sequence surface through a comprehensive analysis of a number of ways, however, it is not the regional unconformity; authors have finally solved the attribution problem of the Y1 formation by the comparison of Tc, Td unconformity level .Using of logging, drilling, seismic and other data, combining with seismic and wells, suming up the characteristics of each sequence stratigraphy, systematically dividing and comparing the formation ofYitongBasin, the standards of division and correlation of various layer are set up.

Overview of research into formation mechanism and distribution law of stratigraphic reservoir

LI Fuheng， ZOU Caineng， HOU Lianhua， TAO Shizhen，WANG Lan

2009, Vol.21(4): 32–36 Abstract ( 493 ) PDF (449 KB) ( 983 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.006

The importance of stratigraphic reservoir exploration is rising day by day on the condition that the field of national oil and gas exploration is transferred fromstructural reservoir to litho-stratigraphic reservoir. On the basis of the former research, this paper centers on the unconformity and classifies the stratigraphic trap into three types: the on- lapping typed trap above the unconformity, the barrier typed trap belowthe unconformity and the truncation type of trap between the former unconformity and the later unconformity according to the difference of trap mechanism. This paper summarizes the formation mechanism of stratigraphic reservoir from the strength and the structure of the unconformity. Furthermore, authors point out the distribution law of different type of stratigraphic reservoirs and exploration suggestion for different type of stratigraphic reservoirs. Finally, this paper points out some theories and techniques which are in great need for stratigraphic reservoir exploration.

The discovery of crater in Eastern Junggar Basin

WANG Jun，GUO Hongli，ZHU Rukai， LI Wenke，MAO Zhiguo

2009, Vol.21(4): 37–40 Abstract ( 512 ) PDF (505 KB) ( 398 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.007

Eastern basements of Junggar Basin mainly are andesite and the basalt of the Middle Carboniferous. In recent years, many volcanic rock oil and gas fields have been discovered in this area which become the important oilproducing area. The craters’ accurate positions were determined in preliminary survey of field geology in Eastern Junggar Basin in 2008, authors elaborated these craters’ types and the surface characteristics. Four actual geologic cross-sections were surveyed which are Bai Jiangou, Shuangjingzi, Jinshangou and Shaerbulake. Authors divided these craters into three different types-radiated craters, the ring-like crater and half ring-like crater, and summarized five kind of crater identification sign according to these three different type’s craters:①the pearlite of intrusive facies;②the ring-like belt-shaped distribution of volcanic rock lithologic character and facies; ③the deposition of sulfur ore; ④the big area of hydrothermal dissemination; ⑤large-scale cryptoexplosion breccias and packing structure. Finally the importance of crater discovery is discussed.

Provenance analysis of the 8th oil-bearing member of Yanchang Formation，Upper Triassic，Jiyuan area，Ordos Basin

WANG Wenting, ZHENG Rongcai，WANG Chengyu，WANG Haihong

2009, Vol.21(4): 41–46 Abstract ( 595 ) PDF (931 KB) ( 766 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.008

During the deposition of the 8th oil-bearing member of Yanchang Formation, Upper Triassic, deltaic depositional systems were developed and muti-provenances were provided around Jiyuan area, which was located in the middle-western part ofOrdos Basin. Based on the analysis of thin sections，detrital framework grains and heavyminerals and their associations, and with the combination of sedimentary structures, paleontology and the tripartite trend surface analysis of sandbody distributions, the provenance of the 8th member in Yanchang Formation was studied, and the following results were concluded: ①The sources during the deposition of the 8th oil-bearing member of Yanchang Formation were fromnortheast, northwest and south.②There were certain differences in the nature of source rocks. The northwest source area was dominated by volcanic rocks and light tomiddle metamorphic rocks association, the northeast by volcanic rocks-lower metamorphic rocks association, and the southwest by metamorphic rocks-sedimentary rocks association.③The distribution directions of sand bodies were same to that of the lithologic reservoirs. The above results would provide important geological basis for the prediction of sand bodies and lithologic reservoirs in the 8th oil-bearing member ofYanchang Formation.

Analysis of main controlling factors of Chang 6 reservoir in West Panguliang area， Ordos Basin

NIU Xiaobing，ZHU Yushuang，LIANG Xiaowei，XIN Honggang，LIU Xiaojing

2009, Vol.21(4): 47–52 Abstract ( 410 ) PDF (583 KB) ( 419 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.009

Based on the analysis of lithological characteristics, porosity and permeability characteristics, micro- pore structure characteristics and types of Chang 6 reservoir in West Panguliang area, the results showthat the sedimentary environment of Chang 6 reservoir is a delta front. Reservoir characteristics take on lower compositional maturity and medium textual maturity. The reservoir space types include residual intergranular pores, secondary corrosion pores, moldic pores and so on. The sedimentary microfacies, diagenesis and heterogeneity are main control factors for the reservoir properties. The diagenetic period of affecting reservoir development is stage A-B of middle diagenesis. And the gain-coating chlorite facies, feldspar corrosion facies and laumonite corrosion facies are favorable diagenetic facies belts for reservoir development. Five oil displacement types are distinguished by studying reservoir microscopic heterogeneity.

Fracture identification of reservoir of Yan’an and Yanchang Formation in Mahuangshan area

ZHANG Juan，ZHOU Wen，DENG Hucheng，WANG Xu，LV Jing

2009, Vol.21(4): 53–57 Abstract ( 496 ) PDF (542 KB) ( 464 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.010

Yan’an Formation and Yanchang Formation in Mahuangshan region of southern Ordos Basin are typical sandstone reservoirs with low permeability and low porosity. The fractures are the major filtration passages in the reservoirs and they have close relationship with the result of exploitation and the formation of the reservoir. Therefore, the characteristics and the identifications of the fracture are the key research work to the evaluation of the reservoir in this area. At present, the applications of new logging technique can identify fractures effectively, but they are always confined by the limitation of lacking data, and cannot be used in a large scale. The study starts fromthe fractures in the core, analyses the behaviour character of normal logging curve of the fractures in the reservoir, identifies the fractures by stepwise discriminant analysis, and builds up the fracture discriminant model according to the core and log parameters. Through the examination of coring samples and actual application, this model has a good effect.

Research on classification and evolution procession of buried hills in Budate Group in Beier Depression

SU Yuping，LI Jian，LIU Yafeng，WEI Jianbo，DENG Zhaoyuan

2009, Vol.21(4): 58–62 Abstract ( 441 ) PDF (503 KB) ( 494 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.011

The balanced geological section technique was applied in studying the evolving process of buried hills in Berer Depression. For the first time, the formation time and origin of these buried hills were confirmed, the classification shows that there are three kinds of buried hills:①the early formed palaeogeomorphology;②the subsequent buried hills by medium-term deformation; ③contemporaneous buried hills controlled by growth faults. Different buried hills experienced different evolution procession. By analyses of evolution procession of balanced geological section, the relation between evolution of buried hills and oil accumulation was successfully interpreted, the distribution of these threes buried hills was marked on the map. Finally, two kinds of buried hills favorable for exploration were pointed out by comparing with the actual exploration achievements.

All digital seismic pre-stack reservoir prediction technique and its application for gas exploration in the Sulige area

DOU Weitan，DU Yubin，YU Bo

2009, Vol.21(4): 63–68 Abstract ( 472 ) PDF (833 KB) ( 787 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.012

The Sulige area is an important area of natural gas exploration and development with complex surface conditions and lateral variable continental sedimentary reservoirs. In recent years, in view of the complex geological conditions and the Paleozoic gas exploration, the higher-coverage acquisition techniques with long array, small interval and single digital receiver were formed through the seismic exploration study of the all-digital seismic acquisition, processing and interpretation. The seismic pre-stack processing techniques, pre-stack inversion and post-stack interpretation methods have been gotten many achievements. All above could meet the needs of seismic pre-stack effective reservoir prediction and help the rapid and efficient exploration and development in the Sulige area.

The experimental application of large well interval cross-well seismic technique in Shu 68 area of Liaohe Oilfield

DONG Shi-tai，ZHANG Lixin，XU Guangcheng，SUN Rong

2009, Vol.21(4): 69–72 Abstract ( 518 ) PDF (563 KB) ( 471 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.013

The large well interval cross-well seismic techniquewas carried out in Shu 68 area ofLiaohe Oilfield. The spatial location of sand-shale alternating beds, the connection ofmain reservoir and the distribution of fluids were achieved by P-wave and S-wave tomography and reflection migration imaging fromcross-well data. The commercial oil flows were got from three wells based on integrated geological study of cross-well seismic technique. This was the first time that the well interval ofcross-well seismic technique was lager than 800m,which improved the cross-well technique application very much.

Sedimentary evolution model and petroleum significance of Chang-7 member turbidite，Ordos Basin

PANG Jungang，LI Wenhou，SHI Shuo，XIAO Li

2009, Vol.21(4): 73–77 Abstract ( 604 ) PDF (461 KB) ( 570 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.014

The extensive extent turbidite can be identified by such apparent signatures as lithology, sedimentary structure, sedimentary sequence and well logs ofChang-7 member deep lake, Ordos Basin. During the paleo-geographic evolution of Chang-7 member, lake basin and deep lake are both at their maximum extent during Chang-73 stage, and turbidite was distributed fragmental-like in plane view, due to interplay of extensive extent deep lake and limited clastic supplying. Deep lake line was graduallymoved toward lake center and turbidite sand bodies were gradually developed better from stages of Chang-73, Chang-72 and Chang-71. And depositional evolution model in study area is established. There is better petroleum accumulation in deep lake, and turbidite sandstone can be better reservoir in deep lake. At present, some commercial oil wells were found in Southwest Ordos Basin and the turbidite sandstones can be the main exploration targets in the near future.

The seismic wave field reverse-time migration in transversely isotropic media

CHEN Mo

2009, Vol.21(4): 78–81 Abstract ( 404 ) PDF (520 KB) ( 511 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.015

According to elastic theory and generalized Hooke’s Law, the scalar wave equation in isotropic media is deduced. The solution of the equation is given by the difference. Author gives the stability condition of the difference equation. Referring to the previous research results, the absorbing boundary condition is injected. During the migration, the underground images is identified by using the eikonal equation solution. At last, author uses this method to process the seismic forward data and real seismic data.

The crack prediction of T₁ j₄² bottom of Luojiazhai structure

WANG GUOgang，SU Peidong，QIN Qirong

2009, Vol.21(4): 82–86 Abstract ( 529 ) PDF (859 KB) ( 512 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.016

Based on the theory of rock mechnics, tectonic geology and the fracture structure features of Luojiazhai area, the palaeotectonic stress and crack distribution of T1 j42 bottom were studied and predicted by use of numerical simulation. The results show that crack and fracture were developed in Jialingjiang Formation and they were mainly distributed nearly faults, especially in the fault intersections and high structures.

Volcanic rock lithology recognition technique and its application in Malang Depression, Santanghu Basin

LIU Juntian，ZHANG Daisheng，HUANG Weidong，LI Zaiguang，QIN Xinping，WEI Cheng

2009, Vol.21(4): 87–92 Abstract ( 540 ) PDF (866 KB) ( 506 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.017

In recent years, volcanic rock reservoir exploration has become a hot spot in Turpan-Hami Oilfield, and breakthrough has been made in different strata of volcanic rock reservoir. The reservoirs have been affected more greatly by its complex and variable lithology than the fluid, so lithology recognition is particularly important in the area.Accurate description of the lithology of volcanic rocks is the basis for precise reservoir evaluation of such type and is the major problemfor logging evaluation. In this paper, a newtechnique is developed based on volcanic rock slices data of Kalagang Formation ofMalang Depression in Santanghu Basin. It uses conventional logging information to identify the mineral composition, and applies imaging logging information to identify the volcanic rocks and tectonic structure, and finally integrates them into volcanic rock lithology comprehensive identification, which is suited for the Turpan-Hami Oilfield. The method has got good application effect in the lighology identification in Malang Depression.

Quantitative relations between oil-gas filling degree and channel seepage flow capacity of the reservoir：Example of Shuanghe Oilfield in Biyang Depression

ZHAI Zhongxi， QINWeijun， GUO Jinrui

2009, Vol.21(4): 92–95 Abstract ( 517 ) PDF (335 KB) ( 372 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.018

Shuanghe Oilfield is a typical “small and fat” oil field with great oil abundance in China. However, as a big oil field, it was found that mostly traps have not been filled with oil and gas. Further more，oil-gas filling degrees of different traps showgreat differences in the oil field. The result of research shows that the difference has great relationship between reservoir permeability grade differential and dominant channel, that is, the process of the oil and gas filling is controlled by channel seepage flowcapacity and the oil group’s grade difference of reservoir.

Influence factor of stress-sensitivity on gas well abandoment pressure and recovery ratio in low permeability reservoirs

FU Chunmei，TANG Hai，ZOU Yifeng，LV Dongliang，FU Chunyan

2009, Vol.21(4): 96–98 Abstract ( 607 ) PDF (297 KB) ( 431 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.019

Tight and lowpermeability reservoirs have obvious stress-sensitivity phenomenon. The relationship between permeability ratio and effective stress is established by the stress-sensitivity experiment of core and the research on the rules of core permeability changing with effective stress. Effective permeability reduces with the increasing of effective pressure .The inconvertible permeability damages reach to 0.55％～24％ and the average is 8.1％.The pressure equation considering stress-sensitivity of gas well can be given by the influence of stress-sensitivity on abandonment pressure. And then the influence of stress-sensitivity on recovery ratio are studied referring to a simple equation compution of recovery ratio.

The division and character of clastic reservoir flowing unit：An example from Chang 2 reservoir of Yanchang Formation in Fuchang area, Northern Shanxi

SHI Yujiao， GAO Zhendong，WANG Qicong，WANG Gang

2009, Vol.21(4): 99–104 Abstract ( 538 ) PDF (909 KB) ( 603 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.020

This article introduced the concept and the research approach of clastic reservoir flowing unit. Taking the Chang 2 reservior of Upper Triassic in Shanbei Fuchang area as an example, the flowing units are divided according to flowing index FZI. The petrophysical characteristics of flowing units are studied on the basis of experimental data of thin section analysis, image analysis, SEM, mercury penetration and so on. The Chang 2 reservior can be divided into 5 kinds of flowing unit by flowing indexes FZI . Every kind of flowing unit has certain relationship between porosity and permeability. The result shows that the method of the classification of flowing unit with FZI is efficient path for the classification, evaluation and genetic analysis of reservoir.

The optimization of well patterns of CO₂ -flooding for low-permeable reservoir

XIA Weiwei，WANG Xinhai，LEI Juanqing

2009, Vol.21(4): 105–107 Abstract ( 558 ) PDF (375 KB) ( 686 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.021

The effects of four flooding patterns（parallel CO2-injection, parallel interval CO2-injection, parallel waterflooding, leaping parallel water-flooding） for low-permeable reservoir by the numerical stimulation are studied. The result shows that the recovery factor of parallel CO2-injection（rowspacing: 300 m, well spacing: 150 m） is more optimal than other patterns. The plan will enhance the recovery factor of low-permeable reservoir.

The analysis on the sources of water body and characteristic of water breakthough at Block 12 in Tahe Oilfield

QIMinghui1， LU Zhengyuan1， YUAN Shuai2， LI Xinhua3

2009, Vol.21(4): 108–110 Abstract ( 467 ) PDF (306 KB) ( 497 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.022

The heterogeneity of the reservoir ofOrdovician systemin Tahe Oilfield is serious, and the water-oil relation is complex, water breakthrough in the oil well is the main reason that causes production drawdown. The sources of the water body in the water breakthrough well include the leakage fluid and the acid fracturing fluid remained, relic water in the bottom of the fracture-cave unit. The water body in the lower part of the fracture-cave unit is connected by acid fracturing. The output of the leakage fluid always presents the pattern of water cut decline which has lowinfluence on the production. The output of the relic water and the water body in the lower part are different because of the energy of the water body, the height of the oil-water contact and the difference of the vertical permeability. It is a effective way to enhance the ultimate degree of reserve recovery in the reservoir that take steps to stabilize oil production and control water cut of the different resources of the water body and different characteristics ofwater breakthough.

The evaluation of natural energy for small fault block edge water reservoir

ZHOU Chunxiang,LI Lezhong，WANG Min

2009, Vol.21(4): 111–114 Abstract ( 446 ) PDF (407 KB) ( 517 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.023

The small fault block edge water reservoirs are characterized by small volume, narrow oil bearing area. In early development stage，if geological knowledge is not clear, the accurate evaluation of the size of edge water is not carried out, it will reduce development efficiency. Authors analyze the geology and production characteristic ofWest 58- 8 fault block reservoir, calculate the size of the water aquifer by use ofmaterial balance equation and evaluate the edge water energy by use of numerical simulation. The calculation results showthat twomethods （material balance equation and numerical simulation） are quite consistent. The model is accurate and reasonable.

The analysis on the sources of water body and characteristic of water breakthough at Block 12 in Tahe Oilfield

QI Minghui，LU Zhengyuan，YUAN Shuai，LI Xinhua

2009, Vol.21(4): 115–119 Abstract ( 429 ) PDF (580 KB) ( 546 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.024

The heterogeneity of the reservoir of Ordovician systemin Tahe Oilfield is serious, and the water-oil relation is complex, water breakthrough in the oil well is the main reason that causes production drawdown. The sources of the water body in the water breakthrough well include the leakage fluid and the acid fracturing fluid remained, relic water in the bottom of the fracture-cave unit. The water body in the lower part of the fracture-cave unit is connected by acid fracturing. The output of the leakage fluid always presents the pattern of water cut decline which has low influence on the production. The output of the relic water and the water body in the lower part are different because of the energy of the water body, the height of the oil-water contact and the difference of the vertical permeability. It is a effective way to enhance the ultimate degree of reserve recovery in the reservoir that take steps to stabilize oil production and control water cut of the different resources of the water body and different characteristics of water breakthough.

Equivalent depth method is not equivalent

LI Chuanliang

2009, Vol.21(4): 120–123 Abstract ( 467 ) PDF (263 KB) ( 897 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.025

Based on the theory of rock mechanics, the deformation mechanismof rock was studied. The porosity of rock depends on the arrangements and the size distribution of grains, not the size of grains. The porosity curve can be divided into the compaction portion and the compression portion. Porosity in the compaction portion changes with stress, while the porosity in compression portion keeps constant and does not change with stress. However the theory of petroleum geology takes the compression portion as the undercompaction portion, and the constant porosity as the result of increased pore pressure. The equivalent depth method is used to calculate the pore pressure. Actually the equivalent depth method is not equivalent. The dependence of porosity on the pressure is lack of theoretical basis. The abnormal pressures in the compression portion by the equivalent depth method are not consistent with practice. Prediction of pressure by the equivalent depth method is meaningless in practice which maymislead the relative researches.

A new idea for lithologic trap description with little wells: Taking Liaodongwan area as an example

JIA Donghui，ZHOU Xinhuai，LI Jianping，LAIWeicheng，LIU Xiaohong，LI Jun

2009, Vol.21(4): 124–129 Abstract ( 458 ) PDF (874 KB) ( 461 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.026

Lithologic reservoir of gravity flow deposits are an important exploration target of fault-controlled lake basins. Exploration is difficult for the conversion of object, such as play choice, trap identification and description. Now petroleum geologists often pay attention to trap identification, but systemic study of formation mechanismand inner composition （specially not typical submarine fan deposits） are ignored. This paper first introduces the conception of lithologic trap description with the content of lithologic trap. It links geological dynamic analysis and geophysical static escription, and figures out the problemof play choice, trap identificationand description according to formation mechanism, development model and inner composition of fault-controlled lake basins. Then authors expound the main study methods and techniques. Exploration practice proves that the conception, method and technique are effective for lithologic trap and will promote the exploration of lithologic reservoirs.

Progress in the research of “continuous” petroleum accumulations abroad

GONG Yanjie，ZOU Caineng，YUAN xuanjun，TAO Shizhen，ZHU Rukai，WANG Lan

2009, Vol.21(4): 130–134 Abstract ( 458 ) PDF (431 KB) ( 604 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2009.04.027

The exploration and development of unconventional oil and gas abroad have made significant progress, some unconventional oil and gas reservoirs have continuous geological features. It is meaningful to summarize the geologic features of continuous petroleum accumulations for guiding domestic hydrocarbon exploration. The background, definition and characteristics of the “continuous” petroleumaccumulations were depicted through studying a number of related foreign papers. It shows that “continuous” petroleumaccumulations have large spatial dimensions and indistinctly defined boundaries, and exist more or less independent water column, and can be assessed with FORSPAN methods different from conventional accumulations resource-assessment.