Control factors and porosity evolution of high-quality sandstone reservoirs of Kela-2gas field in Ku

Control factors and porosityrocks, oil and gas pool, integrated petroleum geology research, advantageously promoting the course of petroleumevolution of high-qualitexploration of the Tarim Basin. For example, the studiesof structure deformation and its evolution/ 2+, sedimen-sandstone reservoirs of Kela-2 tary and reservoir geology", paleotologic stratigraphysource rocks 9, oil and gas pools, petroleum geology ofgas field in Kuqa Depression Kuqa Depression! o0.l have been performed. Thus, most ofgeologists and explorers believe that Kuqa Depression hasJIA Jinhua& GU Jiayusesseed the condition of forming huge oil and gas fieldResearch Institute of Petroleum Expleand Development, Petro-There are two suits of favorable source rocks deposited influvial-lacustrine-swamp environment during Triassic andCorrespondence should be addressed to Jia Jinhua (e-mail: jh@ JuJurassic 9. It is the characteristics for hydrocarbon sourcepetrochina. com. cn)rocks of great thickness, high contents of organicAbstract By using the integrated methods including abundance and high degree of maturity, strong intensity ofsandbodies modelling of the outcrops, sedimentary facies of natural gas generation. It supplied the plenty of naturalthe cores and well logs of the drilled wells, and the reservoir gas for the Kela-2 gas field. They are developed high-correlation of interwells it is thought that the sandstone quality reservoir-seal assemblage constituted by Cretaral gas reservoirs with great thickness, extensive and con- ceous sandstones and Paleocene gypseous salt rocksl5, 6)tinuous distribution, high porosity and permeability, and a Faults and unconformity surfaces resulting from multifew barrier beds. Sedimentary facies and microfacies are the stage tectonism 2-4 are in favor of petroleum migrationmain factors controlling the reservoir distribution and interior heterogeneity. Based on a great deal of data of rocksDeveloping structure traps corresponded to generation andthin sections, porosity, permeability, and the parameters of discharge of hydrocarbonscapillary pressure, the reservoir diagenesis, controls, mechaPrecise description of Kela-2 gas pool has been car-nism and evolution of pores have been studied. It is consid- ried out for accurately proven reserves. Reservoir deered that compaction in the early stage and diagenetic dolo- scription and evaluation! 2) are the key of integrately demite and calcite cements have effect on the decline of reser.oirs property Now compaction is chiefly middle to weak. scription of gas pool. At present, reservoir description inThe better reservoirs have no or a few calcite cements In the exploration stage is much more precise. At macro scale,early of deep buried stage there are still mainly remainder combining reservoir architecture with sequence stratigraprimary intergranular pores. The authigenic kaolinite of phys, 14, different architecture units of reservoirs havereservoirs is the production of the dissolution of feldspars been established[5]. Sequentially, we can further study theand lithic fragments. The dissolution results in the partlyreservoir heterogeneous and the variety of porosity andthe late of deep buried stage, structure fissures and overpres. permeabilityllbl. At micro scale, by means of most of testsure were in favor of improving and preservation of these ing, we can study the reservoir pore geometry and itsevolution, sequentially analyzing the reservoir controlsKeywords: Kuga Depression, Kela-2 gas field, high-quality sand- and its forming mechanism!7-9. This paper focuses onstone reservoirs, control factors, porosity, permeabilitythe characteristics of high-quality reservoir with hugethickness, controls and forming the mechanism of Kela-2The Kela-2 gas field is located in the middle sectiongas field.of the Kelasu structure belt in Kuqa Depression, adjacentto the northern monoclinal belt and southwestern bai- 1 Reservoir characteristics of Kela-2 gas fieldcheng Depression. The first exploration well of Kela-2 gas(1) Distribution of reservoirs. The Kela-2 gasfield was drilled in January 1998. Other appraisal wells, field is a pure gas pool of block sandstone anticline trapKela-201, Kela-203, Kela-204, and Kela-205, were drilled with high temperature, overpressure, high production, andfrom 1998 to 2001 respectively. High production gas flow high abundance ). The main reservoirs of the Kela-2 gaswas gained from the five wells. And then, proved reserves field include sandstones in Lower Cretaceous Bashijiqikeof 2840. 29.>10 natural gas have been obtainedFormation basal sandstones and marine dolomitesExploration success of natural gas in Kuqa Depres- Lower Paleogene Kumugeliemu Groupl. The sandstonesion profits from researching progress of petroleum geol- reservoirs are brown medium to fine grained arenites. Itsogy for the foreland thrust belt of foreland basin By total thickness is 231.3-357 m. The Lower Cretaceoustackling key problems of science and technology, many saneimportant results and recognition have been achieved on Low中国煌455 m in thickness:heLe reservoir is 11--19.5 m2tectonics, stratigraphy, sedimentology, reservoir, source inCNMH Ge overlying Early Terti-I)Wang Zhaoming, Li Qiming, Pi Xuejun et alof proved reserve of Kela-2 gas field (in Chinese), Tarim Petroleum Ce2 2Jia Jinhua, Wang Yuehua, Zou Yisheng et al., Study of sedimentology and reservoirs of Cretaceous to Lower Paleogene in Kela-2 gas field,im Basin(in Chinese), Tarim Petroleum Company, 2000, 1-136Chinese Science Bulletin Vol 47 Supp. December 2002y strata of the huge thick gypseous salt rocks and gyp- Kela-2 gas field (fig. 1)with the sandbody architecture ofseous mudstones, these reservoirs constitute a high-quality the adjacent outcrop section in the Kelasu Rivers, Bashreservoir-seal assemblage in Kuqa Depressionjiqike Formation reservoirs reflect"toy bricks type"arBased on Paleontology data, stratigraphic division chitecture. It is made up of many braided -channel sand-and correlation of Kela-2 gas field, the Lower Cretaceous bodies superposed and incised each other 5-7. Reservoirhas been divided descending by Bashijiqike Formation, thickness of each submember in the Bashijiqike Forma-Baxigai Formation, Shushanhe Formation and Yageliemu tion occurs quite stably. Reservoir porosity and permeFormation, but lacks Upper Cretaceous strata. The Lower ability of each submember are very corresponding InterCretaceous Bashijiqike Formation is divided by three bedded mudstones are not continuity and have no covermembers and ten submembers 61. The rocks of the third effect. the best reservoirs are the second member and themember(the lower sections) are dominated by grey sandy lower of first member; the next are the third member ofconglomerates, with conglomeratic coarse-grained sand- Bashijiqike Formation and the basal sandstones of Lowerstones interbedded with dark brown thick mudstones and Paleogene Kumugeliemu Group. In general, they aresandy mudstones. The second member(the middle sec- suit of high- quality gas reservoirs with huge thickness,tions) is composed of brown medium to fine-grained very good connectivity, and a little partition bedssandstones interbedded with a few brown thin mudstonese )Porosity, permeability and pore geometry ofThe first member(the upper sections)is characterized by reservoirs. Based on the abundant data of porosity andbrown medium to fine-grained sandstones with few thin permeability, the porosity of sandstone reservoirs rangesmudstones, from Well Kela-2 to western Well Kela-201 from 1. 1%o to 22.4%0, 12.8% on average, and the permeand Well Kela-203, the thickness of the first member be- ability ranges from 0.004.->10- to 1770.15.>10-umcomes thinner. so lacks 1-2 submembers. There is a The correlation of porosity and permeability is well, indiregional denudation unconformity surface(viz. Ts seismcating that these sandstones possess a favorable reservoirreflection surface), overlying the basal sandstone member space (fig. 2)of Lower Paleogene Kumugeliemu Group. It is brownBy identification of a lot of thin sections, it is conconglomeratic coarse to medium-grained sandstones of sidered that the remaining primary intergranular pores arethe basal sandstones memberthe main reservoir space in Kela-2 gas field. Pores are ofBy comparing the reservoirs of the drilled wells in irregular, elongated, and even super-size. Throats areEWell Kela-204Well Kela-2GR出DψWell Kela-201GRD·KGRmD中Well Kela-2033756,0370804000(×10pmn)402240ll.5中国煤化工CNMHGreservoirs in well logs of Lower Cretaceous to Lower Paleogene in Kela-2 gasfield. A, Paleagene: B, Kumugeliemu Group; C, Basal sandstone; D, lithologic columnChinese S序嫂弻 etin Vo.47Supp. December2002R2=0.7922aqueous distributary channel sandbodies, distributarymouth bar sandbodies and distal braided channel sandbodies 5. This is the most favorable geologic basis ofhigh-quality reservoirs in the Kela-2 gas fieldhe third member of the bashijiqike Formation inthe Kela-2 gas field is characterized by sedimentary faciesof fan-delta front and byfacies of the subaqueousdistributary channel sandbodies (fig 3). Their thickness isusually 5--10 m Porosity and permeability are lowerPorosity of cores ranges from 1. 1%0 to 17.3 %, averagely8.4%. Permeability of cores ranges from 0.004 x 10to311.8.10-3um2,13.4.×10-3elated to rapid deposition and high contents of matrix offan delta facies Reservoirs of the first and second members are dominant subaqueous distributary channel sandbodies of braided delta fresandbodies reworked by lacustrine waves, as well as distalof Lower Cretaceous to Lower Paleogene in the Kela-2 gas hcl ervoirFig. 2. Porosity and permeability correlogram of sandstone reservoirsbraided channel sandbodies of braided delta plain. Theirthickness is usually 3-6 m. The best reservoirs arechiefly narrow neck types. The sorting of pores and subaqueous distributary channel sandbodies Porosity ofthroats is moderate to well. The main throat radius is cores is in the range of 18%0-20%. Permeability of cores0. 4-16 um. The displacement pressures of sandstonereservoirs reflected byrange0.035 to 1. 2 MPa, 0.76 MPa on average. The poresGamma ray Depositionalcurvegeometry is generally medium to small pores and mediumto fine throats. In vertical, the best pores linking to sec-tions are the first and second members of the bashijiqike3770Formation. The median and maximal displacement pres-sures are relatively low, 1.072". 293 and 0. 274--0.685MPa on average respectively, which reflects the powerpermeability for fluid. The average and the maximal porethroat diameters are respectively 1. 844-2.62 and 7.8810.53 um. The maximal index of pore throat coordinationis 4. The sorting of pore throat is well. The pores linkingof the third member and the basal of lower paleocene arerelatively poor. The median and maximal displacementpressures are higher, and the average is respectively 4.639-7.556 and 1. 118--2.798 MPa. Their permeability isrelatively low. The average and maximal pore throatdiameters are 0.44--1.47 and 2. 16--5.97 um respectively2 Sedimentary facies and microfacies are the domi-nant control on high-quality reservoir distribution andinterior hetel(1) Different types of sandbodies controlling theporosity and permeability of reservoirs. The sandbodiesof different types of microfacies in fan delta and braided中国煤化工delta facies obviously control the reservoir property 9.20. o LCNMHfferent microfacies sandbodiesBy comparing the sedimentary facies of the drilled welation of Well Kela-2015.百Progradational distributary channel; C distributary mouth bar; Ewith that of the outcrop sections, there developed mainly retrogradational distributary channel; C aggradational distributarythree types of sandbodies in Kela-2 gas field, i.e. sub- channel; E littoral mudstoneChinese Science Bulletin Vol 47 Supp. December 2002ranges fro:>100.×103to1000.×103μum2. Next aredistributary mouth bar sandbodies. Porosity of cores is10-3to603.×10the range of 10%-15%, and permeability of cores 3 Influence of diagenesis on reservoirs0.1×103-10.×10-m2The clay mineral assemblages of sandstone reser-i) Texture and grain size of sandstones having the voirs of Lower Cretaceous to Lower Paleogene in thedistinct control on reservoir property Different compo- Kela-2 gas field are allogenic illite, chlorite and mixednents, textures and grain sizes of sandstones have different illite/semectite, and the next are authigenic kaolinite andcontrol on reservoir property. Based on the data of thin mixed chlorite/smectite. They have reflected partially thesections of cores, the reservoir rocks of the Kela-2 gas alkaline diagenetic environment. There presents acid difield are brown medium-to fine-grained arenites. The agenetic environment followed by the organic acid entercontent of quartz is 46.2%--49%. Feldspar is chiefly ing the late stage[22 The influence of diagenesis on reserpotassium feldspar, the next is plagioclase, with the cevoirs exhibits compaction during early diagenetic stage 231,tent of 9.3%--16%. The content of lithic fragments is cementation of dolomite and calcite diminished primary40%-45.5%. They are mainly siliceous metamorphic pores during late diagenetic stage, and dissolution of feld-fragments, the next are sedimentary fragments, and igne- spars and lithic fragments which could partly enlarge theous fragments are lesser. Detrital grains occur with thesecondsubangular to subround shape contact as point to line,(1) Compaction during early diagenetic stage is themedium to well sorted. In general, maturity of texture is dominant factor of porosity loss of reservoirs. From themoderate to high and maturity of component is relatively data of lots of thin sections in the Kela-2 gas field, grainscontact as point to line, reflecting the middle to weakStatistics of porosity and permeability of different compaction. The correlation between sonic time differgrain-size sandstone in Kela-2 gas field indicate that the ence and depth shows the deviation from normal compacreservoirs of medium- to coarse-grained sandstones are tion and present undercompaction below the seal of Low-the best, the next are fine-grained sandstones, and the er paleogene gypseous salt rocks This also reflects thepoorest are the siltstones(fig. 4). The porosity of the medium-to coarse-grained sandstones ranges from 4.71%toCompaction ratio may be expressed by the degree of20.15%, and the permeability 0.22.>10- to 551.x10- rocks pressed. Compaction ratio=(primary porosityum?. The porosity of the fine-grained sandstone ranges intergranular volume)primary porosity. >100%2. Prifrom 2.67% to 17.8%,and the permeability 0.017>103mary porosity= 20.91+ 22.9/S (S is Trask sorting coeffito 198>10-3 um2. The porosity of the siltstone ranges cient). When the compaction ratio is less than 30%,comfrom 5.16% to 14.38%, and the permeability from 0.024 paction is relatively weak; when the compaction ratio isat the middle de10000gree;when the compaction ratio exceeds 70%0, compacgrained sandstonetion is relatively strong 251. Calculation by upper formulaFine-grainedshows that the compaction ratio of sandstone reservoirs insandstonethe Kela-2 gas field is 11%0-40%0, indicating the middlex SiltstoneThe influence of normaland permeability commonly occurred in the early diagenetic stage, which results in the primary porosity lossabout18.2%-248%2he weak compaction in this area is due to the spe-cial diagenetic background. The long-term shallower bur-led history and subsequently rapid deep buried historydetermine that compaction did not carry out completelyDuri中国煤化工, Kuga Depression was in1525thenment. The clay mineralasseCNMHGalkaline diagenetic enyronment. There are a few matrix and certain extent earlyFig 4. Correlogram of porosity and permeability of different grain- dolomite cements in the sandstone reservoirs, and termisize sandstones in the Kela-2 gas field.Chinese S序嫂 letin Vo.47Supp. December2002103nal overpressure upon the reservoirs. All of these factors 60%. This reflects the middle to weak cementation. Withrestrained the compaction of the reservoirs in the Kela-2 burial depth increasing, the cementation ratio increasedgas fieldThe porosity loss of reservoirs due to cementation is about(1) Dolomite and calcite cements have important 2.5%--13.4%effect on the reduction of porosity and permeability ofBased on the observation of thin sections at least thereservoirs. The condition of partial to alkaline and partly two-stage cementation of sandstone reservoirs in the Kela-acid diagenetic water medium determined that cementa- 2 gas field has been found In the early stage, there existedtion initiated early, endured for a long time, with more more dolomite cements originated in deposits that standkinds of cements. Cementation of the drilled wells in the against the compaction. In the late stage, they are mostlyKela-2 gas field is worse than the outcrops. The content of euhedral crystal ankerite and calcite cements that surroundcements filling the pores is 2.5%-9% on average. The on the early dolomites. Analcite, formed in the early stage.content of the matrix of the mainly pelitics and ferriferous reflects the alkaline with high dissolved solids diageneticelitics is 6%09% on average. There are mainly dolo- water environment with rich SiO,, Ca, K, and Na ionsmites, ferrous dolomites, ankerite, and gypseous cements Quartz overgrowth may be related to the dissolution ofin the basal sandstones of Lower Paleogene Kumugeliemu feldspars and lithic fragments. Gypseous cements, formedGroup. Authigenic cements of Cretaceous Bashijiqike in the late stage, reflects the alkaline diagenetic waterFormation are mainly dolomite, and the next are calcite, a envoirnment with high salinity and high-dissolved solidfew gypseous, siliceous, analcite and pyrite. In the Baxi(Lii) Dissolution improvpore geometrygai Formation, there are chiefly calcite, dolomite, ferrous reservoirs. Mostly, dissolution of feldspars and lithiccalcite, ankerite, siliceous and pyritefragments and a few dissolution of part quartz resultedIn vertical, the content and type of authigenic miner- in a certain extent of authigenic kaolinite appearing in theals change regularly. The content of authigenic cements in sandstone reservoirs which lack in the mudstones. Thethe gas beds commonly is fewer than that in the dry beds. relative content of kaolinite in the clay minerals isDolomite and ankerite are mainly distributed in the sec- 59%0, 17.2%0-18.3% on average. In the slight acidond and third members of the Bashijiqike Formation. medium (pH5), K-feldspar dissolved to be K and Al**,Calcite occurred only in the first and third members of the forming kaolinite and SiO,(viz. quartz overgrowth)Bashijiqike Formation and the Baxigai Formation. Gyp- Dissolution made the pores of the sandstoneseous cements appeared in Paleogene, analcite chiefly in rearrangement and improved the pore geometry ofthe second member of the Bashijiqike Formation. The reservoirs. Dissolution altered and expanded thecontents of siliceous cements increase from the second remaining intergranular pores, formed the supersize poremember of the Bashijiqike Formation to the Baxigai For- and broadened pores, and then made the pores link bettermation. Calcite and siliceous of the sandstones in the Dissolution increases the pores by about 0.4%-1.2'Baxigai Formation are more than that in the Bashijiqike Dissolution of reservoirs in the Kela-2 gas field has aFormation. The forming of calcite in the Bashijiqike For- relation to the open diagenetic system during the earlymation has relation to the sequence boundary at the base stage of deep burial. After the appearance of theand top of the Bashijiqike Formation Sequence5. There overpressure in the late stage, relatively close diageneticmay be a certain amount of calcites resulted from the system commenced, so dissolution was also weakerinfiltration of the meteoric water nearby the sequenceRegional comparison shows that dissolution of re-boundary. This coincides with the poor reservoirs of the servoirs in the Kela-2 gas field is stronger than that ofsubaerial sandstones of Cretaceous which possessed cal- adjacent Well Kela-3. Both of them are in the same sedicite cements but had no dolomites. This is an important mentary facies belt, own the same buried depth and pofactor of influencing the reservoir property.rosity, but they have distinctly different permeabilities. InThe cementation degree can be expressed by the the Kela-2 gas field, reservoir sections have a certaincementation ratio. Cementation ratio the content of content of authigenic kaolinite, but those of Well Kela-3cements/ primary volume of pores.X100%. When the have no authigenic kaolinitecementation ratio is less than 30%o cementation is relatively weak. When the cementation ratio is in the range of中国煤化工 rable to improving the30%-60%. cementation is moderate. When the cementa- pernCNMHGtion ratio exceeds 60%, cementation is relatively strongIn this area, some well-developed faults and fissuresBy the data of thin sections, the cementation ratio of sand- are due to the intensive deformation of foreland thrust belt,stone reservoirs in Kela-2 gas field is currently less than which have strong influence on reservoir space. Structure104Chinese Science Bulletin Vol 47 Supp. December 2002fissure not only exerts a channel for migration of liquid, stage, it represents the gradually primary porosity loss.but also is important reservoir space itself or improves theIn the early rapid deep buried stage(from 23.3 to 5.3permeability of reservoirs/ 28). From the observation of the Ma, corresponding to Jidike and Kangcun stages in Miocores in the Kela-2 gas field, a lot of high angle extension cene), there were intensive dissolution and weak compacand shear fissures have been revealed. Each space be- tion and cementation. First is the dissolution of quartz andtween fissures arranged in conjugate is only several cen- siliceous fragments in alkaline diagenetic environment 511timeters. Fissures are mostly filled with dolomites and Next, from 7 to 5.3 Ma, because of the southward activitygypseous cements, or half-filled and even filled with of thrust belt and the entry of amount of organic acidnothing. There are clear dissolution phenomena along the originated from Triassic and Jurassic maturated organifissures that make the pores link better and improve the matters, there presents partly acid diagenetic environmentpermeability of reservoir resulting in the local permeabil- resulting in the dissolution of feldspars and lithic frag-ity up to 2040.X10-Hmments. The remaining primary intergranular pores had5 Overpressure is favorable to preservationof po- been modified and broadened, showing the status withmainly remaining primary intergranular pores and partlyecondary poresThe pressure of reservoir in the Kela-2 gas field isvery high. The pressure coefficient reaches 1.94--2.223.35.3The compaction curve reflected from the relation betweendepth and the sonic time difference of mudstones showsthat overpressure was mainly distributed in the regionalseal of Paleogene gypseous salinic rocks 291From the origin of the overpressure in Kela-2 gasfragment: replacementfield. there are several dominant interactional factors such6000as strong tectonic compression from the adjacent Tianshanand replacementorogenic belt, rapid deep buried in the late stage, andha.lower buried stagehigh-quality seals 29. In the leakage state of overpressure,stagethe solution capability of overpressure pore fluid is greatlyhigher than the subaerial normal pressured fluid. They areEarly diagenetic stage A-Bfavorable to producing the secondary pores and makingthe pores resulted from solution of the minerals and cements link better (301 On the other hand, rapid subsidence Hydroc arbonand loading in the deep buried stage are not only benefitto maturation and generation of hydrocarbon sources re- Fig. 5. The diagenetic evolution diagram of Cretaceous and Paleogenesulting in enhancing of the pore fluid pressures of reser- in the Kela-2 gas field.oirs, but also favorable to pore preservation due to overIn the late rapid deep buried stage(from 5.3 Ma topressure pore fluidpresent, corresponding to the Kuqa stage in Pliocene and6 Pore evolution of reservoirsQuaternary), there were mainly cementation and replaceThe strata of Cretaceous to lower Paleogene in the ment exhibiting euhedral ankerite crystal filled partly theKela-2 gas field experienced a long-term shallower buried Intergranular pores or ring surrounded the early dolomitehistory (14023.3 Ma)and subsequently rapid deep The late overpressure background originated from southburied history (23.3 Ma to present)(fig. 5 ). Based on ward strong tectonic compression from adjacent Tianshaninclusion temperature, clay mineral assemblage and orogenic belt were favorable to preservation of these re-diagenesis, it is estimated that the diagenetic stage of mained primary intergranular pores, simultaneouslyreservoirs in the Kela-2 gas field has reached late diagene- structure traps formed and had the advantage of petroleumsis a stage 5. 7)In the shallower buried stage(before 23.3 Ma), there AckI中国煤化工 nk Jia Chengzao of PetroChina.were mainly persistent compaction and weakly dissolution. PresiInstitute of tarim petroleumThe early dolomite cements resisted the compaction, he mpCN MH Groleum Geology Departmentcontemporaneous compaction was intensive where it wanstitute of Jianghan Oilfield fotheir reviews and many constructive suggestions. This work was suppelitic matrix. Pore fluid was mainly idiogenous water ported by the Key Technological"Tackle the Problem"Project of thereflected partial to alkaline diagenetic environment. In this "Ninth Five-Year"Program( Grant No. 99-111-01-02-05Chinese S序嫂弻 etin Vo.47Supp. December2002ferences16. Jiao Yangquan, Li Sitian, Li Zheng et al., Heterogeneity of o-1. Jia Chengzao, He Dengfa, Lei Zhenyu et al., Petroleum Explora-osity and permeability in clastic rock reservoirs, Oil- &Gas Ge-tion of Foreland Thrust Belt (in Chinese), Beijing: Petroleum hnology (in Chinese), 1998, 2dustry Press, 2000, 1-35117. Scherer, M, Parameters influencing porosity in sandstones: A2. Lu Huafu, Jia Dong, Chen Chuming et al. Tectonic characteristicsmodel for sandstone porosity prediction, AAPG Bulletin, 1987,and deformation times of Kuqa Cenozoic, Earth Science Frontiersin Chinese),1999,6(4):21518. Huang Sijing, Hou Zhongjian, Spatio-temporal variation of sub-3. Wei Guoqi, Jia Chengzao, Shi Yangshen et al., Tectonic characsurface porosity and permeability and its influential factor, Actateristics and petroleum prospects of Cenozoic compound rejuveSedimentological Sinica(in Chinese), 2001, 19(2): 224nated foreland basins in Tarim, Acta Geoligica Sinica(in Chinese19. Luo, J. L, Morad, S, Zhang, X, L et al., Reconstruction of the2000,74(2):123diagenesis of the fluvial-lacustrine-deltaic sandstones and its in-lence on the reservoir quality evolution"-"-Evidence from Ju-4. Wang Xin, Jia Chengzao, Yang Shufeng et al., Tectonic deforma-tion age of Kuqa thrust fold belt, south of Tianshan" --Kugarassic and Triassic sandstones, Yangchang Oil field, Ordos Basin,Science in China, Series D, 2002, 45(7): 616er as an example, Acta Geoligica Sinica(in Chinese), 2002, 76(1): 20. Atkinson. C. D, McGowen,JH, Bloch, S et al., Braidplain anddeltaic reservoir, Prudhoe Bay Field, Alaska, in Sandstone Petre5. Jia Jinhua, Depositional sequece and reservoir of Cretaceousleum Reservoir(eds. Barwis, J. H, McPherson, J. G, Joseph, RBashijiqike Formation in Kuqa foreland basin, Earth ScienceJ), New York: Springer-Verlag, 1990, 729.Frontiers(in Chinese), 2000. 7(3): 13321. Beard, D. C, Weyl, R. E, Influence of texture on porosity and6. Jia Jinhua, Gu Jiayu, Guo Qingyin et al., Sedimentary facies ofpermeability of unconsolidated sand, AAPG Bulletin, 1973, 57Kela-2 gas field of Tarim Basin, Journal ofPalaeogeography (in Chinese), 2001, 3(3): 6722. Surdam, R. C, Crossey, L J, Sven Hagen, E et al., Oganic7. Gu Jiayu, Fang Hui, Jia Jinhua, Diagenesis and reservoir characinorganic interactions and sandstone diagenesis, AAPG Bulletin,teristics of Cretaceous braided delta sandbody in Kuqa Depression1989,73(1):1Tarim Basin, Acta Sedimentological Sinica(in Chinese), 2001, 23. Bloch, S, Empirical prediction of porosity and permeability in19(4):517sandstones, AAPG Bulletin, 1991, 75(7): 1145Wang Qifei, Gao Qinqin, Lu Huinan et al., Discuss about the age 24. Marfil, R, Schere, M, Turrero, M. J, Diagenetic processes influof Bashijiqike Formation in Kuqa Depression, Journal of Stratigencing porosity in sandstones from the Triassic Buntsandstein ofraphy (in Chinese), 2001, 25(4): 299the Iberian Range, Spain, Sedimentary Geology, 1996, 105: 203Wang Feiyu, Zhang Shuichang, Zhang Baomin et al., The organic 25. Atkin, J. E, McBride, E F, Porosity and packing of Holocenematuration of Mesozoic hydrocarbon source rocks in Kuqariver, dune and beach sands, AAPG Bulletin, 1992. 76(3): 339pression, Tarim Basin, Xinjiang Petroleum Geology (in Chinese), 26. Robinson, A G, Gluyas, J. G, Model calculations of sandstone1999,20(3):221porosity loss due to compaction and quartz cementation, Mar Pet.10. Zhou Xingxi, Petroleum accumulation and model of KuqaGeol.,1992,9:319leum system, Petroleum Exploration and Development (in27. Fu Wanjun, Influence of clay minerals on sandstone reservoirnese),200l,28(2):8ies, Journal of Palaeogeography(in Chinese), 2000, 2(3)11. Lu Xiuxiang, Jin Zhijun, Zhou Xinyuan et al., Petroleum accu-mulation related to gypseous salitic rocks in Kuqa Depression, 28. Shou Jianfeng, Si Chunsong, Zhu Guohua et al., The control fac-Tarim Basin, Petroleum Exploration and Development (in Chitors of properties of lower Jurassic Sandstone Reservoirs in Kuqanese),2000,27(4):20.Depression Tarim Basin, Geological Review (in Chinese), 2001Yinan, Xue Shuhao, Technique of Petroleum Reservoir47(3):272.Evaluate(revised edition)(in Chinese), Beijing: Petroleum Indu29. Zhou Xingxi, The Mesozoic-Cenozoic fluid pressure structure andtry Press, 1997, 1-343reservoir-forming machinary process in the Kuqa petroleum sys13. Zhao Hanqing, Fu Zhiguo, Lii Xiaoguang et al., The method ofm in Tarim Basin, Earth Science Frontiers (in Chinese), 20018(4):351.precisely reservoir description of huge fluvial--delta deposits, 30. Wilkinson, M, Darby, D, Haszeldine, R. S et al., Secondary po-Acta Petrolei Sinica(in Chinese ), 2000, 21(4): 109rosity generation during deep burial associated with overpressureEschard,R, Lemouzy, P, Bacchiana, C. et al., Combining seleak-off. Fulmar formation, U. K. Central Graben AAPG Bulletindata for modeling a fluvial reservoir in the Chaunoy Field (Trias- 31中国煤化工Yingchang et al.. Alkaline disic, France), AAPG Bulletin, 1998, 82(4): 545CN MHGervoir in the biyang Depression15. Miall. A. D. Architecture elements: a new method of facies ana-Science in China, Series D, 2002, 45(7): 643lysis applied to fluvial deposits, Earth Science Reviews, 1985, 22:261(Received August 9, 2002Chinese Science Bulletin Vol 47 Supp. December 2002