摘要
通过物源分析、沉积相和沉积体系分析结合储层微观特征分析等方法,本论文对吐哈盆地山前带中下侏罗统的沉积体系和储层特征进行了综合研究。
运用重矿物分析和古水流分析方法推断出研究区中下侏罗统发育有南北两大物源体系控制沉积体系的平面展布。北部物源为近端物源,南部物源为较远端物源。
采用野外调查与室内研究相结合,综合地质背景、岩性组合、沉积构造及地球化学等的分析资料,推测中下侏罗统主要发育辫状河三角洲、扇三角洲,湖泊、曲流河三角洲以及冲积扇沉积相。整个中下侏罗统发育的有利沉积相砂体是形成优质储层的基础。
对研究区开展了沉积体系展布特征及空间演化分析,山前带沉积体系演化经历了八道湾组沉积期的浅水河流-泛滥平原沼泽-滨浅湖体系、三工河组沉积期的浅水三角洲-泛滥平原-滨浅湖体系、西山窑组沉积期的扇三角洲—泛滥平原沼泽—滨浅湖—浅湖沉积体系、三间房组沉积期的的扇三角洲(辫状河三角洲)—泛滥平原—滨浅湖—浅湖体系、七克台组沉积期的的扇三角洲—滨湖砂坝—泛滥平原沼泽—滨浅湖—浅湖沉积体系五个明显不同的演化阶段。
通过岩石薄片、铸体薄片、电镜等测试分析资料,研究区储层岩石类型主要为长石岩屑砂岩,其次为岩屑砂岩,成分成熟度明显偏低,胶结物以粘土矿物和碳酸盐胶结物为主,有少量的自生石英等其他矿物。发育的孔隙类型主要为粒内孔,其次为裂缝孔隙及粒间孔。其中裂缝能够大大提高了低渗透砂岩储层的有效渗透率。孔隙结构分为单峰粗孔型、单峰中孔型、单峰细孔型以及单峰微孔型四种类型。
研究区内成岩作用主要为压实作用、胶结作用、交代作用以及溶解、溶蚀作用等。山前带断裂活动也较剧烈,断裂的活动对储层的储集空间也有一定的改造作用。成岩阶段主要处于早成岩阶段B期到晚成岩阶段A2期。不同层段不同埋深成岩阶段不同。次生孔隙的发育程度及分布规律主要受沉积作用、成岩作用以及构造作用等因素控制。
综合沉积、成岩、物性分析,对山前带中下侏罗统的储层进行了分类和综合评价,研究区主要为低孔特低渗、特低孔特低渗储层,以Ⅱ、Ⅲ类储层为主,但存在一定规模的良好储集层。七泉湖、恰勒坎、核桃沟、鄯勒、柯克亚等构造带中下侏罗统发育优势沉积相带,储层物性较好,且分布广泛,具有良好油气的储集能力,可作为下一步重点勘探目标。
The depositional system and reservoir characteristics of the Lower and Middle Jurassic in Bogeda foreland basin were analyzed by applying the techniques of provenance together with depositional system and reservoir micro-characteristics.
Sediment of the Lower and Middle Jurassic was deduced to have two provenance systems which came respectively from the north Bogeda foreland and the south provenance by analyzing the heavy mineral assemblage and the distribution of heavy mineral assemblage zone. Relatively, the north provenance was a near-end provenance, and the south provenance was a far-end provenance.
The distribution and evolution of sedimentary facies in Bogeda foreland basin is analyzed after dividing the type of depositional system and considering the stack style of sub-succession of strata. We can figure out the types of developed sedimentary facies in this area include braided river deltas, Fan deltas, alluvial fan, meandering river delta and lake facies.
Through the sequence-tract mapping of the Lower and Middle Jurassic, the distribution and evolution of depositional systems in different periods have been revealed, including following five stage: a shadow lake-river- floodplain- marsh- shore shallow lake system of Badaowan group,a shadow lake-deltaic-floodplain-shore shallow lake system of Sangonghe group, a Fan deltas- floodplain- marsh- shore shallow lake-shallow lake of Xishanyao group, a Fan deltas(braided river deltas)- floodplain- shore shallow lake-shallow lake of Sanjianfang group, a shore lacustrine-delta- shore shallow lake group.
This paper also uses lots of data of conventional rock thin sections, casting slices, scanning election micrographs, mercury injection, for discussing reservoir feathers. Reservoir rocks are mainly feldspathic litharenite, lithic arkose . Grade of maturity of rock structure and contents are low. The sandstone's cementation matter are mainly mud , carbonate etc, together with minor authigenic quartz.
Dissolution pore, constricted fissure and structure fracture are the main reservoir space. Fracture is an important controlling factor for the distribution of reservoirs. The pore structure includes large hole with large throat, medium hole with medium throat, small hole with small throat and small hole with micro-throat. The result shows that there are four diagenetic events which are compaction, cementation, replacement and dissolution in Bogeda foreland basin. Since polyphase tectonic movements and long-term fault activities were experienced, faults are abundant in this sag. The Jurassic fault active period matched well with the hydrocarbon generation and expulsion periods and had an important effect on hydrocarbon migration and accumulation. Diagenetic stage is at from B period of early diagenesis to A2 period of late diagenesis. Developing degree and distribution of secondary pore are controlled by the sedimentation, the diagenesis, the tectonism and so on.
Based on the synthetic analysis of sedimentation, diagenesis and reservoir properties, classification and evaluation of reservoir of Bogeda foreland basin are done. The second and the third reservoir dominate in thereservoir of Bogeda foreland basin. The Jurassic reservoirs mainly are pore- type clastic rocks with low porosity and low permeability. The structural zone of Qiquanhu, Qalekan, Shanle, Kekeya and so on have apparent good reservoir conditions horizontally. Vertically, have favorable reservoir properties and good oil-gas accumulation which can be acted as the next exploration focus.
引文
[1] L. F. Brown and Fisher, W.L.:1977, Seismic stratigraphic interpretation of depositional Systems: examples from Brazilian rift and Pull apart basins, In Seismic Stratigraphy-Applications to Hydrocarbon Exploration (C. E. Payton,Ed.), AAPG Memoir26,P213~248.
[2] R .G. Walker and James, N.P., 2002, Fancies Models, Geological Association of Canada.
[3] H. E. Reineck and Singh I. B., 1980, Depositional sedimentary environments with references to terrigenous classics. Berlin: Springer-Verlag.
[4]李思田.论沉积盆地分析领域的追踪与创新[J] .沉积学报:1992,Vol.10,p10~140.
[5] H.G. Reading,1978, Sedimentary Environments and Fancies. London: Blackwell Scientific Publication.
[6] E. J. pittijohn, 1975, Sedimentary Rocks,New York: Harper & Row.
[7] A.D. Miall, 2000, Principle of sedimentary basin analysis, Third Edition, Springer.
[8]刘宝珺等.岩相古地理基础和工作方法[M] .北京:地质出版社,1985.
[9]吴元燕,陈碧珏.油矿地质学[M].2版.北京:石油工业出版社,1996.
[10]裘亦楠,薛叔浩.油气储层评价技术[M].修订版.北京:石油工业出版社,2001.
[11]罗明高.定量储层地质学[M].北京:地质出版社,1998.
[12]毛志强.非均质储层夹层控油作用初论——非均质储层油气分布规律及测井响应特征[J].地球科学:中国地质大学学报,2003,28(2):196~200.
[13] Guangming Ti, Baker Hughes INTEQ, Ogbe DO et al.1995.Use of flow unit as a tool for reservoir description: A case study [J].SPE Fornation Evalution, 10.
[14]寿建峰,朱国华.砂岩储层孔隙保存的定量预测[J].地质科学,1998,32(2):64~72.
[15] Log Interpretation Volume I-Principles, Volume-11 -Application. Schlumberger, Limited, 1974.
[16]于兴河,李剑峰.油气储层研究所面临的挑战与新动向[J].地学前缘,1995,2(3)、(4):213~219.
[17] Amaefule J O, Altunbay M. Enhanced Reservoir Description:Using Core and Log Data to Identify Hydraulic(Flow)Units Andpredict Permeability in Uncored Intervals/Well[C]// R SPE26436 Presented at the 68th Annual SPE Conference and Exhibition.Houston,Texas,1993.
[18] W.J.Ebank.1987.Flow unit concept in tegrated apporch to reservoir description for engineering project[J].AAPG Annual Meeting,AAPG Bulletin,71(5).
[19]裘怿楠,薛叔浩,应凤祥.中国陆相油气储集层[M].北京:石油工业出版社,1997.
[20]袁明生,梁世君,燕列灿,等.吐哈盆地油气地质与勘探实践[M].北京:石油工业出版社,2002,610.
[21]贾承造,魏国齐,李本亮.中国中西部燕山期构造特征及其油气地质意义[J].石油天然气地质,26(1):9~15.
[22]李文厚,周立法,赵重远,等.1994.博格达南缘构造特征及形成机理[M].中国石油吐哈油田分公司内部资料.西北大学地质系、吐哈石油会战指挥部勘探开发研究大队.
[23]汪正江,陈洪德,张锦泉,物源分析的研究与展望[J].沉积与特提斯地质,2000年12月,第20卷,第4期.
[24]赵红格.物源分析方法及研究进展[J].沉积学报,2003年9月,第21卷,第3期.
[25]何钟铧,刘招君,张峰.重矿物分析在盆地中的应用研究进展[J].地质科技情报,2001,20(4):29~32.
[26] Morton A and Hurst A. Correlation of sandstones using heavy minerals: an example from the Statfjord Formation of the Snorre Field,northern North Sea. In: Dunay R E,Hailwood E A , eds.Non-biostratigraphical Methods of Dating and Correlation. Geological Society Special Publication,1995,89:3~22.
[27].Morton A C,Hallsworth C R.Identifying Provenance specific features of detrital heavy mineral assem blages in sandstones. Sedimentary Geology,1994,90(3):241~256.
[28] Morton A C. Influences of Provenance and diagenesis on sandstone,Paleocene Central North Sea. Sediment Petrol,1987,57;1027~1032.
[29]李文厚,周立发等.1997.吐哈盆地沉积格局与沉积环境的演变[J].新疆石油地质,02期.
[30]原宏壮,陆大卫,张辛耘,孙建孟.测井技术新进展综述[J].地球物理学进展.2005年9月:786~795.
[31]裘择楠,薛叔浩等.中国陆相油气储集层[M].北京:石油工业出版社,1997.
[32]戴启德,纪有亮.油气储层地质学[M].石油大学出版社,1996.
[33]熊琦华,吴胜和.储层地质学[M].石油大学出版社,1994.
[34]吴元燕,徐龙.油气储层地质[M].北京:石油工业出版社,1995.
[35]邸世祥.中国碎屑岩储集层的孔隙结构[M].西安:西北大学出版社,1991年5月.
[36]罗蛰潭,王允诚.油气储集层孔隙结构[M].北京:科学出版社,1986.
[37] G. M. Friedman, Sanders J.E., 1978, Principles of sedimentology, New York: John Wiley& Sons.
[38] W. E. Galloway, 1989, Genetic stratigraphic sequences in basin analysis, I architecture and genesis of flooding-surface bounded depositional units, AAPG Vol.73,P125~142.
[39]李文厚,柳益群,冯乔等.1997.吐哈盆地侏罗系沉积相带与砂体的展布特征[J].石油实验地质,02期.
[40]张文朝,赵岩,李胜明等.1998.吐哈盆地扇三角洲沉积特征及油气意义[J].新疆石油地质,04期.
[41]刘建清,赖兴运等.成岩作用的研究现状及展望[J].石油实验地质.第28卷第1期,2006年2月.
[42]刘宝珺,张锦泉.1992.沉积成岩作用[M].北京:科学出版社.
[43]周东升,饶丹等.成岩矿物相带及其与油气的关系——以四川盆地川西坳陷为例[J].河南石油. 2004年18卷2期:17~19.
[44]郭燕华,熊琦华,吴胜和等.2000.吐哈盆地中侏罗统储集层岩石物理相研究-以葡北-胜北-连木沁地区为例[J].新疆石油地质,01期.
[45] F.J. Pittijohn, Potter P.E., SieverR.1971, Sands and sandstones,Berlin: Springer-verlag.
[46]寿建峰,斯春松,等.塔里木盆地库车坳陷下侏罗统砂岩储层性质的控制因素[J].地质论评,2001,47(3):21~26.
[47]寿建峰.碎屑岩储层控制因素及钻前定量地质预测[J].海相油气地质,1999,1:21~26.
[48]禚喜准,王琪,史基安.鄂尔多斯盆地盐池2姬塬地区三叠系长2砂岩成岩演化特征与优质储层分布[J] .矿物岩石,2005,25(4):98~106.
[49] Brown SR,Scholz CH.Closure of rock joints[J].J GeophysRes,1986,91(B5):4939~4948.
[50]贺永红.2006.吐哈盆地中下侏罗统有利区带综合评价[M].吐哈油田勘探开发研究院(内部资料).
[51]张进学,张明山,代瑜.2000.台北凹陷北部山前带、鄯善弧形带评价与目标优选[M].中国石油吐哈油田分公司内部资料.物探局吐哈研究中心.
