【作者】 陈晓智；

【导师】 汤达祯；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2011， 硕士

【摘要】 吐哈盆地鄯勒油田处于博格达山前构造带,地质条件复杂,砂层与煤层交互发育。鄯勒油田为特低孔特低渗型煤系储层油田,虽建产规模逐年扩大,但受制于地质构造背景,前期构造分析并不完善,构造及断裂对油气成藏的影响研究不够深入,加上物源方向变化快及生储盖配置多样化等因素,导致近几年多次勘探与开发没有大的突破。论文针对以上问题,以地震、测井及钻井资料为基础,结合研究区地质背景,利用Landmark工作站重新认识并分析鄯勒油田构造特征,总结了典型区块的构造类油藏的油气成藏规律,建立了油气成藏模式,预测了有利油气圈闭,最后指出了下一步勘探开发的有利区块。研究表明:(1)鄯勒地区主要发育基底卷入式、盖层滑脱式和撕裂型三种断裂类型。研究区两侧的基底大断裂形成于印支末期,并在后期不断活化改造;中部的盖层滑脱式断裂形成于燕山Ⅱ幕运动时期;燕山Ⅲ幕运动时期,撕裂断层形成,并对早期形成的盖层滑脱断层进行切割。(2)断裂是油气成藏的重要控制因素。基底断裂形成时期产生了大量的构造裂缝,沟通了中下侏罗统及三叠系烃源岩,为油气向上或侧向运移提供了有利通道。盖层滑脱断层形成时期伴生的构造裂缝多被方解石、硅质等矿物充填,利于早期生成油气的保存,但受后期燕山晚期及喜山期构造运动的影响,早期断裂活化,断面错开,导致早期油藏内油气散失并在浅层有利圈闭处聚集成藏。(3)鄯勒地区油藏类型可以划分为构造类和岩性类油藏,细分为断背斜型、断块型、断鼻型、砂体上倾尖灭型和透镜状砂体型等五个亚类。(4)研究区典型区块已发育的构造类油藏成藏规律可归纳为:①靠近可沟通油源的基底断裂;②圈闭形态受构造与断裂双重作用的控制;③有效储集体下部多发育高角度未充填裂缝且上部多发育低角度充填裂缝。(5)预测了断鼻型和岩性型油气圈闭,并指出了下一步油气勘探开发的有利区块。研究区南部基底大逆断层下盘封闭条件好,西山窑组一、二段地层中容易形成断鼻型油藏;研究区中部靠西侧西山窑组二段的三角洲相前积砂体受后期构造运动影响,易形成砂体上倾尖灭型油藏;研究区中部靠西侧西山窑组三、四段时期形成的湖相浊积砂体容易形成透镜状砂体型岩性油藏。更多还原

【Abstract】 The Shanle oil field of the Tuha basin is located in the tectonic zone of the front of the Bogda mountain, the geological condition of which is complex, and the sand layer and coal layer are developed interactively. The Shanle oil field is coal reservoir featured in extra-low porosity and extra-low permeability. Although the production increased yearly, there were no major breakthrough in the exploration and development in recent years, which was the result of the complex geological background, preliminary imperfect structural analysis, no enough in-depth studies of the effect of structure and fracture on the hydrocarbon accumulation, the rapid changed source direction and the multiple source-reservoir-cap assemblage. To solve the above problems, based on the seismic, well logging and drilling data and combined the geological conditions of the study area, this paper recognized and analyzed the structural characteristics of the Shanle oil field using Landmark workstation, on this basis, the rules of hydrocarbon accumulation of the structural reservoir in the typical blocks were summarized, the mode of hydrocarbon accumulation was established, the favorable hydrocarbon trap was predicted, and finally, the favorable areas for further exploration and development were indicated. The results show that:(1) The Shanle area mainly developed three types of fracture: basement-involved fault, seal-detachment fault and tear fault. The basement-involved thrust faults in the both sides of the study area formed in the Late Indosinian, and were active in the late period. The seal-detachment faults in the central of the study area formed in the second-stage of the Yanshan movement, while in the third-stage of the Yanshan movement, the tear faults formed and cut the seal-detachment faults formed in the earlier period.(2) In the Shanle area, faults are the important factors for hydrocarbon accumulation. During the period of forming the basement fault, a plenty of structural cracks developed, which communicated the source rocks deposited in the Lower-Middle Jurassic and Triassic formations, and provided the favorable channel for the upward or lateral migration of hydrocarbon. The associated structural cracks in the period of the seal-detachment faults formation were mostly filled by calcite, silica and other minerals, which was beneficial for the preservation of the early generated hydrocarbon. However, affected by the late Yanshan movement and Himalayan movement, these faults formed in the earlier period activated and the fault surface staggered, which caused the hydrocarbon loss of the earlier reservoirs and accumulated in the favorable traps of the shallow layers.(3) The reservoir types of the Shanle area can be divided into structural reservoir and lithological reservoir, which were subdivided into five subclasses: faulted anticline type, faulted block type, faulted nose type, upward thinning out sand body type and lens-shaped sand body type.(4) The hydrocarbon accumulation rules of the structural reservoirs in the typical blocks are:①close to the basement-involved faults that could communicate the source rocks;②the trap morphology is controlled by both structure and faults;③the lower of the effective reservoir mainly develops unfilled high-angle cracks and the upper of that mainly develops filled low-angle cracks.(5) The hydrocarbon traps of the faulted nose and lithological types were predicted and the favorable areas for further exploration and development were pointed out. The sealing condition of the footwall fault of the basement-involved thrust fault in the south of the study area is good, which is easy to form faulted nose reservoir in the first and second members of the Xishanyao formation. In the second member of the Xiashanyao formation in the middle-west of the study area, the foreset sand body of delta facies is likely to form the upward thinning out sand body reservoir by the result of the later tectonic movements, while the turbidite sand body of lacustrine facies deposited in the third and fourth member of the Xishanyao formation is prone to form the lens-shaped sand body reservoir.更多还原