【作者】 马锋；

【导师】 钟建华；

【作者基本信息】 中国石油大学 ， 矿物学、岩石学、矿床学， 2007， 博士

【摘要】 塔中Ⅱ号构造带为目前塔里木盆地中央隆起带勘探重点地区,但仅在塔中4油田奥陶系见到工业油气流,塔中Ⅱ号构造带的中、西部勘探效果并不理想,构造发育、演化及其对储层、油气成藏的控制作用不清是其主要原因。通过对塔中Ⅱ号构造带构造几何学特征精细分析、古构造恢复和应力模拟,综合分析构造与油气成藏的关系,提出塔中Ⅱ号构造带油气勘探的有利区带。通过对塔中Ⅱ号构造带地震资料进行构造综合解释,定量分析断裂平面几何要素和剖面几何要素特征,确定塔中Ⅱ号构造带主要构造样式,揭示了塔中Ⅱ号构造带圈闭类型;同时将塔中Ⅱ号构造带垂直断距等几何要素的变化特征与研究区重要储层上泥盆统的东河塘组砂岩的分布联系起来,揭示断裂几何要素特征对油气成藏的控制作用。综合分析区域构造演化资料,通过平衡剖面法恢复了塔中Ⅱ号构造带中寒武统顶、上奥陶统底、志留系底、上泥盆统东河塘组底和二叠系底五个关键界面的构造形态,将塔中Ⅱ号构造带构造演化分为五个阶段,计算五个界面之上的地层相对缩短量,提出塔中Ⅱ号构造带构造演化模式;将缩短量变化与火山岩主要发育时期联系起来研究,在缩短量最小的二叠系地层处于伸展状态,为火山岩的侵入创造了条件。通过分析区域应力场和现今应力场方向,在古构造恢复基础上建立地质模型,采用有限元方法进行构造应力的数值模拟,确定了塔中Ⅱ号构造带在不同地质时期应力分布特征,进而揭示了不同时期断裂的封闭性和油气运移的优势指向。利用前人对塔里木盆地中央隆起带的研究成果,综合分析塔中Ⅱ号构造带沉积演化特征、烃源岩特征、地层剥蚀特征、成藏期次、储盖组合特征,识别出局限碳酸盐岩台地相和开阔碳酸盐岩台地相,分析研究区三套主力烃源岩和碎屑砂岩、碳酸盐岩两大类储集层特征,揭示了塔中Ⅱ号构造带油气藏存在多源、多期,生储盖组合多套的特点。通过研究断裂与不整合面对油气成藏控制作用,对比了塔中Ⅱ号构造带东部和西部油气成藏条件差异,指出了西部油气成藏的“碗大锅小”不利条件;揭示岩溶储层的分布规律与构造应力分布规律具有正对应关系;利用应力模拟成果,找出有利油气聚集的应力区带,将这些区带与有利构造圈闭进行对比,圈定了不同时期研究区有利圈闭,指出塔中Ⅱ号构造带勘探有利方向。更多还原

【Abstract】 TheⅡstructural zone is the key area for further prospecting in the central uplift of Tarim Basin. But constrained mainly by the insufficient research on the structure development and evolution and its controls on reservoir and hydrocarbon accumulation, the exploration result of the central and westernⅡstructural zone in Central Tarim is not good, with discovered industrial oil and gas flow only in Ordovician system of TZ 4 oil field. Through accurately analyzing the geometric features of theⅡstructural zone, recovering palaeostructure, and simulating stress, synthetically study the relation between structure and hydrocarbon accumulation, and put forward the hydrocarbon-exploring favorable zone ofⅡstructural zone in central Tarim.In the light of the accurate seismic structure interpretation of theⅡstructural zone, quantitatively analyze the horizontal and the section geometric elements of the faults, and determine the main structure styles of theⅡstructural zone, then find out the trap types of theⅡstructural zone in central Tarim; meanwhile, connect the geometric elements’distribution characteristics of theⅡstructural zone such as vertical fault throw with the donghetang formation sandstone who is the key reservoir of the research area, then reveal the controls of fault geometric elements on hydrocarbon accumulation.Synthetically analyze regional tectonic evolution data, and recover the structure patterns of the five key interfaces-the top of the Middle Cambrian series, the base of the Upper Ordovician series, the base of the Silurian series, the base of Upper Devonian Donghetang formation and the base of the Permian series-by the balanced cross section, then divide theⅡstructure zone into five evolution stages, and through calculating the relative shorting amounts of the cross-sections above these five interfaces, put forward the tectonic evolution patterns of theⅡstructure zone in central Tarim; the result of researching on the shorting amount variety combined with the major time of volcanic rocks developing, shows that the Permian stratum with minimum shorting amount is in the state of extension, which created the conditions for volcanic-intruding.Through analyzing the characteristics of the regional stress field and the present stress field, set up geological model base on recovered paleo-tectonics, and numerically simulate its tectonic stress by using finite element method to gain the stress distribution characteristics of theⅡstructure zone in central Tarim in different geological age, then reveal the fault closure and its opening extent in each age and the predominant direction of hydrocarbon migration, which supplies the important reference and guidance for hydrocarbon reservoir’exploration.Combined with the previous findings about the Central Tarim uplift, synthetically analyzing the sedimentary evolution, the source rocks, the strata denudation, the hydrocarbon accumulation stages and the reservoir cap rock combination, divide the unconformity interface of theⅡstructure zone in central Tarim into three levels, and identify restricted carbonate platform and open carbonate platform, and Study the characteristics of the three sets of source rocks and the two types of reservoirs-clastic sandstone and carbonate rocks, which indicates polygenetic - multiphase -multi-source-reservoir-cap rocks assemblage hydrocarbon reservoir characteristics in theⅡstructure zone of central Tarim.Discussing the controls of the faults and the uniformity on hydrocarbon accumulation and correlating the hydrocarbon accumulation conditions of the eastern and the westernⅡstructure zone in central Tarim, point out the“massive container and little oil sources”(called the model of big bowl and little pot)disadvantage conditions of western hydrocarbon accumulation; reveal the coincidence relation between the distribution law of karst reservoir rocks and the distribution law of tectonic stress; use the stress simulation result to find out the stress zone which is advantage for hydrocarbon accumulation, and compare these stress zone to the advantage structural traps to outline the advantage traps of each age, then predict the favorable target for further prospecting in theⅡstructure zone of central Tarim.更多还原