南美亚诺斯盆地油气成藏条件及区带评价

发布时间：2018-08-20 13:47

【摘要】：本文研究区为南美亚诺斯(Llanos)盆地,该盆地是南美乃至世界范围内重要的油气富集盆地。其构造位置处于南美板块北部,其西以东科迪勒拉山造山带为界,东部以圭亚那地盾为界,南部边界为沃佩斯隆起,北部以北西南东走向的Arauca隆起为与巴里那斯突起的分界线而分隔。亚诺斯盆地在哥伦比亚境内面积为23.5×104km2。通过对前人研究成果的总结,本文勾勒出亚诺斯盆地构造演化过程,并将之分为古生代被动大陆边缘、中生代弧后裂谷、新生代前陆盆地3个演化期。同时,在亚诺斯盆地构造演化史研究基础上,以P.R.Vial层序地层学为指导,利用钻井、测井和地震资料综合分析,建立亚诺斯盆地层序地层格架。在中生界-新生界内部识别出5个二级层序。本文对盆地内部油气成藏条件,包括烃源条件、储集条件、封盖条件及圈闭条件进行了综合分析。盆地内发育多套烃源岩,主要为古生界泥岩、上白垩统加切塔组深海-浅海相页岩、古近系含煤泥页层。通过对烃源岩分布特征、有机质丰度、有机质成熟度和演化程度进行综合分析,详细刻画出不同烃源层的生烃情况。在多套烃源岩层中以加切塔组烃源岩对盆地内油气成藏贡献最大。盆地烃源灶位置位于盆地西缘及现今东科迪勒拉区域。盆地内多套储层发育,主要为白垩系乌内组和瓜达卢佩组、始新统米拉多尔组和渐新统卡沃内拉组(C7、C5、C3段)。通过对盆地内储层物性及发育情况进行综合分析,明确了盆地内储层平面展布特征以及发育的有利位置。盆地内多套盖层发育,其中主要的区域盖层为莱昂组。通过盆地内典型井的测井曲线对莱昂组地层封闭能力进行了综合评价,明确盆地内部盖层封盖条件较好。盆地内圈闭类型多样,常见构造圈闭、构造-地层圈闭、地层圈闭及水动力圈闭。此外,不同构造区带内主要圈闭类型往往不同。以石油地质学为指导,本文对盆地内主要四个富油气区带,即阿瑞-阿培地块、斜坡正断带、山前逆掩带以及阿普雷隆起内典型油田进行成藏特征评价。评价结果显示:盆地西部地区,受构造作用影响强烈,主要发育大型构造圈闭;盆地东部地区受构造作用影响较弱,主要发育小型地层圈闭,也见水动力圈闭。各油田的烃源灶往往并不位于油田内部,烃类流体多来自盆地西缘及东科迪勒拉山地区。在此基础上,结合盆地内构造演化、沉积作用影响,揭示了亚诺斯盆地内油气成藏特征,建立了全盆范围内油气成藏模式。盆地内油气成藏具有远距运移,混源充注,断砂立体,持续输导,阶梯式捕集成藏的特点;主力产层表现为近灶优先捕集形成中深层大中型构造油气田,远灶接替捕集形成浅层小型复合型油气田的油气分布规律。在盆地油气成藏模式的基础上,根据盆地内部根据受构造作用影响的强烈程度,划分油气聚集区带。进而根据砂体发育程度,确定油气富集有利区。最终,在此基础上,根据油气运移距离、沉积特征、储层物性、圈闭类型以及周边油田发育情况等五项特征确定了盆地内6个油气勘探目标优选区。此成果对指导盆地内油气勘探具有重要的指导意义。
[Abstract]:The Llanos basin is an important oil and gas enrichment basin in South America and even in the world. It is located in the north of the South American plate, bounded by the Cordillera orogenic belt to the west, bounded by the Guiana shield to the east, bounded by the Vopez uplift to the south, and by the Aruca uplift to the north, Southwest and east to the north. The area of the Yanos Basin in Colombia is 23.5 6550 Based on the study of the structural evolution history of the Yanos Basin and under the guidance of P.R.Vial sequence stratigraphy, the sequence stratigraphic framework of the Yanos Basin is established by comprehensive analysis of drilling, logging and seismic data. Five secondary sequences are identified within the Mesozoic-Cenozoic. The sealing conditions and trap conditions are comprehensively analyzed.There are many sets of source rocks in the basin,mainly Paleozoic mudstone,upper Cretaceous Jiaqita deep-sea-shallow-sea facies shale and Paleogene coal-bearing shale.Through comprehensive analysis of distribution characteristics of source rocks,organic matter abundance,maturity and evolution degree of organic matter,the differences are described in detail. The source rocks of Gacheta Formation make the greatest contribution to hydrocarbon accumulation in the basin. The basin is located in the western margin of the basin and the present East Cordillera region. There are many sets of reservoirs in the basin, mainly Cretaceous Wunei Formation and Guadalupe Formation, Eocene Mirador Formation and Oligocene Carvone Formation. La Formation (C7, C5, C3). Through comprehensive analysis of reservoir physical properties and development in the basin, the characteristics of reservoir plane distribution and favorable position of development are defined. There are many sets of caprock in the basin, the main regional caprock is Lyon Formation. The sealing ability of Lyon Formation is carried out by logging curves of typical wells in the basin. In addition, the main types of traps in different structural zones are often different. Guided by petroleum geology, this paper presents four major oil-gas-rich zones in the basin, namely Arei. The evaluation results show that the western part of the basin is strongly influenced by tectonism and mainly develops large-scale structural traps; the eastern part of the basin is weakly affected by tectonism, mainly develops small-scale stratigraphic traps and hydrodynamic traps. The hydrocarbon source stoves of each oilfield are often not located in the interior of the oilfield, and most of the hydrocarbon fluids come from the western margin of the basin and the eastern Cordillera Mountains. On this basis, combined with the tectonic evolution and the influence of sedimentation in the basin, the characteristics of hydrocarbon accumulation in the Yanos basin are revealed, and the oil and gas accumulation model in the whole basin is established. Distance migration, mixed source filling, three-dimensional sand faulting, continuous transporting and stepped trapping are the characteristics of the reservoirs; the main reservoirs are characterized by preferential near-stove trapping to form medium-deep large and medium-sized structural oil and gas fields, and the distant stove successively trapping to form shallow and small complex oil and gas fields. Finally, based on the five characteristics of oil and gas migration distance, sedimentary characteristics, reservoir physical properties, trap types and peripheral oilfield development, six oil and gas exploration targets in the basin are optimized. This result has important guiding significance for guiding oil and gas exploration in the basin.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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