辽东湾坳陷油气成藏差异性及主控因素研究

发布时间：2018-12-08 18:36

【摘要】：辽东湾坳陷位于渤海海域东北部,是下辽河坳陷向海域的延伸部分,是渤海湾盆地的一个富烃坳陷。本文系统研究了辽东湾坳陷不同构造带成藏条件差异性,并剖析了成藏主控因素,确立了成藏模式。辽东湾坳陷的三套主力烃源岩中,以沙三段最优,有机质丰度高、类型好、热演化程度高;沙一段次之,东三段热演化程度低,大部分未进入主生烃期。总体上北部优于南部,辽中凹陷优于辽西凹陷。由于区带构造背景、沉积相带、成岩程度、储集空间类型等的差异,不同类型区带储集条件、盖层、生储盖组合明显不同。低凸起区潜山带沙三段盖层质量极为优越,主要生储盖组合为新生古储式;披覆构造带东三段盖层封盖能力最强,主要生储盖组合为下生上储式,断层是沟通源储的最重要媒介;凹中断块构造带由于断层的沟通,盖层封盖能力变差,主要生储盖组合亦为下生上储式。构造圈闭是辽东湾坳陷最主要的圈闭类型,不同类型区带代表性圈闭类型不同。凹中断块构造带主要发育半背斜、断块圈闭。凸起区潜山带主要发育不整合遮挡、断块低潜山圈闭。凸起披覆构造带主要发育披覆背斜、半背斜、断块圈闭。洼陷带主要发育岩性圈闭。不同类型的构造带输导体系特征各异。靠近大型断裂带的凹中断块构造带发育以断层作为最关键油气输导通道的断层型输导体系;凸起区潜山带主要发育以不整合为最主要输导通道的不整合型输导体系;凸起披覆构造带主要发育以断层-砂体匹配组合为最主要输导通道的断层-砂体复合型输导体系;而洼陷带主要发育以砂体侧向输导为主要特征的油气输导体系。在分析油气分布特征的基础上,剖析了JZ20-2N,JX1-1,JZ25-1三个典型油气田的成藏过程,总结了四个成藏主控因素:(1)烃源岩对油气分布差异的控制,(2)断裂对油气运聚成藏的控制,(3)储层对油气成藏的控制,(4)异常高压对油气成藏的控制。建立了典型区带的成藏模式:(1)凹陷断块构造带油气成藏模式,(2)凸起区潜山带成藏模式,(3)凸起披覆构造带成藏模式,(4)洼陷带成藏模式。
[Abstract]:The Liaodong Bay depression is located in the northeast of Bohai Sea, which is an extension of the lower Liaohe depression and a hydrocarbon rich depression in the Bohai Bay basin. In this paper, the differences of reservoir forming conditions in different structural zones in Liaodong Bay depression are systematically studied, and the main controlling factors of reservoir formation are analyzed, and the reservoir forming model is established. Among the three sets of main hydrocarbon source rocks in Liaodong Bay depression, the third member is the best, the organic matter abundance is high, the type is good, the thermal evolution is high, the first member of the sand is the second, the thermal evolution degree of the third member in the east is low, and most of them have not entered the main hydrocarbon generation stage. On the whole, the north is better than the south, and the central Liaoning sag is better than the western Liaoning sag. Because of the difference of tectonic background, sedimentary facies belt, diagenesis degree and reservoir space type, the reservoir conditions, caprocks and assemblages of source, reservoir and caprock in different types of zones are obviously different. The caprock quality of the third member of the buried hill belt in the low uplift area is extremely superior, and the main assemblage of the source, reservoir and caprock is the new paleo-reservoir type. The caprock sealing ability of the eastern third member of the drape structural belt is the strongest, the main assemblage of the source, reservoir and caprock is the lower generation and upper reservoir type, and the fault is the most important medium to communicate the source and reservoir. Because of the communication of faults, the sealing ability of caprock is poor, and the main assemblage of reservoir, caprock and caprock is lower generation and upper reservoir. Structural traps are the main types of traps in Liaodong Bay depression, and different types of traps represent different types of traps. The structural belt of the concave interrupt block mainly developed semi-anticline and fault block trap. The buried hill zone in the uplift area mainly develops unconformity occlusion and low buried hill trap of fault block. Drape anticline, semi-anticline and fault block trap are mainly developed in the uplift drape structural belt. Lithologic traps are mainly developed in the sag zone. Different types of tectonic belt transport systems have different characteristics. The fault type transportation system is developed in the concave block structural belt near the large fault zone, in which the fault is the most critical passage for oil and gas transportation, and the unconformity is the most important channel in the buried hill belt in the uplift area, and the unconformity is the most important channel in the fault-type transport system. The fault-sand complex transport system is mainly developed in the uplift drape structural belt with fault-sand body matching combination as the most important channel, while the oil and gas transport system with the main characteristics of lateral sand transport is developed in the sag zone. On the basis of analyzing the characteristics of oil and gas distribution, this paper analyzes the process of oil and gas accumulation in three typical oil and gas fields in JZ20-2N,JX1-1,JZ25-1, and summarizes four main controlling factors of oil and gas accumulation: (1) the control of hydrocarbon distribution difference by source rock; (2) the control of fault on hydrocarbon migration and accumulation, (3) the control of reservoir on oil and gas accumulation, and (4) the control of abnormal high pressure on oil and gas accumulation. The reservoir forming models of typical zones are established as follows: (1) oil and gas accumulation model of fault block structural belt in depression, (2) reservoir forming model of buried hill belt in uplift area, (3) accumulation model of uplift drape structural belt, (4) reservoir forming model of sag zone.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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