【作者】 慕小水；

【导师】 张金川；

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

【摘要】 文留地区是东濮凹陷北部盐岩分布的主要地区之一,勘探实践证实盐岩发育对油气成藏有重要影响。本论文在前人研究基础上,利用有限空间实验模拟技术等现代成烃、成藏研究最新方法技术和理论,在文留地区开展了盐湖环境烃源岩成烃机理、油气运聚机理、保存机理及成藏机理研究,总结了成藏模式,对该区勘探深入有重要指导意义。通过烃源岩有机质丰度、类型、沉积环境、生标特征等综合研究,将东濮烃源岩划分为北部含盐区好-优质烃源岩、北部无盐区中等-好烃源岩、南部无盐区差-中等烃源岩三种类型。含盐区地层沟鞭藻类化石丰富,保存条件有利,有机质丰度高、类型好。利用有限空间实验模拟技术针对北部含盐区与无盐区湖相泥岩特点建立了生排烃模型,明确含盐区湖相泥岩生烃潜力明显高于无盐区,并且进入生烃高峰期较早。模拟实验得出的油气有效较长距离运移的临界压力差值(3MPa),是对油气成藏研究的重要贡献。通过文留地区温压场特征与油气运移、分布关系研究,结合油源对比、输导体系研究,将文留地区油气运聚单元划分为四个,即文东油气运聚单元、文中油气运聚单元、文西油气运聚单元、文南—刘庄油气运聚单元,不同单元表现出不同油气成藏特点。文留地区盖层、储层特征与盐岩发育密切相关。盐岩作为盖层突破压力一般在20MPa以上,是良好的区域盖层;盐岩发育形成异常高压可以明显减缓压实作用,抑制胶结作用,促进溶蚀作用进行和泥岩、砂岩裂缝的形成,利于深层储层物性的改善。通过成藏要素研究建立了盐湖环境油气成藏动态过程,明确了成藏机理。三个主要成藏期次成藏特点不同:沙二-东营沉积时期主要是以C—P系煤系源岩为气源岩,中央隆起带高部位文23盐下成藏;东营运动期是油气规模运聚期,主要以沙三段烃源岩为基础,油气多在构造高部位成藏;馆陶组—现今沉积期,断层封闭性变好,油气多在构造低部位成藏,异常高压对成烃抑制作用导致烃源岩晚期仍有大量油气生成,为低部位成藏提供了物质基础。构造低部位晚期成藏新观点为低部位勘探潜力挖掘提供了理论基础。在成藏机理研究基础上,文留地区划分四种成藏模式:①文东混源、多期、断层-砂体-盐控型成藏模式;②文西混源、多期、断层型成藏模式;③文中它源、单期、断层-砂体型成藏模式;④文南—刘庄混源、多期、断层-砂体型成藏模式。这四种成藏模式油气聚集特点不同,对相应地区的勘探有指导作用。更多还原

【Abstract】 Wenliu area is one of the primary areas for salt to distribute in the north of Dongpu depression. Exploration has proved that salt development has a primary effect in hydrocarbon formation. On the basis of previous research, this article has made full use of newest methods and techniques and theorys for hydrocarbon formation and reservoir formation such as confined space experimental modeling technique to conduct research on hydrocarbon formation mechanism of source rock, hydrocarbon migration mechanism, preservation mechanism and reservoir formation mechanism for salt lake environment in Wenliu area and has generalized reservoir formation pattern as well, which plays an important role in guiding further exploration in this area.Through comprehensive study on organic abundance, its type, sedimentary environment, generative characteristic and so on, source rock of Dongpu depression is divided into three types: good-high quality source rock in north salt area, medium-good source rock in north non-saline area and poor-medium source rock in south non-saline area. Abundant dinoflagellate fossils have been found in strata in salt area, available for preservation with high organic abundance and good type. Hydrocarbon generation and expulsion model has been built for limnic mudstone in north salt area and south non-saline area by using confined space experimental modeling technique. It has been determined that hydrocarbon potential of limnic mudstone in salt area is obviously higher than that of non-saline area and entered into hydrocarbon generation peak earlier. Critical pressure difference (3MPa) of effective longer distance migration for oil and gas obtained by simulated experiment is a great contribution for hydrocarbon reservoir formation study.By study on relation between therobaric field and hydrocarbon migration and distribution in Wenliu area and combined with oil sources correlation and transforming system study, hydrocarbon migration and accumulation unit in Wenliu area is divided into 4 subunits: Wendong hydrocarbon migration and accumulation subunit, Wenzhong hydrocarbon migration and accumulation subunit, Wenxi hydrocarbon migration and accumulation subunit, Wennan-Liuzhuang hydrocarbon migration and accumulation subunit, each of which shows different characteristic for hydrocarbon reservoir formation.Cap rock and reservoir bed are closely related with salt development in Wenliu area. As good regional cap rock, breakthrough pressure of salt is generally more than 20MPa. Abnormal pressure formed by salt development can slow down compaction apparently, restrain cementation, accelerate denudation and formation of mudstone and sandstone fissures, favorable for improving petrophysical property of deep reservoir bed.Study on essential factors of reservoir formation has helped to build up dynamic procedure of reservoir formation in salt lake environment and reservoir formation mechanism has been made definite. Three main stages for reservoir formation have different characteristics: during S2-Dongying depostional stage, C-P coal measure source rock was primary gas source rock and sub-salt Wen23 reservoir formed in top central uplift. Dongying movement stage was scale migration and accumulation stage for oil and gas. S3 source rock was taken as basis and reservoir mainly formed at structure high. During Guantao formation-present depositional stage, fault closure became better and reservoir mainly formed at structure low. Inhibition for reservoir formation produced by abnormal pressure caused generation of plenty of oil and gas in later period of soure rock, providing material base for reservoir formation in structural low. New view that reservoir formed in later period at structural low has provided theoretical basis for potential exploration of structural low.Based on reservoir formation mechanism study, there are four patterns of reservoir formation classified for Wenliu area:①Wendong mix-sourced, multi stage, fault-sand body-salt controlled pattern,②Wenxi mix-sourced, multi stage, fault pattern,③Wenzhong out-sourced, single stage, fault-sand body pattern,④Wennan-Liuzhuang mix-sourced, multi stage, fault-sand body pattern. The four patterns have different characteristics for hydrocarbon accumulation, which will be helpful for guiding exploration in corresponding area.更多还原