【作者】 冯建辉；

【导师】 傅家谟； 盛国英； 潘长春；

【作者基本信息】 中国科学院研究生院（广州地球化学研究所） ， 地球化学， 2003， 博士

【摘要】 本文通过对东濮凹陷杜桥白地区深层烃源岩及油气地球化学特征的研究，系统分析了该区深层天然气与原油的成因；通过含油砂岩孔隙中自由态烃、颗粒吸附态烃及油气包裹体烃的地球化学特征分析，研究了油气不同注入期次的流体性质；通过油藏饱和压力法、自生矿物K／Ar同位素测年、油气包裹体均一化温度等多种方法研究了杜桥白地区不同油气成藏期次及时间与油气成藏期次分布规律，分析了杜桥白地区油气成藏的主控因素及油气富集规律。取得了如下主要认识： 白庙与桥口地区天然气虽同属湿气，但成分有一定差异，桥口地区天然气甲烷含量均小于80％，甲烷／重烃为5左右；而白庙地区天然气甲烷含量相近，普遍高于88％，甲烷／重烃＞10。产生桥口、白庙天然气组份差异的主要原因除成熟度影响外，天然气的母源类型起决定作用。白庙地区天然气主要来源于前梨园洼陷第三系烃源岩和石炭—二叠系煤系地层，靠近兰聊断裂带构造高点，浅层ES₂^下—ES₃²气层具有较高的Ar⁴⁰／Ar³⁶比值，为煤型气及混合气。而远离兰聊断裂带，且处于构造低部位的ES₃¹—ES₃⁴气层具有较低的Ar⁴⁰／Ar³⁶比值，为油型气；桥口构造ES₃³、ES₃⁴段气层主要为油型气；杜寨地区ES₃³段气层为油型气，来自于ES₃³段气源岩。 油源对比结果表明杜寨地区濮深15井的凝析油来源于本区ES₃³～ES₃⁴地层，前8井ES₃²原油来源ES₃²地层；桥口地区东翼葛岗集洼陷一侧的桥14、20、23、25、60井深层油气与葛岗集洼陷烃源岩有关，桥口垒块桥38井原油与前梨园洼陷烃源岩有关；白庙构造翼部白12井原油主要与前梨园洼陷ES₃³～ES₃⁴段烃源岩有关，构造腰部白54、17、9等井的凝析油与前梨园洼陷ES₃²段烃源岩有关，白16井原油来源于葛岗集生油洼陷。 应用伊利石测年法、包裹体测温法、饱和压力法等综合分析了杜桥白地区深层天然气成藏时期，杜桥白地区天然气成藏主要分为两大阶段：第一阶段为东营组—馆陶组沉积早期，这一阶段是天然气藏最为主要的形成期。这一阶段天然气藏成藏年龄绝大部分对应于剥蚀期27-17Ma，剥蚀期，压力减小，有利于天然气成藏。第二阶段为第四纪以来，第四纪以来一方面是已形成气藏的调整，另一方面是二次生成气的继续注入。伊利石测年法确定的天然气成藏时期主要为东营—馆陶组早期，其中杜寨主要为43.0-38.0Ma及25.4Ma；桥口地区为37.8-25.4Ma及24.4-18.4Ma；白庙地区为38.0-25.4Ma及23.4-20.4Ma；杜寨地区成藏较早，伊利石测年确定的是天然气藏最早形成时期，是天然气藏形成的上限，伊利石测年法确定的天然气成藏期是两大主要成藏期的第一阶段。包裹体测温法不仅确定了第一阶段天然气成藏期为28-20Ma，也确定了第二阶段天然气成藏期，即第四纪以来（2Ma以来）。 本文应用多种方法对杜桥白地区深层油气藏地球化学特征、油气藏形成期次及成藏控制因素进行了深入研究，在油气来源、油气藏形成期次及油气成藏规律性方面取得了一系列新的认识，对杜桥白地区油气勘探有重要的指导意义。更多还原

【Abstract】 Based on the research for the deeply buried source rocks and the geo-chemical properties of the oil and gas within Duqiaobai area in Dongpu depression, the formation principle of the deeply buried gas and crude oil are systemically analyzed in this paper. The properties of the fluids in different period of the injection of the oil and gas are studied by analyzing geo-chemical properties of the free hydrocarbon in pores in oil-bearing sandstone, of the hydrocarbon adsorbed on grains and of the oil and gas in inclusion enclaves. The injection periods and time of the oil and gas are also studied by testing reservoir saturation pressure, authigene K/Ar isotope and homogeneous temperature of oil and gas in inclusion enclaves. Major controlling factors were also obtained by studying hydrocarbon distribution and accumulation so as to get a further understanding of reservoir forming principle.Composition of natural gas is different in Baimiao and Qiaokou, though they are both wet gas. In Qiaokou area, the content of methane CH4%<80%, the value of the ratio between methane CH4 and heavy hydrocarbon is about 5, while in Baimiao area, the value of methane CH4>88%, the value of the ratio between methane CH4 and heavy hydrocarbon is more than 10. This difference is caused not only by maturity but also by source rock. Natural gas in Baimiao area is mainly derived from Tertiary source rock and Carboniferous Permian formation in Qianliyuan sag, which is near the high point on Lanliao fracture belt. The ES2-ES32 gas net pay Shallowly buried has a high value of Ar40/Ar36, which generates coal-type gas or mixed gas; while in the lower part off the Lanliao fracture belt, ES3’-ES34 as net pay has a low value of Ar40/Ar36, which generates oil-type gas, so does ES33, ES34 gas net pay in Qiaokou structure and ES33 in Duzhai area.The correlation between the oil and source rock shows that in Duzhai area, condensate in well Pushenl5 is from formation ES33-ES34, and crude oil in well Qian8 is from ES32. In Qiaokou area, deep parts of well Qiaol4, 20, 23, 25, 60 are related to source rock in Gegangji sag, while crude oil in well Qiao38 is related to source rock in Qianliyuan sag; in Baimiao structure, crude oil in well Bail2 is related to source rock of ES33-ES34 in Qianliyuan sag, while condensate in well Bai54, 17, 9 is related to source rock of ES32 in Qianliyuan sag and crude oil in well Bai6 is from oil kitchen Gegangji.The study on illite age testing, inclusion enclave temperature testing and saturation pressure testing has been used to know the time of the deeply buried gas net pay formed. The time of the deeply buried gas net pay formed can be divided into two stages. The first is early period of Dongying-Guantao, which is the main stage for natural gas forming with erosion and decrease of pressure. The second is from the beginning of Quaternary to update, during which gas reservoir is reforming and the reforming gas is refilling into the reservoirs. According to the value K/Ar in Illite, the time to form the gas reservoirs can be determined as the period of Dongying -Guantao, among which Duzhai is 43.0-38.0Ma and 25.4Ma, Qiaokou area 37.8-25.4Ma and 24.4-18.4Ma, Baimiao 38.0-25.4Ma and 23.4-20.4Ma. Natural gas in Duzhai area was formed the earliest. Inclusion enclave temperature testing not only determined the first stage for natural gas formed to be 28-20Ma but also the second stage to be from Quaternary (2Ma).更多还原