东海平湖油气田烃源岩特征与油气生成  

Characteristics of Source Rocks and Hydrocarbon Generation in Pinghu Field,East China Sea

作　　者：陈敬轶[1] 王飞宇[2] 刘晓[2] 

机构地区：[1]中国石油化工股份有限公司华北分公司勘探研究院,郑州450006 [2]中国石油大学地球科学学院,北京102249

出　　处：《地质科技情报》2010年第6期80-83,100,共5页Geological Science and Technology Information

基　　金：上海石油天然气有限公司项目"东海平湖复合油气田成藏分析"(2008SHPCYZ011)

摘　　要：东海平湖油气田平湖组地层天然气饱和-超饱和油气藏广泛分布,油气藏垂向分布特征明显。基于PH1~PH5井470多个岩石热解数据的分析表明,平湖油气田源岩为典型的煤系源岩,源岩类型属于Ⅱ~Ⅲ型,有机质丰度w（TOC）大于6%的碳质泥岩（或煤层）对应的氢指数[I（H）]为200~350 mg/g。原油和源岩分子地球化学参数对比分析显示,原油为成熟原油,源岩在大约3 500 m以下开始大量生排烃,平湖组是平湖油气田油气的主要贡献层段。在烃源岩定量表征基础上,分别计算了PH1~PH5井有效源岩的排烃强度和气油比（GOR）,分别为1.44×106~23.61×106t/km2和7 225~7 792 m3/t,说明源岩的类型[表现为I（H）]和厚度决定了平湖地区排油气强度的大小,煤系源岩以生气为主,由于这种类型源岩的存在,决定了平湖地区高GOR油气藏分布的局面,并进一步导致现今油气成藏的独特特征。Most reservoirs of Pinghu Formation have saturated or supersaturated gas in Pinghu Field,East China Sea,which displays obvious vertical distribution characteristics.The Rock-Eval data from the well PH1 to the well PH5 show that hydrocarbon source rocks of Pinghu Field are typical coal source rocks and belong to type Ⅱ-Ⅲ,and hydrogen index（HI） corresponding to carbargilite or coal with total organic carbon（TOC） greater than 6%,varying from 200 mg/g to 350 mg/g.The analysis of molecular geochemical data of crude oil and source rock extracts demonstrates that the crude oil is mature and the depth of hydrocarbon generation and expulsion is mainly below about 3 500 m,with Pinghu Formation as the primary active source rocks in the field.Based on the information,hydrocarbon expulsion intensity and components are calculated in active Pinghu Formation source rocks by the wells from PH1 to PH5 are 1.44×106—23.61×106 t/km2 and 7 225—7 792 m3/t respectively.The results show that the resource rocks type（HI） and thickness control the hydrocarbon expulsion intensity,and that the hydrocarbon generated from coal source rocks is mainly gas.This resulted in reservoirs with high GOR,and the formation of unique characteristic of the present oil and gas reservoirs.

关 键 词：烃源岩 成熟度 油气生成 GOR 排烃强度 平湖油气田 

分 类 号：TE122.113[石油与天然气工程—油气勘探]