辽宁北部秀水盆地秀D1井下白垩统义县组烃源岩生物标志化合物特征及意义  

CHARACTERISTICS OF BIOMARKER COMPOUNDS IN THE SOURCE ROCKS OF LOWER CRETACEOUS YIXIAN FORMATION FROM XD1 WELL IN XIUSHUI BASIN,NORTHERN LIAONING PROVINCE:Geological Implication

作　　者：李晓海[1] 孙求实[1] 李文博[1] 丁秋红[1] 陈树旺[1] 张健[1] 何大祥[2] LI Xiao-hai;SUN Qiu-shi;LI Wen-bo;DING Qiu-hong;CHEN Shu-wang;LI Yong-fei;HE Da-xiang(Shenyang Center of China Geological Survey,Shenyang 110034,China;Key Laboratory of Oil-Gas Resources and Exploration Technology of Ministry of Education,Yangtze University,Wuhan 430100,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034 [2]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100

出　　处：《地质与资源》2021年第6期690-697,共8页Geology and Resources

基　　金：中国地质调查局项目“松辽盆地北部及外围石炭-二叠系油气地质调查”(编号DD20190097);“松辽外围西部盆地油气基础地质调查”(编号DD20160163).

摘　　要：应用气相色谱、气相色谱-质谱技术,研究了秀水盆地秀D1井下白垩统义县组烃源岩的生物标志化合物特征,对烃源岩有机质来源、沉积环境、热演化程度等进行了分析.结果表明,秀水盆地秀D1井下白垩统义县组烃源岩有机质丰度高,有机质类型为Ⅱ型,处于成熟演化阶段;(C_(20)+C_(21))/(C_(23)+C_(24))三环萜烷为0.66~5.06,C_(24)四环萜烷/C_(26)三环萜烷为0.38~2.25,具有典型湖相烃源岩特征;烃源岩Pr/Ph主要介于0.5~1.0之间,指示还原环境;伽马蜡烷/C_(30)藿烷比值为0.05~0.41之间,指示处于强还原性沉积环境,并且烃源岩沉积时水体的盐度较低以及可能存在水体盐度分层;Pr/nC_(17)、Ph/nC_(18)关系表明有机质类型主要为Ⅱ_(1)型,C_(27)-C_(28)-C_(29)甾烷的相互关系反映有机质来源应为低等水生生物和陆生高等植物的混合来源;Ts/Tm比值为0.45~1.82,C_(31)αβ22S/(22S+22R)比值为0.41~0.62,表明烃源岩处于低成熟—成熟演化阶段,并且具有义县组中、下部烃源岩成熟度较义县组上部高的特点.综合认为秀水盆地早白垩世义县组烃源岩形成于水体盐度较低的还原—强还原环境,有机质来源为混合来源,有利于有机质的富集,义县组具有较好的油气勘探前景.The gas chromatography and gas chromatography-mass spectrometry(GC-MS)are used to study the characteristics of biomarker compounds in the source rocks and analyze the organic matter source,sedimentary environment and thermal evolution degree of source rocks of Lower Cretaceous Yixian Formation in XD1 well of Xiushui Basin.The results show that the source rocks have high organic matter abundance,with II-type organic matter,which are in the mature stage.The(C20+C21)/(C23+C24)tricyclic terpane ratio of 0.66-5.06 and C24 tetracyclic terpane/C26 tricyclic terpane ratio of 0.38-2.25 reflect the characteristics of typical lacustrine source rocks.The Pr/Ph ratio of 0.5-1.0 indicates the reduction environment.The gammacerane/C30 hopane ratio of 0.05-0.41 indicate the strong reducing sedimentary environment,with low water salinity and possible water salinity stratification during the deposition of source rocks.The relationship of Pr/nC17 and Ph/nC18 shows the organic matter is mainly II1 type,and the correlation of C27-C28-C29 steranes reflects that the organic matter is derived from a mixture of lower aquatic organisms and higher terrestrial plants.The Ts/Tm ratio of 0.45-1.82 and C31αβ22S/(22S+22R)ratio of 0.41-0.62 reveal that the source rocks are in the low mature-mature evolution stage,with the maturity of source rocks in the middle and lower parts of Yixian Formation higher than that in the upper part.It is concluded that the source rocks of Lower Cretaceous Yixian Formation in Xiushui Basin were formed in a reduction-strong reduction environment with low water salinity,the mixed source of organic matter is conducive to the enrichment of organic matter,and the Yixian Formation has good prospects for oil-gas exploration.

关 键 词：秀水盆地 下白垩统义县组 烃源岩 生物标志化合物 辽宁省 

分 类 号：P618.13[天文地球—矿床学] P593[天文地球—地质学]