柴达木盆地阿尔金山前带侏罗系含油气系统成藏差异性及其主控因素  

Hydrocarbon accumulation differences and main controlling factors of Jurassic petroleum system in Altun piedmont of Qaidam Basin

作　　者：田光荣[1] 王建功[1] 孙秀建[1] 李红哲[1] 杨魏 白亚东 裴明利[1] 周飞 司丹 TIAN Guangrong;WANG Jiangong;SUN Xiujian;LI Hongzhe;YANGWei;BAI Yadong;PEI Mingli;ZHOU Fei;SI Dan(PetroChina Research Institute of Petroleum Exploration and Development-Northwest,Lanzhou 730020,China;Research Institute of Exploration and Development,PetroChina Qinghai Oilfield Company,Dunhuang 736202,Gansu,China)

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020 [2]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202

出　　处：《岩性油气藏》2021年第1期131-144,共14页Lithologic Reservoirs

基　　金：国家科技重大专项“柴达木复杂构造区油气成藏、关键勘探技术与新领域目标评价”(编号:2016ZX05003-006);中国石油天然气股份有限公司重大科技专项“大中型岩性地层油气藏富集规律与关键技术研究”(编号:2019 B-0306)联合资助。

摘　　要：为明确柴达木盆地阿尔金山前带东段油气差异成藏及富集规律,利用地质及地球化学测试资料,围绕侏罗系含油气系统开展油气藏特征研究,分析成藏期次、明确关键成藏因素并建立成藏模式。结果表明:①阿尔金山前带成藏差异性明显,牛东地区天然气成熟度较低、干气与湿气并存,以渐新世中晚期、中新世早中期共2期成藏为主,纵向上多层系富集;东坪地区以干气为主,成熟度变化大,气藏持续充注,表现为渐新世早期至全新世多期成藏特征,以基岩富集油气为主;尖北地区以干气为主,成熟度较高,中新世早中期成藏,仅基岩富集油气。②沟通侏罗系生烃灶的断裂系统控制了油气垂向运移,关键成藏期不整合面的构造形态控制了油气运移方向,路乐河组膏泥岩盖层的发育程度控制了油气藏的富集层系。③阿尔金山前带发育3种成藏模式:断层垂向输导的源上立体成藏模式、远源输导的阶梯状复式成藏模式和远源输导的盐下成藏模式。该研究成果对阿尔金山前带侏罗系含油气系统勘探具有指导作用。In order to clarify the differential accumulation and enrichment rules of oil and gas in the eastern part of Altun piedmont in Qaidam Basin,a large number of geological and geochemical test data were used to study the characteristics of oil and gas reservoirs around Jurassic petroleum system,analyze the accumulation periods,identify the key accumulation factors and establish the accumulation model.The results show that:(1)There are obvious differences in hydrocarbon accumulation in Altun piedmont.Natural gas maturity is low in Niudong area,dry gas and wet gas coexist,mainly in the middle and late Oligocene and the early and middle Miocene,with multi-layer accumulation vertically.Dongping area is dominated by dry gas,with great changes in maturity,and the gas reservoir is continuously filled and characterized by multi-stage accumulation from early Oligocene to Holocene,mainly enriched by bedrock.Jianbei area is dominated by dry gas with high maturity,and only bedrock enriches oil and gas in early and middle Miocene.(2)The vertical migration of oil and gas is controlled by the fault system connecting the Jurassic hydrocarbon-generating kitchen,the structural form of unconformity surface in the key accumulation stage controls the oil and gas migration direction,and the development degree of gypsum mudstone caprock in Lulehe Formation controls the enrichment layer series of oil and gas reservoir.(3)There are three kinds of hydrocarbon accumulation models in Altun piedmont:three-dimensional accumulation model with vertical fault transportation,step-by-step composite accumulation model with far-source transportation and subsalt accumulation model with far-source transportation.The research results have a guiding role in the exploration of Jurassic oil and gas system in foothill belt.

关 键 词：油气系统 成藏期次 输导体系 区域盖层 运移路径 差异成藏 侏罗系 柴达木盆地 

分 类 号：TE122.31[石油与天然气工程—油气勘探]