玛湖凹陷二叠系风城组全油气系统成藏机理  

Hydrocarbon Accumulation Mechanism of Total Petroleum System in Permian Fengcheng Formation,Mahu Sag

作　　者：何文军[1,2] 宋永 汤诗棋[1] 尤新才 白雨[1] 赵毅[1] HE Wenjun;SONG Yong;TANG Shiqi;YOU Xincai;BAI Yu;ZHAO Yi(Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China;School of Earth Sciences,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000 [2]中国石油大学(北京)地球科学学院,北京102249

出　　处：《新疆石油地质》2022年第6期663-673,共11页Xinjiang Petroleum Geology

基　　金：中国石油前瞻性基础性技术攻关项目(2021DJ0108,2021DJ1801)。

摘　　要：准噶尔盆地西部玛湖凹陷风城组勘探揭示了常规—非常规油气有序共生特征。通过精细解剖玛湖凹陷风城组油藏特征,结合储集层宏微观分析及生产资料,剖析全类型油藏成藏机制。结果表明,全油气系统中常规油、致密油和页岩油有序成藏,核心为“源储耦合”以及储集层孔喉结构对油气的“动态封闭”成藏。致密储集层和页岩储集层在成岩早期为中—大孔喉的常规储集层,烃类浮力成藏;成岩中—后期演化为微米—纳米孔喉,浮力作用减弱,毛细管力增强,与烃源岩“相邻或一体”的储集层烃类持续发生初次或微运移,直至生排烃形成的源储压差与微米—纳米孔喉形成的毛细管力达到动态平衡,形成“自封闭”的连续型非常规油气聚集。常规储集层孔喉结构对烃类产生的毛细管力远小于浮力作用,需外部条件“他封闭”,形成圈闭中的油气聚集。总体表现为储集层孔喉结构的时空演化与油气生—排—运—聚的动态耦合。The exploration practice in the Fengcheng formation in the Mahu sag,western Junggar basin,has revealed the orderly coexistence of conventional and unconventional hydrocarbons.By finely dissecting the characteristics of the total petroleum system in the Fengcheng formation in the Mahu sag,and combining with the macroand microanalysis and production data of the reservoirs,the hydrocarbon accumulation mechanism of the total petroleum system was analyzed.The results show that conventional oil,tight oil and shale oil accumulate in an orderly pattern in the total petroleum system,which essentially complies with the hydrocarbon accumulation pattern of“sourcereservoir coupling”and“dynamic sealing”of oil and gas.In the early diagenesis stage,the present tight reservoirs and shale reservoirs were conventional reservoirs with medium-large pore throats,where hydrocarbons accumulated because of buoyancy.In the middle-later diagenesis stage,the medium-large pore throats gradually evolved to microto nanopore throats,the buoyancy was weakened,and the capillary force was strengthened.The hydrocarbon in the reservoir adjacent to or integrated with the source rocks underwent primary or micro migration continuously until the sourcereservoir pressure difference resulted from hydrocarbon generation and expulsion and the capillary force originated from microto nanopore throats reached a dynamic equilibrium,forming a“selfsealing”continuous unconventional oil and gas accumulation.The capillary force in the present conventional reservoirs is far less than the buoyancy,so“external sealing”is needed for hydrocarbon accumulation in traps.Generally,the hydrocarbon accumulation in the Fengcheng formation is represented by the spacetime evolution of the pore throat structure in the reservoir and the dynamic coupling of source rock and reservoir on hydrocarbon generation-expulsion-migration-accumulation.

关 键 词：准噶尔盆地 风城组 常规油气 非常规油气 全油气系统 动态封闭作用 成藏机理 源储耦合 

分 类 号：TE122[石油与天然气工程—油气勘探]