摘要
为明确柴达木盆地深层天然气勘探潜力,基于地震、地质、地球化学、录井及钻井等多种资料分析了柴达木盆地深层天然气藏的富集条件,并指出了有利勘探方向。结果表明:柴达木盆地深层具备形成大型气田的成藏条件,深层发育柴北缘侏罗系和柴西古近系两套优质气源,演化程度高,生气能力强;柴北缘深层发育基岩和古近系碎屑岩储层,柴西深层发育古近系湖相碳酸盐岩储集层,多种类型储层平面上分布广泛,纵向上组成多套储盖组合,发育的原生孔、溶蚀孔及裂缝等多种孔隙类型被认为是深层气藏富集的储存空间;持续活动的深大断裂是深层气源的优质通道;同时深层构造的形成与天然气生成具有良好的匹配关系,深层烃源岩具有早生烃、持续生烃特征,早期生成的液态烃在后期深埋过程中高温裂解成气,生气能力强,深层资源潜力大;盆地深层广泛发育的盐岩、泥质岩层及异常高压层有利于深层天然气保存。综合认为柴达木盆地深层气藏富集于断裂发育的生烃凹陷周围的圈闭中,柴北缘山前古隆起基岩、腹部构造带古近系碎屑岩和柴西环英雄岭构造带碳酸盐岩是深层天然气勘探有利区。
This paper examines the enrichment conditions of deep natural gas reservoirs in the Qaidam Basin and delineates the exploration potential utilizing seismic,geological,geochemical,well-logging,and drilling data.The findings indicate the presence of two high-quality gas source formations,namely the Jurassic and Paleogene formations,along the northern margin and the western part of the basin,respectively.The formations both exhibit advanced evolution and robust gas-generating capacity.The deep layers along the northern margin consist of bedrocks and Paleogene clastic reservoirs,while the western deep layers feature Paleogene lacustrine carbonate reservoirs.The reservoirs west of Qaidam Basin are widely distributed on the plane and vertically form multiple reservoir cap combinations.The primary pores,dissolution pores,fractures,and other pore types developed in the reservoirs are considered as the storage space for deep gas accumulation.The continuous active deep faults serve as high-quality channels for deep gas sources;furthermore,the formation of deep structures is well-matched with natural gas generation.The deep hydrocarbon source rocks in the western Qaidam Basin are characterized by early and continuous hydrocarbon generation.Early-generated liquid hydrocarbons undergo high-temperature cracking into gas during later burial,resulting in a robust gas-generating capacity and significant potential for deep resources.The widely developed salt rocks,argillaceous rock,and abnormally high-pressure layers in the deep Qaidam Basin contribute to preserving deep natural gas.In conclusion,it is believed that deep gas reservoirs in the Qaidam Basin are enriched in the traps around hydrocarbon-generating sags with developed faults.Key favorable areas for deep-seated natural gas exploration include the basement rocks of the ancient piedmont uplift in the northern margin of Qaidam,the Paleogene clastic rocks in the central structural belt,and the carbonate rocks along the Yingxiongling structural belt in the western part of th
作者
李剑
田继先
王波
朱军
周飞
李森明
邵泽宇
李海鹏
乔柏翰
LI Jian;TIAN Jixian;WANG Bo;ZHU Jun;ZHOU Fei;LI Senming;SHAO Zeyu;LI Haipeng;QIAO Bohan(Research Institute of Petroleum Exploration and Development of PetroChina,Langfang 065007,Hebei,China;Research Institute of Drilling and Production Technology,PetroChina Qinghai Oilfield Company,Dunhuang 736200,Gansu,China;PetroChina Hangzhou Research Institute of Geology,Hangzhou 310000,Zhejiang,China)
出处
《地质力学学报》
CSCD
北大核心
2023年第5期618-630,共13页
Journal of Geomechanics
基金
中国石油天然气股份有限公司前瞻性与基础性重大科技项目(2021DJ0603)。
关键词
深层气藏
富集条件
勘探潜力
湖相碳酸盐岩
柴达木盆地
deep gas reservoir
accumulation conditions
exploration potential
lacustrine carbonatite
Qaidam Basin Qaidam Basin
