摘要
四川盆地东部南雅地区二叠系吴家坪组获高产工业气流,显示研究区具有较大页岩气勘探潜力。基于区域构造演化特征,结合钻井、测井及地震等资料,分析了构造特征及其对页岩气的生成、储集和保存的控制作用。研究结果表明:①四川盆地东部南雅向斜地区经历了3期构造运动的改造,塑造了现今隔挡式褶皱带格局。断层可分为5级,以NE—SW走向Ⅰ级断层为主,断距大于300 m,该类断层对页岩气保存有较大的破坏作用。②受拉张应力形成的“开江—梁平”海槽为研究区深水陆棚相页岩的形成提供了有利场所,构造运动导致地层发生抬升和沉降,直接影响了页岩中有机质的热演化程度,主要排烃期为侏罗纪,主要生气期为中侏罗世—早白垩世早期。③构造作用形成的微裂缝以及纳米级孔隙为页岩气提供了储集空间,网状缝系统与水平最大主应力方向匹配,有效改善了页岩的物性,也有利于页岩气的运移和富集。断层是页岩气逸散的主要通道,页岩气的保存主要受Ⅰ级断层的影响,部署井位应与Ⅰ级断层的距离至少大于1.5 km。④构造作用对页岩气的生成、储集和保存均具有重要影响,“适中的构造改造、有效的网状裂缝、完整的封闭系统”是页岩气成藏的关键,南雅向斜区域为川东页岩气勘探有利区。
Permian Wujiaping Formation in Nanya area of eastern Sichuan Basin has obtained high-yield industrial gas flow,which shows great shale gas exploration potential in the study area.Based on the characteristics of regional tectonic evolution,combined with drilling,logging,and seismic data,the structural features and their control over the generation,storage,and preservation of shale gas were analyzed.The results show that:(1)Nanya syncline area in eastern Sichuan Basin has undergone three tectonic movements,shaping the current pattern of barriertype fold belts.Faults can be classified into 5 levels,levelⅠfaults in NE-SW direction are the main ones,with a fzult space greater than 300 m.This type of fault has a significant destructive effect on shale gas preservation.(2)“Kaijiang-Liangping”trough,formed by extensional stress provides a favorable location for the formation of deep-water shelf facies shale in the study area.Tectonic movements cause uplift and subsidence of the strata,directly affecting the thermal evolution of organic matter within the shale.The primary hydrocarbon expulsion period occurred during Jurassic,while the main gas generation phase was the early period of Middle Jurassic-Early Cretaceous.(3)The micro-fractures and nano-scale pores formed by tectonic activity provide storage space for shale gas.The reticular fracture system matches the direction of the maximum horizontal principal stress,effectively improving the physical properties of shale and facilitating the migration and enrichment of shale gas.Faults are the main channels for the escape of shale gas,and the preservation of shale gas is mainly affected by levelⅠfaults.The deployment of well locations should be at least 1.5 km away from level I faults.(4)Tectonic activity has an important impact on the generation,storage,and preservation of shale gas,and“moderate structural transformation,effective reticular fractures,and complete sealing system”are the key factors for shale gas reservoir formation.Nanya syncline area is a favorable area for shale gas exploration in eastern Sichuan Basin.
作者
詹淋
范存辉
唐雯
杨西燕
刘冬玺
李博
杨昕睿
ZHAN Lin;FAN Cunhui;TANGWen;YANG Xiyan;LIU Dongxi;LI Bo;YANG Xinrui(School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;Chongqing Gas Field,PetroChina Southwest Oil and Gas Field Company,Chongqing 401120,China;Shale Gas Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China)
出处
《岩性油气藏》
北大核心
2025年第5期133-144,共12页
Lithologic Reservoirs
基金
国家自然科学重点项目(企业联合基金)“注采交变作用下断层稳定性与储气库动态密封性评价研究”(编号:U24B2038)
油气藏地质及开发工程全国重点实验室开放基金“差异构造-热演化过程及对页岩气富集保存的影响机理”(编号:PLN-2023-31)
中国石油西南油气田分公司2023年科研计划项目“龙门—巫山坎区块吴家坪组页岩储层特征及勘探开发潜力研究”(编号:20230304-10)联合资助。
关键词
页岩气
构造控藏
隔挡式褶皱带
“开江—梁平”海槽
深水陆棚相
网状缝
吴家坪组
二叠系
南雅地区
川东地区
shale gas
structural control hydrocarbon accumulation
barrier-type fold belts
“Kaijiang-Liangping”trough
deep-water shelf facies
reticular fracture
Wujiaping Formation
Permian
Nanya area
eastern Sichuan Basin
