四川盆地泸州北区五峰组—龙马溪组深层页岩气储层地应力地震预测技术  

Stress seismic prediction technology of deep shale gas reservoir of Wufeng-Longmaxi formations in North Luzhou District, Sichuan Basin

作　　者：石学文 王畅 张洞君 杜炳毅 高建虎[2] 董雪华 吴涛 张建新[2] Xuewen SHI;Chang WANG;Dongjun ZHANG;Bingyi DU;Jianhu GAO;Xuehua DONG;Tao WU;Jianxin ZHANG(Southwest Oil&Gasfield Company Shale Gas Institute,PetroChina,Chengdu 610056,China;Research Institute of Petroleum Exploration and Development Northwest,PetroChina,Lanzhou 730020,China)

机构地区：[1]中国石油西南油气田分公司页岩气研究院,四川成都610056 [2]中国石油勘探开发研究院西北分院,甘肃兰州730020

出　　处：《天然气地球科学》2024年第11期2040-2052,共13页Natural Gas Geoscience

基　　金：中国石油天然气股份有限公司前瞻性基础性科研项目(编号:2024DJ87);中国石油天然气股份有限公司科技项目(编号:kt2021-11-01)联合资助。

摘　　要：四川盆地泸州北区深层页岩储层受多期构造运动的影响,构造条件复杂、地应力变化快的特征,导致其预测难度大。鉴于此,针对性地提出了一种基于叠前各向异性反演的地应力地震预测技术,在贝叶斯理论框架下,利用各向异性AVA(Amplitude Versus Angle,振幅随入射角变化)方程构建叠前AVAZ(Amplitude Versus Azimuth,振幅随方位角变化)反演方法,从叠前偏移距矢量片(Offset Vector Tile, OVT)道集出发,反演获得页岩储层的弹性参数与各向异性参数;同时,推导了基于裂缝密度和泊松比表示的水平应力差异比(Differential Horizontal Stress Ratio, DHSR)计算公式,用于估算储层的DHSR。利用该方法对四川盆地泸州北区五峰组—龙一1亚段深层页岩气开展DHSR预测,并划定了页岩气勘探开发的有利区,为研究区的评价部署、井轨迹设计及储层改造等提供可靠的地球物理依据。The deep shale gas reservoirs in the north Luzhou District of the Sichuan Basin are affected by multiple phases of tectonic movements,and are characterized by complex tectonic conditions,rapid changes in in-situ stress,which leading to the difficulties of in-situ stress prediction.A specific in-situ stress seismic approach based on pre-stack azimuthal anisotropic inversion is proposed.Pre-stack AVAZ inversion approach applied azimuthal anisotropy AVA equation under Bayes theory framework.The elastic and anisotropic parameters of the shale gas reservoir are inverted from pre-stack Offset Vector Tile(OVT)gather.Meanwhile,a formula Differential Horizontal Stress Ratio(DHSR)based on the fracture density and Poisson's ratio representation is derived,which is utilized to estimate the DHSR of shale gas reservoir.Wufeng Formation-Long 1 submember and favorable areas for shale gas exploration and development were delineated.This provides reliable geophysical evidence for reserve evaluation,well trajectory design,and reservoir stimulation in the study area.Using this method,deep shale gas in the Wufeng Formation–Long11 subsection of the northern Luzhou area in the Sichuan Basin was predicted by DHSR,and favorable areas for shale gas exploration and development were delineated.This provides a reliable geophysical basis for the reservoir evaluation,well trajectories designment,and reservoir modification.

关 键 词：四川盆地 泸州北区 页岩储层 各向异性 叠前反演 地应力 

分 类 号：TE132.2[石油与天然气工程—油气勘探]