摘要
通过岩心、电成像测井及常规测井等资料,对川南泸州地区奥陶系五峰组—志留系龙马溪组深层页岩地层开展了电成像测井图像上的裂缝类型及组合特征、裂缝信息提取、裂缝发育模式等研究,分析了不同裂缝发育模式的声波测井响应及对后期压裂改造的影响。研究结果表明:(1)川南泸州地区奥陶系五峰组—志留系龙马溪组页岩随地层深度增加裂缝倾角逐渐减小、构造裂缝种类复杂程度逐渐降低,离构造活动强烈带较近的井靶体段可见明显的中、高角度构造裂缝发育。(2)按照构造裂缝和层理发育的关系,可将研究区裂缝发育模式分为构造裂缝与层理混合发育型、中密度层理型、紧密层理型、强构造裂缝弱层理型、大尺度构造裂缝型、致密型等6种,其中构造裂缝与层理混合发育型和中密度层理型是压裂的优选类型。(3)引入L曲线(σ=k/n,k为常数,σ为平均开度,n为层理条数),σ和n值的范围能够有效表征构造裂缝和层理的相对发育程度,从而可在坐标系内对不同裂缝发育模式进行划分与识别。(4)不同裂缝发育模式在纵、横波时差和岩石力学性质方面具有一定差异:构造裂缝与层理混合发育型和强构造裂缝弱层理型的纵波时差小于中密度层理型和紧密层理型,中密度层理型的抗剪强度小于紧密层理型。
Based on the data of cores,electrical imaging logging and conventional logging,the fracture types and combination characteristics,fracture information extraction and fracture development models of the deep shale of Ordovician Wufeng Formation-Silurian Longmaxi Formation in Luzhou area of southern Sichuan Basin were studied on the electrical imaging logging images,and the acoustic logging response of different fracture development models and their impact on the later fracturing stimulation were analyzed.The results show that:(1)With the increase of formation depth,the fracture dip angle and the complexity of structural fracture types gradually decrease of Ordovician Wufeng-Silurian Longmaxi shale in Luzhou area,southern Sichuan Basin.The well target section near the strong tectonic activity zone shows obvious development of medium and high angle structural fractures.(2)According to the relationship between structural fractures and bedding development,the fracture development models in the study area can be divided into six types:mixed development of structural fractures and bedding,medium-density bedding,tight bedding,strong structural fractures and weak bedding,large-scale structural fractures,and dense type.Among them,the mixed development of structural fractures and bedding and the medium-density bedding are the preferred types of fracturing.(3)Curve L was introduced(σ = k/n,k is a constant,σ is the average opening,n is the number of bedding),the range of k and n values can effectively characterize the relative development degree of structural fractures and bedding,so as to divide and identify different fracture development models in the coordinate system.(4)Different fracture development models have certain differences in the P-wave and S-wave time difference and rock mechanical properties.The P-wave time difference of the mixed development of structural fractures and bedding and the strong structural fracture and weak bedding is smaller than that of the medium-density bedding and the tight bedding.The shear strength of the medium-density bedding is lower than that of the tight bedding.
作者
闫建平
罗静超
石学文
钟光海
郑马嘉
黄毅
唐洪明
胡钦红
YAN Jianping;LUO Jingchao;SHI Xuewen;ZHONG Guanghai;ZHENG Majia;HUANG Yi;TANG Hongming;HU Qinhong(School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;Shale Gas Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China;PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China;Southwest Branch,CNPC Logging Company Limited,Chongqing 400021,China;Department of Earth and Environmental Sciences,University of Texas at Arlington,Arlington,TX 76019,USA)
出处
《岩性油气藏》
CAS
CSCD
北大核心
2022年第6期60-71,共12页
Lithologic Reservoirs
基金
中国石油-西南石油大学创新联合体科技合作项目“川南深层与昭通中浅层海相页岩气规模效益开发关键技术研究”(编号:2020CX-020000)
四川省自然科学基金项目“页岩气储层低电阻率成因机制及对含气性的影响研究”(编号:2022NSFSC0287)。
关键词
深层页岩气
裂缝发育模式
电成像测井
声波时差
岩石力学
五峰组—龙马溪组
泸州地区
川南
deep shale gas
fracture development model
electrical imaging logging
acoustic time difference
rock mechanics
Wufeng-Longmaxi Formation
Luzhou area
southern Sichuan Basin
