库车坳陷深层盐下白垩系储集层氯盐分布模式及意义  

Distribution Patterns and Significance of Salt in Deep Cretaceous Subsalt Reservoirs in Kuqa Depression,Tarim Basin

作　　者：罗丹婷 罗静兰[1,2] 邓超 年涛 韩剑发[4] 程道解 袁龙 LUO Danting;LUO Jinglan;DENG Chao;NIAN Tao;HAN Jianfa;CHENG Daojie;YUAN Long(Northwest University,State Key Laboratory of Continental Dynamics,Xi’an,Shaanxi 710069,China;Northwest University,Department of Geology,Xi’an,Shaanxi 710069,China;School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an,Shaanxi 710065,China;Research Institute of Exploration and Development,Tarim Oilfield Company,PetroChina,Korla,Xinjiang 841000,China;Geological Research Institute,China National Logging Corporation,Xi’an,Shaanxi 710077,China)

机构地区：[1]西北大学大陆动力学国家重点实验室,西安710069 [2]西北大学地质学系,西安710069 [3]西安石油大学地球科学与工程学院,西安710065 [4]中国石油塔里木油田分公司勘探开发研究院,新疆库尔勒841000 [5]中国石油集团测井有限公司地质研究院,西安710077

出　　处：《新疆石油地质》2024年第1期1-12,共12页Xinjiang Petroleum Geology

基　　金：国家科技重大专项(2011ZX05046-03);陕西省教育厅科研计划项目(19JK0851);博士后面上基金(2019M663803)。

摘　　要：库车坳陷克拉苏构造带盐下白垩系巴什基奇克组储集层分布了一批高产、稳产的天然气藏群,其储集层为超深、高温、超压致密砂岩储集层,孔隙度越高,氯盐含量越高,储集层视电阻率越低,储集层中氯盐的分布严重影响流体识别,其对盐下致密砂岩物性的影响较明显。利用岩心观察、铸体薄片、扫描电镜、氯盐含量、常规测井曲线分析等,系统分析了库车坳陷盐下白垩系巴什基奇克组储集层氯盐的分布特征。根据氯盐含量、电阻率、氯盐来源等的差异,提出盐下储集层氯盐分布具有顶渗、侧渗和局部封存3种模式。顶渗模式与侧渗模式的电阻率仅受氯盐含量的影响,顶渗模式储集层氯盐含量呈垂向分带特征,随氯盐含量的降低,电阻率升高;侧渗模式储集层氯盐含量呈横向分带特征,电阻率自构造带边缘向中心表现出由高到低再升高的趋势;局部封存模式电阻率受应力和氯盐含量的共同影响,氯盐含量分布具有偶发性,电阻率变化幅度大。根据测井响应特征划分了各模式的分布段序列,顶渗模式自上而下发育盐层段、泥岩封隔段、饱和氯盐强影响段、未饱和氯盐强影响段、未饱和氯盐影响过渡段和氯盐未影响段;侧渗模式在顶渗模式基础上多发育过饱和氯盐影响段;局部封存模式从上到下划分为盐层段、泥岩封隔段、强挤压应力氯盐未影响段、氯盐应力混合影响段和氯盐应力未影响段。The Cretaceous Bashijiqike formation in the Kelasu structural belt in the Kuqa depression of Tarim basin hosts a number of high and steady⁃yield subsalt gas reservoirs in ultra⁃deep,high⁃temperature,and overpressure environment.For these subsalt tight sandstone reservoirs,the higher the porosity,the higher the salt content and the lower the apparent resistivity.The distribution of salt in the reservoirs not only significantly affects fluid identification but also has a noticeable impact on the reservoir physical properties.The distribution of salt in the subsalt reservoirs in the Bashijiqike formation were systematically analyzed based on the data of cores,cast thin sections,scanning elec⁃tron microscopy,salt content,and conventional logs.According to the differences in salt content,resistivity,and salt source,three distribution patterns of salt in subsalt reservoirs were proposed:top source,lateral source and local sealing.For the top and lateral source patterns,the reservoir resistivity is only affected by salt content.In the reservoirs with the top source pattern,the salt content shows a vertical zonality,and the reservoir resistivity increases as the salt content decreases.In the reservoirs with the lateral source pattern,the salt content shows a lateral zonation,and the reservoir resistivity shows a trend of high to low and then to high value from the edge of structural belt towards its center.In the reservoirs with the local sealing pattern,the resistivity is influenced jointly by stress and salt content,and changes greatly because the distribution of salt content is sporadic.According to well logging responses,the reservoir is divided into intervals for each pattern.In an ideal top source pattern,the reservoir comprises a salt interval,a mudstone barrier,an interval strongly affected by saturated salt,an interval strongly affected by unsaturated salt,a transition interval affected by unsaturated salt,and a salt⁃unaffected interval from top to bottom.In an ideal lateral source pattern,there are se

关 键 词：库车坳陷 深层 白垩系 盐下储集层 高温高压 氯盐含量 测井响应 氯盐分布模式 

分 类 号：P631.8[天文地球—地质矿产勘探]