克深气田巴什基奇克组致密砂岩储层孔隙结构特征及影响因素分析  

Porosity Structure Characteristics and Influencing Factors Analysis of Basijiqike Tight Sandstone Reservoir in Keshen Gasfield

作　　者：王翠丽 李红波[2] 陈东[1] 陈宝新[1] 刘磊[1] 罗明高[3] Wang Cuili;Li Hongbo;Chen Dong;Chen Baoxin;Liu Lei;Luo Minggao(Research Institute of Exploration ＆ Development;Department of Development Projects,Tarim Oilfield Company,PetroChina,Korla Xinjiang 841000,China;Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]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 [2]中国石油塔里木油田分公司开发事业部,新疆库尔勒841000 [3]西南石油大学,成都610500

出　　处：《地质科技情报》2018年第5期70-77,共8页Geological Science and Technology Information

基　　金：国家科技重大专项"复杂天然气藏开发关键技术"(2016ZX05015006-004)

摘　　要：塔里木盆地库车坳陷克深气田巴什基奇克组埋藏深度主要为6 000～8 500m,岩石致密,为典型的超深致密砂岩储层。应用普通薄片、铸体薄片观察,扫描电镜、激光共聚焦显微镜、场发射扫描电镜分析和恒速压汞、核磁共振、离心等实验资料,研究其储层岩石学和孔隙结构特征,并从构造、沉积、成岩等地质角度入手,探讨影响孔隙结构的因素。结果表明,储层岩性主要为长石岩屑砂岩及岩屑砂岩,成分成熟度及结构成熟度中等;储集空间以原生粒间孔为主,粒内溶孔、粒间溶孔次之,存在微裂隙,孔隙结构复杂,属于裂缝-孔隙型致密砂岩储层;根据离心前后核磁共振T_2谱图(T_e=0.2ms)形态对比特征及束缚水饱和度的不同,可将储层分为3类,Ⅰ类储层占样品数的35%,为大孔隙占优,离心后束缚水饱和度约为25%;Ⅱ类储层占样品数的20%,大、小孔隙相当,离心后束缚水饱和度约为45%;Ⅲ类储层占样品数的45%,以小孔隙为主,束缚水饱和度平均高达50%;成岩作用是影响储层孔隙结构的主要因素,沉积作用是影响孔隙结构的先决条件,而后期的构造应力作用产生的侧向挤压应力和微裂隙则是孔隙结构复杂化的重要因素。The Bashijiqike Formation in Keshen Gasfield of Kuqa Depression,Tarim Basin is a typical ultradeep tight sandstone reservoir with the burial depth mainly at 6 000-8 500 m,whose rock is compact.By using the experimental data such as normal and casting thin sections observation,scanning electron microscopy,laser confocal microscopy,field emission electron microscopy,rate-controlled porosimetry,nuclear magnetic resonance,and centrifugation,this paper studies the petrological and pore structure characteristics of Bashijiqike sandstone reservoir.At the same time,the paper discusses the factors influencing the pore structure from the geological point of view of structure,sedimentation and diagenesis.The results show that the reservoir lithology is mainly feldspar lithic sandstone,and the composition maturity and structure maturity are moderate.The reservoir space is dominated by intergranular pores,followed by the intragranular dissolution and the intergranular dissolution,and then microfratures.Hence,the pore structure is complex and belongs to the fractured-pore type sandstone reservoir.According to the differences of the morphological characteristics of the nuclear magnetic resonance T2 spectrum（Te=0.2 ms）before and after centrifugation and the irreducible water saturation,the reservoir can be divided into three categories.The macropores dominate in the first category reservoir,taking up 35% of the samples mainly,in which irreducible water saturation is 25% after centrifugation;the macropores and micropores are fairly typical for the second category reservoir,taking up 20% of the samples,in which irreducible water saturation is 45% after centrifugation;the micropores dominatein the third category reservoir,taking up 45% of the samples,in which irreducible water saturation is 50%after centrifugation.Diagenesis is the main factor affecting the pore structure of reservoir and sedimentation is a prerequisite for pore structure and the microfracture produced by the later tectonic stress is an important factor forthe

关 键 词：孔隙结构 致密砂岩 成岩作用 巴什基奇克组 克深气田 

分 类 号：P618.13[天文地球—矿床学]