塔河地区志留系柯下段致密砂岩储层特征及控制因素研究  

Study on quality control factors and tight sandstone reservoir genesis in Kexia member of Silurian in the Tahe area

作　　者：沈倩 王铭伟 吴玟 李松[4] SHEN Qian;WANG Mingwei;WU Wen;LI Song(Exploration and Development Research Institute of Northwest Oilfield Branch of Sinopec,Urumqi 830011,China;School of Oil&Natural Gas Engineering,Southwest Petroleum University,Chengdu 610500,China;Development Department of PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China;Engineering Research Institute of PetroChina Southwest Oil and Gas Field Company,Chengdu 610017,China)

机构地区：[1]中国石化西北油田分公司勘探开发研究院,新疆乌鲁木齐830011 [2]西南石油大学石油与天然气工程学院,四川成都610500 [3]中国石油西南油气田分公司开发事业部,四川成都610051 [4]中国石油西南油气田分公司工程技术研究院,四川成都610017

出　　处：《复杂油气藏》2023年第2期175-178,184,共5页Complex Hydrocarbon Reservoirs

基　　金：国家自然科学基金“多场耦合条件下甲烷/二氧化碳在页岩非均质储层中的动力学特征研究”(41772150)。

摘　　要：塔河地区志留系柯坪塔格组下段(柯下段)致密砂岩储层具低孔低渗特征。研究表明,该地区沉积微相控制了砂体的展布规律,是本区优质储层发育的先决条件。沉积分异作用使储层砂岩粒度、成分和结构等发生变化,影响了砂岩在成岩过程中原生孔隙的保留或次生孔隙的形成,从而控制了储层物性品质的好坏,因此是优质储层形成和分布的关键因素。综合评价了塔河地区志留系柯下段储层沉积相、成岩作用、断裂等储层控制因素,砂岩储层粒度、分选性、磨圆度特征参数与储层物性呈较好的正相关性;断裂可直接改善储层物性,并且作为成岩流体的主要运移通道,为后期溶蚀作用提供了有利条件。通过沉积相、储层、断裂、油气成果等综合分析,沉积、裂缝及成岩作用是影响储层物性的主要原因,砂坪、潮道、下切水道发育区是塔河地区柯下段的有利勘探区带。储层综合评价表明兰尕、托甫台中部等地区发育优质储层,为下步勘探部署提供了有力依据。The tight sandstone reservoir of the lower section of the Silurian Kepingtag Formation(Kexia member)in the Tahe area is characterized by low porosity and low permeability.The study shows that the sedimentary microfacies control the spreading pattern of the sand body in this area,which is a prerequisite for the development of high-quality reservoirs in this area.Sedimentary differentiation causes changes in the grain size,composition,and structure of the reservoir sandstone,which affects the retention of primary pores or the formation of secondary pores in the diagenesis process of sandstone,thus controlling the quality of reservoir physical properties.Therefore,it is a key factor in the formation and distribution of high-quality reservoirs.A comprehensive evaluation of reservoir control factors such as sedimentary phase,diagenesis,and fractures in the Kexia member of the Silurian reservoir in the Tahe region shows that sandstone reservoir grain size,sortability,and roundness characteristics are positively correlated with reservoir properties;fractures can directly improve reservoir physical properties.and act as the main transport channel for diagenetic fluids,providing favorable conditions for later dissolution.Through comprehensive analysis of sedimentary facies,reservoirs,fractures,and oil and gas achievements,it is found that sedimentation,fractures,and diagenesis are the main factors affecting the reservoir's physical properties.The development area of the sand flat,tidal channel,and undercut channel is a favorable exploration area for the Kexia member in the Tahe area.The comprehensive reservoir evaluation shows that high-quality reservoirs have been developed in the central part of the Langa and Tuofu platforms,which provides a strong basis for the next exploration deployment.

关 键 词：致密砂岩 沉积分异 成岩作用 断裂 主控因素 志留系 

分 类 号：TE32[石油与天然气工程—油气田开发工程]