塔里木盆地古城地区奥陶系成岩流体与碳酸盐岩储层形成关系研究  

Study on the relationship between the Ordovician diagenetic fluid and carbonate reservoir development in Gucheng area,Tarim Basin

作　　者：冯子辉 邵红梅[1,2] 刘云苗 卢曦[1,2] 赵威 白雪晶 许智禹[1,2] Feng Zihui;Shao Hongmei;Liu Yunmiao;Lu Xi;Zhao Wei;Bai Xuejing;Xu Zhiyu(Daqing Oilfield Research Office,CNPC Key Laboratory of Carbonate Reservoirs;Research Institute of Exploration&Development,PetroChina Daqing Oilfield Company)

机构地区：[1]中国石油天然气集团有限公司碳酸盐岩储层重点实验室大庆油田研究分室 [2]中国石油大庆油田公司勘探开发研究院

出　　处：《中国石油勘探》2022年第4期47-60,共14页China Petroleum Exploration

基　　金：中国石油天然气股份有限公司重大科技专项“塔东天然气成藏理论及勘探配套技术研究”(2016E-0204)。

摘　　要：不同类型的成岩流体控制了油气储层孔隙的演化和储集能力,是储层发育的关键因素。常规的岩相学研究方法难以揭示成岩演化过程中多期成岩流体类型及其对孔隙改造的影响,为了进一步明确不同成岩流体类型对储层的控制作用,主要采用岩相学与地球化学方法相结合的分析手段,对塔里木盆地古城地区奥陶系成岩流体进行识别。结果显示研究区储层主要经历10期不同类型的成岩流体:准同生期大气淡水、准同生期中等盐度蒸发海水、浅埋藏阶段中等盐度封存海水、中—深埋藏阶段有机酸性水、中—深埋藏阶段地层卤水、第Ⅰ期与钠长石化有关的热液流体、第Ⅱ期与热液重结晶作用有关的深部卤水流体、第Ⅲ期与外源流体相关的贫镁热液流体、第Ⅳ期与硅质发育相关的富硅流体,以及第Ⅴ期与晚期方解石充填相关的富钙流体。通过分析各期成岩流体对储层发育的影响,认为准同生期大气淡水和第Ⅲ期与外源流体相关的贫镁热液流体对优质储层起建设性作用;准同生期大气淡水淋滤形成一间房组—鹰二段石灰岩岩溶型储层;第Ⅳ期与硅质发育相关的富硅流体对储层改造具有双重性;热液溶蚀作用可形成局部优质白云岩储层。The pore evolution and storage capacity of oil and gas reservoirs are controlled by various types of diagenetic fluids,which are the key factor for reservoir development.However,the conventional petrographic methods are challenging to identify the types of multiphase diagenetic fluids and their influence on pore transformation in the diagenetic process.The Ordovician diagenetic fluids in Gucheng area are determined by integrating petrographic and geochemical methods,so as to further clarify the control effect of various types of diagenetic fluids on reservoir development.The results show that,there are 10 phases of diagenetic fluids with various types in the process of carbonate reservoir development in the study area,including quasi-contemporaneous atmospheric freshwater,quasi-contemporaneous medium salinity evaporated seawater,shallow buried medium salinity sealed seawater,medium-deep buried organic acid water,medium-deep buried formation brine,phaseⅠhydrothermal fluid related to albitization,phaseⅡdeep brine fluid related to hydrothermal recrystallization,phaseⅢmagnesium poor hydrothermal fluid related to exogenous fluid,phaseⅣsilicon rich fluid related to siliceous development,and phaseⅤcalcium rich fluid related to the late calcite filling.By analyzing the influence of diagenetic fluids in each phase on reservoir development,it is concluded that the quasi-contemporaneous atmospheric freshwater and phaseⅢmagnesium poor hydrothermal fluid played a constructive role in the development of high-quality reservoirs;The phaseⅣsilicon rich fluid related to siliceous development had dual reconstruction on reservoir development;The local high-quality reservoirs can be formed by hydrothermal corrosion.

关 键 词：流体识别 元素地球化学 碳酸盐岩储层 奥陶系 古城地区 塔里木盆地 

分 类 号：TE112[石油与天然气工程—油气勘探]