深层—超深层优质碎屑岩储层成因及主控因素——以河套盆地临河坳陷古近系渐新统临河组为例  

Genetic mechanism and main controlling factors of high-quality clastic rock reservoirs in deep and ultra-deep layers:A case study of Oligocene Linhe Formation in Linhe Depression,Hetao Basin,NW China

作　　者：史原鹏 刘占国 王少春 伍劲 刘喜恒 胡延旭 陈树光 冯广业 王标 王浩宇 SHI Yuanpeng;LIU Zhanguo;WANG Shaochun;WU Jin;LIU Xiheng;HU Yanxu;CHEN Shuguang;FENG Guangye;WANG Biao;WANG Haoyu(PetroChina Huabei Oilfield Company,Renqiu 062552,China;PetroChina Hangzhou Research institute of Geology,Hangzhou 310023,China)

机构地区：[1]中国石油华北油田公司,河北任丘062552 [2]中国石油杭州地质研究院,杭州310023

出　　处：《石油勘探与开发》2024年第3期478-489,共12页Petroleum Exploration and Development

基　　金：中国石油天然气集团有限公司基础性前瞻性重大科技专项“叠合盆地中下组合油气成藏与保持机制研究”(2023ZZ02);中国石油天然气集团有限公司攻关性应用性科技专项“超深层碎屑岩大中型油气田形成条件与有利区评价”(2023ZZ14-01)。

摘　　要：基于岩心、钻井和测井等新资料,结合大量岩矿测试分析,对河套盆地临河坳陷古近系渐新统临河组深层—超深层碎屑岩储层特征、成岩作用类型、异常高孔储层成因及发育控制因素开展系统分析。研究表明:(1)临河组深层—超深层碎屑岩异常高孔储层储集空间以原生孔为主,抗压实能力强的物质组构基础、弱压实成岩动力场和流体弱压实-弱胶结成岩环境等3大有利成岩要素耦合利于原生孔大量保存;(2)临河组碎屑岩先存物质组构优越,石英、长石和刚性岩屑总含量平均值可达90%,抗压实能力强;(3)临河坳陷地温梯度低,仅为(2.0~2.6)℃/100 m,与早期长期浅埋—晚期快速深埋的埋藏方式共同形成弱压实成岩动力场环境;(4)咸化湖盆沉积地层的成岩环境中,成岩流体产生的压实作用弱,同时古盐度具有分异性,低盐度区胶结作用弱,利于原生孔保存;(5)沉积水动力条件、咸化湖盆古水体盐度分异和砂体厚度等3大因素共同控制临河组优质储层分布。Based on new data from cores,drilling and logging,combined with extensive rock and mineral testing analysis,a systematic analysis is conducted on the characteristics,diagenesis types,genesis and controlling factors of deep to ultra-deep abnormally high porosity clastic rock reservoirs in the Oligocene Linhe Formation in the Hetao Basin.The reservoir space of the deep to ultra-deep clastic rock reservoirs in the Linhe Formation is mainly primary pores,and the coupling of three favorable diagenetic elements,namely the rock fabric with strong compaction resistance,weak thermal compaction diagenetic dynamic field,and diagenetic environment with weak fluid compaction-weak cementation,is conducive to the preservation of primary pores.The Linhe Formation clastic rocks have a superior preexisting material composition,with an average total content of 90%for quartz,feldspar,and rigid rock fragments,and strong resistance to compaction.The geothermal gradient in Linhe Depression in the range of(2.0–2.6)℃/100 m is low,and together with the burial history of long-term shallow burial and late rapid deep burial,it forms a weak thermal compaction diagenetic dynamic field environment.The diagenetic environment of the saline lake basin is characterized by weak fluid compaction.At the same time,the paleosalinity has zoning characteristics,and weak cementation in low salinity areas is conducive to the preservation of primary pores.The hydrodynamic conditions of sedimentation,salinity differentiation of ancient water in saline lake basins,and sand body thickness jointly control the distribution of high-quality reservoirs in the Linhe Formation.

关 键 词：河套盆地 临河坳陷 古近系渐新统临河组 深层—超深层 异常高孔 储层成因 

分 类 号：TE122.2[石油与天然气工程—油气勘探]