川东北地区凉高山组致密砂岩孔隙特征及成因机制——以川东北铁山金窝剖面为例  

Pore characteristics and genesis mechanism of tight sandstone in Lianggaoshan Formation in northeast Sichuan:a case study of Jinwo section in Tieshan,northeastern Sichuan

作　　者：章海燕[1] 张釜源 林思臣 祝海华[2] 王明磊[3] 李育聪 ZHANG Haiyan;ZHANG Fuyuan;LIN Sichen;ZHU Haihua;WANG Minglei;LI Yucong(Northeast Sichuan Gas Mine,Southwest Oil&Gas Field Company,PetroChina,Dazhou 635000,China;School of Geosciences and Technology,Southwest Petroleum University,Chengdu 610500,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;Exploration and Development Research Institute,Southwest Oil&Gas Field Company,PetroChina,Chengdu 610041,China)

机构地区：[1]中国石油西南油气田分公司川东北气矿,四川达州635000 [2]西南石油大学地球科学与技术学院,四川成都610500 [3]中国石油勘探开发研究院,北京100083 [4]中国石油西南油气田分公司勘探开发研究院,四川成都610041

出　　处：《断块油气田》2025年第1期63-70,共8页Fault-Block Oil & Gas Field

基　　金：中石油-西南石油大学创新联合体科技合作项目“四川盆地湖相页岩油地质评价参数、标准及体系研究”(2020CX050103);国家自然科学基金项目“致密砂岩孔吼模型构建及对可动流体影响研究”(42202176)。

摘　　要：文中以川东北铁山金窝剖面凉高山组为研究对象,综合野外露头样品,开展岩石铸体薄片、全岩X衍射、扫描电镜及孔隙度测试,系统分析了凉高山组砂岩的岩石学、储集空间、物性及成岩作用特征,探讨物性控制因素,明确储层成因机制。结果表明:研究区凉高山组砂岩成分及结构成熟度中—差,岩石类型以细粒长石岩屑砂岩为主;孔隙类型以残余原生粒间孔、粒内微孔、杂基/胶结物微孔为主,孔隙度介于0.64%~14.71%,平均为6.65%,物性较差;砂岩成岩特征表现为强压实、弱胶结、弱溶蚀。砂岩物性是物源、沉积条件及埋藏成岩过程共同作用的结果:小湖盆、近物源导致了砂岩搬运距离短,淘洗不充分,岩屑及塑性组分含量高;早期持续快速埋藏压实导致粒间孔隙快速损失、后期胶结和溶蚀受抑制。互层的烃源岩品质较差导致储层晚期溶蚀改造有限。喜山期抬升改造有利于改善储层物性。现今有利砂岩主要形成于水下分流河道。Taking Lianggaoshan Formation in Jinwo section,Tieshan,northeast Sichuan as the research object and combining field outcrop samples,this paper systematically analyzes the petrology,reservoir space,physical properties and diagenetic characteristics of Lianggaoshan Formation sandstone,discusses the main controlling factors of physical properties and clarifies the genetic mechanism of the reservoir by carrying out rock casting thin sections,whole-rock X-ray diffraction,scanning electron microscope and porosity tests.The results show that the sandstone of Lianggaoshan Formation in the study area has medium to poor component and structural maturity,mainly consisting of fine-grained feldspathic clastic sandstone.The dominant pore types are residual primary intergranular pores,intragranular micropores,and heterogeneous matrix/cement micropores.The porosity ranges from 0.64%to 14.71%,with an average value of 6.65%,and the physical properties are relatively poor.The sandstone diagenesis is characterized by strong compaction,weak cementation and weak dissolution.The physical properties of the sandstone are the result of the joint action of source,sedimentary conditions,and burial diagenesis process.Small lake basin and close source result in short sandstonetransportationdistance,insufficient elutriation,high content of cuttings and plastic components.Early continuous rapid burial compaction results in rapid loss of intergranular pores,and later cementation and dissolution are inhibited.The limited stimulation of the reservoir by dissolution in the late stage is attributed to the poor quality of the interbedded hydrocarbon source rocks.The uplift reconstruction in the Xishan period improves reservoir physical properties.The current favorable sandstones are mainly formed in the underwater distributary diversion channel.

关 键 词：砂岩储层 孔隙特征 成因机制 凉高山组 侏罗系 川东北地区 

分 类 号：TE122.2[石油与天然气工程—油气勘探]