渤海湾盆地南堡凹陷碳酸盐岩潜山储层裂缝发育特征及分布规律预测  

Fractures development characteristics and distribution prediction of carbonate buried hills in Nanpu Sag,Bohai Bay Basin

作　　者：巩磊[1,2] 秦欣楠 卢俊 高阳[4] 孟令箭[5] 袁红旗[2] 卢崎 尹晓曦 GONG Lei;QIN Xinnan;LU Jun;GAO Yang;MENG Lingjian;YUAN Hongqi;LU Qi;YIN Xiaoxi(Bohai-Rim Energy Research Institute,Northeast Petroleum University,Qinhuangdao 066004,China;College of Geosciences,Northeast Petroleum University,Daqing 163318,China;Jiangsu Geological Bureau,Nanjing 210007,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China;Research Institute of Exploration and Development,PetroChina Jidong Oilfield Company,Tangshan 063004,China)

机构地区：[1]东北石油大学环渤海能源研究院,河北秦皇岛066004 [2]东北石油大学地球科学学院,黑龙江大庆163318 [3]江苏省地质局,江苏南京210007 [4]中国石油勘探开发研究院,北京100083 [5]中国石油冀东油田勘探开发研究院,河北唐山063004

出　　处：《天然气地球科学》2024年第6期925-937,共13页Natural Gas Geoscience

基　　金：国家自然科学基金项目(编号:42072155);黑龙江省优秀青年科学基金项目(编号:YQ2022D006)联合资助。

摘　　要：天然裂缝系统在渤海湾盆地黄骅坳陷南堡凹陷古潜山碳酸盐岩致密油气的成储成藏过程中发挥关键作用,影响着优质储层的分布和油气的运移与聚集。利用野外露头、岩心、微观薄片以及成像测井等资料,对南堡凹陷古潜山碳酸盐岩储层裂缝在纵横向上的发育规律开展定量化描述,明确了裂缝发育的主控因素。在此基础上,利用构造应力场数值模拟技术,对南堡凹陷古潜山碳酸盐岩储层裂缝发育规律进行定量预测。研究区古潜山碳酸盐岩储层主要发育构造裂缝、成岩裂缝、风化裂缝和溶蚀裂缝4种类型,以构造裂缝为主。裂缝矿物填充程度不高,有效性较好,59%为有效裂缝。岩心构造裂缝线密度分布在3~10条/m之间,平均为5.6条/m,构造裂缝高度一般小于30 cm,主要分布在5~20 cm之间。微观裂缝面密度分布在25~50 cm/cm^(2)之间,平均为32.3 cm/cm^(2),微观裂缝孔隙度主要分布在0.24%~0.69%之间,平均为0.55%。微观裂缝为致密储层提供了有效的油气储集空间,同时使孔隙连通性增强,有利于流体运移聚集。研究区主要发育3组裂缝,以近E—W向和NE—SW向最发育,其次为NW—SE向。南堡凹陷致密碳酸盐岩储层裂缝的发育程度主要受岩性、岩石力学层和断层的影响。储层裂缝在白云岩和白云质灰岩中发育较好,在泥岩中往往不发育。不同级别岩石力学界面影响着裂缝的几何形态、规模和发育强度。层控裂缝一般垂直并终止于岩石力学界面,穿层裂缝可以跨越多个岩石力学层,受更高级别的岩石力学界面控制。断层是控制裂缝非均质发育的重要因素,在断层核附近的裂缝发育程度高,尤其是断层端部、叠覆区、交叉区以及断层伴生褶皱的转折端等构造部位是裂缝发育密集带,而随着远离断层带,裂缝数量呈递减趋势。The natural fracture system plays a key role in the formation of hydrocarbon reservoirs in the carbon⁃ate buried hill of Nanpu Sag of Bohai Bay Basin,affecting the distribution of high-quality reservoirs and the mi⁃gration and accumulation of oil and gas.Using data from outcrops,cores,thin sections,and image logs,quanti⁃tative description was conducted on the development patterns of fractures both in vertical and horizontal direc⁃tions,and the main controlling factors for fracture development was clarified.On this basis,numerical simula⁃tion techniques were used to quantitatively predict the development patterns of fractures in the carbonate reser⁃voir of the ancient buried hills in Nanpu Sag.There are four types of fractures in the study area:Structural frac⁃tures,diagenetic fractures,weathering fractures and dissolution fractures,of which tectonic fractures are the main ones.The fracture filling degree is low,hence the fracture effectiveness is good,59%of them are effec⁃tive fracture.The linear density of structural fractures is distributed in the range of 3-10 m−1,with an average of 5.6 m−1.The height of structural fractures is generally less than 30 cm,mainly distributed in 5-20 cm.The mi⁃croscopic fracture areal density is distributed in the range of 25-50 cm/cm^(2),with an average of 32.3 cm/cm^(2).The porosity of micro-fractures mainly ranges from 0.24%to 0.69%,with an average of 0.55%.Micro-frac⁃tures provide effective storage space for tight reservoirs,and enhance pore connectivity,which is conducive to oil and gas migration and accumulation.Three groups of fractures are mainly developed in the study area,of which the nearly E-W and NE-SW trending fractures are the most developed,followed by NW-SE trending fractures.The degree of fracture development in the study area is mainly affected by lithology,rock mechanical layer and fault.The fractures are most developed in dolomite and dolomitic limestone,while the fractures are less developed in mudstone.Different rock mechanical interf

关 键 词：南堡凹陷 古潜山 碳酸盐岩储层 裂缝 发育特征 定量预测 

分 类 号：TE122.1[石油与天然气工程—油气勘探]