塔北隆起南斜坡带三道桥气田寒武系裂缝型白云岩储层裂缝期次差异与分布规律  

Fracture stages and distribution patterns in Cambrian fractured dolomite reservoirs,Sandaoqiao gas field

作　　者：孟庆修 曹自成[2] 丁文龙[3] 杨德彬[1] 马海陇[1] 刁新东 王明[1] 韩鹏远 王欢欢[4] MENG Qingxiu;CAO Zicheng;DING Wenlong;YANG Debin;MA Hailong;DIAO Xindong;WANG Ming;HAN Pengyuan;WANG Huanhuan(Research Institute of Exploration and Production,Northwest Oilfield Branch Company,Sinopec,rümqi 830011,China;Northwest Oilfield Branch Company,Sinopec,rümqi 830011,China;School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;Changqing Oilfield Company,PetroChina,Xi’an 710018,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]中国石化西北油田分公司,新疆乌鲁木齐830011 [3]中国地质大学(北京)能源学院,北京100083 [4]中国石油长庆油田分公司,陕西西安710018

出　　处：《地学前缘》2024年第5期247-262,共16页Earth Science Frontiers

基　　金：国家自然科学基金项目(42072173,42372171);中国石化西北油田分公司博士后科研项目(KJ202337)。

摘　　要：塔里木盆地北部三道桥气田在深层寒武系发育典型的裂缝型白云岩储层。在岩心、显微镜下、成像测井等多尺度多视角下均显示白云岩储层溶蚀作用弱,构造裂缝是研究区白云岩储层储集空间及物性的主控因素。本研究综合岩心、镜下、显微CT视角下的裂缝交切关系、声发射实验对古构造强度的分析以及区域成岩与埋藏史,得到了研究区主要发育的两期裂缝的差异特征。结果显示:第一期为雁列式高角度裂缝,裂缝宽度大,缝面粗糙,充填胶结严重,主要形成期为加里东晚期—海西早期;第二期呈中高角度裂缝,裂缝宽度小,缝面平直,多呈半充填,推测形成期为海西晚期—印支期;第二期裂缝交切了先期裂缝,局部错位位移现象明显。通过岩心裂缝线密度和单井裂缝发育段定量参数的统计分析,定量表征了不同构造部位白云岩储层裂缝发育程度,指出了在三道桥气田寒武系白云岩古潜山的挤压褶皱背斜翼部高部位具有最高的裂缝发育程度,挤压褶皱背斜的翼部低部位与挤压向斜裂缝发育程度较低,并建立了研究区非对称挤压褶皱剖面裂缝发育模式。本研究对裂缝期次差异和分布规律的认识可为区域上的裂缝发育期次、有效裂缝识别及特征、裂缝定量分布预测和有利区的评价起到一定的参考意义。The Sandaoqiao gas field in northern Tarim Basin,southern slope zone of Tabei Uplift,develops typical fractured dolomite reservoirs in deep Cambrian.The dolomite reservoirs show weak dissolution where structural fractures are the main controlling factors of reservoir storage space and physical properties.Through comprehensive analysis of fracture intersections using core logs,microscope,and micro CT,and analysis of the strength of ancient structures through acoustic emission experiments,combined with regional diagenesis and burial history,the characteristics of differential development of two main fracture stages are clarified.The first stage,mostly between the late Caledonian to early Hercynian,forms a wide,high-angle echelon fracture,with rough fracture surface and severe filling and cementation.The second stage,considered between the late Hercynian and Indosinian,forms finer,medium-to high-angle fractures,with straight fracture surface,mostly semi-filled.The intersection between the two stages results in significant local displacement.Through statistical analyses of core fracture densities and single-well fracture development parameters the degree of fracture development in the dolomite reservoirs at different structural locations is quantitatively characterized.The top parts of the limbs of anticlines in the Cambrian dolomite buried hill have the highest degree of fracture development while the lower parts show relatively low fracture development.A fracture development model for asymmetrical anticlines in the research area is established.The understanding of the differences and distribution pattern of fracture stages in this study can provide a reference for the regional fracture development stages,identification/characterization of effective fractures,quantitative prediction of fracture distribution,and evaluation of favorable fracture zones in the study area.

关 键 词：裂缝期次 裂缝定量表征 裂缝分布规律 白云岩储层 寒武系 三道桥气田 

分 类 号：P618.130.21[天文地球—矿床学]