低孔低渗储层各向异性研究在增产中的作用——以东海A凹陷为例  

The roles of anisotropy in production increasing in low porosity and low permeability reservoir: an example in Sag A, East China Sea

作　　者：胡文亮 罗健 张国栋 魏晓晗 蔡军 张武 HU Wenliang;LUO Jian;ZHANG Guodong;WEI Xiaohan;CAI Jun;ZHANG Wu(Shanghai Branch of CNOOC(China)Co.,Ltd.,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《海洋地质前沿》2023年第4期76-84,共9页Marine Geology Frontiers

基　　金：中海石油(中国)有限公司上海分公司七年行动计划科技项目“西湖凹陷西部地区勘探开发关键技术研究”(CNOOC-KJ135ZDXM39SH01)。

摘　　要：东海盆地A凹陷主要以低孔低渗储层发育为主,经生产实践证实,该类储层运用常规直井或低角度定向井(产能低)难以实现商业产能,因此,渗透率各向异性和储层“甜点”攻关显得尤为重要。碎屑岩储层各向异性特征普遍存在,基于全直径岩芯360°分扇区各向异性实验(渗透率、声波时差)结果表明:6个扇区的水平渗透率分布范围为(3.7~17.3)×10^(-3)μm^(2),轴向90°渗透率为0.06×10^(-3)μm^(2),渗透率各向异性分布范围为62~288,其中水平优势方向的渗透率是非优势方向的3~5倍,且渗透率高值与纵波时差、横波时差低值存在较小夹角。进一步利用成像测井资料与区域地应力分析证实,最大水平主应力方向与构造裂缝发育方向(渗透率优势方向)存在较小夹角,结合“甜点”储层展布形态,并垂直于最大水平主应力方向布井有利于产能释放,助力低渗储层的经济有效开发。The Sag A of the East China Sea Basin is dominated by low porosity and low permeability reservoirs.Production practice has proved that such reservoirs cannot be economically and effectively developed in conventional vertical wells or low-angle directional wells(low productivity). Therefore, it is particularly important to tackle permeability anisotropy and reservoir "sweet spot". The anisotropy characteristics of clastic rock reservoir are common in the Sag A. The results of the anisotropy experiment of 360° sub-sector of full-diameter core(permeability and sonic time difference) show that: the horizontal permeability distribution range of six sectors is(3.7~17.3)×10(-3)μm^(2), the axial permeability of 90° is 0.06×10(-3)μm^(2), and the permeability anisotropy distribution range is 62~288. The permeability in the horizontal dominant direction is 3~5 times of that in non-dominant direction. Moreover, the high permeability has a small angle between the P-wave time difference and the low S-wave time difference. Further imaging logging data and regional stress analysis confirm that the direction of maximum horizontal principal stress has a small angle with the development direction of structural fracture(permeability predominant direction). Combined with the distribution pattern of the "sweet spot" reservoir, the well distribution perpendicular to the direction of maximum horizontal principal stress is conducive to productivity release, which facilitate the economical and effective development of low permeability reservoir.

关 键 词：低孔低渗 各向异性 “甜点”储层 大斜度定向井 水平分支井 东海 

分 类 号：P744.4[天文地球—海洋科学] P618.13