中东东鲁卜哈利盆地碳酸盐岩微孔型低电阻率油层饱和度评价方法  

Saturation evaluation of microporous low resistivity carbonate oil pays in Rub Al Khali Basin in the Middle East

作　　者：王拥军[1,2] 孙圆辉[1,2] 杨思玉[1,2] 吴淑红[1,2] 刘辉[2] 童敏[1,2] 吕恒宇 WANG Yongjun;SUN Yuanhui;YANG Siyu;WU Shuhong;LIU Hui;TONG Min;LYU Hengyu(State Key Laboratory of Enhanced Oil Recovery,Beijing 100083,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]提高石油采收率国家重点实验室,北京100083 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2022年第1期81-92,共12页Petroleum Exploration and Development

基　　金：中国石油天然气集团有限公司科学研究与技术开发项目(2019D-4410)

摘　　要：针对中东地区东鲁卜哈利盆地海相碳酸盐岩低电阻率油层常规测井识别度低的问题,综合利用模拟成藏和开采过程的驱替电阻率实验,以及岩石薄片、压汞、核磁共振实验数据,分析驱替过程中流体分布和岩石导电性变化特征,结合地质认识分析低电阻率油层成因并优选饱和度解释模型,确定模型参数的变化规律和分布范围,提出一套适合研究区的低电阻率油层饱和度测井解释方法。研究区低电阻率油层电阻率小于1Ω·m,与水层相当甚至略低,地质研究揭示其发育于低能沉积环境,储集空间受微细孔喉控制,平均孔喉半径小于0.7μm,是典型的微孔型低电阻率油层。该类储集层与砂泥岩低电阻率油层不同,其岩石导电路径迂曲度低于常规储集层,导致相同饱和度条件下电阻率低。研究区低电阻率油层饱和度解释适用阿尔奇公式,其胶结指数值为1.77~1.93、饱和度指数值为1.82~2.03,分别比常规储集层低0.2~0.4。采用基于岩石物理相分类统计的方法确定解释参数,计算的低电阻率油层含油饱和度为30%~50%,比常规方法高约15%,与DeanStark、储集层饱和度测井、试油及生产数据基本一致。经过15口井试油测试和生产验证,符合率超过90%,进一步验证了该方法的可行性。To solve the problem that it is difficult to identify carbonate low resistivity pays(LRPs) by conventional logging methods in the Rub Al Khali Basin, the Middle East, the variation of fluid distribution and rock conductivity during displacement were analyzed by displacement resistivity experiments simulating the process of reservoir formation and production, together with the data from thin sections,mercury injection and nuclear magnetic resonance experiments. In combination with geological understandings, the genetic mechanisms of LRPs were revealed, then the saturation interpretation model was selected, the variation laws and distribution range of the model parameters were defined, and finally an updated comprehensive saturation interpretation technique for the LRPs has been proposed. In the study area, the LRPs have resistivity values of less than 1 Ω·m, similar to or even slightly lower than that of the water layers. Geological research reveals that the LRPs were developed in low-energy depositional environment and their reservoir spaces are controlled by micro-scale pore throats, with an average radius of less than 0.7 μm, so they are typical microporous LRPs. Different from LRPs of sandstone and mudstone, they have less tortuous conductive paths than conventional reservoirs, and thus lower resistivity value under the same saturation. Archie’s formula is applicable to the saturation interpretation of LRPs with a cementation index value of 1.77-1.93 and a saturation index value of 1.82-2.03 that are 0.2-0.4 lower than conventional reservoirs respectively. By using interpretation parameters determined by classification statistics of petrophysical groups(PGs), oil saturations of the LRPs were calculated at bout 30%-50%, 15%higher than the results by conventional methods, and basically consistent with the data of Dean Stark, RST, oil testing and production.The 15 wells of oil testing and production proved that the coincidence rate of saturation interpretation is over 90% and the feasibility of this method h

关 键 词：碳酸盐岩 低电阻率油层 微孔型储集层 阿尔奇公式 胶结指数 饱和度指数 白垩系 东鲁卜哈利盆地 

分 类 号：P631.4[天文地球—地质矿产勘探]