基于相控地质统计学叠前反演的致密砂岩薄储层含气性预测——以鄂尔多斯盆地临兴中区为例  

Gas-bearing prediction of thin tight sandstone reservoirs based on facies-controlled geostatistical pre-stack inversion: A case study of the middle Linxing Block in the Ordos Basin

作　　者：林利明 郑颖 史浩 李忠城[1] 时靖雪 师素珍[3] 郭俊超 LIN Liming;ZHENG Ying;SHI Hao;LI Zhongcheng;SHI Jingxue;SHI Suzhen;GUO Junchao(China United Coalbed Methane Co.,Ltd.,Beijing 100015,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China;State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中联煤层气有限责任公司,100015 [2]中海油研究总院有限责任公司 [3]“煤炭资源与安全开采”国家重点实验室·中国矿业大学(北京),100083

出　　处：《天然气工业》2023年第2期56-66,共11页Natural Gas Industry

基　　金：中央高校基本科研业务费专项“CO_(2)封存地质体结构的多尺度透明化表征方法研究”(编号:2022JCCXMT01);煤炭资源与安全开采国家重点实验室开放基金项目“含煤岩系非常规气储层地球物理识别方法研究”(编号:SKLCRSM19ZZ02);中海石油(中国)有限公司重大科技专项“中联公司上产60亿立方米关键技术研究”(编号:CNOOC-KJ 135 ZDXM 40)。

摘　　要：鄂尔多斯盆地东缘砂岩储层厚度薄、纵向多期叠置、横向变化快,常规确定性反演结果的分辨率难以满足薄储层及其含气性预测的要求。为此,以鄂尔多斯盆地东缘临兴中区为例,根据已钻井资料和地质先验信息,利用贝叶斯判别原理,将地震数据驱动下叠前同步反演得到的敏感弹性参数体转换为砂岩储层岩相概率密度,并以此作为三维空间约束项,添加到三维地质统计学叠前反演过程中,得到更加符合地质、测井、地震认识的岩性预测结果,然后运用协模拟技术获取各个目的层段的孔隙度、渗透率和饱和度参数,形成了一种相控地质统计学叠前反演储层预测技术,最终实现了有利储层的含气性预测。研究结果表明:(1)相控地质统计学叠前反演薄储层预测技术特点在于利用岩性敏感弹性参数建立了三维空间储层先验约束,提高了岩性空间预测的准确性;(2)利用协模拟技术可以将相控地质统计学叠前反演得到的弹性参数体与储层参数孔隙度、渗透率、饱和度建立关系,能够更加直观地反映气层特征;(3)在鄂尔多斯盆地东缘的临兴中区推广应用,该方法实现了5 m薄气层的识别,有效地指导了该区致密气勘探开发。结论认为,在相控地质统计学叠前反演基础上进行协模拟,采用“逐步反演、分级预测”的思路可以有效提高致密砂岩薄储层含气性预测的精度,该方法具有较广泛的应用价值和前景。The sandstone reservoirs in the eastern margin of the Ordos Basin have small thickness, vertical multi-phase superposition and rapid horizontal change. The resolution of conventional deterministic inversion results is difficult to satisfy the requirements of precise prediction of thin reservoirs and gas-bearing properties. Aiming at the above problems, this paper takes the middle block of Linxing in the eastern margin of the Ordos Basin as an example. Firstly, according to the drilling data and prior information of geology, the Bayesian discriminant principle is used to convert sensitive elastic parameters obtained from the pre-stack synchronous inversion driven by seismic data into the probability density of lithofacies in sandstone reservoirs. In addition, as a reservoir constraint term in 3D space, it is added to the 3D geostatistical pre-stack inversion process, so as to obtain lithologic prediction results which are more consistent with geology, well logging and seismic cognition. Finally, the porosity, permeability and saturation parameters of each target interval are obtained by the cosimulation technique. Thus, a technique of facies-controlled geostatistical pre-stack inversion reservoir prediction is developed, and the gasbearing prediction of favorable reservoirs is finally realized. The following results are achieved. First, the characteristic of the thin reservoir prediction technique of facies-controlled pre-stack inversion is that the 3D spatial reservoir prior constraints are established by using lithologic sensitive elastic parameters, which improves the accuracy of lithologic spatial prediction. Second, the co-simulation technique can be used to establish the relationship between the elastic parameter cubes obtained by facies-controlled geostatistical pre-stack inversion and the physical parameters such as porosity, permeability and saturation, which can directly reflect the characteristics of gas reservoirs more. Third, applied to the middle Linxing Block in the eastern margin of the Ordos Basin

关 键 词：鄂尔多斯盆地 致密砂岩 薄储层 相控地质统计学反演 含气性预测 

分 类 号：P618.13[天文地球—矿床学]