摘要
碳酸盐岩油藏中隔夹层成因多样,隐蔽性强,测井曲线难以有效识别,严重制约了油藏高效开发。以伊拉克M油田白垩系Mishrif组生物碎屑灰岩为例,通过岩心观察、铸体薄片和物性分析数据识别隔夹层,通过岩-电精细标定确定不同类型隔夹层测井值域分布,优选特征测井曲线,基于成因控制,开展未取心井隔夹层判别。结果表明:M油田Mishrif组发育局限沉积型、深水沉积型、风化胶结型、淋滤胶结型和局限暴露型5类隔夹层。采用雷达图比较不同隔夹层测井响应特征,采用"误判率"来表征每种测井曲线对储集层和隔夹层的区分度。研究发现:应用密度曲线值2.55 g·cm-3可实现储集层和隔夹层的划分,通过相控原则,在浅滩相储集层内部以密度测井值2.45 g·cm-3或声波测井值70μs·m-1识别淋滤胶结型隔夹层。隔夹层中分别通过伽马测井值80 API和密度测井值2.65 g·cm-3判别局限暴露型隔夹层和风化胶结型隔夹层。基于层控原则,在MB2.2层识别深水沉积型隔夹层,在MA、MB1和MB2.1层识别局限沉积型隔夹层。不同类型隔夹层的展布规律和隔挡性能差异较大,实现不同类型隔夹层表征对厚层碳酸盐岩油藏分层系开发提供依据。
The interlayers in carbonate reservoirs had various genesis. They were difficult to identify by the logging because of being hard to recover, which affected greatly on the efficient development of reservoirs. Thus, the bioclastic limestone of the Cretaceous Mishrif Formation in the M oilfield of Iraq was studied. The interlayers were identified by core observation, casting thin section and physical property data. The distribution of well logging values of different types of interlayers was defined by rock-electric fine calibration and the most representative log of different interlayers was selected. Under the controlling of interlayers genesis, different interlayers in uncoring well were interpreted. The results show that there are five categories in the Mishrif formation in M oilfield. They are the deposition type, the deep water deposition type, the weathered and cemented type, the leaching and cemented type, and the restricted exposure type. The radar chart is used to compare the log characteristics of different interlayers, and the false judgment rate is used to characterize the discrimination ability of different logging between the reservoir and the interlayer. Moreover, the reservoir and interlayers can be effectively separated by the density value of 2.55 g·cm-3. Under the control of facies, the leaching and cemented interlayers is identified by a density value of 2.45 g·cm-3 or a sonic curve value of 70 μs·m-1 inside the shoal reservoir. The restricted exposure interlayer and the weathered and cemented interlayer are preferentially identified among the interlayer by gamma value of 80 API and density value of 2.65 g·cm-3 respectively. Under the control of stratigraphic unit, the deep water deposition interlayer is identified in the MB2.2 layer, and the restricted deposition interlayer is identified in the MA, MB1 and MB2.1 layers. Different interlayers have different distribution law and barrier properties. The study results can provide basis for the separated development of thick carbonate reservoirs.
作者
李峰峰
郭睿
刘立峰
宋世琦
LI Feng-feng;GUO Rui;LIU Li-feng;SONG Shi-qi(Research Institute of Petroleum Exploration&Development Petrochina,Beijing 100083,China;Faculty of Earth Science,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《科学技术与工程》
北大核心
2020年第19期7650-7657,共8页
Science Technology and Engineering
基金
国家科技重大专项(2017ZX05030-001)。
关键词
碳酸盐岩
隔夹层
白垩系
Mishrif组
成因控制
carbonate rock
interlayers
Cretaceous
the Mishrif Formation
genesis controlling
