超深层非均质低孔砂岩储层复杂流体识别方法

Complex Fluid Identification Method for Ultra Deep Heterogeneous Low Porosity Sandstone Reservoirs

赵元良 虞兵 郭克才 王美玲 帅士辰

ZHAOYuanliang YUBing GUOKecai WANGMeiling SHUAIShichen

中国石油塔里木油田勘探事业部, 新疆 库尔勒 841000 中国石油测井有限公司地质研究院, 陕西 西安 710000

Exploration Division, Tarim Oilfield, PetroChina, Korla, Xinjiang 841000, China Geological Research Institute, China National Logging Corporation, PetroChina, Xi'an, Shaanxi 710000, China

塔里木盆地库车拗陷博孜—大北地区白垩系巴什基奇克组埋藏深度超6 000 m，孔隙度主要分布在6%~9%，孔隙结构复杂、区域地层水矿化度及地应力变化大，导致气水层之间电阻率对比度低。利用阵列声波计算岩石力学参数以及中子密度曲线包络等非电法流体识别手段的适用性差。针对博孜—大北地区储层气水层电阻率对比度低的识别难题，开展区域地质特征精细分析，建立了分应力区精细孔隙度电阻率交会图、纯水层电阻率反演及邻近砂泥岩电阻率对比3种电法识别方法，同时引进二维核磁-交会图非电法识别方法，该套流体识别方法应用于博孜—大北地区探井跟踪解释后解释符合率提升16.7%，有效解决了研究区复杂地层条件导致的气水层电阻率对比度低的识别难题，为避免研究区油气层的漏失提供了有力技术手段，同时在新疆准噶尔南缘前陆盆地、华北油田河套盆地等国内超深致密砂岩储层具有重要的应用与推广意义。

The burial depth of Cretaceous Bashkirchik Formation in Bozi-Dabei area of Kuqa Depression, Tarim Basin is more than 6 000 m, and the porosity is mainly distributed between 6%~9%. At the same time, the complex pore structure, significant changes in regional formation water mineralization and geostress result in low contrast in electrical resistivity between gas and water layers. The poor physical properties of the matrix result in poor applicability of non electrical fluid identification methods such as array acoustic rock mechanics parameters and neutron-density envelope. A detailed analysis of regional geological characteristics was conducted to address the identification problem of low contrast in gas and water layer resistivity in the Bozi-Dabei Region, and three electrical identification methods have been developed, including the precise establishment of porosity resistivity intersection diagram method in stress zones, pure water layer resistivity inversion method, and adjacent mudstone resistivity comparison method. At the same time, a non electrical identification method for two-dimensional nuclear magnetic - intersection map that is not affected by the skeleton was introduced. This fluid identification method was applied to the tracking and interpretation of exploration wells in the Bozi-Dabei Area, interpretation coincidence rate increased by 16.7%, effectively solved the difficulty of fluid identification caused by low contrast of gas and water layer resistivity due to complex geological conditions in the Bozi-Dabei Region. It provides a powerful technical means to avoid oil and gas reservoir leakage in the study area. It has important application and popularization significance in the domestic ultra-deep tight sandstone reservoirs such as the southern margin foreland basin of Junggar, Xinjiang and Hetao Basin of Huabei Oilfield.

10.11885/j.issn.1674-5086.2023.11.26.01