Acta Petrolei Sinica ›› 2025, Vol. 46 ›› Issue (10): 1906-1915.DOI: 10.7623/syxb202510006

• OIL FIELD DEVELOPMENT • Previous Articles    

A gas-bearing evaluation method for tight sandstone gas reservoirs based on elastic mechanical parameters

Liang Zhongkui1, Li Xueying2, Sun Aiyan1, Meng Lingjian1,2, Yan Changqing1, Zhou He1   

  1. 1. Research Institute of Exploration and Development, PetroChina Jidong Oilfield Company, Hebei Tangshan 063004, China;
    2. School of Earth Sciences, Northeast Petroleum University, Heilongjiang Daqing 163318, China
  • Received:2024-08-29 Revised:2025-07-01 Published:2025-11-04

基于弹性力学参数的致密砂岩气储层含气性评价方法

梁忠奎1, 李雪英2, 孙爱艳1, 孟令箭1,2, 闫长青1, 周贺1   

  1. 1. 中国石油冀东油田公司勘探开发研究院 河北唐山 063004;
    2. 东北石油大学地球科学学院 黑龙江大庆 163318
  • 通讯作者: 李雪英,男,1972年4月生,2009年获中国科学院地质与地球物理研究所博士学位,现为东北石油大学教授、博士生导师,主要从事测井处理与解释评价工作。Email:lxy8403@sina.com
  • 作者简介:梁忠奎,男,1979年9月生,2025年获东北石油大学博士学位,现为中国石油冀东油田公司勘探开发研究院高级工程师,主要从事非常规储层测井精细解释评价工作。Email:liangzhongkui23@163.com
  • 基金资助:
    黑龙江省自然科学基金联合引导项目(LH2021D010)资助。

Abstract: A gas-bearing evaluation method based on array acoustic logging is proposed to overcome the difficulties in fluid property discrimination and saturation estimation arising from poor reservoir quality and complex pore structures in tight sandstone gas reservoirs. Through integrated experiments of nuclear magnetic resonance (NMR)and variable saturation acoustic velocity, the variation patterns of elastic mechanical parameters with water saturation under different pore structure conditions were investigated. The bulk modulus and geometric mean of NMR transverse relaxation time (T2)were optimized to construct a sensitive composite parameter. Combined with the velocity ratio of P-wave to S-wave, a fluid property identification cross-plot was established. The cross-plot method significantly reduces the influence of pore structure heterogeneity and enables accurate identification of gas layers, gas-water coexistence layers, and water-bearing layers. Within the framework of Gassmann theory, Gassmann-Brie equation with an adjustable Brie’s exponent was developed to calculate the bulk modulus of reservoirs with different pore structures. Based on this, a water saturation calculation model was constructed using a composite parameter derived from the differential ratio of variable-frame elastic moduli. Element capture spectroscopy was employed to accurately obtain the bulk modulus and shear modulus of the formation matrix. This enabled precise calculation of water saturation based on array acoustic logging, with an average relative error of less than 5 % . The proposed method provides technical support for both qualitative identification and quantitative evaluation of tight sandstone gas reservoirs.

Key words: tight sandstone gas reservoir, elastic mechanical parameter, array acoustic logging, differential ratio of modulus ratio, gas-bearing evaluation

摘要: 针对致密砂岩气藏储层物性差、孔隙结构复杂所导致的流体性质判别和饱和度计算难题,提出了一种基于阵列声波测井的含气性评价方法。通过开展核磁共振-变饱和度声波速度联测实验,研究了不同孔隙结构条件下弹性力学参数随含水饱和度的变化规律,优选体积模量和核磁共振横向弛豫时间(T2)几何均值构建敏感复合参数,与纵波/横波速度比交会,建立了流体性质判别图版,该图版显著降低了孔隙结构的影响,实现了气层、气-水同层和水层的准确识别。基于Gassmann理论框架,建立了变Brie系数的Gassmann-Brie方程以计算不同孔隙结构储层的体积模量,进而构建了基于变骨架弹性模量比的差比综合参数的含水饱和度计算模型。通过地层元素测井精确获取地层岩石骨架体积模量和剪切模量,实现了基于阵列声波测井的含水饱和度精确计算(平均相对误差小于5%)。该方法为致密砂岩气藏的定性识别与定量评价提供了技术支撑。

关键词: 致密砂岩气藏, 弹性力学参数, 阵列声波测井, 模量比的差比, 含气性评价

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