Liu Yi, Liu Shanyong, Lou Yishan, Yin Biao, Zhang Yan
Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering, Yangtze University, Wuhan, 430100, China.
School of Petroleum Engineering, Yangtze University, Wuhan, 430100, China.
Sci Rep. 2025 Feb 19;15(1):6061. doi: 10.1038/s41598-025-90371-y.
The LX tight gas reservoir displays significant heterogeneity, with a lack of alignment between engineering treatment and geological evaluation, leading to an unsatisfactory development outcome. Focusing on the Shihezi Formation of LX, a new comprehensive evaluation method is proposed for identifying sweet spots, taking into consideration both geological and engineering factors. The objective function utilized is post-frac production, and the grey correlation method was employed to quantitatively characterize the weight coefficients of geological and engineering parameters. The dual sweet spots index F was obtained through a normalized process. Utilizing the Petrel integrated exploration and development platform, the dual sweet spots index was incorporated into the geological model using coarse-interpolation. Subsequently, a dual sweet spots evaluation model was established to enhance the overall assessment process. The findings indicate the following: (1) There is a strong correlation between open flow production and the F-value, and the model's predicted value closely aligns with the actual value. (2) A section with an F-value greater than 0.5 is identified as the optimal sweet spot, prioritizing development in this area. Sections with F-values within the range of 0.3 to 0.5 may be considered for fracturing but are not the primary choice. Sections with an F-value below 0.3 are deemed inefficient areas. (3) Based on the dual sweet spots evaluation model, it is recommended to focus on single layers He2, He5, and He6 in the LX area due to their superior quality compared to other layers. The research results offer crucial technical support for assessing fracability in this region, and hold significant importance for the selection of fracturing wells and the optimization of frac design.
LX致密气藏非均质性显著，工程处理与地质评价不匹配，导致开发效果不理想。针对LX地区的石河子组，提出了一种兼顾地质和工程因素的甜点识别综合评价新方法。采用的目标函数是压后产量，运用灰色关联法对地质和工程参数的权重系数进行定量表征。通过归一化处理得到双甜点指数F。利用Petrel一体化勘探开发平台，采用粗插值法将双甜点指数纳入地质模型。随后建立双甜点评价模型，以完善整体评价流程。研究结果表明：（1）无阻流量与F值相关性强，模型预测值与实际值吻合度高。（2）F值大于0.5的区域为最优甜点区，优先开发；F值在0.3至0.5之间的区域可考虑压裂，但非首选；F值小于0.3的区域为低效区。（3）基于双甜点评价模型，建议在LX地区重点关注单层盒2、盒5和盒6，因其品质优于其他层位。研究结果为该地区的可压裂性评价提供了关键技术支撑，对压裂井的选择和压裂设计的优化具有重要意义。
