煤层气藏缝网压裂直井生产动态规律

发布时间：2018-04-12 10:08

本文选题：煤层气 + 体积压裂　；参考：《天然气工业》2017年02期

【摘要】：体积压裂技术在煤层气藏开发中已得到广泛应用,针对体积压裂形成的裂缝网络(SRV),矩形边界复合模型相比于传统的径向复合模型能够更加准确合理地描述流体的渗流规律。解析或半解析函数方法无法对考虑SRV的矩形复合模型进行求解,而应用线性流模型对其求解则又会产生较大的误差。为此,利用双重介质模型对煤层气藏体积压裂区进行描述,综合考虑煤层气的吸附与解吸、扩散、渗流等多重运移机制,建立了基于非稳态扩散的煤层气藏矩形复合压裂井试井模型。结合Laplace变换、Stehfest数值反演以及计算机编程技术,采用边界元方法对模型进行求解,得到了煤层气藏生产动态变化的规律。对试井典型曲线进行了流动阶段划分,并分析了气藏边界尺寸、体积压裂区渗透率、吸附气含量、储层渗透率以及SRV尺寸等参数对生产动态规律变化的影响,实现了对体积压裂改造后的煤层气藏更为准确合理的描述。该项研究成果为深入认识煤层气运移规律和高效合理评价及开发煤层气藏提供了理论依据。
[Abstract]:Volume fracturing technology has been widely used in the development of coalbed methane reservoirs. In view of the fracture network formed by volume fracturing, the rectangular boundary composite model can more accurately and reasonably describe the fluid seepage law than the traditional radial composite model.The analytical or semi-analytic function method can not solve the rectangular composite model with SRV, but the application of linear flow model will result in a large error.A well test model of rectangular composite fracturing wells for coalbed methane reservoirs based on unsteady diffusion is established.Combined with the Laplace transform Stehfest numerical inversion and computer programming technology, the boundary element method is used to solve the model, and the dynamic change law of coalbed methane reservoir production is obtained.The flow stages of typical well test curves are divided, and the effects of gas reservoir boundary size, volume fracturing area permeability, adsorption gas content, reservoir permeability and SRV size on production performance are analyzed.A more accurate and reasonable description of CBM reservoir after volume fracturing is realized.The research results provide a theoretical basis for further understanding the migration law of coalbed methane and evaluating and developing coalbed methane reservoir efficiently and reasonably.
【作者单位】： "油气藏地质及开发工程"国家重点实验室·西南石油大学;
【基金】：国家自然科学基金重点项目“致密气藏储层干化、提高气体渗流能力的基础研究”(编号:51534006) 西南石油大学科研启航计划(编号:2015QHZ003)、西南石油大学青年学者发展基金(编号:201599010088)
【分类号】：TE37

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