开采井周边储层渗透率演变对天然气水合物产能影响机理研究  

Study on the influence of reservoir permeability evolution around production wells on production capacity of natural gas hydrate

作　　者：申鹏飞 侯嘉欣 吕涛[3] 毕昊媛 何娟 李小森 李刚[1,4] SHEN Pengfei;HOU Jiaxin;L Tao;BI Haoyuan;HE Juan;LI Xiaosen;LI Gang(Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development,Guangzhou 510640,China;School of Mining and Geomatics Engineering,Hebei University of Engineering,Handan 056038,China;College of Petroleum Engineering,Xi'an Shiyou University,Xi'an 710065,China;Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China)

机构地区：[1]广东省新能源和可再生能源研究开发与应用重点实验室,广东广州510640 [2]河北工程大学矿业与测绘工程学院,河北邯郸056038 [3]西安石油大学石油工程学院,陕西西安710065 [4]中国科学院广州能源研究所,广东广州510640

出　　处：《地学前缘》2025年第2期166-177,共12页Earth Science Frontiers

基　　金：国家自然科学基金项目(52404029,51976228);广东省新能源和可再生能源研究开发与应用重点实验室开放基金项目(E239kf0601);陕西省自然科学基础研究计划项目(2023-JC-QN-0389);河北省教育厅科学技术研究项目资助(QN2022027)。

摘　　要：水合物储层采用压裂技术改造增产已被证明具有水合物生产的应用前景。本研究主要目的是分析两个生产井之间相互作用下的储层产气规律,获得生产井之间的最佳距离。本文以祁连山冻土区DK-2站位的水合物赋存参数为基础,以双水平井形式对开采井外储层进行压裂,并以数值模拟的方式评估了此方法开采冻土区水合物沉积物的生产潜能。模拟结果表明,利用水力压裂方法提升开采井周边储层的渗透性突破了仅采用降压法开采水合物的技术瓶颈,产气率和累积释放气体量均高于传统降压法,并且平均气水比得到显著上升。水平井周围的岩石基质破裂后,会增加压裂区的流动特性,进而促进压降的传播距离,有效降低储层内冰赋存与聚集。水平生产井之间水合物分解区域的渗透有利于促进分解气体和水流向生产井。此外,水力压裂方法对固有渗透率低于1 mD的水合物储层是十分有效的,生产井之间的最佳距离建议为45~60 m。The use of fracturing technology to transform and increase production in hydrate reservoirs has been proven to have application prospects for hydrate production.The main purpose of this study is to analyze the gas production patterns of reservoirs under the interaction between two production wells,and to obtain the optimal distance between production wells.This article is based on the hydrate occurrence parameters of DK-2 station in the permafrost region of the Qilian Mountains.The reservoir outside the dual production wells were fractured by fracturing,and the production potential of this method for extracting hydrate sediments in the permafrost region was evaluated through numerical simulation.The simulation results show that the use of hydraulic fracturing method to enhance the permeability of the surrounding reservoirs of the mining well has broken through the technical bottleneck of using only depressurization method to extract hydrates.The gas production rate and cumulative gas release are higher than traditional depressurization methods,and the average gas water ratio has significantly increased.After the rock matrix around the horizontal well ruptures,it will increase the flow characteristics of the fracturing zone,thereby promoting the propagation distance of pressure drop.The infiltration of hydrate decomposition areas between horizontal production wells is conducive to promoting the decomposition of gas and water flow towards the production wells.In addition,hydraulic fracturing methods are very effective for hydrate reservoirs with intrinsic permeability below 1 mD,and the recommended optimal distance between production wells is 4560 m.

关 键 词：天然气水合物 储层改造 渗透率 冻土区 井距 

分 类 号：TE38[石油与天然气工程—油气田开发工程]