天然气水合物藏径向井充填辅助降压开发模拟方法及产能变化规律研究  

Simulation method of radial well filling assisted depressurization development for hydrate reservoirs and research on the variation law of production

作　　者：刘永革[1,2] 张旭 侯健[1,2] CLARKE Matthew 郭天魁[1,2] 杜庆军 刘建新[1,2] 白雅洁[4] 陈掌星[3] 徐鸿志 赵二猛[1,2] 纪云开 陈立涛 LIU YongGe;ZHANG Xu;HOU Jian;Matthew CLARKE;GUO TianKui;DU QingJun;LIU JianXin;BAI YaJie;CHEN ZhangXin;XU HongZhi;ZHAO ErMeng;JI YunKai;CHEN LiTao(State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China;Schulich School of Engineering,University of Calgary,Alberta T2N1N4,Canada;SINOPEC Petroleum Exploration and Production Research Institute,Beijing 100083,China;CNPC Engineering Technology Research Company Limited,Tianjin 300451,China;Qingdao Institute of Marine Geology,Qingdao 266237,China)

机构地区：[1]中国石油大学(华东)深层油气全国重点实验室,青岛266580 [2]中国石油大学(华东)石油工程学院,青岛266580 [3]卡尔加里大学舒立克工程学院,阿尔伯塔T2N1N4,加拿大 [4]中国石化石油勘探开发研究院,北京100083 [5]中国石油集团工程技术研究有限公司,天津300451 [6]青岛海洋地质研究所,青岛266237

出　　处：《中国科学：物理学、力学、天文学》2024年第12期119-135,共17页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：中国石油大学(华东)深层油气全国重点实验室自主研究课题(编号:SKLDOG2024-ZYTS-09);国家自然科学基金重点项目(编号:52334002);青岛市自然科学基金(编号:23-2-1-227-zyyd-jch);中国石油天然气集团有限公司重大科技项目(编号:ZD2019-184-002)资助。

摘　　要：针对天然气水合物藏径向井充填辅助降压开发缺乏有效模拟手段的缺陷,首先对Tough+Hydrate软件进行了二次开发,分别建立了基质和充填区中的质量和能量守恒方程,并对离散裂缝方法进行了修正,形成了径向井充填辅助降压开发数值模拟方法.然后,对比了直井降压、水平井降压、径向井降压和径向井充填辅助降压4种开发方式的产能和物理场变化规律.最后,分析了产能影响因素并提出了提高产能的措施和方向.研究结果表明,径向井充填区可有效加快自由水和分解气的产出,进而大幅提高储层降压速率.但由于充填区中的多孔介质会对流体渗流产生阻力作用,径向井充填后相比于无充填时累产气量降低了17.6%.充填区直径和渗透率越大,降压开发产能越高,但充填区分支长度存在最优值.在保证作业安全的前提下,应使用大尺寸钻头和大粒径支撑剂,进而提高降压开发产能.In response to the lack of effective simulation methodologies for radial well filling-assisted depressurization in natural gas hydrate reservoirs,secondary development was conducted on the Tough+Hydrate software.Mass and energy conservation equations were established separately for the matrix and radial well filling zones,and the discrete fracture method was refined to devise a numerical simulation approach for radial well filling-assisted depressurization.Subsequently,a comparison was made of the production rates and physical field variation patterns of four development methodologies:vertical well depressurization,horizontal well depressurization,radial well depressurization,and radial well filling-assisted depressurization.Finally,an analysis of influencing factors was conducted,and strategies to enhance production rates were proposed.The findings indicate that the formation of high-conductivity channels post-radial well filling significantly expedites the release of free water and dissociated gas in the reservoir,thereby notably enhancing gas depressurization rates.Nonetheless,the presence of porous media post-filling exerts a resistance effect on fluid flow,resulting in a 17.6%reduction in cumulative gas production compared to scenarios without filling.Larger diameters and permeabilities in the filling zone correlate with higher gas production rates,albeit with an optimal lateral length for the filling zone.To ensure operational safety while enhancing productivity,larger drill bits and proppant particles should be used.

关 键 词：天然气水合物 径向井 降压开发 双重介质 数值模拟 

分 类 号：P744.4[天文地球—海洋科学]