沁南地区煤层气井二次压裂技术研究  

Study on refrac technology of coalbed methane in southern Qinshui Basin

作　　者：张云鹏 张璐 李宇 李昀昀 赵战江 杨生文 ZHANG Yunpeng;ZHANG Lu;LI Yu;LI Yunyun;ZHAO Zhanjiang;YANG Shengwen(CNOOC Energy Development Co.,Ltd.,Engineering Technology Branch,Tianjin 300452,China;CNOOC(China)Co.,Ltd.,Tianjin Branch,Tianjin 300452,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司,天津300452 [2]中海石油(中国)有限公司天津分公司,天津300452

出　　处：《石油化工应用》2022年第2期72-77,共6页Petrochemical Industry Application

摘　　要：针对SZN区块大量煤层气井水力压裂后产能无法满足要求的现状,需要进行二次压裂改造,提高单井产量。然而,煤层气储层由于其结构的复杂性以及初次人工裂缝的存在、前期生产活动的扰动,其二次压裂过程裂缝产生的条件和扩展机制极为复杂,增产效果差异较大,改造效果无法令人满意。本文通过从地质、压裂、排采等多方面入手,对区块前期已施工二次压裂井进行分析,研究发现,在地质条件类似,井况完好,排采合理的情况下,二次压裂过程裂缝能否有效延伸、新裂缝形成与否;二次压裂前煤层地应力与原始地应力的变化情况是决定二次压裂改造效果的关键。两者与二次压裂后产量相关性规律明显,提出了新的二次压裂改造理念,通过大规模体积改造形成大规模新裂缝,结合区块前期施工经验优化二次压裂改造工艺参数,为煤层气二次压裂提供了新的技术方向,为区块低产井的提产稳产提供了新的技术途径。In view of the current situation that the productivity of a large number of coalbed methane wells in SZN block after hydraulic fracturing can not achieve the requirement,it is necessary to carry out refracturing treatment to improve the production of single well.However,due to the complexity of coalbed methane reservoir structure,the existence of primary hydraulic fractures and the disturbance of early production activities,the conditions and propagation mechanism of fractures in the refracturing process are very complex,the stimulation effect is quite different,and the production performance is not satisfactory.This paper analyzes the refracturing wells treated in the early stage of the block from the aspects of geology,fracturing,drainage and production.It is found that under the conditions of similar geological conditions,good well conditions and reasonable drainage and production,whether the fractures in the refracturing process can be effectively extended and whether new fractures can be formed.The change of coal seam in-situ stress and original in-situ stress before secondary fracturing is the key to determine the effect of refracturing.The correlation between the two and the output after refracturing is obvious.A new concept of refracturing treatment is proposed.Large scale new fractures are formed through large-scale volume transformation.Combined with the early hydraulic experience of the block,the treatment parameters of refracturing are optimized,which provides a new technical direction for the refracturing of coalbed methane and a new technical way for increasing and stabilizing the production of low production wells in the block.

关 键 词：沁南地区 煤层气 二次压裂 新裂缝 工艺参数 

分 类 号：TE357.11[石油与天然气工程—油气田开发工程]