井筒漏失对桥射联作施工的影响及对策  

Influence of wellbore loss on bridge plugging+perforation and countermeasures

作　　者：张秋冬 董拥军 马阔 王英杰 林鹏 ZHANG Qiudong;DONG Yongjun;MA Kuo;WANG Yingjie;and LIN Peng(Tianjin Company,China National Logging Corporation,Tianjin 300280,China;Huanding Energy Services,Beijing 102200,China)

机构地区：[1]中国石油集团测井有限公司天津分公司,天津300280 [2]北京环鼎科技有限责任公司,北京102200

出　　处：《天然气勘探与开发》2024年第1期97-103,共7页Natural Gas Exploration and Development

摘　　要：煤层气桥射联作施工中井筒漏失是影响工程质量、安全的重大风险点,基于从射孔基础理论研究与应用实践形成的认识,以及山西煤层气大量施工经验的总结,针对井筒漏失问题,结合工程事故复杂案例,进行模拟计算。结果表明:①井筒漏失速度过快导致桥塞座封时端面产生强烈的水击效应,可能导致电缆头弱点断脱,工具串落井;②井筒严重漏失产生的空井筒现象,极易导致投球失败及次生工程复杂。结论认为:①煤层气桥射联作施工中井筒漏失过程中套管内流体流速及井筒内液面高度的变化对泵送排量、桥塞坐封及井口投放可溶球等关键环节的施工安全均可能造成严重影响;②从漏失位置和漏失程度切入进行模拟计算,确定不同井况下的安全施工边界条件,有针对性地制订应对井筒漏失的对策,可以有效保证井筒漏失井桥射联作的施工安全。Wellbore loss is a significant risk threatening the quality and safety of bridge plugging+perforation in coal-bed methane(CBM).So,combined with complex engineering cases,some simulation was conducted on well-bore loss based on achieved awareness on perforation from basic theoretical studies and application practices,as well as numerous ex-periences from CBM operation in Shanxi Province.Results indicate that(i)the loss with too rapid velocity may lead to a strong wa-ter hammer effect on the end face of bridge plug during plug sitting,further to cause the weak point of cable he-ad to break off and downhole tools to fall into a well;and(ii)the phenomenon of empty wellbore induced by strong loss can eas-ily result in ball-drop failure and secondary engineering complexities.It is concluded that changes in both fluid flow rate in-side casing and liquid level in wellbore during bridge plugging+clustering perforation in CBM reservoirs in case of well-bore loss may seriously affect the key issues such as pumping rate,bridge plug sitting,and soluble ball drop at wellhead;and tak-en leakage position and degree into account,boundary conditions under safe operation are determined through simulation calcula-tion,and then countermeasures against wellbore loss are made,so that the safety of bridge plugging+perforation can be ensured.

关 键 词：井筒漏失 漏失位置 漏失速度 桥塞座封 投球 

分 类 号：TE257.1[石油与天然气工程—油气井工程]