连续油管携氮气排液工艺理论研究

Theoretical study on liquid drainage technology with nitrogen by coiled tubing

王海涛 赵全民 李相方

WANG Haitao ZHAO Quanmin LI Xiangfang

中国石油大学石油工程教育部重点实验室，北京　102249 江汉石油管理局，湖北潜江　433124

Key Laboratory for Petroleum Engineering of the Ministry of Education, China University of Petroleum, Beijing 102249, China Jianghan Petroleum Group Corporation, Qianjiang 433124, China

井底积液是导致单井产量下降和储层污染的主要??因，如何实现积液井快速有效地排液复产是确保油气田开发及正常生产的关键。在重点分析现场采用的两种连续油管携氮气排液工艺方法及特点的基础上，提出了连续油管携氮气排液优化设计流程。针对其间歇流作业方式建立了最大排液指数模型，进一步阐述了最大平均采出液量、最小氮气注入量和最佳积液时间间隔的优化设计及应用。以连续油管代替普通作业管柱携氮气进行单井排液，其管柱起下方便，不受井型限制，注气点及注气速度灵活可控，作业周期短而效率高，对于深层及复杂结构油气井排液复产有重要的推广应用价值。

Bottom hole liquid loading is the primary factor leading to the reduction of single well production rate and reservoir pollution. So how to drain the bottomhole liquid rapidly and effectively is the key to ensure the normal development and production of oil and gas field. By analyzing two methods of liquid drainage technology widely adopted in the field, we put forward the optimization design process of liquid drainage with nitrogen by coiled tubing in this paper. In addition, according to the intermittent flow operation, we developed a maximum liquid drainage index model. Optimal design of maximum average produced fluid volume, minimum nitrogen injection rate and optimum time interval of liquid loading and their application were described also. In this technology coiled tubing is adopted instead of common operation string to drain the fluid with nitrogen. The technology has important populized values for the liquid drainage of deep and complex oil-gas wells due to these characteristics including convenience, no limitation of well pattern, flexible gas injection point and gas injection rate and short operation cycle.