气体循环钻井井口气量控制技术

Wellhead gas volume control techniques in gas circulation drilling

杨顺吉 柳贡慧 李军 徐自强 刘小静

YANG Shunji LIU Gonghui LI Jun XU Ziqiang LIU Xiaojing

中国石油大学石油工程学院，北京 102249 北京信息科技大学，北京 100058 长庆油田公司油气工艺研究院，陕西西安 710018 长庆油田公司油藏评价部，陕西西安 710018

Institute of Petroleum Engineering, China Petroleum University, Beijing 102249, China Beijing Information Science andTechnology University, Beijing 100058, China Oil and Gas Technology Research Institute of Changqing Oi.eld CO.,Xi’an 710018, China Reservoir Evaluation Department of Changqing Oil.eld CO., Xi’an 710018, China

以气体瞬变流理论为基础 , 结合地层渗流相关理论和气体循环钻井工艺原理建立了一套气体循环钻井井口气量控制的理论模型。模型根据气体在流动过程中应遵从的基本规律 ,描述了地层渗流和井口流体的各种运动特性以及动态压力平衡关系 ,详述了气体循环钻井钻遇气层时井口气量的控制方法。通过 Mac Cormack方法求解理论模型 , 利用数值模拟方法对气体循环钻井钻遇气层过程进行了系统的模拟计算和分析，研究结果对气体循环钻井钻遇气层进行动态过程的描述对指导现场施工具有现实意义。

Based on the theory of gas transient flow, a set of wellhead gas volume control theoretical models in gas circulation drill-ing are set up in combination with the formation porous flow and gas circulation drilling technique principles. According to the basic laws with which the gas flow should comply, various movement properties and dynamic pressure equalization relations of borehole fluid are illustrated, and the gas volume control method are comprehensively explained when taking gas circulation drilling technology to pen-etrate a gas zone. The Mac.Cormack method is adopted to solve the theoretical models, and numerical simulation is used to calculate and analyze the process of penetrating the gas zone. The results of study have a certain practical significance for the descriptions of dynamic process of penetrating gas zone using gas circulation drilling and the onsite application.