摘要
积液是含水气井的常见问题,也是导致气井产量和生产效益下降的主要因素,及时对气井井筒积液情况进行诊断并计算积液高度是后续生产措施设计与实施的基础。目前国内外计算积液高度的方法或较为单一,不易得到准确、可靠的结果,或需要进行井下压力测试,费时费力,经济效益差,也不能满足目前油气田智能化、信息化建设的需要。针对该问题,从气井积液规律和井筒气液分布状态出发,基于"U"型管原理和井筒流体的压力平衡,研究了井筒中油管与油套环空内气液两相流动机理,建立了气井井筒积液高度计算模型,实现了基于地面实时监测资料的油管中积液高度的计算和积液液面的确定,并经现场10口井的实测数据检验,积液液面深度的平均绝对误差为39. 67 m,积液液面深度的平均相对误差为2. 02%,积液高度的平均绝对误差为39. 67 m,平均相对误差为12. 71%,能够满足工程计算的需要,为气井排水采气工艺优选与生产参数优化提供依据。
Liquid loading is a common problem in water-producing gas wells,which is also a main cause of decline in gas well production rate and productivity benefit. Real-time diagnosis of gas wells and correct calculation of liquid loading height are the basis for the design and implementation of subsequent production stimulation measures. At present,the existing domestic and foreign methods for calculating liquid loading height are either too simple to get accurate and reliable results,or needing downhole pressure test,which is time-labor consuming with a poor economic benefit and can not meet the requirements of intelligentization or digitization in current oil and gas fields. Based on the situation,the gas-liquid two-phase flow mechanism in both oil tubing and casing-tubing annulus was studied on the law of liquid loading in gas well and the gas-liquid distribution state in wellbore. Based on the " U"-shaped pipe principle and the pressure balance of the wellbore fluid,a calculation model of the liquid loading height in the gas well was established,realizing the calculation of the liquid loading height in the tubing and the determination of the liquid loading level based on the ground real-time monitoring data. According to the field test data of 10 wells,the average absolute error of the depth of liquid loading is 39. 67 m,the average relative error is 2. 02%,and the average absolute error of the height of liquid loading is39. 67 m,the average relative error is 12. 71%. The results meet the requirement of engineering calculation and can provide references for gas extraction and drainage process optimization as well as production parameter optimization.
引文
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