摘要
吉林油田CO2驱区块注气井当前普遍存在较高的环空持续带压现象。环空持续带压预示着井筒发生泄漏,井筒完整性受到削弱,这将对生产和环境带来一系列的危害。对环空压力测试曲线的诊断对评估、控制环空压力带来的风险具有重要意义。为了解决此问题,针对CO2注气井环空压力的形成,建立了相应的数学模型,研究了环空液柱压缩系数、侵入区域压力、气顶高度、水泥环渗透率以及泄漏点大小对环空带压的影响规律,从机理上分析了环空持续带压的原因,该数值分析方法,现场实践证明真实可靠。该方法可通过拟合现场实测数据,预测环空压力的发展趋势,并估计环空井筒泄漏的速度甚至泄漏的位置。
Sustained Casing Pressure (SCP) is common problem in the CO2 injection well of Jilin Oilfield. SCP indicated that the leakage existed in wellbore, the well integrity has been impaired, it would have adverse effect on production and environment. The diagnostic testing of annulus pressure is important to assess and control risk. To solve the problem, a corresponding mathematical mode was established based on the form of Casing Annulus Pressure of CO2 injection well, meanwhile, the influence laws of compressibility coefficient of annulus fluid, invaded area pressure, casing gas cap, cement permeability and size of leakage point on Casing Annulus Pressure were studied, and the reasons of SCP in annulus were analyzed. The numerical analysis method was proved that it could predict the development trend of casing annulus pressure and assess the leakage speed and leakage position by fitting the field pressure date.
出处
《钻采工艺》
CAS
北大核心
2011年第3期55-57,115-116,共3页
Drilling & Production Technology
基金
中国石油天然气股份有限公司重大科技专项“吉林油田CO2驱油与埋存关键技术研究”项目,项目编号(2009E-02)
关键词
CO2驱注气井
环空持续带压
井筒完整性
压力预测
injection CO2 well, sustained casing pressure, well integrity, pressure prediction
