摘要
海上油田热采井多为224.5 mm水平井,井身结构复杂,作业环境苛刻,目前主要采用的井筒隔热方式相对单一.卡瓦式封隔器结构比较复杂,在解封过程中如果操作不当,可造成卡瓦断裂或落井,甚至引起卡井事故.为此,研制了RX361-210型热敏封隔器.该封隔器依靠热胀剂受热膨胀实现坐封,采用组合密封件以及锁紧装置增强密封性能,利用密封件随着温度的降低收缩,上提管柱实现解封.利用模拟试验井系统开展了室内试验.试验结果表明:封隔器坐封温度200 ℃,耐温350 ℃,耐压21 MPa,解封力25~35 kN,可多次坐封,且密封性能不受温度交变的影响.该封隔器坐封灵敏,解封安全,密封性能良好,在海上稠油热采方面具有良好的推广应用前景.
Abstract
Most of thermal recovery wells in the offshore oilfield are 224.5 mm horizontal wells with complex wellbore configuration and harsh operation environment.The current wellbore heat insulation method is only "heat insulation tubing+annulus nitrogen injection".Commonly used slip-type packer structure is complex.If operation is not properly handled, slip fracture or fall and even well accident may occur.In view of this, RX361-210 type heat-sensitive packer has been developed.The packer expands and get set depending on the thermal expansion agent.Composite seal elements and locking device were used to enhance the sealing performance.The seal elements shrink with the decrease of temperature, then pulling the string to achieve release.The simulation test well system was used to conduct indoor test.The test results showed that the packer has a setting temperature of 200 ℃, the temperature rate of 350 ℃, the pressure rate of 21 MPa and the releasing force of 25~35 kN.Multiple setting could be allowed and the sealing performance is temperature-independent.The packer, with easy setting, safe releasing and good sealing performance, has a good application prospect in the offshore thermal recovery of heavy oil.
基金项目
国家科技重大专项"大型油气田及煤层气开发"之子课题(2016ZX05058-003-009)
NETL
NSTL
维普
万方数据