摘要
注完水泥后因水泥浆体积收缩和胶凝产生失重导致地层流体窜流仍然是影响固井质量重要原因之一。分析了目前固井防窜存在的问题,阐述了井口脉冲加压防窜固井技术的基本原理和关键问题。建立了井口脉冲压力在环空中的传播规律及环空流体在脉冲压力作用下运动幅度的数学模型,并通过实例分析了初始脉冲压力大小、水泥浆初切力和环空流体综合压缩系数等对环空中脉冲压力衰减和流体运动幅度的影响规律。研究表明,脉冲加压防窜固井技术是可行的,通过施加较小的压力脉冲可使环空水泥浆往复运动,减少甚至消除因水泥浆体积收缩和失重所导致地层流体的窜槽,对提高固井质量有重要作用,研究可为脉冲加压装置的设计与工艺参数优化提供理论依据。
Formation fluid migration after cementing as hydraulic pressure loss due to cement slurry shrinkage and gelatinization weightlessness is the one of main causes to effect cementing quality.Firstly,the problems existent in cementing anti-migration were put forward,and then the principle and key factors about anti-migration cementing technology with wellhead pulse pressurizing were introduced.Thereafter,mathematical mode of pulse pressure transmitting along well annuli and maximum fluids movement amplitude with pulse pressure were established.Meanwhile,according to an example,the influence of pressure pulsing range,initial shear stress of cement slurry and the compression factors of whole annular fluid on pulse pressure attenuation and annular fluid displacement were studied.The investigation showed that the wellhead pulse pressurizing technology for anti-migration cementing was feasible.Annular cement slurry can move up and down under a small pressure pulse.Therefore,formation fluid migration after cementing would be decreased,or even eliminated by the means of wellhead pulse pressurizing,and cementing quality would be also improved.The study will be helpful to pulse pressurizing device design and parameters optimization.
出处
《钻采工艺》
CAS
北大核心
2008年第1期40-43,151-152,共4页
Drilling & Production Technology
基金
中国石化集团公司项目(JP01022)资助
关键词
脉冲压力
固井
水泥浆
防窜
失重
Pulse pressure,cementing,cement slurry,anti-migration,weight loss
