摘要
页岩气井由于大规模压裂导致井筒完整性破坏而引起大量环空带压问题,严重影响页岩气井的安全生产。针对页岩气井环空带压问题,基于API RP 90-2环空带压临界控制值计算方法,考虑页岩气井储层压力、产量变化、腐蚀以及磨损等因素,分析实际生产中环空各组件承压能力随服役时间的变化情况,建立了页岩气井环空带压临界控制值计算方法及环空带压控制图版,并进行了实例计算。研究结果表明,页岩气井环空带压临界控制值在服役早期主要受井口装置、技术套管承压能力影响,到服役后期时,随着腐蚀及地层压力降低,主要受油管薄弱点抗外挤强度影响,且随服役时间、腐蚀速率增加而不断降低,当环空带压控制值小于地层压力时,需要对环空压力值进行监测并采取相应措施,以保证现场安全生产。
Large scale fracturing of shale gas wells leads to the destruction of well integrity,a sustained annulus pressure problems,seriously affecting the safe production of shale gas wells.Aiming at the problem of annular pressure in shale gas wells,based on the calculation method of critical control value of annular pressure in API RP 90-2,considering the factors such as formation pressure,production change,corrosion and wear of shale gas wells,the change of pressure bearing capacity of each annulus component with service time in actual production is analyzed,the calculation method of critical control value of sustained annular pressure and its control chart are established in this paper,and an example is given.The results show that the critical control value of annular pressure in shale gas well is mainly affected by the pressure bearing capacity of wellhead device and technical casing in the early stage of service.In the late stage of service,with the decrease of corrosion rate and formation pressure,it is mainly affected by the external extrusion strength of weak point of tubing,and it decreases with the increase of service time and corrosion rate.When the control value of annular pressure is less than formation pressure,it is necessary to monitor the sustained annulus pressure value and take corresponding measures to ensure the safety of production on site.
作者
张智
丁剑
赵苑瑾
邓虎
卢齐
ZHANG Zhi;DING Jian;ZHAO Yuanjin;DENG Hu;LU Qi(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Drilling&Production Technology Research Institute,CNPC Chuanqing Drilling Engineering Co.Ltd.,Guanghan,Sichuan 618300,China)
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2019年第6期155-164,共10页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家科技重大专项(2016ZX05026-002
2016ZX05028-001-006)
高等学校学科创新引智计划(111计划)(D18016)
中国石油科技创新基金(2017D-5007-0315)
关键词
环空带压
磨损
环空带压管控
页岩气井
安全图版
sustained annular pressure
wear
sustained annular pressure control
shale gas well
safety plate
