考虑温度效应的高温高压直井井壁稳定性规律
|
摘要
海外A区块探井的高温高压井段因频繁发生井漏、卡钻等井下复杂情况,井壁不稳定,导致原井眼报废。根据经典的坍塌压力和破裂压力计算模型,钻井液安全密度窗口为0.2 g/cm3,但实际作业过程中发现在高温高压井段安全密度窗口更窄。由于温度变化产生的温变应力会对井壁稳定性造成影响,因此考虑井壁温度效应,探索了温度变化对高温高压直井井壁稳定性的影响。通过分析井壁附加温变应力场,建立了考虑温度效应的坍塌压力和破裂压力计算模型,发现了温度变化对井壁稳定性的影响规律。低温钻井液在高温地层循环产生的附加温变应力,使地层坍塌压力和破裂压力减小。该方法为该区块后续生产井的顺利实施提供了技术支撑,相比探井,钻井周期大幅缩短。考虑温度效应的地层坍塌压力和破裂压力计算模型,对今后窄安全密度窗口高温高压直井的井壁稳定性研究具有参考价值。
In the high temperature and high pressure section of exploration wells in Block A overseas often occurs complex downhole conditions such as leakage and sticking, resulting in unstable wellbore and abandonment of original wellbore. The safe window is determined to be 0.2 g/cm3 by classical wellbore stability analysis, but it is found that the safe window is narrower in high temperature and high pressure section during actual operation. After consulting the literature, it is found that the temperaturedependent stress produced by temperature change will affect the wellbore stability. Therefore, this paper takes the wellbore temperature effect into account and explores the influence of temperature change on the wellbore stability of high temperature and high pressure wells. Through the analysis of the additional temperature-dependent stress field on the borehole wall, the calculation model of collapse pressure and fracture pressure under the coupling effect of temperature and pressure is established. The influence of temperature change on the stability of the borehole wall is found. The additional temperature-dependent stress generated by the circulation of low temperature drilling fluid in the high temperature formation reduces the formation fracture pressure and the collapse pressure. The conclusion supports the successful implementation of the follow-up production wells in this area, which greatly reduces the working time of exploration wells. The calculation model of formation collapse pressure and fracture pressure under the coupling action of temperature and pressure established in this paper has reference value for the future study of sidewall stability of high temperature and high pressure wells with narrow density windows.
In the high temperature and high pressure section of exploration wells in Block A overseas often occurs complex downhole conditions such as leakage and sticking, resulting in unstable wellbore and abandonment of original wellbore. The safe window is determined to be 0.2 g/cm3 by classical wellbore stability analysis, but it is found that the safe window is narrower in high temperature and high pressure section during actual operation. After consulting the literature, it is found that the temperaturedependent stress produced by temperature change will affect the wellbore stability. Therefore, this paper takes the wellbore temperature effect into account and explores the influence of temperature change on the wellbore stability of high temperature and high pressure wells. Through the analysis of the additional temperature-dependent stress field on the borehole wall, the calculation model of collapse pressure and fracture pressure under the coupling effect of temperature and pressure is established. The influence of temperature change on the stability of the borehole wall is found. The additional temperature-dependent stress generated by the circulation of low temperature drilling fluid in the high temperature formation reduces the formation fracture pressure and the collapse pressure. The conclusion supports the successful implementation of the follow-up production wells in this area, which greatly reduces the working time of exploration wells. The calculation model of formation collapse pressure and fracture pressure under the coupling action of temperature and pressure established in this paper has reference value for the future study of sidewall stability of high temperature and high pressure wells with narrow density windows.
引文
[1]刘玉石,周煜辉,黄克累.井眼温度变化对井壁稳定的影响[J].石油钻采工艺,1996,18(4):1-4.
[2]何湘清,刘向君,罗平亚.温度扰动对井壁稳定和油田开发的影响[J].天然气工业,2003,23(1):39-41.
[3]丁乙,梁利喜,刘向君,等.温度和化学耦合作用对泥页岩地层井壁稳定性的影响[J].断块油气田,2016,23(5):663-667.
[4]张培丰.地层温度对科学超深井井壁稳定的影响[J].探矿工程(岩土钻掘工程),2011,38(10):1-5.
[5] DUSSEAULT M B. Stress changes in thermal operations[R]. SPE25809,1993.
[6]胜亚楠,管志川,许玉强,等.井壁稳定问题的不确定性分析方法探讨[J].断块油气田,2017,24(6):847-850.
[7] MAURY V,IDELOVICI J L. Safe drilling of HP/HT wells,the role of the thermal regime in loss and gain phenomenon[R]. SPE 29428,1995.
[8] CORRE B, EYMARD R, GUENOT A. Numerical computation of temperature distribution in a wellbore while drilling[R]. SPE 13208,1984.
[9] CHEN G,EWY R T. Thermoporoelastic effect on wellbore stability[J].SPE Journal,2005,10(2):121-129.
[10]刘奎,高德利,曾静,等.温度与压力作用下页岩气井环空带压力学分析[J].石油钻探技术,2017,45(3):8-14.
[11] NGUYEN D A,MISKA S Z,YU M,et al. Modeling thermal effects on wellbore stability[R]. SPE 133428,2010.
[12]王江帅,李军,柳贡慧.循环钻进过程中井筒温度场新模型[J].断块油气田,2018,25(2):240-243.
[13]洪国斌,陈勉,卢运虎,等.川南深层页岩各向异性特征及对破裂压力的影响[J].石油钻探技术,2018,46(3):78-85.
[14] AKONG B,DOSUNMU A,LONNA U,et al. Geomechanical modeling of thermal effects on wellbore stability using the thermo-poro-elastic model in HPHT wellbores[R]. SPE 150771,2011.
[2]何湘清,刘向君,罗平亚.温度扰动对井壁稳定和油田开发的影响[J].天然气工业,2003,23(1):39-41.
[3]丁乙,梁利喜,刘向君,等.温度和化学耦合作用对泥页岩地层井壁稳定性的影响[J].断块油气田,2016,23(5):663-667.
[4]张培丰.地层温度对科学超深井井壁稳定的影响[J].探矿工程(岩土钻掘工程),2011,38(10):1-5.
[5] DUSSEAULT M B. Stress changes in thermal operations[R]. SPE25809,1993.
[6]胜亚楠,管志川,许玉强,等.井壁稳定问题的不确定性分析方法探讨[J].断块油气田,2017,24(6):847-850.
[7] MAURY V,IDELOVICI J L. Safe drilling of HP/HT wells,the role of the thermal regime in loss and gain phenomenon[R]. SPE 29428,1995.
[8] CORRE B, EYMARD R, GUENOT A. Numerical computation of temperature distribution in a wellbore while drilling[R]. SPE 13208,1984.
[9] CHEN G,EWY R T. Thermoporoelastic effect on wellbore stability[J].SPE Journal,2005,10(2):121-129.
[10]刘奎,高德利,曾静,等.温度与压力作用下页岩气井环空带压力学分析[J].石油钻探技术,2017,45(3):8-14.
[11] NGUYEN D A,MISKA S Z,YU M,et al. Modeling thermal effects on wellbore stability[R]. SPE 133428,2010.
[12]王江帅,李军,柳贡慧.循环钻进过程中井筒温度场新模型[J].断块油气田,2018,25(2):240-243.
[13]洪国斌,陈勉,卢运虎,等.川南深层页岩各向异性特征及对破裂压力的影响[J].石油钻探技术,2018,46(3):78-85.
[14] AKONG B,DOSUNMU A,LONNA U,et al. Geomechanical modeling of thermal effects on wellbore stability using the thermo-poro-elastic model in HPHT wellbores[R]. SPE 150771,2011.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |