摘要
为了实现中石化川西气田钻井工程整体提速提效的目的,以前期已完钻的四川盆地川西气田彭州海相区块的9口井为研究对象,主要分析了超深水平井随钻轨迹控制技术的影响因素。研究结果表明:①川西海相三叠系雷口坡组碳酸盐岩气藏平均埋深超过了6000 m、岩石致密、可钻性差,三叠系小塘子组地层异常高压,多套压力系统同存,安全窗口较窄,井漏问题突出,部分“喷漏同存”地层采用简化钻具组合施工,又增加了轨迹控制难度;②二开造斜点深,裸眼段长达3000 m左右,摩阻扭矩大,对钻具抗拉、抗扭强度及钻井液性能要求高,且因施工周期长,钻井液长时间浸泡后易发生井壁失稳,增加了施工风险;③三开储层雷口坡组局部区域破碎严重,井壁易垮塌,井下状况复杂,同时旋转导向工具抗温性、抗震性不足,故障率高,轨迹控制难度大。结论认为,所形成的川西气田超深水平井轨迹控制技术有助于该区实现钻井提速提效的目标。
In order to increase the drilling speed and efficiency in western Sichuan gasfield subordinated by Sinopec,9 drilled wells in Pengzhou marine block were taken as objectives to analyze some factors influencing trajectory control while drilling ultra-deep horizontal wells.Results show that(1)for most carbonate gas reservoirs of the Triassic Leikoupo Forma⁃tion in western Sichuan Basin,their burial depth is over 6000 m on average and their rocks are tight with poor drillability.Furthermore,the Triassic Xiaotangzi Formation with abnormal high pressure is characterized by multiple pressure system,narrower safety window,and serious circulation loss.After an application of the simplified bottom hole assembly(BHA)to certain strata where blowout and circulation loss coexist,there is more difficulty in trajectory control;(2)as for the second section,the kick-off point is deep,the openhole interval is as long as about 3000 m,and the torque and drag are large,so it needs higher requirement in both tension and torsion strength of drilling tools as well as drilling-fluid properties.What's more,because of long construction cycle,wellbore instability tends to occur after being soaked in drilling fluid for a long time,which may increase construction risk;and(3)part Leikoupo reservoirs of the third section are broken seriously,bring⁃ing about collapse wellbore and downhole complexity.Meanwhile,rotary steerable tool is not good enough in temperature resistance and mechanical shock tolerance,resulting in a higher failure rate and more difficulty in trajectory control.In conclusion,the technologies of trajectory control developed for ultra-deep horizontal wells in western Sichuan gasfield are conducive to achieving the goal to increase the drilling speed and efficiency.
作者
陈瑶棋
杨洁
何焱
CHEN Yaoqi;YANG Jie;HE Yan(Southwest Measurement and Control Company,Sinopec Matrix Corporation,Chengdu,Sichuan 610100,China;No.1 Drilling Company,Sinopec Southwest Petroleum Engineering Co.,Ltd.,Chengdu,Sichuan 610100,China;Sichuan Changning Gas Develop-ment Co.,Ltd.,Chengdu,Sichuan 610051,China)
出处
《天然气技术与经济》
2021年第4期52-56,共5页
Natural Gas Technology and Economy
关键词
川西海相
破碎地层
超深水平井
轨迹控制
Marine stratum in western Sichuan Basin
Broken stratum
Ultra-deep horizontal well
Trajectory control.
