摘要
查302井是位于松辽盆地南部长岭断陷查干花次凹缓坡带构造的一口重点评价井,该井三开营城组凝灰岩发育,实钻过程中在3686 m、3726 m、3955 m分别发生失返性漏失,常规堵漏作业失效。针对该井凝灰岩地层承压能力低,漏点多,常规堵漏方式提高地层承压能力效果差的问题,室内研制了固结堵漏配方,当温度为150℃时,固结时间缩短至9.8 h,承压压力为15.8 MPa,固结堵漏浆悬浮稳定性强,满足现场施工要求。现场应用表明,承压过程压力两次明显下降后缓慢上升,最高开泵压力达到16.2 MPa,扫塞后井底当量密度达到1.38 g/cm^(3),提高了凝灰岩地层的承压能力,为区块开发提供了新的堵漏技术思路。
Well Cha-302 is a key appraisal well located in a gentle slope belt structure in the south of the Songliao Basin.This well penetrated in the third interval the Yingcheng formation which is developed with tuff into which mud is easy to lose.During drilling,lost circulation was encountered several times at depths 3,686 m,3,726 m and 3,955 m.When drilling into the deeper Huoshiling formation,higher formation pressure required that the upper section be strengthened to increase the pressure bearing capacity to an equivalent density of more than 1.38 g/cm^(3).Since the tuff formation drilled has low formation pressure,the mud is easy to lose into this formation,and when mud losses happen,the conventional lost circulation control methods are unable to effectively control the mud losses.To overcome these difficulties,a low density cementable lost circulation slurry was adopted.Based on the severity of mud losses in different spots,the total concentration of the bridging agents,the ratio of the different particles and the cement strength of the lost circulation slurries were accordingly adjusted.For the three main points of mud losses,the formation strengths were gradually increased by a certain increment.The results of the field operation show that during formation strengthening,the pressure decreased twice significantly and then increased slowly,and finally the pump pressure reached 16.2 MPa.After drilling out the cement plug,the equivalent circulation density at the bottom was 1.38 g/cm^(3),and the lower Huoshiling formation was successfully drilled.This technique of controlling lost circulation is first used in the Chaganhua block in the south of the Songliao Basin,it effectively strengthens the tuff formation and provides a new technical clue for controlling mud losses.
作者
王立锋
WANG Lifeng(Liupu Drilling Branch,SINOPEC East-China Petroleum Engineering Co.,Ltd.,Zhenjiang,Jiangsu 212000)
出处
《钻井液与完井液》
CAS
北大核心
2024年第5期617-621,共5页
Drilling Fluid & Completion Fluid
基金
中国石化科技部科研攻关项目“多尺度裂缝储层保护钻井液研究与应用”(P2021-Z06)。
关键词
胶凝固结
堵漏
分级承压
树脂片
承压
Cement
Mud loss control
Stagewise strengthening
Resin flake
Formation strengthening
