复杂井眼轨迹条件下的钻井液技术

Drilling Fluid Technology in Complicated Bore Hole Trajectories

TK330井是塔河油田一口简化井身结构的长裸眼深井,完钻井深为5390m,裸眼井段长达4385.51m。该井在钻进过程中由于井斜和方位变化导致井眼轨迹异常,钻具入井后因扭曲变形上贴下靠井壁严重,摩阻和扭矩增大,极易发生卡钻,且由于裸眼跨度大,钻遇地层复杂,钻井液施工难度大。在1004.49～4400m井段选用低固相强包被不分散钾基聚合物钻井液,在4400～5390m井段选用抗高温、抑制性强、防塌能力好、性能易于控制的聚合醇防塌聚磺钻井液,并配合了有效的钻井液技术措施。现场应用结果表明,合理的技术措施及良好的钻井液性能,有效地解决了钻进过程中地层掉块、垮塌、岩屑携带及阻卡问题,起下钻畅通,井底干净无沉砂,3次测井、下套管均一次成功,双级固井施工顺利;二开井段平均井径扩大率仅为0.53%,全井段没有发生井下复杂情况。

Well TK330,a long open hole deep well,with its casing program simplified,was drilled to a depth of 5390 m and an open hole length of 4385.51 m.Bore hole trajectory had been distorted because of unexpected changes in ell angles and azimuth.Friction and drag were increased.Drilling fluid engineering became very difficult.Based on the analyses of downhole conditions,a low solids inhibitive potassium mud was selected for use in 1 004.49-4 440 m,and a poly glycol/polymer/sulfonate mud for use in 4 400-5 390 m.Combined with sound drilling fluid technology,the well was successfully completed.No drilled cuttings were found at the bottom of the hole.Electric logging and casing running were all smoothly done,and average hole washout in the second interval was only 0.53%.