摘要
为了确保ZS103井直径149.2 mm钻头在直径215.9 mm井眼内侧钻成功,针对该井侧钻井段水泥塞非均质、钻头与井眼尺寸差距大、地层硬、泵压高、排量受限、页岩易垮等侧钻难题,以内外水泥塞强度特性和不同侧钻技术为研究对象,前期采用弯接头侧钻方式,因外水泥塞质量差,弯接头点支撑力太弱,无法形成有效夹墙导致侧钻失败;分析了内水泥芯比外水泥环强度高的特点,下移支撑点,通过内水泥塞芯强度支撑钻头侧钻,利用弯螺杆比弯接头支撑点更接近钻头,改变侧钻方式,采用弯螺杆定向控时侧钻技术最终侧钻成功。研究结果表明:(1)侧钻前认真分析侧钻井段水泥塞质量、地层岩性特点、井眼尺寸等是确保侧钻成功的前提条件;(2)侧钻时严格控制好钻时、排量、工具面等关键参数的过程管控;(3)根据不同侧钻方式的特点和井眼环境,优选侧钻方式是侧钻成功的关键。结论认为:弯螺杆定向控时侧钻技术在小井眼大环空非均质水泥塞侧钻方面的成功应用经验值得进一步推广。
There exist many difficulties in the sidetracking of ZS103 well,such as heterogeneity in cementing plug,big dif-ference between drilling bit and borehole size,hard strata,high pump pressure,limited discharge,and easy shale collapse.So,not only strength characteristics of internal and external cementing plug but various sidetracking technologies were ana-lyzed to overcome these difficulties in order for the successful sidetracking with 149.2 mm bit in 215.9 mm borehole.Bend joint sidetracking was adopted in the early stage,and effective sandwich wall,however,could not be formed due to the ex-ternal cementing plug with poor quality and too feeble support at the joint,resulting that the sidetracking was in failure.Then,a nature that the strength of inner cement core is higher than that of outer cement sheath was analyzed.Thus,depen-dent on the other feature that the support point of bending screw was closer to drilling bit than that of bend joint,the side-tracking mode was changed by moving this point downward to sustain the sidetracking of drilling bit with the strength of in-ner cementing plug core.Eventually,the sidetracking was in success by virtue of directional time-controlled sidetracking technology with bending screw.Results show that(i)the prerequisite for ensuring successful sidetracking is to carefully an-alyze the quality of cementing plug,lithological characteristics in strata and borehole size at sidetracking segments before the sidetracking;(ii)principle parameters such as drilling time,discharge and tool surface shall be implemented strictly during the sidetracking;and(iii)the hinge to carry on successful sidetracking is to select a sort of sidetracking mode based on characteristics of different sidetracking approaches and wellbore environment.In conclusion,the technology of di-rectional time-control sidetracking with bending screw is worthy of intensive promotion to the cementing plug sidetracking with slimhole,large annulus and heterogeneity.
作者
贺立勤
黄兵
刘德平
李勇政
朱旭
刘风云
HE Liqin;HUANG Bing;LIU Deping;LI Yongzheng;ZHU Xu;LIU Fengyun(Chuandong Drilling Company,CNPC Chuanqing Drilling Engineering Company Limited,Chongqing 400021,China)
出处
《天然气技术与经济》
2023年第3期42-47,73,共7页
Natural Gas Technology and Economy
基金
中国石油集团川庆钻探工程有限公司科技研究项目“复杂条件下定向侧钻工艺技术研究”(编号:CQ2021B-F-16-3)。
关键词
ZS103井
非均质
小井眼
弯接头
弯螺杆
侧钻
ZS103 well
Heterogeneity
Slimhole
Bend joint
Bending screw
Sidetracking