塔深1井寒武系地层钻井技术

Drilling Technique of Well Tashen-1 in Cambrian Formation

塔深1井是探索塔河油田深层寒武系—奥陶系地层的第一口重点探井。该井钻进寒武系地层时首先采用了随钻扩孔技术,由于钻具受力复杂,发生了掉钻头事故,回填侧钻后,井斜角增大至7.20°,在采用常规钻具组合纠斜无效的情况下,采用了井下动力钻具进行纠斜,井斜得到控制并钻至井深8 408 m。针对寒武系地层易发生坍塌、井温高的情况,选用抗高温聚磺钻井液体系,采用稠浆段塞携砂技术,解决了超深井段(大环空、钻井液密度低、高压耗、低返速)携砂困难的问题。详细介绍了塔深1井寒武系地层的钻进情况和所采用的工艺技术。

Well Tashen-1 is the first key exploration well to explore formations from Cambrian to Ordovician in Tahe Oilfield.Reaming-while-drilling technique was used in Cambrian formation.A drill bit lost accident occurred due to the complex downhole forces so the sidetrack was used.After sidetracking,the hole inclination was increased up to 7.20°.After the failure of the conventional bottom hole assembles in recovering the wellpath,a downhole mud motor was used to 8408m within the expected inclination angle.Considering the high bottom hole temperature and that wellbore collapse due to stress,the difficulty problem of cutting transport in ultra-deep well（large annulus,low drilling fluid density,high pressure loss,and low annular velocity） was solved using the high temperature polysulphonate drilling fluid combined with thick mud for cuttings transportation. This paper described in detail the drilling process and drilling techniques in used in Cambrian formation.