沾北3-5区块水平井石炭二迭系地层钻井技术

Horizontal well drilling technology in Permo-carboniferous formation of Zhanbei Block 3-5

沾北3-5区块为胜利油田于2008年在义东油田投入水平井开发的新区块,为石炭、二迭系地层。由于石炭系地层煤层及碳质泥岩发育、水平井段特殊,在沾北3-平51井的施工中已发生地层严重坍塌造成被迫填井侧钻,二迭系目的层掉牙轮、井漏等事故。针对沾北3-5区块石炭二迭系的地质情况,在后续施工的2口水平井中采取了一系列工程技术措施,并应用胺基铝强抑制钻井液体系有效地解决了石炭系煤层及碳质泥岩的坍塌问题,为今后在易坍塌地层水平井施工提供了借鉴。

Block 3-5 in Zhanbei area is a new block put into horizontal well production in Yidong Oilfield of Shengli in 2008. Horizontal wells are drilled to develop the Permo-Carboniferous reservoir.Due to the abundance of the Carbonaceous shale and the coal layers in Carboniferous Formation,plus the peculiarity of horizontal well,some serious downhole accidents occurred such as caving in, sidetrack,bit leg lost and leakoff in pay zone.A series of engineering and drilling fluid measures have been taken during the subsequent drilling operation of two horizontal wells.The high performance aluminum-amine water base drilling fluid effectively resolves the cavingin problem of the coal layers and carbonaceous shale in Carboniferous Formation,and a new anti-caving-in kind of mud system is produced.