BH-WEI抗三高钻井液技术在克深2-1-14井的应用

Application of BH-WEI Three-high Drilling Fluid in Well Keshen2-1-14

克深2-1-14井位于塔里木油田山前构造带,由于地层倾角大,压力系数高,盐层厚度大,使得钻井时极易发生井壁垮塌,石膏、膏泥岩吸水膨胀等多种复杂问题,极大地制约了钻井提速。因此,针对克深2-1-14井钻井液技术难点,结合其地层特点和岩性理化特性,研究和优化了BH-WEI抗三高钻井液技术。现场应用表明,该钻井液体系具有优良的防塌防垮性能和润滑能力,完全能够满足该区块易垮、高温高压高密度、大段复合盐层、喷漏同层等特点的钻进需要,有效的改善了井壁的失稳程度,抑制了盐膏层"软泥岩"蠕变,同时该体系优良的流变性解决了窄压力窗口条件下的压力平衡问题,单井事故复杂率降为1.7%,钻井速度同比提高30%以上,大幅度降低了勘探开发成本。

Keshen2-1-14 well is located in the piedmont area of Tarim Basin. High inclination angle, high pressure coefficient and thick salt bed make the problems occur easily, such as wall collapsing, gypsum and mudstone swelling, which restricts the drilling speed greatly. Therefore, according to the drilling fluid difficulties, formation conditions and physical and chemical characteristics of rock, BH-WEI three-high drilling fluid was researched and optimized. Field application showed that BH-WEI drilling fluid system has excellent anti-collapse performance and lubricating ability, which can absolutely meet the drilling needs, such as collapse, high temperature and high pressure and high density, multiple salt layer, blowout and loss in the same layer, and so on. It can improve the instability of the well effectively and repress the creep of salt and gypsum layer. Furthermore, the good rheological property can solve the pressure balance problem under the condition of narrow window, making the single well accident rate drop to 1.7% and the drilling speed increase by more than 30%, which will reduce the exploration and development costs significantly.