孔隙-裂缝性漏失层防漏堵漏技术

本文针对LZ地区地质特征,在分析钻井井漏的基础上,以架桥性材料有机智能可变形堵漏剂SY-5和膜承压材料双膜承压处理剂SY-20复配,探讨既能封堵孔隙-裂缝性地层漏失,又能适当提高地层承压能力的钻井液技术及施工工艺。实验结果表明:加入SY-5和SY-20后,钻井液的流变性能变化不大,但降滤失性能明显提高,加入1.5%SY-20+2.5%SY-5后,钻井液的API和HTHP滤失量分别从20.0 mL和38 mL降为8.5 mL和14 mL;SY-5与SY-20复配使用后能有效建立封堵膜,而且一旦形成就不会有钻井液漏失,砂床的承压强度由0提高到10 MPa,岩心承压强度由3.2 MPa提高到25 MPa。使用该技术在LZ地区孔隙-裂缝性发育的易漏失井段进行现场应用,安全钻井液密度由1.10 g/cm3提高到1.20 g/cm3,显著提高了地层的承压能力,解决了LZ地区沙河街组生物灰岩地层漏失技术难题。表3参3

The Research on Leak Protection and Sealing Technology of Porous-Fractured Leakage Bed

Considering the formation characteristics of LZ area,the reason of leakage was concluded,and the formulation and process of the drill fluid,aimed at improving the sealing ability of the leakage and the bearing ability of porous-fractured formation,were probed by adding bimodal pressurization treating reagent SY-20 with organic,intellect and flexible bridging particles SY-5 to the common drillfluids.The results showed that the rheological properties of the drill fluids were not changed by the addition of the...