北部湾盆地防塌型无固相有机盐钻井液技术

Technology of Solid Free Organic Salt Anti-sloughing Drilling Fluid in Beibuwan Basin

南海西部油田的北部湾盆地储层段地质情况复杂,夹层多,泥岩极易水化,钻井液体系维护难度大,难以兼顾井壁稳定与储层保护。以涠洲6-9/6-10油田为例,介绍了北部湾盆地储层段的地质概况和钻井液技术难点;介绍了研发的一种新型无固相有机盐防塌钻井液体系及其实验评价结果。该钻井液体系既有效解决了北部湾盆地复杂储层段砂泥岩互层井壁失稳的问题,又防止了储层污染,还降低了井下复杂情况的发生率。该技术为北部湾盆地的石油勘探开发提供了强有力的技术保障。

In the oilfield of western South China Sea, the geological situation is complicated in Beibuwan basin reservoir section with the interlayer, the mudstone is easy to be hydrated, the drilling fluid system maintenance is difficult, and it is hard to give consideration to both borehole stability and reservoir protection.Take WZ6-9 and 6-10 oilfields as the exam-ples, the paper introduces the geological situation in Beibuwan basin reservoir section and the difficult points in drilling fluid technology;also presents a new kind of solid free organic salt anti-sloughing drilling fluid system and the results of experimen-tal evaluation.This drilling fluid system is effective for solving the sand-shale interbed borehole instability in complex reser-voir section of Beibuwan basin, preventing the pollution of the reservoir and reducing the incidence of downhole accident. This technology provides a powerful technical support for the petroleum exploration and development in Beibuwan basin.