深水钻井条件下合成基钻井液流变性

目前合成基钻井液体系在深水钻井中应用比较广泛，其低温流动性也成为深水钻井中较受关注的问题。通过测定线性α-烯烃合成基钻井液在不同组成时的黏度-温度特性，研究了乳化剂种类、有机土加量、油水比以及钻井液密度等对合成基钻井液低温流动性影响，探讨了基油种类和黏度对油包水钻井液的黏度-温度特性影响。实验结果表明，乳化剂种类是影响线性α-烯烃合成基钻井液低温流动性的最主要因素，其次是有机土加量和油水比，而加重材料对合成基钻井液低温增稠程度影响较小；基油低温黏度是影响深水合成基钻井液体系黏度的重要因素。线性α-烯烃合成基钻井液较矿物油和气制油基钻井液具有更优的低温流动性，可以应用于深水钻井作业。

Rheological properties of the synthetic drilling fluid in deep-water drilling conditions

The synthetic drilling fluid system is currently widely applied in deep-water drilling operation.Meanwhile,the low temperature rheological property of the synthetic drilling fluid was one of the problems widely concerned in deep-water drilling.The present paper investigated effects of various factors,such as emulsifier types,organic clay addition,oil-to-water ratio and mud density,on the low temperature rheological property of the liner α-olefin synthetic drilling fluid by measuring its viscosity-temperature properties at different compositions.Then,the paper discussed the influence of base-oil types and viscosity on viscosity-temperature properties of the water-in-oil drilling fluid.The experimental results demonstrated that the low temperature rheological property of the liner α-olefin synthetic drilling fluid was significantly influenced by the emulsifier type,followed in turn by organic-clay addition and oil-to-water ratio,while weighting materials affected the low temperature rheological property of the synthetic drilling fluid much less.The low temperature viscosity of base oil was most decisive to the viscosity of the deep-water synthetic drilling fluid system.The liner α-olefin synthetic drilling fluid was superior to the mineral-oil-base and gas to liquid-base drilling fluids in low temperature flowability,being applicable to deep-water drilling operation.