气制油合成基钻井液研究与应用

The Study and Application of a GTL Based Drilling Fluid.

新型气制油合成基钻井液是一种以水滴为分散相,气制油为连续相并添加高效乳化剂、润湿剂、亲油胶体等配制而成的乳化钻井液。该钻井液基液黏度低,无多环芳烃,生物降解能力强,能满足环境保护要求。所配成的钻井液塑性黏度小、抑制性好、润滑性强,高温高压滤失量低,形成的泥饼质量好且完井时易被清除,岩心的渗透率恢复值高,储层保护效果好。该钻井液在渤海及印尼油田的应用效果好,在渤海油田的平均机械钻速较常规油基钻井液提高了30%,而在印尼油田的机械钻速则更高。

A new GTL based drilling fluid was formulated with water being the internal phase and GTL (gas-to-liquid) the continuous phase. Other necessary additives such as high performance emulsifiers, wetting agent and organophilic gel were added to improve the function of the fluid. The base fluid (GTL) has low viscosity and is highly biodegradable. There is no polycyclic aromatic hydrocarbon found in the base fluid. The prepared drilling fluid has low plastic viscosity and low HTHP filtration rate, and good lubricity. Mud cakes formed by this drilling fluid are easy to remove. Permeability recovery testing done on cores gives good results. This drilling fluid has been used in Bohai Bay area and in Indonesia, and average ROP was increased by 30% in Bohai Bay, and greater than 30% in Indonesia, compared with conventional oil based drilling fluids.