煤层气水平井钻井液优化技术探讨

Technology optimization of coal seam gas horizontal well drilling fluid

煤层气多分支水平井具有单井产量高、生产周期短、采收率高、生产井场占地面积小的特点,但我国煤层地质条件较为复杂,开采问题的关键是煤层钻井井壁稳定。实验室内在水包油钻井液体系中加入不同种类和用量的乳化剂、油水比和增黏剂以及不同种类和用量降滤失剂和流变性调节剂并对其进行优选,并优选出了油水比分别为4:6、5:5和6:4的水包柴油钻井液配方和油水比为4:6的水包原油钻井液配方。该低固相水包油钻井液具有密度低、润清性好、滤失量低、稳定性好等特点,且具有良好的抗阻、抗污染能力,配制简单,密度和流变性易于控制。

CBM multi branch horizontal well has high single well production, short production cycle, high recovery ratio,production site covers an area of small,but the geological condition of coal seam in our country is relatively complex,the key problem is the coal mining borehole instability.With different types and amount of emulsifier in the laboratory internal oil in water drilling fluid system in,oil-water ratio and tackifier and different types and amount of filtrate reducer and rheology regulator and optimize,and optimized the oil-water ratio was4：6,5：5 and 6：4 of water in diesel oil drilling fluid formula and oil-water ratio of 4：6 of the crude oil in water drilling fluid formulation.The low solid oil in water drilling fluid with low density,good lubrication,low filter loss,good stability and so on,and has good anti depression,anti pollution ability, simple preparation,density and rheological property is easy to control.