高密度油基钻井液在威204H37-5井的应用

威204H37-5井是四川威远地区的一口页岩气水平井,三开油基钻井液使用密度大于2.15g/cm~3。通过正交实验优选了该井油基钻井液体系配方,并分析了各处理剂对钻井液性能的影响。研究了温度、油水比和CaCl_2浓度对不同密度油基钻井液性能的影响。研究发现,高密度油基钻井液受温度、油水比和CaCl_2浓度的影响程度比低密度大。数据表明,威204H37-5井高密度油基钻井液黏度和破乳电压控制得当,抑制性和封堵性较好,具有良好的性能。

Application of High-density Oil-based Drilling Fluid in Wei 204H37-5 well

Well Wei 204H37-5 was a horizontal shale gas well in Weiyuan, Sichuan. The density of the drilling fluid in8-1/2" section was greater than 2.15 g/cm~3. In this paper, the formulation of oil-based drilling fluid system was optimized by orthogonal experiment, and the influence of each treatment agent on the performance of drilling fluid was analyzed. The effects of temperature, oil-water ratio and CaCl_2 concentration on the performance of different density oil-based drilling fluids were investigated. The study found that high-density oil-based drilling fluids were more affected by temperature, oil-water ratio, and CaCl_2 concentration than low-density. The field data showed that the high-density oil-based drilling fluid viscosity and demulsification voltage of Wei 204 H37-5 well were well controlled, and the inhibition and plugging properties were good.