新型“三强”钻井液在磨溪气田快速钻井中的应用

APPLICATION OF NOVEL "3-REINFORCEMENT" DRILLING FLUID SYSTEM IN MOXI GASFILED FOR FAST DRILLING

磨溪气田长期以来由于地层的垮塌和多个油气层的存在,使其从311.2mm井段开始钻井液密度就一直居高不下,到完井时钻井液密度高达2.30g/cm3以上,严重地影响了该气田的钻井速度。为了加快对该气田的钻探,在经过大量的室内试验的基础上,形成了从无固相到低密度再到高密度的新型“三强”钻井液体系。实践证明,“三强”钻井液体系,从无固相转化到低固相再到高密度钻井液,工艺简单、技术可行,有利于钻井液费用的控制。通过多口井的应用见到了明显的效果,钻井速度得到了大幅度的提高,钻井周期大幅的缩短。

Due to the tendency of formation caving-in and the existence of several payzones, during the past years the drilling fluid density used in wells in Moxi gasfield was always adjusted high from the Φ311.2mm section downwards, up to 2.30g/cm3 or even higher when drilling to TD, which severely impeded the drilling speed in this gasfield. In order to quicken the exploratory drilling there, on basis of numerous experiments, a new drilling fluid system referred to as '3-reinforcement drilling fluid system' is developed, including no-solids, low-density, and high-density. The field application demonstrates this system can be converted from no-solids, to low-density, then to high-density with very simple operation, and technically feasible. It will be helpful for cost reduction. Remarkable improvements have been observed in application on several wells, the drilling speed has been improved largely, and the drilling cycle has been reduced by several times.