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一种可以提高钻井性能的新技术已在理论上和实践中得到证实。该技术取得的进步在于应用一种能够精确论证井底压力、流量、动能的模型,因此,可以迅速估算不同钻柱、不同井眼几何尺寸以及气体流量。该模型论证了在钻头之上将一部分气体分流转入井眼的作用。一种新的工具——井下空气分流器安装在钻柱上,可以根据模型的模拟,精确分流最适宜的气体流量。应用这种新技术控制钻头处的井底压力的结果是,通常由于摩擦而损失的能量可以转化为有利因素,可以降低地面压缩气体的费用、减少井眼冲蚀、提高机械钻速、延长钻头寿命、提高钻达总井深的成功率,而不会转化为不可压缩流体。压力波动效应(文丘里效应)一般用于在地面从井口脱气,在井底也可以产生压力波动效应以降低井底环空压力。通过这种方式降低井底压力后,可用较少的空气和较低的摩擦提高气体流量。该技术已成功地应用于现场不同条件的井眼,提高了机械钻速,增强了井眼稳定性,延长了钻头寿命,降低了总成本。
A new technique that can improve drilling performance has been proven both in theory and in practice. The advancements made in this technology are based on the application of a model that accurately demonstrates bottomhole pressure, flow, and kinetic energy so that different drill string geometries and different borehole geometries and gas flows can be quickly estimated. This model demonstrates the role of diverting part of the gas into the wellbore above the drill bit. A new tool, the downhole air diverter, is mounted on the drill string to accurately divert the most appropriate gas flow based on model simulations. The result of using this new technology to control bottom hole pressure at the bit is that the energy normally lost due to friction can be converted into favorable factors that can reduce the cost of compressed gas on the ground, reduce wellbore erosion, increase ROP, extend drill bit Life expectancy, increase the drilling success rate of total well depth, and will not be transformed into incompressible fluid. The pressure fluctuation effect (Venturi effect) is generally used to degas the wellhead from the ground and can also create pressure fluctuation effects at the bottom of the well to reduce the downhole annular pressure. By reducing the bottom hole pressure in this way, the gas flow rate can be increased with less air and lower friction. The technology has been successfully applied to different conditions of the borehole on site, to improve the ROP, enhance the stability of the borehole, extending bit life, reducing the total cost.