关键词: 定压差, 钻速模式, 影响系数, 统计分析, 中原油田, 井深, 压持效应, 计算模式, 影响规律, 钻头

Abstract: The bottomhole pressure difference is an important factor affecting the rate of penetration. Their quantitative relation is necessary both for optimizing drilling parameters and for predicting the rate of penetration. Statistic analysis and standardization is used to determine the effect of bottomhole pressure differentiel on ROP. All parameters other than the pressure differential are standardized by analyzing a large amount of fielb data in order to highlight the effect of pressure differential. A mathematic model is then developed to fit the curves obtainod from the field data. Field data indicate that the effect of bottomhole pressure differential on ROP decreases as the hole depth increases. A model regarding to the factor of the effect of bottomhole pressure differential on ROP versus well depth has been established based on the bit data from Zhongyuan Oilfield. By analyzing these data, it can be clearly seen that the effect of pressure differential on ROP varies with well depth. Therefore, the models generally used without considering well depth are not accurate.