Influence of drilling mud pulsations on well cleanout efficiency

Abstract

Purpose. Determination of the influence of the non-stationary flow regime of the drilling mud on the efficiency of cleaning the wellbore in the annulus from drill cuttings. Methodology. The study on the carrying capacity of the drilling mud in a laboratory installation is carried out by simulating the process of its pulsations at different frequencies. The choice of the studied frequencies was made on the basis of previous studies. The evaluation of the influence of factors on the efficiency of rock removal was carried out using Latin experimental plans, which allowed us to evaluate the influence of the selected factors with a minimum number of experiments without losing the quality of the result. Findings. The influence of factors (mud flow rates, eccentric placement of the drill string, plastic viscosity of the drilling mud, pulsation frequency, rotation of the drill string) on the efficiency of cuttings removal along the annular space of the wellbore is analyzed. Three factors with the best interaction were found, which made it possible to build dependencies of their influence on the efficiency of rock removal on the surface. The effect of changing the frequency of pulsations of the drilling mud has been studied, and graphical dependences of their influence on the decrease in the volume of rock particles in the annular space have been obtained. Originality. Based on the results of experimental studies, the effectiveness of the impact of drilling mud pulsations on cleaning the well from rock particles has been proven. Practical value. The effectiveness of the use of drilling mud pulsations for hydrotransportation of cuttings along the horizontal section of the wellbore has been confirmed.