Studying joint influence of a number of factors on borehole cleaning

Abstract

Studying the behavior of cuttings transport under various conditions using experimental observations and computational fluid dynamics is the main method for analyzing the influence of cuttings, fluid and operating parameters on well cleaning. Despite the existing abundant models and recommendations of researchers, still there are problems with the accuracy of determining the cuttings layer height, critical velocity and other key parameters, which complicates the task of effective solution of the problem of borehole cleaning. The purpose of the study is to analyze the models obtained via the organization of a full factorial experiment and variance analysis to identify the influence of such factors as viscosity and flow rate of the drilling fluid in the annular space and the inclination angle of the well on the degree of cuttings transport. The studies of the kind are carried out using special devices called flow loops. Experimental data were taken from literature sources. To organize a full factorial experiment, the data of the dependent variable were combined into a combinational square, which simplified the coding of factor values. After setting the full factorial experiment, the models were obtained that made it possible to assess the contribution of the studied factors to the process of destruction product removal within the intervals determined while setting the research tasks. The obtained models allowed to determine the influence degree of each of the factors on the process under investigation. The results of the succeeding analysis of variance confirmed the indicated degree of influence and determined the rank of each of the factors in percentage.