Analytical and Numerical Modeling of the Wall Scraper for Horizontal Wells

Abstract

Abstract Horizontal wells are being widely used with the increase of oil and gas demand and the development of extraction technology. During the drilling process of horizontal wells, cuttings are easily deposited on the bottom of the annulus to form cuttings bed due to the gravity, which may lead to safety accidents, such as, high friction and high torque, and pipe sticking. In recent years, downhole tools have been innovatively proposed to use to improve the hole cleaning efficient. There are many factors that affect the effectiveness of the downhole tools. This paper establish the model of the wall scraper and utilizes a Computational Fluid Dynamics (CFD) to obtain hole cleaning efficiency with different parameters. The simulations were conducted at steady state and the results for maximum cutting concentrations in the annulus were analyzed. The results shows that the flow rate, drillpipe rotation speed, cuttings size, and cuttings concentration have significant impact on cuttings transport. This study could provide theoretical support for the subsequent development and application of downhole tools.