Numerical study on improving the performance of a descaling tool for solving scale failure in oil and gas wellbore

Abstract

Mineral precipitation or scale formation in oil and gas wellbore is recognized as an obstacle to hydrocarbon recovery. A method using computational fluid dynamics for structure optimization of downhole descaling tools is presented in this paper. The effects of key parameters, such as the nozzle structure style, cone angle, and incidence angle on the descaling performance, are systemically investigated. Numerical results indicate that the cone nozzle has higher jet efficiency because of its smoother velocity and pressure changes, as well as less energy loss. Under the conditions considered, key parameters of the downhole descaling tool are optimized as an incidence angle of 10° and a cone angle of 14°. Furthermore, the numerical results are validated with experimental results, in which the average error between the experimental and numerical results is ∼7.1%. The proposed numerical approaches can accurately predict the jetting status, which consequently has technical guiding significance for the design of downhole descaling tools.