Erosion prediction of bypass seat in oil well auto-fill equipment using CFD approach

Abstract

Throughout the course completion of oil and gas wells, it is important to run casing in a wellbore that is normally laden with wellbore fluids. The wellbore fluid, or mud, serves two essential purposes. First, it helps to keep the inflow of formation fluids into the wellbore by exerting hydrostatic pressure on the formation. The hydrostatic pressure that is applied must be sufficiently high enough to keep fluid inflow but not high enough to crumble down the formation. During casing run, the impacts of surge and swab must be considered when deciding casing running rates to ensure the boundary between the hydrostatic pressure column and formation pressure keep at equilibrium. Second, the mud assists to circulate cuttings from the wellbore during the drilling commencement. Occasionally during running casing in the wellbore, it is important to have dependable auto-fill equipment to help limit the surge and swab effect. The concept is enabling wellbore fluids to enter the casing from the lower end of the casing is called auto-fill or self-fill. Filling the casing consequently from the lower end wipes out the requirement for manual filling the casing from surface while running in hole (RIH) and casing running efficiencies can increased. In the event that circulation time and additionally rate while RIH or well conditioning surpasses pre-determined mud weight and flowrate, erosion on the valve could happen, which lead to higher than anticipated auto-fill deactivation rates. Thus, this study aims to assess flow behavior and erosion characteristics of the auto-fill valve assembly at the highest acceptable predetermined flowrate parameter.