Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
Modeling the displacement of drill string immersed in cuttings bed
Submission Author:
Maryelen Miyoshi , PR , Brazil
Co-Authors:
Maryelen Miyoshi, Cezar Otaviano Ribeiro Negrao
Presenter: Maryelen Miyoshi
doi://10.26678/ABCM.COBEM2019.COB2019-0543
Abstract
Although usually more expensive, drilling and directional well may be useful for targeting a particular oil reservoir. Nevertheless, the more inclined the well towards the horizontal direction, the higher the risk of rock fragment sedimentation at the lower part of the well. When the drill string immersed in the cuttings bed is pulled out of the well, solid particles may accumulate at the drill bit forming a plug that increases the required force to remove the drill pipe. Depending on the cuttings bed height, on the kind of sediment, on the open cross section area, on the drilling fluid viscosity and on the drill pipe speed, the drill pipe may be stuck at the cuttings plug. The current work puts forward a mathematical model to simulate the displacement of a drill string immersed in cuttings bed. The model that is based on lumped mass and momentum conservation equations applied to the solid-liquid two-phase flow is used to predict the cuttings plug length and also the forces acting on the drilling string. The forces due to cuttings bed are determined using theories of granular flow and soil mechanics. This model might help well drilling teams to accurately predict the drill pipe motion so as to minimize well costs and ensure a safe drilling process.
Keywords
Granular materials, Drag, packed bed
