Separating coarser solids from drilling mud - by rotating sweeping drum in contact with mud layer adhering to rotating carrier drum

摘要

The process is intended for separating (part of) the solid phase contained in a (colloidal) drilling mud suspension (1). A drum (4) is rotated through the suspension contained in a vessel (21) so that a layer (2) adheres to the drum surface (3), and another drum (6) is rotated whilst its surface (5) is in contact with the layer (2). The rotational speeds are such that the surface (5) and the contact region of the layer (2) have approximately the same linear velocity. The coarser particles in the layer (2) are moved to the radially outermost boundary by centrifugal force. If the layer (2) is formed on the outside of the drum (4) (as shown), these particles transfer to the drum (6). If the layer is formed on the inside of a drum, the second drum collects the treated (i.e. cleaned) suspension on its outer surface. Process is used for removing drill cuttings particles from used drilling mud to restore its consistency required for re-use. The process (partic. as used in conjunction with an applied electric field) permits efficient separation within a wide range of particle sizes and concentrations by controlling the variable parameters, which is not achievable using previously available, e.g. multi-stage methods. It thus produces a better quality drilling mud which allows greater drilling speed and reduces emergency break-downs.