Drilling fluid solids control equipment into three categories of cyclone separator and the centrifuge
1, vibrating screen,
Vibrating screen with high frequency vibration function will flow through the drilling fluid on the screen cloth to achieve solid phase separation, the particle diameter of solid phased particles is greater than the sieve hole through the sieve hole and move from the screen cloth, which is less than the screen hole diameter of solid phased particles along with the drilling fluid into drilling fluid tank by screen cloth.
Vibrating screen screen cloth has a variety of perforation models should be according to the return of cuttings in drilling fluid and the size of the solid phase of all sizes the percentage content of solid phase to choose appropriate mesh sieve screen cloth usually use 40 mu or more coarse screen cloth vibrating screen is mainly to clear more than 0.5 mm of debris and sand. The screen cloth closest to the use of the 200 mesh, it can get rid of coarse particle barite.
2, cyclone separator.
Cyclone separator in under the action of centrifugal force, the coarser particles separated from the drilling fluid. According to the separated particle size of cyclone separator can be divided into:
(1) cyclone desander: separation, solid phase particles in more than 74 microns in diameter (separation can also be a small number of 40-74 microns of solid phased particles).
(2) the hydrocyclone desilter: separation of solid phased particles 10 to 74 microns (mostly in the range of 20-40 microns).
(3) the micro cyclone separator: separation of solid phased particles 5-10 microns, bentonite can be isolated in the drilling fluid.
3, centrifugal separator
Under the action of centrifugal force large mass of solid phased particles in drilling fluid is flung to the rotating cylinder wall sink (shell), and then by screw conveyor will pile up of solid phased particles pushed to centrifuge end, from the end of the discharge hole and drainage hole at the other end of the drilling fluid from the centrifuge.
Centrifugal separator mainly have two aspects of use:
(1) in the removal of compound drilling fluid solid phase, in this case the centrifuge is used to remove a minimum of 2 to 5 microns of coarse particle, mainly silt particle size range. Drilling fluid is returned from the other end from the centrifuge system.
(2) from the increase in drilling fluid recycling barite weighting materials such as increase after drilling through centrifuge, barite and some other ingredients of coarse particle separation recycling, and the other end of the discharge of the drilling fluid is rejected.
To achieve effective solid phase control, the solids control equipment must be used, the removal of solid phase process must be according to the vibrating screen, desander, desilter, micro cyclone centrifuge and the order of arrangement. If only use part of the equipment, to reach a good solid phase control effect. If only the use of vibrating screen and desander, only coarse particle separation of more than 74 microns. If you don't use vibrating screen and desander, direct use of desilter, centrifuge and micro cyclone, these devices will be chocked up with coarse particle, not work properly.
In order to improve the use effect of solids control equipment, more conducive to eliminate the greatest influence on drilling rate under 1 mu m sol particles, together with polymer flocculant is effective.