The shale shaker is the most important equipment in the drilling fluid solid control system, it is the first process of the mud purification. Not only using in deep well, but also using the shallow well, the mud must through the shale shaker to filter.
Working principle
The shale shakers are mainly drive by the electrical machine to rotate to produce the periodic changed inertia force, drilling fluid solid phase enters into the sieve screen, do the throwing movement on the sieve surface, and then the solid phase particles with different size will be removed. The separation diameters and throughput of the shale shakers are the most important factors of matching. The technology level of shale shakers mainly show at the handing ability (throughput and separated granularity), the stability of working, the length of life and the flexibility of operation. The handing ability of shale shakers is related with the structure of shale shakers, the movement locus, the vibration frequency, the vibration intensity, the area of shale shakers and the degree of thickness. In order to make the shale shakers match with the drilling machineries, the maximum displacement of the drilling pumps and the quantity of drilling cuttings produced must be considered.
Classification
Usually according to the movement locus, the shale shakers can be grouped into round screen shaker, the common elliptic screen shaker, linear screen shaker, equilibrium elliptic screen shaker. The common elliptic screen shaker: also can be called the disequilibrium elliptic screen shaker, there is a exciter devices fixed right above of the screen box barycenter, It requires the screen boxes tilt an angle, gets rid of sand by gravity, avoids the sand having the tendency of backward throwing. From this, the tilt of the screen boxes really improved the moving performance of sand, but the disposed amount of the drilling fluid reduced, this is the main shortcoming of the common elliptic screen shaker. The linear shale shakers
liner shale shaker
: Two main axises with eccentric blocks do synchronous reverse rotation to produce the liner vibration. Because the direction of the liner shale shaker is unchanged, which makes the particles difficult to drop, and then the screen paste phenomenon appeares, which makes the valid over flowing area of screen and throughput reduced. When the number of screens increases, the phenomenon of screen paste will be more serious. So when the linear shale shakers use the super details screen, it could not meet the requirements of the using amount of drilling fluid.
The equilibrium ellipse screen: In recent years to develop a new type screen, the movement locus of long axis and short axis are all the same, the size and direction of the throwing angle are completely consistent. The equilibrium ellipse screen combined with the basic advantages of the round screens and liner screens, the throughput of the equilibrium ellipse screens is bigger twenty percent to thirty percent than the liner screens, is a relatively advanced drilling fluid shale shaker screens, representative the development direction of the drilling fluid shale shakers.