In a complete drilling rig system, there are 8 sub-systems. One of which could be a closed loop system not so involved with other 7 systems, it is the solids control system.
As during drilling, there is drilling mud to be used to protect the drill bit by lubrication and to bring out the drilling cuttings after drilling. The drilling mud contains lots of chemicals and it is quite expensive, at this point, it should be recovered and recycled for further use. At the other hand, it could pollute the environment if discharged directly along with the cuttings. That’s why the solids control system is a must to a rig, in order to separate the cuttings from the drilling mud.
There are mainly 4 steps in a solids control system to choose out the cutting particles based on the cuttings physical character, the sizes. The first step should be a shale shaker. By using shaker screens with suitable API numbers, the particles bigger than 100 microns could be separated out thoroughly. After the shale shaker, there should be a desander and a desilter. Desander and desilter are equipment designed under same working principle. They are both hydrocyclones fed by centrifugal pumps. And with the centrifugal force generated inside the cyclones, the liquid phase, here the drilling mud will go out from top of cyclones, and the solids phase, the cuttings, falls from cyclones’ bottom. Desander cyclones are used for choosing the particles of 40 microns and the desilter cones are used for the 20 micron ones. Some desander and desitlers are equipped with a under flow shaker, which is used for drying. Comparing with the single cyclones, the ones with underflow shakers are used for weighted mud.
Recently, GN Solids Control has provided to an oil field company such desander and desitler with underflow shakers. This desander has 3 nos of 10 inch diameter cyclones and this desilter has 16 nos of 4 inch diameter cyclones, both could serve a capacity of 360cbm/hr. Those are usually used for a large horsepower drilling rig.
For more information, welcome to contact GN directly.