High cuttings in drilling fluids may result in serious consequences.

1. Raised mud density, lowered mechanical drilling speed, shortened lifespan of drill bit;

2. Thickened the filter cakes, softened the formations as well as strong friction, which easily lead to blocked drilling tool when it is running and sticking of drill bit; and larger filtration loss, which result in expansion of inner wall, drawing down, peeling, collapse, etc.; then, more permeable filter cakes, enlarged filtration loss, which reduce oil layer permeability and crude capacity; what is more, higher solids content, thicker filter cake, which may also cementing quality;

3. High silt content, which severely abrades the drill bit, drilling rig and mechanical equipment, thus hindering the normal drilling operation;
 

4. Unsteady mud propertied, larger viscosity & shearing force, inadequent flowability, all of which produce clay and chemical contamination;

5. Miscellaneous silts, hindered electric logging, inaccurate logging data;

6. Complicated treatment process, which ups the cost in drilling fluids.

Impacts that the solid content exerts on drilling speed

1. Drilling speed is inversely proportional to solid content. Suppose the drilling speed in clean water stands at 100%. When the solid content goes up to 7%, drilling speed reduces to 50%, that is half that in clean water. As far as numerous data display, when the solid content is not beyond 7%, 1% down in solid content will bring drilling speed up at least 10%.

2. In different solid content ranges, the increase rates of drilling speed vary. If the solid content remains under 7%(equal to such density as 1.08 g/cm3), drilling speed will climb at the fastest speed; if it goes beyond 7%, it does not make much significance to drilling speed.

3. Drilling speed is influenced, to the greatest extent, by colloidal particles below 1µm in diameter. It is proved by experiments that colloidal particles with diameter below 1µm are 12 times more influential than the coarse particles with diameter above 1 cape. Accordingly, the more the colloidal particle there are, the slower the drilling speed is.

In a word, if the solids control equipment are put into prompt application, they will remove such harmful solids as drill cuttings, silts, coarse clay, etc., keep the content of useful solids like barites and bentonites under the sway of regulations, and, at the same time, recover barites and bentonites from drilling fluids.

So the solids control equipment used in the drilling process are essential, such as oilfield shale shaker, drilling fluids cleaner, mud desander, drilling decanter centrifuge, desilter, drilling mud degasser and other devices. They compose a complete oilfield drilling mud solids control system, which plays an important role in the whole oilfield drilling system.