Drilling fluid and equipment maintenance cost can decrease greatly

The continuing trend of more stringent environmental regulations around the world will require more and more solids control systems to be implemented to minimize haul off of drilling waste not to mention the cost saving on equipment such as mud pumps and mud motors.

Drilling fluid and equipment maintenance cost can decrease greatly when proper solids control practices are utilized. From a fluid control stand point it would be desirable in most cases to remove all drilled solids. Although this is possible, it would be cost prohibitive. The goal of a solids control system is to achieve the balance between mechanical solids separation and dilution that will result in drill solids being maintained at an acceptable level with a minimum of cost.

Drilled solids are those particles that enter the mud system in the form of cuttings from the bit or back reamer or from borehole debris. These solids vary in size from less than one micron & larger depending on the carrying capabilities of the drilling fluid. Note that spindle speed and the amount of push or pull force require to drill play an important factor on the particle size of the cuttings.

One of the most important objectives in solids control is to remove as many of the large particles as is practical the first time that these solids are pumped out of the borehole. This requires properly designed and installed solids removal mechanical treating equipment sized to process a minimum of 100% up to 125% of the mud circulation rate. Solids that are not removed during the first circulation through the surface equipment are subjected to mechanical degradation by the drill bit, reamers and mud pumps during each circulation cycle until they are too fine for removal by mechanical means.