Firstly, we should know the function of surface mud system. The purpose of a surface mud system is to allow maintenance of the mud before it is pumped down the hole. This is accomplished by the effective use of solids control equipment to remove undesirable solids, while simultaneously recovering as much drilling fluid as is feasible. Secondary to the solids removal process is the addition of chemicals and the rapid and thorough mixing of mud materials. Thorough agitation is necessary to effectively accomplish both of these tasks. In the majority of drilling fluids, agitation equipment must be used to suspend solids in the surface tanks and maintain a homogeneous drilling fluid.
There are two types of equipment to do this:
. mechanical agitators, and
. fluid motive devices, also called mud guns.
Both are widely used, and will be discussed by showing basic principles, installations, and sizing guidelines.
Drilling-fluid components such as bentonite (gel), barium sulfate (barite), lost circulation material, polymers, and chlorides (to name a few) must be wetted before they are dispersed throughout the system. Proper introduction of these materials into the drilling fluid is equally important and can enhance drilling efficiency as well as reduce the amount of additives needed. To gain the most advantage, correct addi- tion at the surface will enhance their effectiveness in the well. Several technologies are described to blend, add, hydrate, shear, or mix drilling- fluid additives and enhance their effectiveness.
As stated previously, the purpose of agitators is to suspend solids, completely mix mud materials, and maintain a homogeneous mixture throughout the surface system. For all of these requirements to be met, mud agitator or agitation equipment have to create an upward velocity within the mud tanks that is greater than the settling velocity of the suspended solids. There must be adequate shear and stirring to dissolve, wet, and disperse mud additives. The ability to blend drilling fluid helps maintain consistency. The future discussion illustrates how mechanical agitators and mud guns operate and accomplish these goals
