1.1.3 Gel Strength
The value derived when the shear stress of a drilling mud system is measured after being allowed to set inertly for a period of time usually 10 seconds or 10 minutes according to the American Petroleum Institute (API) standard at a very low shear rate is known as the gel strength it is an important property of a drilling fluid system because it dictates its capacity of the mud to suspend drill cuttings and weighting materials when circulation is stopped. The types of gel strength experienced by a drilling fluids system are shown below [3].