(a) Before removal of the drill pipe or tubing from the hole is begun, the drilling fluid shall be conditioned to provide adequate pressure overbalance to control any potential source of fluid entry. Proper overbalance shall be confirmed by checking the annulus to ensure that there is no fluid flow or loss when there is no fluid movement in the drill pipe or tubing. The drilling fluid weight, the weight and volume of any heavy slug or pill, and the fact that the annulus was checked for fluid movement shall be noted on the driller's log. During removal of the drill pipe or tubing from the hole, a hole-filling program shall be followed to maintain a satisfactory pressure overbalance condition.

(b) Tests of the drilling fluid to determine viscosity, water loss, weight, and gel strength shall be performed at least once daily while circulating, and the results of such tests shall be recorded on the driller's log. Equipment for measuring viscosity and fluid weight shall be maintained at the drill site. Exceptions to the test requirements may be granted for special cases, such as shallow development wells in low pressure fields, through the field rule process.

(c) Disposal of drilling fluids shall be done in accordance with Section 1775, Subchapter 2 of these regulations.