§ 72-42. Drilling fluid.

No well shall be drilled within the city limits without using mud as the drilling fluid after the setting of surface casing as provided in section 72-40 hereof. Prior to the time the well reaches a total depth of 5,000 feet or the depth of the first known or encountered oil and/or gas bearing horizon, whichever is the lesser depth, the weight of the mud-laden drilling fluid shall be at all times maintained at not less than nine pounds per gallon. After the well reaches a total depth of 5,000 feet or the depth of the first known or encountered oil and/or gas bearing horizon, whichever is the lesser depth, the weight of the mud-laden drilling fluid shall be at all times maintained at such weight as will provide a hydrostatic head of not less than 200 pounds per square inch in excess of the formation pressure. In reworking a well, a drilling fluid shall be at all times maintained at such weight as will provide a hydrostatic head of not less than 200 pounds per square inch in excess of the formation pressure.

(Ord. No. 1251-3-01, 3-20-2001)