Alaska Administrative Code
Title 20 - Miscellaneous Boards and Commissions
Chapter 25 - Alaska Oil and Gas Conservation Commission
Article 1 - Drilling
20 AAC 25.033 - Primary well control for drilling: drilling fluid program and drilling fluid system
Current through February 27, 2024
(a) A drilling operation must be equipped with a drilling fluid system meeting the requirements of this section, unless the commission determines that a drilling fluid system is not necessary for primary well control. The operator shall submit with an application for a Permit to Drill (Form 10-401) a proposed drilling fluid program and a diagram with a list of equipment for a drilling fluid system designed to prevent the loss of primary well control. The drilling fluid system must be designed to maintain the wellbore in overbalanced condition except as otherwise provided under (i) of this section. A drilling operation is also subject to the requirements of 20 AAC 25.527.
(b) A drilling fluid program and drilling fluid system intended to maintain the wellbore in overbalanced condition must be designed to provide and maintain
(c) A drilling fluid system intended to maintain the wellbore in overbalanced condition must include
(d) Drilling fluid testing equipment must be on the drill site at all times. Tests to determine drilling fluid density and viscosity must be performed once each tour, or more frequently if conditions warrant.
(e) To ensure that primary well control is effectively maintained, the following practices must be employed in rotary drilling rig operations when tripping the drilling assembly out of the wellbore:
(f) Additional requirements that apply to exploratory and stratigraphic test wells are as follows:
(g) If drilling an exploratory or stratigraphic test well, or if drilling a development or service well while known hydrocarbon-bearing strata are exposed to open hole, the operator shall take a drilling fluid return sample and test the sample to determine density just before tripping the drill pipe. Density test results must be recorded as required by 20 AAC 25.070(1). If the density is less than that of the drilling fluid being pumped down the drilling assembly, the drilling fluid must be circulated and conditioned until a close tolerance of the properties of the return drilling fluid with the input drilling fluid is achieved.
(h) If formation competence at the structural casing setting depth is not adequate to permit circulation of drilling fluids while drilling the conductor hole, a program that provides for safety in that drilling operation must be described and submitted to the commission for approval. This program must be supported by pertinent information including seismic and geologic data, water depth, drilling fluid hydrostatic pressure, and a contingency plan for moving off location.
(i) The commission will approve underbalanced drilling operations and associated equipment changes if the commission determines that underbalanced drilling operations can be performed without loss of well control. A request for underbalanced drilling must include a description of all equipment and procedures to ensure proper containment of formation and return fluids.
(j) Upon request by the operator, the commission will, in its discretion, approve a waiver of the requirements of (c) - (g) of this section if the alternative drilling fluid program and drilling fluid system meet the design criteria of (b) of this section and the corresponding equipment and procedures are at least equally effective in preventing the loss of primary well control.
Authority:AS 31.05.030