UNITED STATES DEPARTMENT OF THE INTERIOR
MINERALS MANAGEMENT SERVICE
PACIFIC OCS REGION

NOTICE TO LESSEES AND OPERATORS OF
 FEDERAL OIL AND GAS LEASES
         IN THE PACIFIC OUTER CONTINENTAL SHELF REGION

Sustained Casing Pressure

This notice supersedes NTL No. 00-P02 on this subject. 

The regulation at 30 CFR 250.517(c) specifies the following:  [b1] “When the tree is installed, the wellhead shall be equipped so that all annuli can be monitored for sustained casing pressure.  If sustained casing pressure is observed on a well, the lessee shall immediately notify the District Supervisor.”

The regulation at 30 CFR 250.617(c) specifies the same requirements for reinstalling of the tree, in connection with well-workover operations.

For purposes of this NTL, we define sustained casing pressure as any measurable annular pressure at the casinghead that:

      1.  will rebuild to essentially the original annular pressure after being bled down, and

2.  is attributable to cause(s) other than

     (a)  an artificially applied annular pressure (i.e., gas lift) that remains isolated from all other annuli, or

     (b)  temperature fluctuations in the well.

According to 30 CFR 250.517(c), you must monitor all wells for casing pressures.  You can achieve this by using a pressure gauge with an appropriate pressure range, on each casing annulus, so that pressure can be detected at all times. When bleeding off pressure in the casing annuli, well fluids should not be vented in the well bay area.

In addition to those wells being used for production or injection, these requirements apply to (a) temporarily abandoned wells (defined as wells with one or more cement plugs set in the casings),  which have not all been cut, consistent with 30 CFR 250.703) and (b) newly drilled wells that have been temporarily plugged pending the installation of production facilities, pipelines, etc. 

Upon initial detection of sustained casing pressure, you must immediately notify the District Supervisor by telephone or telefax.  Upon notification and consultation with the operator, on a case-by-case basis, the District Supervisor will determine what actions, if any, you need to take for approval to continue well operations from the existing completion or to perform workover operations. 

Please be advised that this notice does not supersede any procedures you are currently required to follow for wells identified with sustained casing pressure.  All requirements previously imposed by the District Supervisors as conditions of approval for well production, completion or workover, or other operations remain in effect until you are notified otherwise.

The current operator of the facility is responsible for assuring that new operators are aware of any wells with sustained casing pressure on their facility prior to transfer of operatorship.  This includes all requirements the District Supervisors have imposed as conditions of approval relating to sustained casing pressure.

Paperwork Reduction Act of 1995 Statement:  The collection of information referred to in this notice provides clarification of requirements in 30 CFR 250, subparts E and F.  The Office of Management and Budget (OMB) approved the information collection requirements in these regulations under OMB Control Numbers 1010-0067 and 1010-0043, respectively.  This notice does not impose additional information collection requirements subject to the Paperwork Reduction Act.

If you have any questions or need clarification regarding this NTL, please contact the Office of District Operations at (805) 389-7777.