Uncontrolled Well Flow and Pollution During Workover Operations

Effective Date: 6/18/1985

U.S. Department of the Interior
Minerals Management Service
Gulf of Mexico OCS Region

Notice No. 140

June 18, 1985

Uncontrolled Well Flow and Pollution During Workover Operations

While in the process of a reperforating operation, casing hanger anchor screws began leaking. Without securing the well, two anchor screws and gland assemblies were removed to repair the leaks. The well began to flow through the screw holes. The casing valve was opened to relieve the well pressure and allow reinstallation of the screws, but well pressure would not permit this action. The uncontrolled well flow of gas, crude oil, water and sand resulted in approximately 50 barrels of pollution and sand cutting damage to the wellhead and surrounding wells. The platform was evacuated, the well bridged, and flow ceased after approximately 56 hours. Pollution skimming equipment recovered approximately 10 barrels of oil.

To prevent a recurrence of this type of accident, the operator has reemphasized company policy relevant to this incident:

1. Wellhead repair will be performed in a safe manner, using good judgment.

2. Only trained and qualified personnel will perform wellhead repairs.

3. Personnel performing wellhead repairs will be certified.

4. Under no circumstances will wellhead repair be performed during perforating or other downhole well operations.

5. Repairs to an unsecured well will only be initiated after the recommended procedure has been approved by management at the operator's district office.