Blowout
Effective Date: 6/30/1981
 | Minerals Management Service Gulf of Mexico OCS Region |
Notice No. 103
June 30, 1981
OCS Operations Safety Alert
Blowout
An unusual blowout occurred in the Gulf of Mexico recently. The well blew out through the drill string and not the annulus. A drilling break was noted and drilling was stopped to check for flow. The well was flowing and the annular preventer was closed. The fill-up valve between the stand pipe and the bell nipple was opened to "check for trapped pressure." This valve was inadvertently left open and thereby the well still appeared to be flowing. Both preventer pipe rams were closed but this caused no change. The well unloaded rapidly, and when it was realized that the fill-up valve was still open, it was too late to close it. The lower kelly cock had been positioned out of reach above the derrick floor and was inaccessible. The gas subsequently ignited, one fatality occurred following evacuation of the rig.
Two items of note from a safety standpoint are:
1. If the fill-up valve is opened to check for trapped pressure it should be closed immediately.
2. The kelly should be positioned, if possible, so that the lower kelly cock can be closed from the derrick floor.
[signed] D.W. Solanas
Deputy Conservation Manager
Offshore Operations Support
Gulf of Mexico OCS Region