RIASSUNTO
ABSTRACT
OXY USA Inc. removed four platforms from waters offshore Texas during the summer of 1988. The implementation of a comprehensive salvage plan permitted OXY to complete the platform removals well below original AFE estimates. Salvage operations included equipment decommissioning, pipeline abandonments, use of explosives, platform removals and disposal of platform components through reuse, sale and scrapping.
INTRODUCTION
In late 1986, OXY USA Inc. (OXY) identified several oil and gas fields offshore Texas that were in their ""golden years"" of production. It was projected that these fields would be depleted and need to be abandoned during 1987 and 1988. OXY reviewed the platforms to be removed and formulated a comprehensive salvage plan to minimize expenditures and to coordinate salvage projects with ongoing capital projects.
The salvage plan implemented for the 1988 platform removals achieved cost savings by utilizing the following four methods:
Grouping similar salvage and capital tasks into common work packages. This permitted savings based on economy of scale and shared mobilization costs.
Completing work packages with minimum cost equipment spreads. This included performing certain decommissioning, explosives and salvage activities from a liftboat or utility boat instead of a higher priced derrick barge.
Utilizing regulatory options available to minimize the required scope of work on platform and pipeline removals.
Maximizing the value of the salvaged structures, pipelines and equipment.
DESCRIPTION OF THE PLATFORMS
Mustang Island 773-L NE ¼ (MU 773)
This platform was a single slot, 4-pile well protector located in 50 ft. of water. The platform was installed in 1984 over an existing 72"" caisson. The deck was a two level trussed frame with nominal dimensions of 35 ft × 40 ft. The gas sales pipeline consisted of an OXY owned 120 ft. long 4"" lateral. The OXY pipeline was connected at a subsea manifold to an existing 8"" gas gathering system.
Mustang Island 749-L (MlJ 749)
This platform was a 3-slot, 4-pi1e well protector located in 62 ft. of water. The platform was installed in 1972 over an existing well. The deck was a two leg, two level unit with nominal dimensions of 30 ft. × 30 ft. The top level was a helideck. The platform was located in an anchorage area which required that all pipelines be buried a minimum of 16 ft. The gas sales pipeline consisted of an OXY owned 7 mile long 6"" lateral. The OXY pipeline was connected to an existing 8"" gathering system to shore.