The recently installed Panna facilities, offshore the west coast of India, are designed to produce 50,000 b/d of highly paraffinic, sour oil, 180 MMscfd of sour gas, and 100,000 bw/d. The field lies in about 154 ft of water. Enron Oil & Gas India Ltd. is operator.
Enercon Engineering Inc., Houston, provided detailed design, procurement, and inspection services for the development that includes installation of six platforms and 22 pipelines.
Facilities
According to Enercon, the central complex consists of an eight-pile production platform with a 5,000-ton deck, a four-pile, 60-man quarter/utility platform, and a four-pile flare platform. The central complex platforms are bridge-connected to one another and to an existing wellhead platform.
The facilities include two oil-processing trains with shell-and-tube heat exchangers, plate-and-frame heat exchangers, separators, electrostatic oil treaters, oil pumps, and oil-metering equipment. Gas processing equipment includes separation, filter/coalescers, amine sweetening, glycol dehydration, and sales gas metering.
The complex has a 60-man quarters building, two 3,500-kw turbine generators (with provisions for a third unit), firewater, potable water and compressed air systems.
Because the oil and gas are sour, 1,000-ppm H2S and 8% CO2, the processing vessels have special metallurgies and require the extensive use of corrosion inhibitors.
Enercon says that after start-up this summer, pour-point depressant chemicals will be used because the produced 38° API gravity oil has an 89° pour point.
The fuel/lift gas will be sweetened in a 150-gpm MDEA (methyldi ethano l amine) gas treating system.
A hot oil system with one 5 MMBTU/hr direct-fired heater provides heat for oil treating, amine regeneration, and glycol regeneration.
The gas-compression system consists of two 12,500-hp, turbine-drive, three-stage compressors. Enercon says space has been provided for a future third identical package.
Construction and design
In April 1995, Enercon was awarded the front end engineering design (FEED) for the Panna field development.
In late 1995, Enercon awarded major contracts for the processing equipment, turbine generators, turbine compressors, and living quarters. Purchase orders for the control panels and fire and gas panels were awarded in early 1996. Enercon says these contracts and purchase orders were made with fabricators, manufacturers, and vendors located throughout the world.
In January 1996, the main contract was awarded to McDermott-ETPM East Inc. (MEEI). This contract included the detailed design as well as the procurement of materials, fabrication, outfitting, transportation, installation, and hook-up of the Panna platforms.
Enercon says it was responsible to MEEI for the detailed design and construction engineering of the platforms and facilities as well as the procurement of all utility equipment, instrumentation, switchgear, and master control center (MCC) buildings.
Enercon procured the equipment on a worldwide basis and shipped it to MEEI's Jebel Ali fabrication facility in Dubai where all of the platforms were fabricated.
The fabrication phase of the contract began with the eight-pile central production platform jacket and deck in May 1996. This fabrication as well as the remaining deck and jacket fabrications continued for 9 months until February 1997.
About 10 days were needed for the tow of the central production platform jacket and deck from the Jebel Ali yard to the Panna field. Once on site, the 2,200-ton jacket was launched, floated, upended, and set on-bottom.
Piling, about 4,300-tons total, was then driven to a 430-ft penetration.
The production deck and modules were then installed by lifting and interconnecting two 1,600-ton deck sections, and installing a 1,100-ton gas treating module and two 600-ton turbine gas compression modules.
The adjacent quarters-platform jacket, deck, and quarters building were then installed, followed by the bridge-connected flare platform, the bridge to the existing wellhead platform, and the remote wellhead platforms.
During the 16 month detailed design and construction phase, Enercon calculates that a total of 7,000 tons of jackets, 8,000 tons of decks and modules, and 13,000 tons of piles for five platform sites, were designed, fabricated, and installed.
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