Over the past five years the application of turbomachinery for use in conjunction with the exploration and development of oil and gas has gained increasing popularity within the industry, especially in offshore and isolated or remote locations.
The several operational and environmental considerations leading to the selection of turbomachinery for use on Union Oil's Grayling Platform, located In Alaska's Upper Cook Inlet, Platform, located In Alaska's Upper Cook Inlet, will be reviewed. Also included is performance data on specific turbine driven equipment along with recommendations outlining installation, operation and preventive maintenance procedures to promote a successful turbomachinery application.
The Grayling Platform was originally constructed as a typical Cook Inlet "four poster type" self-contained drilling and poster type" self-contained drilling and production facility. It was designed to production facility. It was designed to accommodate simultaneous operation of two DC powered drilling rigs, and was installed with powered drilling rigs, and was installed with mud pumps and tanks, cementing and logging units, mud and cement storage, etc., to perform all normal drilling functions. The platform also contained oil and gas separation equipment, along with associated manifolding and piping, diesel powered AC generator sets, glycol-water boilers powered AC generator sets, glycol-water boilers for platform heating, instrument air compressors, salt water and dry chemical fire protection equipment, two 50 ton pedestal mounted cranes, and a 70 man quarters with an attached heliport.
The platform is located in Cook Inlet's Trading Bay, approximately 45 miles southwest of Anchorage, Alaska. It is basically supported by four 17 ft. diameter legs in approximately 140 ft. of water. It has three equipment deck levels: the drilling and production decks, spaced 20 ft. apart, which are both 120 ft. square, and a 47 ft. X 60 ft. sub-deck located between four 17 ft. diameter horizontal beam tanks which comprise the top of the structural jacket (See Fig. 1).
The platform is pinned to the Inlet floor by twelve 33 In. diameter piles driven through each of the four legs and grouted in place. These piles also serve as conductors through which as many as 48 wells can be directionally drilled from the platform to measured depths of over 16,000 ft. for the development of subterranean oil producing zones.
The platform is subject to the corrosive and erosive effects of oxygen saturated and silt laden Cook Inlet sea water.