Project Profile
Value: US$1 billion
Location: Gulf of Mexico on Viosca Knoll blocks 867, 868, 911, 912, 913, 955, 956 and 987, USA
Reserves: 250 MMboe, with a 50:50 oil/gas ratio
Production (TLP): 60,000 bopd and 200 MMcf/d (6 MMcm/d)
Water Depth: From 2,000 to 4,000 feet (600 to 1,200 metres).
The Ram Powell Unit was approved by the Minerals Management Service in June 1989. Ram-Powell fields are located in the Gulf of Mexico on Viosca Knoll blocks 867, 868, 911, 912, 913, 955, 956 and 957 in water depths ranging from 2,000 to 4,000 feet (600 to 1,200 metres). The fields came online in September 2000 and connect to the Ram-Powell Tension Leg Platform. The discovery well was drilled on block 912 in May 1985, using the drillship Discoverer Seven Seas. Between 1985 and 1989, Shell, Amoco and Exxon drilled 12 exploratory wells from five locations and carried out one production test. Five potentially commercial pay sands were logged between 5,500ft and 13,500ft subsea. The API gravity is 33°.
Ram-Powell TLP
Approximately 125 miles (201 kilometres) east of New Orleans and 80 miles (129 kilometers) south of Mobile, in water 3,214 feet (980 metres) deep is the Ram-Powell Tension Leg Platform. The Ram-Powell TLP weighs 41,000 tons and is 3,570 feet (1,088 metres) high from seafloor to the crown block of the drilling rig. The Ram Powell TLP is designed to withstand hurricane-force waves. The facility can drill to depths of 19,000 feet (5,791 metres) below the sea floor and is able to produce 200 MMcfd of gas, 60,000 b/d of oil and condensate, and 30,000 b/d of produced water from 20 TLP wells and four subsea wells. . The hull is comprised of four circular steel columns that are 67 feet (20 metres) in diameter and 165 feet (50 metres) high. The deck is an open truss/deep girder design. It measures 245ftx245ft and stands 40ft high. The structure weighs approximately 8,100t and is composed of five modules: well bay, quarters, process, power and drilling. The accommodation module houses up to 110 people, along with a control room and an emergency-response centre. The first deck module was loaded out on 6 November 1996 with shipment of the remaining modules concluded by the end of December 1996.
The TLP consists of 20 wells slots, and the oil and gas is transported to Viosca Knoll 817, which is then transported to Main Pass 289C. The well layout on the seafloor is arranged in a rectangular pattern approximately 60ftx80ft. The drilling programme envisaged pre-drilling four development wells from the 20-slot template. The TLP supports a single modified API Helmlich & Payne platform-type drilling rig (leased), equipped with a surface BOP and a high-pressure drilling riser.
The TLP is secured by 12 tendons, three per corner, each with a diameter of 28in and a wall thickness of 1.2in. Each tendon is approximately 3,145ft long and the total weight for the 12 tendons is approximately 10,000t. The tendons will be attached by the TLP foundation system, comprising tendon receptacles held in place by 12 piles. The piles are 84in in diameter and 349ft long, weighing approximately 270t each.
Production
Initial production will be from 10 wells, seven producers, and three water injectors. Six producers will be completed as horizontal wells, producing from the J, L, and N sands at 12,300-13,400 ft subsea. Water will be reinjected for pressure maintenance.
Ram-Powell can employ 51/2-in. tubing, enabling higher rates of production. Oil and gas will be shipped to platforms on Main Pass Block 289-C and Viosca Knoll Area Block 817, respectively.
Operators:
Stone Energy: 100% interest
Contracts:
Transocean: Drilling contract using the drillship Discoverer Seven Seas
Belleli SpA: The contract for the hull fabrication
McDermott International: The contract for the modular deck
Aker Gulf Marine: The contract for the fabrication of the tendons and piles