PDO Signs EPC Contracts For Qarn Alam Steam-Injection EOR With Dodsal, Galfar
Petroleum Development Oman (PDO) on 27 May signed two major engineering, procurement and construction (EPC) contracts for the Qarn Alam steam-injection enhanced oil recovery (EOR) project. A contract for field facilities was awarded to Dodsal and a contract for the oil and water flowlines and associated hardware outside of the field site was awarded to Galfar Engineering and Contracting. The Qarn Alam steam-injection project is the world’s first full-field steam-injection enhanced oil recovery (EOR) project based on thermally assisted gas/oil gravity drainage (TAGOGD) in a fractured carbonate field. The project scope, according to PDO, includes drilling some 150 wells and installing facilities to treat water and generate around 18,000 tons/day of steam. Additional facilities will be built to process the incremental oil and gas produced at the field, and to dispose of excess produced water in deep reservoirs. The project will require nearly 220km of pipelines and flowlines to connect these facilities with the wells for water supply, oil production, steam injection and water disposal.
The EOR recovery process is based on injecting steam into the formation’s fractures to heat the low-permeability oil-bearing rock. As the rock is heated, gas is liberated and the viscosity of the oil reduced, flowing much more easily into the fractures under the action of gravity. The fractures thus serve as conduits for both the injected steam and the produced oil. Unlike a conventional steam-injection project, in which the steam serves to drive oil to producing wells, the steam at Qarn Alam is used as merely a heating agent to enhance the existing gravity drainage mechanism. This feature of the project allows the number of wells, and hence development costs, to be kept to a minimum. “Most of the steam will be generated by waste heat recovery from the existing Qarn Alam Power Station, thereby significantly reducing the project’s carbon dioxide emissions and saving on gas consumption. The start-up date of all facilities will be around 2010,” said PDO Oil Director for northern assets Saif al-Hinai. Canada’s Worley Parsons won the front-end design contract for the project, which is expected to increase recovery from 4% to 25%, in late 2005 (MEES, 15 August 2005).
