Developing a 10 billion barrel reservoir with modern techniques

Abstract

Abstract A high volume water injection pressure maintenance program was initiated in the Defa Field of the Libyan Arab Republic soon after production began, to maximize oil recovery. As development of this large reservoir proceeds, the injection system can be expanded to a capacity in excess of 400,000 BWPD to support oil production rates of about 350,000 BOPD. Development of Defa contrasts with that of older large fields due to the abundant use and application of modern tools and technology. Computer model studies predicted the need for pressure maintenance and were used to plan the pressure maintenance and were used to plan the large bottom-water injection system which was designed, constructed and put into operation in the Libyan desert only 20 months after the Field was put on production. Thirty-four months after the Field went on production, 163,000,000 barrels of oil had been produced from, and 80,000,000 barrels of water injected into, the Defa reservoir. This water injection program is expected to increase oil recovery at program is expected to increase oil recovery at least 300 percent from about 1 billion barrels to over 3 billion barrels. Introduction The Defa field in the Libyan Arab Republic contains oil-in-place of about 10 billion barrels; however, computer model studies predicted the need for pressure maintenance predicted the need for pressure maintenance early in the producing life of the field. The studies showed that the under-saturated crude would quickly drop below the bubble point and institute an inefficient, solution point and institute an inefficient, solution gas expansion drive without some type of pressure maintenance program. A large-scale pressure maintenance program. A large-scale water injection system, designed with the help of the computer model studies, is predicted to increase oil recovery 300 percent from about 1 billion barrels to over 3 billion barrels. This paper reviews the development of the field and studies leading up to the initiation of water injection, with particular emphasis on the use of modern tools and technology. Such advances in technology reduced the time spans required for major development decisions. This 10 billion barrel field was put on production 500 miles from Tripoli in the Libyan desert only 23 months after development commenced. Twenty months later, a 240,000 BWPD water injection system was in operation.