EOR Survey in the North Sea

Abstract

Abstract This paper provides a summary and a guide of the Enhanced Oil Recovery (EOR) technologies initiated in the North Sea in their period from 1975 until today. The five EOR technologies which have been initiated in the North Sea were hydrocarbon miscible gas injection, WAG injection, SWAG injection, FAWAG injection and MEOR. Each EOR technology which has been initiated in the North Sea was identified with its respective maturity level and / or maturing time frame, technology use restrictions and process efficiency on the basis of incremental oil. Apart from WAG at Ekofisk and FAWAG at Snorre CFB, all technologies have been applied successfully on the corresponding fields. Hydrocarbon miscible gas injection and WAG injection can be considered as mature technologies in the North Sea. The most commonly used EOR technology in the North Sea was WAG and recognized as the most successful EOR technology. The main problems experienced were injectivity (WAG, SWAG and FAWAG projects), injection system monitoring and reservoir heterogeneities (hydrocarbon miscible gas injection, WAG, SWAG and FAWAG projects). About 63% of all the reported EOR field applications have been initiated on the Norwegian Continental Shelf, 32% on the U.K. Continental Shelf and the remainder on the Danish Continental Shelf. Statoil was the leader in conducting EOR field applications in the North Sea. In the future, the majority of research will be conducted on microbial processes, CO2 injection and WAG (including SWAG) injection schemes. In this review laboratory techniques, world statistics, simulation tools and economical evaluation was not considered and is outside the scope of this paper.