Dolphin Field was discovered in October, 1986. The reservoir initially contained 6.3 MMSTB of an undersaturated volatile oil which is miscible with hydrocarbon gas at 4000 psi. Gas injection was initiated in October, 1988 with recovery to date of 31% of the original oil-in-place (OOIP). The ultimate recovery is expected to be 51% of the OOIP, which is 2.7 times the estimated recovery without gas cycling.
This case history paper outlines field development and engineering analysis leading up to initiation of gas injection, and performance review of the project. The Dolphin Field project demonstrates (1) how hydrocarbon recovery from a relatively small oil reservoir can be significantly increased with miscible gas injection and (2) how early reservoir characterization prevented production below the bubble point pressure, which would have eliminated the chance for the additional oil recovery.