TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Natih field in Oman is a densely fractured carbonate reservoir with a STOIIP of 460 million m3. The displacement processes active in the Natih reservoir during the production period are very complex. Production started in 1967 with depletion of the reservoir resulting in production of oil from the fracture system and oil displacement by fluid expansion and solution gas drive. After these processes had ceased, gas oil gravity drainage in the secondary gas cap, water oil imbibition and water oil gravity drainage by aquifer below the secondary oil water contact continued to displace the oil from the matrix.