Publications

A brown-field cluster in South Oman showed high water production from wells producing viscous oil (50-400 cP) from sandstone reservoirs. To increase oil recovery, steam Huff and Puff was trialed but was not commercially successful due to reservoir depth and the cost of steam injection systems. Then the team considered surfactant huff-and-puff. Laboratory tests on core plugs and fluids showed the surfactant could reduce the viscosity of the fluid mixture (oil and water) by a factor of 10. Furthermore, surfactant altered the reservoir wettability, and consequently, imbibition oil recovery after flooding with surfactant at 0.5% concentration was two times higher than flooding with plain injection water. Surfactant was injected into well A1 which produced oil with 50 cP and 26 API under a strong water drive. An incremental oil gain of 130% was found, as predicted. Next, we plan is to continuously inject this chemical into the candidate wells. Another advantage of this program is it will give a clear picture of well-to-well communication.