IMPROVING OIL RECOVERY USING SURFACTANT AS A STIMULATION TOOL FOR A MODERATE OIL VISCOSITY RESERVOIR, A CASE STUDY FROM SOUTH OMAN

摘要

A brown-field cluster in South Oman showedrnhigh water production from wells producingrnviscous oil (50-400 cP) from sandstonernreservoirs.rnTo increase oil recovery, steam Huff and Puffrnwas trialed but was not commercially successfulrndue to reservoir depth and the cost of steamrninjection systems.rnThen the team considered surfactant huff-and-puff.rnLaboratory tests on core plugs and fluids showedrnthe surfactant could reduce the viscosity of the fluidrnmixture (oil and water) by a factor of 10.rnFurthermore, surfactant altered the reservoirrnwettability, and consequently, imbibition oilrnrecovery after flooding with surfactant at 0.5%rnconcentration was two times higher than floodingrnwith plain injection water.rnSurfactant was injected into well A1 whichrnproduced oil with 50 cP and 26 API under arnstrong water drive. An incremental oil gain ofrn130% was found, as predicted.rnNext, we plan is to continuously inject this chemicalrninto the candidate wells.rnAnother advantage of this program is it will give arnclear picture of well-to-well communication.