Case History in Success of Handling Heavy Crude Oils Using Proper Designed Flow Simulation Program

Aghar is an oil field located at western desert in Egypt (Figure 1), 60 % of its oil production is heavy oil (1,085 centipoise @ 16°C & 0.97 sp.gr. @60°F & 14.7 psi). Such oil is too heavy to be transported only by wells head pressures, so this problem was solved by sending production of light oil wells as a carrier fluid (2 centipoise @ 16°C & 0.85 sp.gr. @ 60°F & 14.7 psi) for mixing with production of these heavy oil wells so it could reduce overall viscosity. Mixed oils were sent to a Manifold Header (MH) at 8,200 bbl/d and 250 psi, then sent to the main oil processing area via four parallel branches, 3.5" x 5 km each, where separator pressure is 30 psi. By winter, and summer seasons pressure at the MH raises up to 900 psi and 390 psi respectively, meaning that back pressures at MH are 650 psi and 140 psi respectively, which affect negatively on production rates produced from both of heavy and light oil wells. This problem was solved by adding in parallel other three branches, 3.5" each as a temporary solution, i.e. seven branches each is 3.5" were used. Later a new network was proposed replacing the seven parallel branches with two parallel pipe branches; 6" x 6 km each, which encouraged adding more slots to the MH capable to receive 5,800 bbl/d extra production of new discovered heavy oil wells Currently produced oils reach OPA without back pressure at MH.