DEVELOPMENT OF SHALLOW VISCOUS OIL RESERVES IN NORTH SLOPE

North Slope of Alaska has huge oil deposits in heavy oil reservoirs such as Ugnu, West Sak and Shrader Bluff etc. The viscosity of the last two reservoir oils vary from {approx}30 cp to {approx}3000 cp and the amount in the range of 10-20 billion barrels. High oil viscosity and low formation strength impose problems to high recovery and well productivity. Water-alternate-gas injection processes can be effective for the lower viscosity end of these deposits in West Sak and Shrader Bluff. Several gas streams are available in the North Slope containing NGL and CO{sub 2} (a greenhouse gas). The goal of this research is to develop tools to find optimum solvent, injection schedule and well-architecture for a WAG process in North Slope shallow sand viscous oil reservoirs. In the last quarter, we added numerical solution along streamline subroutines to our streamline compositional simulator. The WAG injection algorithms are being developed. We studied the wettability of the reservoir oil and formulated a four-phase relative permeability model based on two-phase relative permeabilities. The effect of new relative permeability formulations on a five-spot pattern WAG recovery was evaluated. Effect of horizontal wells on pattern sweep has been initiated. A model quarter five-spot experiment is being designed. Plans for the next quarter includes modeling of WAG injection in streamline based simulation, evaluation of complex well-architecture and design of model quarter five-spot experiment