Current And Required Economics In Relation to Further Alberta Enhanced Recovery of Conventional Crude

Abstract

Abstract The status of Alberta crude oil reserves is reviewed briefly in respect to currently established recovery factors and the technical potential for additional recovery enhancement. A hypothetical pool is evaluated, with consideration given to the economics of pressure maintaining the pool by water flood, solvent flood and micellar solution flood. In each case, the technology is assumed to be proven and the recovery factor for each mechanism is established at a level generally believed applicable for a flood of that genre. Projected proration factors are applied to determine the comparative allowable that would result from depletion of the example pool by each of the cited depletion mechanisms. These are then extended into future cash flows and discounted rates of return, using the appropriate capitol cost, operating costs, royalties and taxes associated with each scheme. The schemes are then analyzed on an incremental basis to determine comparative economic potential related to the ultimate recovery of each scheme. The technical practicality of "exotic" depletion schemes is considered in terms of the need to proceed with theexotic scheme early in the producing life of the pool. Economic calculations for the hypothetical pool show that exotic schemes frequently cannot compete economically with waterflood operations. Therefore, under current economic conditions, exotic recovery is normally not feasible and, where it is feasible, would proceed only after the water-flood reserves of the pool have been totally, or almost totally, recovered. This deferment could seriously reduce the incremental tertiary economics to the point of making tertiary recovery entirely impractical. Consideration is given to methods of improving the economic attractiveness of enhanced recovery schemes throughroyalty and tax relief. A simplified cost-benefit analysis of the impact of such relief is presented. Introduction THE ENERGY RESOURCES CONSERVATION BOARD (ERCB) estimated that the year-end 1975 initial recoverable conventional reserves of the Province of Alberta amounted to some 11.5 billion barrels, This represents a recovery factor of 32.5 per cent of 35.4 billion barrels initially in place. The ERCB estimates that without the subsisting enhanced recovery projects, which are mostly water flood and solvent flood, the primary depletion recovery would be some 21.4 per cent. Thus subsisting enhanced recovery projects in Alberta have increased recoverable reserves by 50 per cent. Nonetheless, about 65 per cent of the oil in place discovered to date will not be recovered under current operations. The National Energy Board, in its 1975(1) report Oil Canadian Oil Supply and Requirements, estimated that by 1985 Canadian demand for indigenous feed stocks would exceed available supply by about 500,000 barrels per day. Under such circumstances, it is incumbent upon industry and government to ensure that the recovery of oil from established reserves is optimized. Alberta currently accounts for over 85 per cent of Canada's 6.65 billion barrels of proven remaining crude oil reserves and about 85 percent of its oil producibility. Enhanced recovery can and must play a vital role in meeting Canada's future supply problems. In order to do so, technical research and its application must proceed expeditiously and the economic environment must be favourable.