Unconventional Methods of Recovery of Bitumen And Related Research Areas Particular to the Oil Sands of Alberta

Abstract

Abstract A review was carried out of certain unconventional and untried methods of recovery of bitumen from the tar sands of Alberta. Future areas of research which might provide abreak through with regard to the potential application of these methods have been described. Preliminary laboratory investigations have been described out on the interfacial properties of heavy crudes in the presence of chemically treated waters. The result of this review show that there is a significant amount of research work that must be carried cut dealing with the physics and chemistry of interfaces, and fluid flow through a bituminous oil sand. In addition, the fundamental basic physical properties of interfaces, disturbed oil sands, including electrical and/or thermal properties, and chemical reaction behaviour at high pressures and temperatures, should be investigated. Further studies should be made of sub-surface mining techniques supplemented by external sources of energy, bitumen processing and upgrading techniques, and the utilization of by-products. The interfacial properties were found to be a function of crude oil composition, particularly of the surface-active constituents of the crudes. A new foaming technique was used to concentrate the surface-active agents contained in heavy viscous crude oils, and the dependence of interfacial properties on the surface-active constituents of the crude oil was studied. Introduction IN 1974, it was estimated that the in-place crude bitumen of the oil sands of Alberta (not including the heavy-oil areas of eastern Alberta) were at the proven level of 895 billion barrels. Of this, it was estimated that surface mining could result in the recovery of some 38 billion barrels; no proved recoverable reserves could as yet be assigned to in-situ methods of recovery techniques. From the standpoint of exploitation, it is generally concluded that surface mining is only applicable in areas where the overburden thickness is less than 150 feet and potentially feasible in-situ methods of recovery are probably only applicable where overburden thicknesses exceed some 700 feet. The reserves between 150 and some 700 feet are economically exploitable by current methods; however, some new and untried methods might be applicable here. This paper proposes, in part, to briefly review and describe these largely untried bitumen exploitation proposals, and to occasionally indicate future areas of investigation and research which could lead to a better assessment of their potential applicability. Secondly, some aspects of currently used or at least pilot tested extraction processes will also be discussed. Finally, attention will be focused on the urgent need for broad basic research leading to a better knowledge and understanding of the physical and chemical properties of the tar sands, in particular of the interfacial properties of the bitumen-sand-additives system under various conditions. General Review of Recovery Techniques Figure I, illustrates schematically the processes of in-situ and surface methods of recovery, and the bitumen upgrading common to both.