(172c) Modeling In-Situ Production of Oil from Oil Shale
Production of oil from oil shale reservoirs requires thermal input. In the laboratory, temperatures of about 350 C are seen as necessary to achieve sufficient conversion of kerogen to oil. In in-situ operations, the heat can be imparted to the medium in the form of a convective medium (steam or any other suitable gas) or by resistive heating. The temperature profiles in the reservoir are governed by the rate and mode of the heat transfer method. Once the reservoir begins to be heated, the oil generation and production process is governed by a set of highly complex coupled processes ? heat transfer to the shale, kerogen decomposition, rock transformation and product transfer. In this paper, we explore the modes of heat transfer (convective and conductive) and the interplay of the time-temperature history in the reservoir with geomechanical and multiphase aspects of oil production from oil shale. The conductive heating mode reduces the need to create surface area for fluid injection ? but, the energy requirements are significantly higher. Providing the heat through injected fluids is challenging in this impermeable medium ? but provides an opportunity to explore innovative chemistry options and to lessen energy usage. There are technology options to make the oil production process energy neutral, and these are discussed in the paper.