A steam injection test, carried out in the 1.5 m physical simulator developed at the Alberta Research Council for the evaluation of in situ recovery processes for oil sands is described. The experimental facilities and procedures, together with the test data obtained are described.
Numerical modeling studies performed to simulate the test run using an implicit steam model are outlined. The capabilities of the numerical model, its mathematical formulation are described briefly without using equations. Relevant data for the simulation are given and the experimental results are compared with the model predictions.
Physical and mathematical models are used to obtain 1n understanding of the recovery processes of bitumen from oil sands by steam injection. Both these approaches, in principle, can be used to extrapolate laboratory data to the field and predict the performance of a reservoir. Physical modeling, using scaling factors obtained from dimensional and inspectional analysis, even though desirable, is in fact difficult because, not all relevent mechanisms can be scaled.
Mathematical models, on the other hand can be used effectively provided they have been validated by experiments. These experiments can be performed on reservoir elements or elemental models1. The materials and operating conditions in these elemental models are such that they represent some point in the actual reservoir and the recovery process involves the same mechanisms that operate in the reservoir. The physical shape and side of the elements is determined by the constraints of the test equipment.
In the following sections, the experimental equipment at the Alberta Research Council, to studythe in situ recovery of bitumen from oil sands by steam injection, is briefly described. This equipment, generally known as the 1.5 m physical simulator facility, can be used for scaled models as well as elemental models. The numerical modelswhich have been developed at the Alberta Research Council to simulate steam floods in the physical simulator are introduced. A steam injection testcarried out in the 1,5 m physical simulator and its numerical simulation using an implicit steam model are discussed.
A schematic diagram is shown in Figures 1 and 2. The equipment consists of a high pressure vessel, which contains the oil sand bed, three injection systems (steam, solvent and gas) and equipment to handle the production fluids. Process control and data collection is handled by a FOX 2/10, Foxboro minicomputer.
The physical simulator is designed for a maximum operating pressure of 11.4 MPa. It has an internal diameter of 1.5 m with an overall height of 2.5 m. The vessel is separated into two parts by a flange. The lower part which contains the oil sand is 1.5 m high. The upper part is pressurized with nitrogen gas to simulate the overburden pressure. The nitrogen gas is separated from the oil sand bed by means of a deformable carbon steel plate of thickness L2 AWG, which transfers the overburden pressure to the oil sand bed.