Novel Laboratory-Scaled Modeling of Hybrid SAGD and In Situ Combustion
Creators: name: Aminfar, Ehsan
Publisher: name: Schulich School of Engineering
Year: 2022
Subjects: subject: ISC
subject: Hybrid SAGD
subject: In Situ Combustion
subject: Laboratory Model
subject: 3-D Model
subject: Engineering
subject: Engineering--Petroleum

description: Proper modelling of the emerging technologies in the laboratory is imperative. After reviewing an array of models designed and built-in industry and academia, it was found that models built in academia generally compromise the accuracy of the physical model due to financial burdens associated with construction and operation of such models. In addition, due to conflict in scaling parameters of the recovery technologies, namely SAGD and ISC, the conventional packing methods used in such experiments could not satisfy the two technologies’ scaling criteria. To address the previous model’s shortcomings and enable academia to conduct large-scale three-dimensional (3-D) models design and operation, a novel large-scale 3-D physical model was designed to evaluate the prospect of a hybrid air and steam injection technology in a SAGD configuration utilizing up to three well-pairs. For each test, the 3-D model was packed with a low oil saturation core or lean zone, representing the reservoir portion swept by steam and a high oil saturation core or rich zone representing the un-drained zone between two coalesced steam chambers. These zones were made with preserved native “lean” and “rich” cores from Athabasca reservoirs. Steam was injected into the model to develop a representative steam chamber in the lean zone. This novel model is differentiated from other existing models by size and geometry, a unique heater design and operation strategy and a proprietary packing technique that mimics SAGD chambers at time zero. The one million dollar project was a collaboration the University of Calgary’s In Situ Combustions Research Group (ISCRG) and Statoil Canada’s (now Equinor) to define the representative test criteria using more than one metric tonne of frozen native core material as packing in the three experiments. Multiple disciplines in academia were involved to operate the technology. Test #1 ran at 3,000 kPag (435.1 psig), proving the mechanical integrity of the set up. It revealed a need to re-design the heaters for an optimal outcome. The Test #2 at 2,700 kPag (392.0 psig) and the Test #3 was done at 2,650 kPag (384.35 psig) . Each test utilized Statoil Canada’s (now Equinor) native core and oil samples with a focus on injecting water/steam with air and testing the infill well concept. Analysis of the data demonstrated the ISC process spontaneously ignited immediately after introducing air to the steamed reservoir. ISC addresses a deficiency of SAGD by recovering irreducible oil to steam in the chambers and the untouched oil left in the ‘wedges’ trapped between two chambers by roughly 23.8% which is within range of the simulation modelling. Significant upgrading of oil was observed compared to the original bitumen as well as the difference in the properties of the oil produced from the top and bottom production wells. This production was achieved by burning roughly 75% of the core material and mobilizing 80% of the initial water saturation including the water injected during steaming. 15.5 % of the oil in-place was consumed as fuel. The subject 3-D model’s integrity was achieved and a best practice operation was established.