Evaluation of Solvent Vapour Extraction (SVX) Processes Using a 3D Physical Model — Year 3: In Canada, of the estimated 30 billion barrels of heavy oil in place, about 26 billion barrels are considered unrecoverable using current technology. However, solvent vapour extraction (SVX) processes offer an attractive alternative to thermal recovery processes because they are less energy intensive, use less water, avoid CO2 production and are more suitable for thinner, partially-depleted reservoirs. This third year of research comprises two experimental tests to be conducted on a 2.5-m thick 3D scaled physical model apparatus. The tests will investigate the relationship between oil production rates and recoveries, and solvent-to-oil mass transfer dispersivity for two different oil–solvent systems. Horizontal wells will be used to inject/produce mixed solvents to recover diluted oil. A new live-oil resaturation and residual oil mapping procedure will be used. Semi-analytical and numerical simulation history matches will be conducted. The third year of this four year project will cost $300,000.
Scaled Physical Model of Post-Cold Production: Solvent-based processes are being considered to further recover heavy oil after cold production. Cyclic solvent stimulation of wormholed reservoirs under gravity drainage conditions will be investigated in physical models. A numerical simulator will be used to history match the experimental production data and to predict field recoveries. This one-year project will cost $105,000.
Multi-Well Cold Flow Numerical Model: A multi-well cold flow (production) model is being developed in order to optimize the exploitation of cold production fields and to characterize the wormholed reservoirs for post-cold production processes. This year, the multi-well model is being tested against multi-well field data on the reservoir section scale. The SRC cold production model will be modified to incorporate capillary-number- dependent gas relative permeability curves and water-phase flow equations. This one-year project will cost $99,000.
Gas Relative Permeability Measurements for Solution-Gas Drive: The prime objective of this project is to improve the numerical simulation of the primary oil recovery process by incorporating relative permeability curves performed at field capillary numbers (velocities). More specifically, three solution gas pressure depletion experiments will be performed at capillary numbers (velocities) spanning the range in capillary numbers calculated by SRC’s multi-well cold production model. A correlation will then be obtained between capillary number (velocity) and relative permeability to gas for heavy oil. This 18-month project will cost $150,000.
Equation-of-State Characterization of Heavy Oils — Year 1: This research plan is aimed at establishing a firm basis for characterization of heavy oils. The benefits of establishing reliable correlations for design and field simulation are ultimately expected to be very widespread, especially for the screening and optimization of any composition-sensitive enhanced recovery projects in heavy oil fields. The work will begin with the assembly and evaluation of existing data on heavy oil property measurements, and will continue with a detailed investigation of suitable analytical methods. In view of the broad research scope, a program that extends into two or more additional years of work is anticipated. This one-year project will cost $75,000.
Post Cold Production EOR — Air-Injection Pilot Preparations: Under this project, a research team from both SRC and the University of Calgary will support and encourage interested companies to establish a field pilot for a new air-injection process that is expected to perform well in cold-produced heavy oil reservoirs. If successful, the process will open up a large portion of the Lloydminster fields to enhanced oil recovery. In advance of the field pilot design, the projected operating conditions will be tested through the use of newly available software for simulating cold production. Finally, additional data for the development of a new chemical reaction model — a key prerequisite for future simulation support of the air-injection process — will be obtained. This one-year project will cost $75,000.Br>
Coupling Gas and Polymer Injection to Improve Heavy Oil Recovery: This research is building upon prior efforts of SRC to improve the recovery efficiency of immiscible gas injection/polymer floods through the design of optimal gas and polymer slug size/concentration and injection strategies. The specific objectives of the research are to: 1) measure PVT properties of CO2–oil systems at given conditions; 2) select compatible polymers; and 3) conduct coreflood tests in sandpacks to investigate the technical feasibility of the proposed polymer-alternating-gas process for recovering heavy crude. This work will take one year to complete at an estimated cost of $210,000.
Optimal Solvent Properties in Immiscible Gas Flooding for Improved Heavy Oil Recovery: The main goal of this research is to provide the optimal solvent composition to improve the recovery efficiency of immiscible floods. A full characterization of solvent properties in contact with both oil and porous media could help to optimize the flood process. Several investigations, including the overall effects of solvent components, injection rate, slug size, and injection sequence, and of the effect of solvent characteristics on wetting tendencies, are being conducted to improve solvent sweep efficiency and increase oil recovery. The work will take one year to complete at an estimated cost of $235,000.
Improved Waterflooding of Heavy Oil: Application of heavy oil waterflooding is largely experience-derived as theoretical knowledge is scarce. SRC statistical studies show that conventional waterflooding theory for medium and light oils is not appropriate for heavy oils; therefore, SRC proposes to advance the use of a micromodel to visually reveal oil-brine interactions at the pore scale. This qualitative data will help to determine the fundamental mechanisms. An aspect of this research is a collaborative study on CO2-assisted flooding: adding CO2 to the injection water to improve oil viscosity and mobility and hence recovery by heavy oil waterflooding. The fundamental knowledge research along with the expanded scope would enhance numerical simulation and may also result in operational improvements. The project will run for one year and will cost $315,000.
Success of Heavy Oil Waterfloods ─ Factors and Predictions: This is the third phase of the Saskatchewan Research Council’s statistical work on heavy oil waterfloods. Multivariate analysis of 168 western Canadian waterfloods indicated that there are marked differences between waterflooding heavy oil reservoirs compared with their lighter counterparts. New reservoir and operating parameters will be investigated for their effects on heavy oil waterflooding ─ including injectivity characteristics and factors involved in operations that combine waterflooding and gas injection. The multivariate models will be advanced from a descriptive phase to a predictive phase. Pools currently on primary production will have their waterflooding suitability predicted, and the most similar waterflood identified. The project will last one year and cost $194,000.
Waterflood Additives for Improved Heavy Oil Recovery: The study is aimed at advancing development of a technically and cost-effective enhanced heavy oil recovery process that uses the mechanism of interfacial instability. The research is examining, in a more realistic setting, the in-situ dispersion triggered by the reaction of an injected chemical solution with the natural acids in oil to create interfacial instability and mild mechanical shear. To understand in-situ dispersion in porous media, the study includes emulsification screening, interfacial tension measurements, examination of the effect of chemicals on wetting tendencies, micromodel tests, and a series of corefloods with 1-D sandpacks. This work will take 12 months (the first year of two) to complete at an estimated cost of $235,000.
