PRTISP, still in a conceptual stage, is a combination of four existing heavy oil recovery processes:
- Steam flooding
- Gas injection
- Pulse technology
- Toe-to-heel (TTH) short distance oil displacement (SDOD) process
Each of the processes is either currently being used commercially or validated fully (or to some extent) and separately. Lifeview believes any of these four processes, if applied individually and separately, constrains optimized oil recovery, while the combination of these processes, if integrated properly and applied effectively, could accelerate fluid flow in porous media and increase oil recovery significantly. PRTISP is perceived to be cost-effective and environmentally friendly process and potentially compares favorably to conventional heavy oil recovery techniques, namely, Steam Assisted Gravity Drainage (SAGD) and Cyclic Steam Simulation (CSS). At this stage, Lifeview thinks the PRTISP process can be applied to heavy oil (including oil sand) reserves.
Lifeview is very excited about recent developments and is highly optimistic about the effectiveness and commercialization of the PRTISP process in the future.
In principle, the PRTISP technology consists of continuous hot flue gas (generated at surface) injection and intermittent steam injection generated by hot water or liquid flashing to steam/gas bottom hole. Two thermal units and one mechanical control center (MCC) power generation/fluid storage unit are used for each injector: surface thermal unit generates hot gas and downhole thermal unit (heater) flashes hot water and generate pressure pulse. Acetylene, propane or methane gases are burnt at surface to produce exhaust gas, which is injected along with a hydrogen catalyst of which is added to the back side of the fluid injection. Slugs of hot water and catalyst are added to continuous hot gas injection. As a result of injection of exhaust gas at a high temperature, steam (flashed from hot water) expands. Reservoir is exposed to high temperature exhaust gas and pulsed high temperature flashed steam. Exhaust and make-up gas (Hydrogen) ratio varies depending on in-situ upgrading specifications (There is one notable benefit of adding hydrogen to injected steam: short distance oil displacement (SDOD) preserves potential hydro process upgrading). Pulse energy or p wave is generated downhole at tool ports and it propagates from injection well towards production well. Propagation of pressure wave is proportional to hydraulic diffusivity; permeability, porosity, total compressibility and oil viscosity are important parameters for pulse propagation. The process generates maximum amplitude of pulses so that the frequency of induced bottom hole pulses matches the natural oscillatory frequency of the whole reservoir. This matching is called resonance, which augments pulse penetration into reservoir and enhances short distance mobilization of fluids. Exhaust hot gas temperature and pulse steam frequency are coordinated to maximize production.
PRTISP vs. Traditional methods
Advantages of PRTISP over traditional EOR processes would include:
- Higher oil rates and ultimate oil recoveries, as compared to the conventional heavy oil recovery methods
- Economic: Due to increased recovery and well efficiency with short distance oil mobilization using small, skid mounted, modular hot gas generators, PRTISP has potential for cost savings in steam generation and water treatment, which could change the economics of heavy oil projects dramatically. Also, as PRTISP is less capital-intensive and entails low operating costs, it can be used economically in smaller plays, e.g. plays with only one million barrels of original oil in place (OOIP) where existing technologies such as SAGD and CSS are not economically viable.
- Greener process: PRTISP is a low-carbon recovery process. Carbon emission under this process seems to be substantially less than existing proven technologies. It addresses the environmental concern about the conventional heavy oil and oil sands recovery processes and could be a significant contributor to the industry.
- Widespread application: Application in the challenging situations when current injectors are partially blocked in connection with the previous production mechanisms. Potential attenuation of the negative effect of the bottom water
- Potential slight upgrading of the oil, pending the reservoir conditions, mainly pressure
- Potential attenuation of bottom water pressure
- Excessive power demand being put into the grid, increase to cash flow.
- Removal of wet gases capture and capitalize, increase to cash flow.