Webinar FAQ: Zero GHG Production of Oil Sands Reservoirs Using RF Heating
With increasing pressure on the industry to improve ESG performance, RF heating offers a path to zero emissions where it can rely on entirely renewable sources of power in addition to eliminating the use of fresh water . While the cost of such renewable sources has prevented it’s use on commercial scale, advances in RF heating technologies and in renewable power generation are making this concept a viable alternative for the near future.
The webinar "Zero GHG Production of Oil Sands Reservoirs Using RF Heating" covered the economic and operational realities of producing a zero-GHG barrel of heavy oil or oil sands by applying renewable sources of energy to power a RF heating system. Radio frequency (RF) energy has been considered for downhole heating as early as the 1940’s. Recent developments in this technology have generated new interest due to its economic and environmental benefits and for its ability to produce a wide range of reservoirs including many that to date have not been considered commercially viable. The technology operates by delivering controlled electromagnetic energy (EM) directly into an oil-bearing formation. The electromagnetic energy raises the temperature of existing water in the formation, enabling production.
During the webinar, many great questions were asked, but we ran out of time and didn't get around to answering them all. Below is a list of answers to the questions that we were asked. If you have any more questions, please comment them below.
- How does the ratio of energy out to energy in for RF compare to conventional open pit or conventional SAGD extraction?
Simulations we have performed to date show that RF XL typically requires 40-60% of the energy that SAGD does to produce the same amount of oil from a given reservoir.
- Is this technology applicable for SAGD in heavy oil reservoirs, such as those in Saskatchewan?
Yes, the properties of the reservoir in the whitepaper are typical of heavy oil reservoirs in the Lloydminster region of Alberta and Saskatchewan
- How deep does the bitumen need to be to use this technology? Could it work in shallow (mineable depth) resource? Or is pressure a depth constraint?
Acceleware believes the RF XL technology could support production from shallow resource at 50m deep or more and up to 1000 - 1500m deep.
- Are there any concerns in regards to hazardous EM radiation that can radiate to the surface?
Our RF power generation and delivery system utilizes multiple fail-safe layers of sensors that monitor surface RF signals, and will shut down the system within milliseconds if any stray energy is detected. The technology is designed to completely prevent leakage, both to ensure safety and to ensure maximum efficiency in the use of energy to mobilize oil. In any RF heating deployment, oil operators will provide complete dimensions and parameters of the oil bearing portions of the sub-surface in advance of production. Each RF heating system is then designed and deployed to ensure maximum operational efficiency within those parameters. The result is that the vast majority of energy delivered to the pay zone is absorbed by the connate water within the preprogrammed dimensions, and converted to heat used to mobilize the oil. The amount of RF energy that reaches beyond the edge of the formation is minimal, and is at levels that are well below the safety limits established by the federal agencies and regulatory bodies round the world.
At the end of the production cycle and when the steam chamber is at its largest (and the reach of the RF energy is at its greatest) the magnetic field generated by RF XL at the edge of the oil bearing formation is approximately 1/40th of the field generated by a hair dryer held 15 cm away. The safety exposure limit for the public set by ICNIRP for magnetic fields is almost 7 times that of the same hair dryer, so the RF energy at the peak of its reach underground is 285 times lower than the safety limit.
At that same point in time, the electric field at the surface for an RF XL system 200m below ground is 64 million times less than that of a 120 kV high voltage power line 10m above you. The ICNIRP safety limit for electric fields is 128 million times higher than the RF energy that reaches the surface.
- Would there be any economic benefit of using electricity battery storage in this use case?
At current pricing the cost per MW for battery storage was not deemed to be economic but with prices falling this assumption could change over time.
- Do you anticipate ever having to inject water/steam as the wells deplete to maintain the required heating?
In all simulations performed to date by Acceleware, there has been enough water at the end of the production life cycle to continue to generate and transfer heat to the formation effectively. While the process produces water along with oil, the volume of water is much smaller than what is produced in the SAGD process.
- How much do you suppose the WTI/WCS differential in your economics?
The economic models use a WTI/WCS differential of $12 USD. Our recently released whitepaper provides additional details on the economic assumptions used.
- Why do you use two heating lines per producer? compared to a single steam injection well in traditional SAGD?
The two heating lines are fundamental to the design of RF XL. Our Feb 2019 Whitepaper provides a full explanation of how the tehnology works and why the two lines are needed to heat the formation efficiently and evenly.
- Is this technology amenable to shut-ins during market cycles or would there be detrimental damage to the reservoir?
The idea of short term shut-ins (on a daily basis) has been incorporated into this analysis to accommodate the intermittent nature of the solar power source. In a daily intermittent cycle the heat in the reservoir is maintained (see Zero GHG Whitepaper for additional details on this) and there are no detrimental effects on the reservoir or on production. Long term shut ins where no energy would be applied to the resrvoir would at some point result in cooling, solidification, and then decreased production levels.
- You mentioned it could work in thinner reservoirs. How thin are we talking? 4-6 meters?
Based on the current design of the technology, we have seen simulations showing economic results in pay as thin as 7m. Acceleware is working to develop alternate designs that could provide economic results in 4-5m thick reservoirs.
- Could you briefly comment on applicability of RF heating to remove neatbit from rail cars?
Acceleware sees future potential for RF heating to be used in place of steam to allow neatbit to be shipped safely to market by rail. This adaptaton of the core RF XL converter platform will be further evaluated upon the completion of the commercial scale pilot test at Marwayne.
- Did you consider wind in parallel (or on its own) with solar to increase the renewable energy input?
The analysis shown in the webinar, and in our Zero GHG Whitepaper, used only solar power. It could be advantageous to incorporate wind power as well to take advantage of a diferent cycle of intermittent power.
- The well pair production of 6K bbls per day sounds a lot. How long are the production wells and what diameter?
The 6K bbls/day production level is during short peak periods only. Please refer to our July 2020 Zero GHG Whitepaper to access all of the operating assumptions used in the economic models.
- Have you considered impact of cloudy days?
Yes, the amount of energy generated in each of the three scenarios takes into account the average number of cloudy days and the total amount and intensity of sunlight that will reach the solar array.
- How do formations differ in available water in the formation? I.e. RF creating steam from water in formation.
The RF XL heating process is effective at water saturations ranging from 8 - 35%. Simulations show that half of the initial water saturation remains at the end of the heating and production process.
- The project looks bright with new technology, my questions:
- What is total cost (CAPEX+OPEX) compared to SAGD at same capacity?
- Oil Recovery % compared to SAGD? Is it more?
Please refer to our July 2020 Zero GHG Whitepaper to access all of the operating and economic assumptions used in the analysis shown in the webinar.
- What were the results of the commercial test with Prosper Petroleum?
- What is the difference with Sunco test for them to require a solvent?
- Is Suncor still utilising this technique after teir test?
Acceleware orignally reached an agreement with Prosper Petroleum Ltd. to complete the pilot test at their Rigel project. That project did not proceed and earlier in 2020 the AER approval for the Rigel project was revoked by the AB courts. Acceleware announced an agreement with Broadview Energy in May of 2020 to complete the test at their Marwayne site and expects to start the test in December of this year.
I believe you are referring to the ESEIEH project. Our technology injects only EM energy to moblize the oil. The ESEIEH approach uses a combination of solvent injection and EM energy to achieve mobilization. I believe there are public materials available via ERA and others that may better answer the questions on that process.
I am not able to answer question 3.
- Has there been any investigation of alternative power storage for remote sites instead of batteries. (Ie. Power-trap heat-power generation) I am aware there is a cycle loss factor but may offer increased power storage?
For the purposes of the analysis performed for the webinar and for the Zero GHG Whitepaper alternative power storage options were not considered, but could be explored in the future.
- In near surface applications, is subsidence (sinkholes) an issue?
Depending on the recovery factor and the structure of the overburden subsidence could be an issue to be considered for near surface applications.
- How is the performance of RF XL in a vertical trajectory?
The design and heating process RF XL uses requires a long well to operate efficently. The optimal operating length can range from 500 - 2000m and therefore the current design is not well suited to operate as a vertical heating well. Future designs of RF XL may be able to support the use of vertical heating wells of much shorter length.