Writer Elsie Ross recaps the potential of muon tomography for SAGD reservoir monitoring in this piece that ran in the Daily Oil Bulletin on July 27, 2020 (subscription required).
A Canadian technology that employs cosmic rays to see into SAGD reservoirs could be the next frontier when it comes to reducing monitoring costs and optimizing oilsands recovery rates.
“Muon tomography is essentially a passive source that an operator can harness to be able to discern what’s going on with their reservoir over time,” according to Thor Kallestad, an oil and gas consultant and reservoir specialist for Vancouver-based Ideon Technologies Inc. “If you just put detectors underneath the reservoir, over time it just paints a really nice picture of what’s going on with your reservoir.”
Ideon, a spin-off of the TRIUMF (Canada’s national particle accelerator laboratory at the University of British Columbia) has developed a discovery platform that provides x-ray-like visibility up to one kilometre beneath the earth’s surface. It’s now looking for a SAGD operator prepared to deploy the system on a trial basis, beginning in the first or second quarters of 2021.
Muons (pronounced myoo-aan) are particles that are continuously bombarding the earth. Because they interact with matter, muons are indicators of density changes. Muon tomography uses the paths of many muons to illuminate the subsurface density distribution. During reservoir production, the density distribution changes due to injection and the extraction of material. Muon sensors deployed in boreholes are thus able to monitor production processes and could lead to optimizing production and conserving energy and water.
“As muons pass through the reservoir, they hit the detector and then there’s a connection to service via a wireline cable or some other method,” Kallestad said in an interview. “That information comes to surface, gets processed, and then the client gets a picture of what’s going on with that reservoir, all for the effort and expense of putting sensors below the reservoir.”
Ideon’s proprietary detectors, imaging systems, inversion technologies, and artificial intelligence techniques generate three-dimensional density signature maps that reliably identify underground anomalies, clearly distinguishing them from their surroundings. When working with clients, Ideon delivers a full survey design, analysis and a 3D density model of the surveyed area, which is then integrated into industry-standard software packages.
“It’s definitely early days for these technologies,” said Kallestad. Ideon would install detectors below a segment of the reservoir to demonstrate what its technology can do by way of imaging that part of the reservoir. “If the client’s happy with that, then you can kind of go on to the next steps and expand it,” he said.
“If you have an area that has already been drained, you can really target your steam-oil ratio and how you go about developing that reservoir and you can do it with much more knowledge of what’s going on with the rock and then in so doing lower your cost of production.” It also boosts competitiveness, said Kallestad.
An array of detectors installed underneath SAGD reservoirs would eliminate the need for active monitoring such as 4D seismic while removing a lot of the surface safety risks, he suggested. “You wind up being able to image the fluid dynamics over time, quite effectively in the reservoir.”
Reducing the cost of reservoir monitoring also would enable operators to more rapidly recoup the capital costs of their projects and increase their economic competitiveness, according to Kallestad.
Up until now, Ideon’s main focus has been on mineral exploration for mining but a recently published study published in The Leading Edge, a publication of the Society of Exploration Geophysicists, demonstrated that muon tomography can be an applicable tool for continuous reservoir monitoring, he said.
The paper modelled a McMurray SAGD reservoir, looking at 1.25 years (rising) and five years (spreading phase) after initial reservoir production with muon detectors placed 30 metres below the bitumen reservoir at 230 metres total vertical depth. The numerical modelling approach is able to model a wide range of SAGD reservoir geometries and detector arrays toward planning of optimized monitoring solutions, according to the study, co-led in part by Doug Schouten, Ideon’s chief technology officer and a global expert in muon technology.
The relevance lies in the fact that the muon tomography observations illuminate a reservoir on short time scales, which is often not possible from other geophysical surveys such as seismic, according to the paper. Muon tomography has also high localization power and is able to be integrated with other survey types in inversion models, it concluded.