Addressing Challenges in RTA using New Core Analysis Method
The RTAPK (rate-transient analysis, porosity and permeability) core analysis method reproduces conditions under which wells completed in unconventional reservoirs are operated in the field with the data analyzed similarly. As with rate-transient analysis (RTA) methods applied to wells in the field, RTAPK data analysis involves 1) identification of flow regimes and 2) application of models to extract parameters of interest. The RTAPK method yields multiple estimates of permeability and porosity in a fraction of the time of conventional core testing techniques.
RTA of field data has faced many challenges when applied to unconventional reservoirs including: 1) non-unique flow-regime interpretations (resulting from complex rock and fluid properties), which affects model selection; 2) uncertain reservoir/fracture property estimates as a result of 1); and 3) accounting for the effects of inter-well communication (through hydraulic fractures or the reservoir). Because RTAPK applies the same data analysis approach as field data, it can be used to address some of these challenges in the laboratory.
To address challenges 1) and 2), a case study using low-permeability reservoir samples from the Montney Formation is provided. Samples with different degrees of permeability heterogeneity (parallel to flow) caused by bedding/laminations were studied using RTAPK to assess the impact on flow-regime signatures and permeability estimates. Low to moderate levels of permeability heterogeneity resulted in the flow-regime sequence, similar to field cases of hydraulically fractured wells completed in homogeneous reservoirs. However, a high permeability heterogeneity sample resulted in a flow-regime sequence resembling field signatures previously interpreted to be caused by fracture heterogeneity. The laboratory results suggest an alternative interpretation for the latter.
To address challenge 3), for the first time, inter-well communication in the lab was simulated using RTAPK. A new apparatus allowing flow from both sides of the core plug was constructed for this purpose. The results, as analyzed with flow-regime identification and contacted fluid-in-place plots for the parent well, resembled simulated cases of parent/infill well communication.
Finally, relevant to the energy transition, RTAPK was used to study water production from a low-permeability siltstone core plug, applicable to the evaluation of enhanced geothermal systems, and hydrogen production from a coal core plug, applicable to the evaluation of hydrogen storage in deep subsurface coal reservoirs.
Registration closes on Monday, June 9 at 8AM MDT.
This event will be held in collaboration with the Canadian Energy Geoscience Association (CEGA). CEGA Members will also be eligible for Member pricing. Please select the "CEGA Member" pricing option, and enter in your CEGA Member number when prompted to enter an SPE Member number during the registration process. Visit the CEGA website here: https://cegageos.ca/
Date/Time
Tuesday, June 10, 2025
Registration: 11:45 AM MDT
Start Time: 12:00 PM MDT
End Time: 1:00 PM MDT
Location
Calgary Petroleum Club | 319 5 Ave SW, Calgary, AB, T2P 0L5
*This event will be hosted in-person only, and will not be recorded.
Speaker Bio
Christopher R. Clarkson, PhD, PEng
Tamaratt Research Professor and Adjunct Professor, University of Calgary
Christopher R. Clarkson is the Tamaratt Research Professor in Transitional Energy, and the Ovintiv/Shell Chair in Unconventional Gas and Light Oil research, in the Department of Earth, Energy, and Environment (formerly Geoscience), and an adjunct professor with the Department of Chemical and Petroleum Engineering, at the University of Calgary. His most recent industry work focus has been on exploration for, and development of, unconventional gas (UG) and light oil (ULO) reservoirs. His research focus, since coming to the University of Calgary in 2009, has been on advanced reservoir characterization and evaluation methods for UG-ULO, such as rate- and pressure-transient analysis, flowback analysis, DFIT analysis, and reservoir sample analysis. He is also interested in the application of these advanced reservoir characterization methods to the evaluation of transitional energy pathways using the subsurface, such as geological CO2 storage, hydrogen storage, geothermal energy, and critical elements recovery. Clarkson is the PI of the industry- and government-sponsored research group called “Tight Oil Consortium" and co-PI of the recently initiated “Transitional Energy Consortium”.
**Please Note
Lunch will be served. Please be sure to include your dietary restrictions during the online registration process so we can do our best to accommodate.
Canadian Energy Geoscience Association (CEGA) Members will also be eligible for Member pricing. Please select the "CEGA Member" pricing option, and enter in your CEGA Member number when prompted to enter an SPE Member number during the registration process.
An event reminder will be sent the day before and the morning of the event.