Learn how we successfully applied this process to our 14-29 well in Saskatchewan
CALGARY, Canada (June 4, 2024)—CHOPS (Cold Heavy Oil Production with Sand) is a unique method employed in the production of heavy oil reserves.
At Sonoro Energy, we not only believe—but have successfully shown—that CHOPS production can be successfully applied to horizontal wells. The proof lies in our 14-29 multilateral horizontal well near Kerrobert, Saskatchewan, where we believe CHOPS has been effectively initiated.
Unlike traditional primary and thermal methods, CHOPS focuses on extracting heavy oil in its natural state—utilizing sand as a natural aid, and associated gas drive that causes foamy oil, to enhance recovery.
Traditionally, this process has been carried out on vertical wells with large perforations to allow and not prevent sand production. Sonoro, meanwhile, has taken CHOPS and applied it to a horizontal well by utilizing multiple horizontals along with liners that are unconventionally designed with larger slot sizes to promote sand and foamy oil production.
While early weather and access issues, along with well downtime, prevented optimization at our 14-29 well over the first three months of production, we’ve made operational adjustments that have allowed for continuous sand and foamy oil production, while also controlling sand bridging, to optimize initial production.
At Sonoro, we believe we’re leading the way in the development of additional multi-lateral lined horizontals, using a proprietary junction tool—and that we’ve proven out further economical development of this area.
CHOPS: Maximizing oil production
The CHOPS process is beneficial to production in a number of ways:
Enhanced recovery: CHOPS has been shown to significantly increase the recovery factor of heavy oil reservoirs. By allowing the natural flow of oil and sand, with solution gas drive causing foamy oil, CHOPS taps into previously unrecoverable reserves, maximizing production rates over the life of the well. Sonoro believes this can be further enhanced utilizing horizontal wells with multiple legs and liners with larger slot sizes than is conventionally run in horizontals where slot sizes are restricted to mitigate sand production.
Adaptability: CHOPS is versatile and can be applied to a wide range of heavy oil reservoirs, including those with high viscosity and low permeability. Its adaptability makes it a viable option for maximizing production in challenging environments. The Waseca channel in Saskatchewan has shown to be heavier and more viscous but within flowable ranges for CHOPS, thus making it an effective mechanism.
Long-term sustainability: CHOPS promotes sustainable oil production by minimizing the need for energy-intensive and capital intensive recovery techniques such as steam injection. Its reliance on natural reservoir energy reduces greenhouse gas emissions and environmental impact. The 14-29 well utilizes its own casing gas for energy, fuel and heat with minimal facilities along with fewer overall multi-lateral wells being required versus verticals (and single leg horizontals) for field development results in better capital efficiency and economics.
Increased reservoir contact: Multilateral horizontal wells offer the advantage of accessing larger areas across heterogenous variations and multiple zones within the reservoir from a single wellbore. This increased reservoir contact can potentially enhance oil recovery efficiency when coupled with CHOPS methods.
Improved sweep efficiency: By utilizing multiple lateral branches, CHOPS in multilateral wells can promote better sweep efficiency, ensuring more thorough fluid displacement within the reservoir. This can lead to higher ultimate oil recovery compared to single-lateral wells. The 14-29 well is showing continued increases in production as the well operational continuity continues and is expected to continue to improve as new areas of the reservoir are drawn from and accessed with CHOPS.
Flexible reservoir management: Multilateral wells provide flexibility in reservoir management by allowing selective production from different zones or layers. CHOPS techniques can be tailored to optimize production from each lateral branch, depending on reservoir heterogeneity and fluid properties. The application of our new technical proprietary tool, allowing two horizontal lined sections, provides this flexibility in the longer term.
CHOPS at the 14-29 well: Challenges and solutions
The CHOPS process does present challenges with multiple lined horizontal wells. Here’s how Sonoro met those challenges to successfully apply CHOPS at our 14-29 well.
Challenge: Design complexities. Understanding the reservoir, depths and heterogeneities are key to designing well placed multi-lateral legs. Typically, operators run open-hole horizontal legs or only one lined horizontal with small slots.
The Sonoro solution: To enhance production, Sonoro ran a proprietary tool to allow lining on multiple horizontal legs and several open-hole sections. Sonoro also ran a tracer to understand where production comes from within the reservoir area accessed. In addition, Sonoro incorporated a 3D seismic to plan the well and geo-steering to stay within the top of the reservoir. To date, production is coming from the two lined sections. Over time, we expect additional reserves to come from areas not currently being produced maintaining peak production over a longer time period and overall higher recovery. Sonoro has also learned from further 3D seismic analysis and operational drilling to plan the next well with further improvements. The next well is planned to be a 3-leg lined horizontal well with no open hole sections.
Challenge: Sand management: Managing sand production can pose challenges in CHOPS operations. Historically, sand control measures and wellbore stability management have resulted in the restriction of sand production. With lined horizontal wells and with larger slot size, sand management is a key challenge.
Sonoro’s solution: The 14-29 well exhibited significant sand challenges in the first two months of production along with extreme weather conditions, resulting in well downtime, extra flushby services to maintain runtime, and well services to change pumps. In order to manage this Sonoro installed a coil string in the casing to the inlet of the pump allowing fluid (water with a sand-suspension-carrying chemical) to be recycled. This was installed in March—and since then, the well has not had any significant interruptions in production and the well has now reached its highest rates to date (approximately 80+ bopd).
While recycling fluid has its advantages, it also presents one main drawback—the added back pressure on the reservoir that can reduce inflow (but also helps manage sand influx), while the artificial lift PC pump is required to lift additional volumes. This has been a learning process with the variability of the reservoir inflow and operations but one which we now believe has given us the capability to optimize the current multi-lateral horizontal and also for the next well.
Our next Sonoro Signal on the CHOPS process at our 14-29 well will further describe:
additional history of the well
the continuous improvement of the well to an estimated current 80+ bopd over the past week with recent operational adjustments
our plans to perform an additional well servicing to change to a more optimal pump and reduce/eliminate the recycle.