Annular fracturing has gained tremendous momentum across Western Canada, and Calfrac Well Services has quietly established itself as the leader in sleeve-shifting and fracture treatment execution.
The process of annular fracturing uses coiled tubing to open a sleeve so that a fracture treatment can be pumped down the annulus and into the formation. This pinpoint stimulation process can be repeated numerous times with a single coiled tubing trip. Sleeves may be left opened or closed, allowing for ultimate flexibility for the operator. And, at a later point in time, the wellbore may be re-entered to perform any number of treatment processes, including refracturing.
Chad Leier, Vice President of Sales and Marketing for Calfrac’s Canadian operating division, explains that “all of our field crews – both Frac and Coil – are proficient in this treatment style. We are aligned with several operators who have run thousands of sleeves in their wells. These operators understand the current benefits related to completions cost and well performance, and they also see the future potential.”
Adding traction to its claim as the leader in this completion technique, industry data sources reveal that Calfrac shifted more than 7,700 sleeves in 500 wells in 2015, and more than 3,200 sleeves in 170 wells already in 2016. The biggest recent transition has occurred in the Montney where Calfrac has shifted over 1,000 sleeves this year alone, with seven wells treating at pressures approaching 15,000 psi – conditions where execution and attention to detail are definitely important.
Derek Gorgichuk, Senior Coiled Tubing Advisor, adds “The evolution of annular fracturing has been expedited tremendously over the last two years. This has been highlighted with advancements in our understanding of friction values and annular velocity limits. Our experience has resulted in more effective treatment designs, leading to successful operations in excess of 6,400m in a 4.5” completion with operating pressures approaching 15,000 psi. Furthermore, the transition to 5.5” annular pinpoint completion has allowed for treating rates up to 10m³/min, which has enabled further optimization where rate is required to enhance the fracture complexity.”
Recent milestones demonstrate that this technique is capable of creating tremendous efficiencies. For ORLEN Upstream Canada Ltd., Calfrac recently performed 77 stages (sleeves) in one coiled tubing run. Treatment parameters included 2,700 tonnes of proppant in 23,000 m3 of recycled water at 6 m3 /min. And for Saguaro Resources Ltd., Calfrac successfully shifted and treated 65 stages in only 39 hours, while placing 2,000 tonnes of proppant at 9 m3 /min.
“With crews continuing to execute sleeve treatments in the Viking, Cardium, Montney and Deep Basin, our statistics continue to improve every day. We are also focused on the refrac potential that this market holds. Essentially, we’re now looking for older wells that were not stimulated correctly in the first place,” says Leier. Many wells were completed early in the industry’s development cycle when completions weren’t as efficient, and Calfrac is well positioned to assist operators as they work to continually enhance their understanding of reservoir quality – a highly important decision factor when making refrac choices.