The Duvernay challenge
Much of the Duvernay shale formation in west central Alberta, Canada, requires horizontal drilling and completion. This method requires well-bore deviations to 90 degrees from vertical, along with multi-stage high-pressure fracture stimulations, or “fracking.”
One of Continental Alloys & Services’ clients, Trilogy Energy Corp., began operation in the Duvernay with two wells drilled in early 2012. The wells reached total depths more than 15,750 feet (4,800 m) and 17,400 feet (5,300 m), with horizontal legs of 5,400 and 5,740 feet (1,650 and 1,750 m) respectively.
When the casing string is run into wells like these, it undergoes bending forces. During fracture stimulations, the casing and connections are often subjected to pressures well beyond standard product performance capabilities. To be sure the casing string could reach total depth while handling directional changes, torque and high pressure, Continental Alloys & Services Inc. recommended proprietary High Performance P110 casing grades with enhanced burst and collapse capabilities, and U.S. Steel Patriot TC premium connections. This was the first application of its kind outside the United States.
Bending and twisting
The Duvernay is a perfect example of a play that could never be developed without technological advancements in fracking, horizontal drilling and oil country tubular goods (OCTG). The angles involved in these wells create high bending loads in the pipe and connections, combined with the torque applied during run-in, requiring high-strength alloy steels and reliable, robust connections. Operators require high strength alloy steels, and connections that offer excellent torque resistance and pressure capabilities.
The challenge, overcome
The two initial program wells were drilled as planned by Trilogy, and no problems were experienced during casing-string makeup or running. The Trilogy team was impressed by the high level of technical support provided by Continental Alloys & Services Inc., in addition to the on-time delivery and cost-effective performance of the HP P110 casing and U.S. Steel Patriot connections.