ABERDEEN -- Deep Casing Tools has completed the first offshore run of its new Turborunner reaming system in Petro-Canada’s Saxon field in the central North Sea. The tool was unveiled this week at the company’s booth at OTC.
Turborunner is a fluid-powered reaming system for use with most types of liners and sand face completions. The tool is designed to aid first-time placement, and is run using a low flow rate and low operating pressure in order to protect completion components in the string.
According to Deep Casing Tools CEO Lance Davis, development only started in 2008, and has been heavily supported by BP in particular, which has provided funding “with no strings attached”.
“BP invested early,” Davis adds, “and after witnessing the trial conducted by Petro-Canada, they are now trying to qualify us as one of their vendors.”
Last year Deep Casing Tools built its first two prototype Turborunners. To test the system’s downhole motor, flow tests were conducted at the Weatherford Bridge of Don test center – “the motor has a very low start-up pressure,” Davis points out, “and runs at very low flow rates of around 2-3 b/m. The Aberdeen NOV facility provided dynamometer torque tests which proved that the output power matched design predictions.
Petro-Canada were keen supporters of new technology from the outset, and provided the first offshore trial application. Having had difficulties on a previous development well on Saxon, after encountering hole instability in the sand/shale sequence, “they felt our tool presented no risk, being attached to the bottom of the completion string.”
Turborunner was chosen for a horizontal application in 21/23b-S2, a sidetrack of the aborted well, which was drilled by the semisub JW McLean. “When we entered the well, the hole had partly collapsed,” Davis explains, “so we had to ream through.” After a 12-hour reaming operation, the completion, involving a 3,000-ft (914-m) pre-drilled liner, was successfully run.
The tool is designed to allow drilling engineers to achieve open-hole completion placements, and combines optimized washing with a rotational reaming capability without the need to rotate the completion string. The tool’s low operating pressure facilitates integration with most existing completion systems and eases first-time placement of liners. “It’s basically a very simple insurance system,” Davis claims.
The company also exhibited at OTC Turbocaser, a more powerful drill-thru reaming tool designed to ensure first-time placement of casings or liners at target depth. The system is powered autonomously by a variable-speed motor that is also drillable. Its reamer shoe rotates at relatively high speeds, the upshot being improved reaming rates.
BP has shown an interest for their operations in the North Sea – “they definitely indicated a need to get their casing in the right place,” Davis says. There has also been interest from an operator in the Java Sea, and for Petrobras for use in pre-salt drilling. “When drilling through pre-salt, by putting in a reamer-powered shoe you can improve your prospects of landing the casing correctly in the subsea tree.”
OTC.10: Reaming tool overcomes hole stability issues