Download Issue 131 - January/February 2010 - SPE WA

Drilling AheadAnother hybrid CT unit. Unconventional reservoir CBM plays 650 m TD. Injector, Stewart & Stevenson—maximumcapacity 110,000 lb w/snubbing capacity 60,000 lb, 3-1/2” CT string. Drilling location: 150 km northeast of Calgary.Drilling Contractor: Technicoil Corporation, hybrid CT unit#2120; Operator, Devon Energy.Nabors' hybrid CT unit in the CT drill mode. From a safetystandpoint, there is no human interface; as shown, youcompletely clear the drill-floor of personnel when drillingin CT mode.It allows you to set up a range of drilling andformation parameters based on localisedknowledge of the formation properties, and,most importantly, it can react much faster thana human can. In this fashion you don’t stall themotor, nor buckle the CT string. The advent ofrigless completion in unconventional plays isanother driver in hybrid CT service roles. HybridCT units can perforate wells and do drill-outswhich were typically conducted by conventionalservice rigs. In the past, the well tractor hasbeen the main method of deploying directionaltool packages—however, the limitation ofthe tractor is wellbore integrity. For example,if wellbore trajectory includes any steepinclinations or deviations in the well path, thetractor has a tendency to 'spin-out' and depthsmay not always be achieved. With coil, youhave the ability to use force from the surfacethrough the injector head, thus you don’t relyon wellbore integrity for the ability to moveforward.On the other side, the busiest individual hybridCT unit during 2007 was Trailblazer DrillingCorp’s rig#19, which managed to drill 295wells and 201,310 m of hole over the 12 monthperiod. This is certainly drilling technologywithout borders! In fact, from the beginningof 2000 to the end of 2007 more than 30,000wells have been drilled in Canada using hybridCT technology, proving that hybrid CT rigs areno longer a fad or curiosity but have become aprimary service and a key technology in shallowoil, gas, and especially CBM drill-to-completeapplications.On the left, Eugene Murphy, Investment Principal, Kenda Capital, manager of Shell Technology Ventures—at the KendaOffice in Houston Damir and Eugene have a discussion about hybrid COTD drilling technology.22 SPE NEWS January/February 2010Hybrid CT advantages are:• Flexibility to drill with coil and/or conventionaldrill pipe from spud-to-completion;• Two rigs in one—smooth transition torequired drilling mode;• Ideal for underbalanced drilling andcompletion or controlled pressure drillingapplication;• Can snub if required;• In CT mode no surging and swabbing ofwellbore;• Proven to out-drill conventional three-to-onein Canadian unconventional reservoirs;• Faster penetration rates—coil up to 420 mper hour vs conventional 120 m per hour;www.spe.org