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1/3March 2012 | EPmag.com

Achieving first production is the end goal for theentire drilling process. The gap between spud and

total depth (TD) is a defining success factor for opera-tions onshore and offshore. As operators continue to

push the envelope of viable production targets, technol-ogy companies continue to set the pace for how deepand soon a well can be drilled.

As tools become better defined and new parameters areset, the cycle time for most drilling projects continuallydecreases. And, in many cases, many tools and processesbecome standard operating procedures once they areproven in the field to be a viable way of reaching produc-tion safer, faster, and with fewer costs related to nonpro-ductive time (NPT).

In North America and abroad, several record-settingapplications have shown how operators are investing more

in advanced technology to save on overall project costs.

Hybrid technologyThe benefits of combining multiple qualities into one

component or machine can create improved performance

without necessarily reinventing the wheel. Although the

concept was not new, Baker Hughes recently commercial-

ized its old idea of manufacturing a hybrid drillbit to com-

bine roller cone and PDC technology to produce a hybrid

bit with maximum durability and cutting efficiency in

tough and challenging applications compared to conven-

tional bit technology.

An operator in Norway contacted the company forassistance with a planned exploration well containing ademanding basalt interval.

While basalt drilling is uncommon in conventional

wells, Baker Hughes saw the Kymera hybrid drill bit asideal for this application. To validate the bits ROP andits durability in igneous rock, the company identified apotential geothermal application for a field test.

Baker Hughes drilled two different sections in the geot-hermal test, 17-in. and 12-in., for a total of two runsusing the hybrid drill bit technology. Historically, the bitsused in the offset geothermal offset wells would drill toTD but with reduced ROP. The driller achieved an aver-age ROP of 10.8 m/hr (35.4 ft/hr) in the 173-m (567.6-ft) 17-in. section to TD of 270 m (885.8 ft), which wasalmost three times faster than runs in offset wells.

The company had proven that PDC bits were a viableoption in an Icelandic basalt application in a previous12-in. run. However, controlling downhole vibrationwas a challenge that resulted in severe cutter breakageand overall reduced the cost saving potential comparedto conventional roller cone technology. The team usedthe Kymera hybrid bit on a steerable motor and was ableto control ROP by reducing weight on bit (WOB). Theteam drilled the 12-in. section 487 m (1,597 ft) to TDwith an average ROP of 21.3 m/hr (69.9 ft/hr). Withthe resulting reduction in vibration, both Kymera bitsexperienced minimal wear, proving the value of the

COVER STORY:

DRILLING ADVANCES

New bits,

technologyraise baron drilling

performanceTayvis Dunnahoe, Senior Editor

Improvements highlight benefits of

advanced technology globally.

AS SEEN IN

MARCH 2012

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PDC and roller cone concept in basalt-like formations.The 12-in. interval achieved its directional objec-

tives, including build inclination from 0 degrees to 35degrees. Drilling parameters were held back for bothsections to manage well integrity, yet the Kymera hybridbit drilled more than twice as fast as premium roller-

cone bits compared to offsets.

Shale development, proving groundThe vast amount of growth experienced in North Ameri-can shale plays has provided ample room for a numberof record-setting achievements. Extended-reach drilling,multilateral well bores, and building curve from vertical tohorizontal are not as challenging as they once were. How-ever, continuous improvement is required to maintain lowcosts while drilling. Reducing cycle times brings on thecompletion stage sooner, which can account for around50% of a well cost in most unconventional shale plays.

Bits are big news in the unconventional market.Ulterra recently set a footage record for Roger MillsCounty in Western Oklahoma with its new 12-in.U616M six-blade matrix PDC bit using 16-mm cutters.The bit drilled 2,153 m (7,065 ft) from surface casingdown to a depth of 2,474 m (8,115 ft) for an estimatedcost savings of US $44,500 versus the closest offset. Thissavings increased to $88,500 when compared to the aver-age of five offset wells. The companys latest generationU616M is the result of extensive bit design and cuttertesting in the Granite Wash play and has continued toset records in the area.

In January, the companys U616M 8-in.bit drilled from surface casing to TD at arecord pace of 28 m/hr (93 ft/hr) in the

Eagle Ford. The vertical, curve, and lateralall were drilled with the same bottomholeassembly, which reached TD without a tripout of the well. In all, it took only 107hours to drill 3,035 m (9,953 ft), represent-ing a time savings of 37.5 hours over thefastest offset of 144.5 hours. Cost savingswere estimated at $77,566 versus the directoffset and $133,024 compared to the aver-age of five competitor offsets.

The bit was designed to increase slideefficiency and reduce unnecessarily high

slide percentages. It maintains sharpnessthroughout all three drilling intervals,thereby minimizing torque fluctuationsand resulting in better toolface control,minimized bit-induced stick-slip, andreduced impact damage.

In the Bakken, Halliburton raised the bar for lateraldrilling. On a Williams County, North Dakota well, thecompanys 6-in. FX64 drilled the entire 3,055 m (10,019ft) of the lateral section on a high-speed motor to a TD of6,316 m (20,709 ft) measured depth (MD) in only 95hours. This proved to be the fastest lateral among the off-

sets with an average ROP of 32.1 m/hr (105.4 ft/hr).This bit was the first to drill the entire lateral section, andits performance provided the lowest cost-per-foot amongsimilar offset runs.

Longest running deepwater MPDDrilling technology also is advancing offshore. In theMakassar Straits of Indonesia, Weatherford in conjunc-tion with Transoceans GSF Explorerhas mounted what isnow the worlds longest running deepwater managedpressure drilling (MPD) project.

Installation of the first MPD system integrated into a

marine riser below sea level provided a flexible solutionthat enhanced drilling capabilities across multiple sec-tions throughout the drilling campaign. The MPD systemimproved safety and efficiency through early kick detec-tion and control, riser gas handling, and two variants ofMPD: constant bottomhole pressure and pressurized mudcap drilling. Constant bottomhole pressure is used in nar-row margin drilling scenarios, and pressurized mud capdrilling is used in total lost circulation conditions.

The companys deepwater MPD system is installedabove the intermediate flex joint in the riser and below astandard slip joint. As a result of this configuration, the

COVER STORY:

DRILLING ADVANCES

The Kymera, a hybrid drill bit using both roller cone and PDC technology, drilled

more than twice as fast as premium roller-cone bits in a basalt formation in an Ice-

landic geothermal application. (Image courtesy of Baker Hughes Inc.)

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riser can be used in a conventional manner with full-boreaccess to the well. The entire system is installed throughthe rotary table when the riser and BOP are deployed.

The 12-m (40-ft) MPD system provides riser gas han-dling and early kick detection/control in drilling sec-tions when the BOP is connected to the well. The riserMPD assembly used on the GSF Explorercomprises three

main components: the flow spool, operational annularpreventer, and rotating control device (RCD). The flowspool provides the connection for the flowlines from thetop of the riser to the MPD manifold. Two 6-in. flowlinesare connected at the moonpool to allow returns to flowthrough the MPD manifold to the shale shakers andmud pits. A 21-in. subsea annular BOP is installed

above the flow spool. The annular BOP allows riser gashandling. If a kick is detected in the riser, the annuluscan be closed to provide controlled handling of a riserinflux through the flow spool and back to the surface.The Weatherford Model 7875 Below Tension RingSeashield RCD is installed on top of the annular BOP inthe MPD riser joint. This RCD enables pressure controlfor annulus gas containment and drilling operations. Itsprinciple use is to provide an annular seal around thedrillpipe during drilling and tripping operations. Theinside profile of the RCD includes a hydraulic latchassembly to receive, retain, and release the bearing

seal assembly. With the bearing seal assembly removed,the 2,000-psi RCD system is capable of handling the full-size 18-in. BOP tools.

This RCD currently is the only one in the world thatcan be installed in a deepwater marine riser and supportthe riser tension requirements while conforming to API16 RCD drillthrough specifications. The ability to put

the RCD in tension with the riser allows it to become astandard component of the riser and enables installa-tion below the conventional slip joint.

Weatherford commissioned its MPD package in March2010. As the project is nearing its two-year mark, the com-pany is currently drilling the fifth well for the consortium.

Deepwater MPD using this configuration will soon bedeployed in Brazil as well as the West Coast of Africa,said David Pavel, director business development, DrillingOptimization Services, Weatherford. The diversity ofE&P operators using and requesting this technology

in deep water is evidence that there is a need for thiskey enabler.

At its onset, only one operator in the consortium

agreed to use Weatherfords system. The others were in

a wait and see mode, Pavel said. Upon initial success,

the majority of the consortium contracted the technology

and the project has continued for two years with addi-

tional wells to come.

Weatherfords project has confirmed the viability ofkey technologies that comprise this system. Operatorsin the consortium are evaluating other deepwater basinsin which to deploy this technology, Pavel said.

COVER STORY:

DRILLING ADVANCES

Managed pressure drilling is enabling drilling operations in oth-

erwise undrillable conditions while improving safety and effi-

ciency. (Images courtesy of Weatherford International)