DOE technology manager lauds microhole technology

Feb. 9, 2005
US DOE Strategic Center for Natural Gas and Oil E&P Technology Manager
Roy Long
"The scope of microhole technology is to drive down drilling costs and reduce exploration risk."

Nina M. Rach
Drilling Editor

New drilling technologies are getting a push from government funding; industry needs to "pull" them into implementation, says Roy Long, manager of E&P technology at the Strategic Center for Natural Gas and Oil (SCNGO), Tulsa.

Government funding for upstream research and development often reduces the risk involved in adopting new technologies. SCNGO, an arm of National Energy Technology Laboratory (NETL), which is in turn part of the US Department of Energy, has a mission to develop increasingly efficient solutions to engineering challenges, help independent operators and small businesses, and maintain the US oil and gas industry.

Long says maintaining the petroleum industry is important for job creation and security—every upstream job in oil and gas creates seven jobs downstream.

But, in an exclusive interview with OGJ, he pointed out that commodity-oriented petroleum operating companies have become less involved in R&D and exploration, which are seen as lacking shareholder value.

The trend is for operators to purchase and adapt low-risk, proven technologies, or participate in joint industry programs to share the risk of development. But if we can take the risk out, with the right tools and enough subsurface data, "we can engineer anything," said Long.

The Drilling Engineering Association (DEA) is one such industry effort to develop areas of common interest, Long said. It was formed in 1983 to advance new technology related to drilling wells. Long gave an overview of the microhole technology program and Rocky Mountain Oilfield Technology Center (RMOTC) field activities at a DEA research operations forum in November 2004.

According to the NETL, 407 billion bbl of discovered oil in the US onshore is nonrecoverable with current drilling and production technologies; 218 million bbl of that is 5,000 ft or shallower.

Focus on MHT
Microhole technology (MHT) projects have Long's full attention these days.

The DOE budgets about $3 million/year to fund the microhole systems program, investigating new concepts for miniaturized drilling systems to explore and exploit domestic US shallow (less than 5,000 ft depth) hydrocarbon reservoirs that are uneconomic to develop with conventional drilling systems.

In comparison, oil shale and synfuel research have received about $100 million/year of US government funding.

By reducing the size of the borehole (3 1⁄2-in. to 4 3⁄4-in. diameter) and miniaturizing the downhole equipment, engineers hope to reduce the cost of drilling and simplify access to drillsites. Microholes can be drilled from portable, lightweight, coiled tubing rigs at lower cost than conventional boreholes. "The scope of microhole technology is to drive down drilling costs and reduce exploration risk," he said.

Smaller and more portable equipment means a potentially smaller environmental footprint, something that has not changed much in the history of modern land drilling. The last step-change was the introduction of directional drilling from pads.

Microholes are volumetrically smaller and, in tandem with zero-discharge mud systems, will produce much less waste, a big environmental advantage.

The core research program is being funded in two MHT solicitations. The first set of projects focuses on field demonstrations and development of technology that uses coiled-tubing drilling:

--Demonstrations of existing 43⁄4-in. commercial microhole technology.

--Built for-purpose microhole coiled-tubing rig (Schlumberger IPC, Sugar Land, Tex.).

--Self-contained zero discharge drilling-mud system (Bandera Petroleum Inc., Tulsa).

--Microhole coiled-tubing bottomhole assemblies (three projects: smart steering and LWD system developed by Baker Hughes Inteq, Houston; radar navigation and radio data transmission systems developed by Stolar Research Corp., Raton, N.M.; and a downhole drilling tractor developed by Western Well Tool Inc., Anaheim, Calif.).

--Microhole completion and production equipment (through-tubing artificial lift system developed by Gas Production Specialists LLC, Lafayette, La.).

Latest awards
The second round of solicitations for microhole technology development was posted in August and the application period closed Oct. 6, 2004, for projects in four subject areas:

--Area 1A—Field demonstration (2 awards).

--Area 2A—Advanced monobore concept (1 award).

--Area 2B—Microhole coiled tube bottom hole assemblies (6 awards).

--Area 2C—Microhole completion and production equipment (1 award).

Awards for 10 projects were announced Jan. 22, 2005; they are also listed on the DOE's industry interactive procurement website.

"This is the first solicitation round for demonstrations of advanced technology that might. . .significantly reduce costs for exploration and development," Long said. "Within 3 years, we'll know whether we have commerciality for most of these technologies."

Designer seismic, 4D data
The microhole technology initiative includes development of new economic seismic methodologies for reservoir imaging. Low-cost microholes allow vertical seismic data to be collected where needed, without interrupting production.

In November, Long told OGJ that VSP data were acquired in a 1,000-ft microhole in October 2004, looked good, and would be processed in first-quarter 2005. In spring 2005, he said, one or two more microholes will be drilled, providing additional data across a fault. Microholes can also provide dedicated, permanently installed reservoir-monitoring systems to monitor and optimize improved oil recovery (IOR) processes.

Work is under way at Sandia National Laboratory in Albuquerque, NM, to develop miniature downhole instrumentation using MEMS (microelectromechanical) technologies.

Commercial activities
Industry representatives see several potentially viable industrial applications arising from the microhole technologies initiative, using coiled-tubing drilling to drill:

--Shallow development wells in one-third the space of a traditional rig.

--Reservoir and seismic data holes to obtain 4D data without disrupting production.

--Shallow reentry wells for deep perforations, lateral seismic imaging, or vertical flooding.

--Deep exploration tails to extend existing wellbores and evaluate additional potential zones.

Industry is already embracing fast, lightweight, drilling apparatus to drill cost-effectively, particularly in western Canada's shallow gas and coalbed methane plays, said Long. Nabors Industries Ltd. is building two hybrid CTD rigs in Canada and plans to bring one to the US.

Long also pointed to a November announcement by Calgary's Ensign Resource Service Group Inc. about building 10, state-of-the-art automated drill rig (ADR)-1000-CT coiled-tubing drill rigs. These will be capable of working with coiled tubing up to 31⁄2-in. diameter or conventional jointed pipe.

Delivery will begin in second-quarter 2005.

Other drilling initiatives
Long is also interested in the area of new materials for drilling.

SCNGO is funding Pennsylvania State University and Dallas-based Dennis Tool Co. to develop small-diameter prototype coiled tubing by microwave processing (heating and densifying or sintering) powdered metal. The result will be many segments fused by microwave heating (diffusion bonding) to produce a continuous coil.

This first prototype will be 3⁄4-in. diameter and 1,500 ft long. Long said that mechanical tests of short test lengths will be made by a third-party vendor later this year.

They will attempt to verify the superior strength and flexibility (significantly longer life) of the coiled tubing made by the joining of the individual sections.

Another area of drilling is wired pipe, enabling high-speed communications up drillpipe. Grant Prideco and its Utah-based diamond subsidiary Novatek Engineering Inc., have been working on intelligent pipe ( Long believes this is going to revolutionize the amount of information available from downhole in a truly "real time" data-acquisition environment.

He sees it as one of the enabling technologies for managed pressure drilling, a technology gaining increasing interest in the offshore industry. Transfer rates of 1 million bits/sec and the ability to select which tools to interrogate will allow unprecedented engineering possibilities. Long thinks real time seismic ahead of the bit could become a reality.

He pointed out that microhole "real time" focus is different from that of the intellipipe being developed by Grant Prideco. Microhole long-term monitoring focuses on putting low-cost geophones in a number of strategically placed low-cost boreholes for VSP imaging (microholes dedicated to imaging only, so that production wells do not have to be shut in) of CO2/EOR programs, not just for high-value wells or fields.

The scientific community has used long-term monitoring for years (proof that it's not too expensive). Ernie Majer and other researchers at Lawrence Berkeley National Laboratory are even beginning to see reservoir detail not previously recognized in some California geothermal reservoirs with passive seismic sources from the San Andreas Fault.

Long thinks the long-term seismic monitoring can be done relatively inexpensively both for EOR monitoring and possibly even for exploration, some day. The benefit is to get a "moving picture" instead of just an expensive snapshot in time.

Directional surveying
Long has a longtime interest in directional surveying development, in order to provide the smoothest possible turn with a minimum of doglegs. He developed a new approach to directional surveying and course correction using a sectional method, which he published with Bill J. Mitchell in 1992 in the Journal of Energy Resources Technology.

Long said he learned a great deal by comparing minimum curvature and radius-of-curvature solutions, noting that the radius of curvature, although referred to as a "circular arc" solution, interprets a helical path between all stations except those contained in either a vertical or horizontal plane.

The industry had not really pushed the limits of its technology on surveying, he says, although now he thinks horizontal well technology is beginning to instill more demanding requirements. Long considers Stockhausen and Lesso's three-part series on wellbore positional accuracies to be "one of the key directional surveying articles that have been published recently" (OGJ, Oct. 27, 2003, p. 51; Nov. 3, 2003, p. 50; Nov. 24, 2003, p. 61).

Directional surveying software and supporting documents are available on the SCONGO web site (

Career Highlights

Roy C. Long is technology manager, exploration and production, for the Strategic Center for Natural Gas and Oil (SCNGO), Tulsa, an arm of the US Department of Energy Office of Fossil Energy's National Energy Technology Laboratory. His current work involves industry outreach and program planning for SCNGO's Office of Petroleum E&P technology program.

Following service in the US Air Force, Long joined the former Tenneco Oil Co. in 1978 as a petroleum engineer. He later worked for Petro-Lewis Corp., Bakersfield, Calif., and as an international drilling consultant.

During 1988-96, he worked for DOE at its Yucca Mountain, Nev., project office as principal investigator for the agency's coring technology development program.

Long transferred to NETL in Morgantown, W.Va., in 1996, where he served as project manager for the drilling, completion, and stimulation technologies in NETL's Strategic Center for Natural Gas, predecessor to SCNGO.

He assumed his current position in 2001.

Long is a 1970 graduate of the US Air Force Academy and received his MS in petroleum engineering from the Colorado School of Mines. He is a member of ASME and SPE.