Drilling RD&D Program
At the Morgantown Energy Technology Center of the U.S. Department of Energy
- Steerable Air-Percussion Drilling System
- Integrated Underbalanced Directional Drilling System Development
- Near-Bit Sensor Development
- Slimhole Underbalanced MWD System
- Personal Computer-Based Foam Drilling Model
- Advanced Underbalanced Drilling Fluids
- High-Pressure Downhole Pump for Jet-Assisted Drilling
- High-Power Slimhole Drilling Systems
- Advanced Mud Hammer Development
The U.S. Department of Energy (DOE), through the Office of Fossil Energy, sponsors natural gas drilling research, development and demonstration as part of its overall mission. Fossil Energy focuses its RD&D effort to stimulate sustainable development and utilization of the nation's fossil fuel resources and to assure an ample, secure, clean and low-cost domestic supply of energy. The Fossil Energy natural gas RD&D program is implemented at the Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. This article presents the drilling RD&D part of the program. The goal in this area is to develop and test drilling products and technologies which reduce cost and/or improve efficiencies. This RD&D program goal will ultimately lead to a lower unit cost of natural gas.
Though clearly designed to benefit the natural gas industry, and thereby the ultimate consumers of natural gas, the advances sought in this program will just as clearly be of benefit to many other industries dependent upon drilling and excavation.
As in all fields of energy and materials production, substantially improved technologies are deemed necessary to compete effectively in a global economy. It is estimated that the number of successful natural gas wells completed each year in the contiguous 48 states must more than double, from more than 7,200 in 1994 to more than 16,000 in 2010, to meet the production requirements for those states. Domestic drilling costs were more than $10 billion in 1993, and are expected to approach $30 billion in 2010. Therefore, the prospect of even slight reductions in drilling costs can justify a substantial RD&D program.
The Office's program is industry-driven to assure rapid and smooth transfer of advanced technologies to commercial applications. Industry participation includes cost-sharing up to 50% of total project costs, depending on the stage of technology development and associated risk. The program is closely coordinated with that of the Gas Research Institute and with other programs within the DOE Office of Energy Efficiency and Renewable Energy. The Fossil Energy Gas Drilling RD&D program also coordinates and jointly funds projects within the National Advanced Drilling and Excavation Technology (NADET) program.
Of particular interest to readers of the NADET News, the Drilling RD&D product development effort is focused on a high rate of penetration drilling system for medium to hard formation drilling. The RD&D effort can be further defined into two broad categories. The first category is "underbalanced drilling systems, models, and fluids" which consist of a steerable air percussion drilling system, a steerable underbalanced drilling system, near-bit sensor development, slimhole electromagnetic measurement-while-drilling (MWD) development, personal computer-based foam drilling models, and new advanced underbalanced drilling fluids. The second category is "improved high-performance drilling systems" which consists of a high-pressure, jet-assist drilling system, an advanced slimhole motor/bit system, and a mud hammer drilling system. Brief summaries of some of the projects follow:
Steerable Air-Percussion Drilling System
A steerable air-percussion drilling system is being developed for use in hard-rock applications. The drilling assembly will be independent of drill string rotation, and include auxiliary components such as bent subs, stabilizers, etc. Wireless telemetry systems are also being investigated for steering the hammer, although wireline steering tools will be used initially to transmit the directional information.
Integrated Underbalanced Directional Drilling System Development
A fleet of newly designed motors combined with an electromagnetic MWD telemetry system will form the basis of the most advanced directional drilling system capable of operating in the complete family of underbalanced fluids to include air, natural gas, nitrogen, air-mist, foam, aerated mud, nitrified mud, and underbalanced mud. Specially designed motors will be matched to the underbalanced drilling fluid application resulting in higher mean time between failures and cost savings to the Industry.
Near-Bit Sensor Development
Accurate placement of horizontal and directional wells becomes more critical as well lengths increase. Measurements of directional data and formation parameters at the drill bit are required to drill effectively within a small window in the target horizon. A near-bit sensor, consisting of a gamma ray and inclinometer telemetry sub, has been designed and fabricated to acquire and transmit data from just behind the bit to a base MWD system. The system is compatible with all manufacturers and can be used with electromagnetic or mud pulse telemetry.
Slimhole Underbalanced MWD System
A slimhole electromagnetic MWD system is under development. The system will be capable of operating with underbalanced drilling fluids such as nitrified mud, aerated mud, foam, air-mist, air, nitrogen, or natural gas. Field testing of the prototype system is ongoing in the United States.
Personal Computer-Based Foam Drilling Model
A PC-based foam drilling model has been developed to assist the drilling engineers with design and field execution of foam drilling operations on a well location. Onsite engineering of mechanical and electrical equipment requires system analysis real-time in order to assure quality control during foam drilling operations. Currently, there is a lack of PC-based models for foam drilling in the industry.
Advanced Underbalanced Drilling Fluids
There is increasing interest in lightweight muds for underbalanced drilling. Additives capable of significantly reducing fresh water mud into the 6-8 pound per gallon level are being tested in anticipation of their use in preventing or minimizing formation damage and lost circulation. In addition, higher rates of penetration are expected with underbalanced drilling fluids.
High-Pressure Downhole Pump for Jet-Assisted Drilling
A high-pressure downhole mud pump is being developed and demonstrated. Designed to produce 30,000 psi, the pump operates by extracting power from the lower pressure mud flow to raise the pressure of a fraction of the total flow. Rate of penetration increases of one and a half to two times are expected with jet-assisted bits.
High-Power Slimhole Drilling Systems
A slimhole multi-lobe downhole drilling motor has been designed and fabricated to better match the advanced capabilities of thermally stable polycrystalline diamond bits. The high power motor is a four-fifths design and is expected to deliver higher horsepower, torque, and speed.
Advanced Mud Hammer Development
A prototype mud hammer is being developed to increase the rate of penetration while drilling in medium and hard rock formations. Mud hammers offer a potential cost-effective alternative to motors in these target formations. A prototype hammer has been laboratory- and field-tested and redesigned based on a recent design review with industry. The project is being technically directed and monitored by the Morgantown Energy Technology Center and funded by DOE's Small Business Innovative Research Program.Increased rate of penetration, the aim of all these projects and others not described here, is obviously beneficial in other areas. For example, directional drilling at higher rates in hard rock would benefit the mining and geothermal industries. Similarly, more accurate directional drilling will benefit oil drilling, mining, geothermal drilling, and construction projects. Underbalanced drilling technology could significantly benefit the nation's environmental restoration and radioactive waste program. There are cross benefits of applying this technology developmental effort among NADET members as well as their customer base.
This summary of Fossil Energy's Gas Drilling Program was prepared by the Albert Yost, William Gwilliam, and John Duda of DOE/METC. The NADET Institute staff provided editorial support in final preparation of the article. For copies of the references or for further information on the METC programs, including additional projects not covered here, please contact Albert Yost at the US DOE/METC office in Morgantown, West Virginia at (304) 285-4479. His internet address is ayost@metc.doe.gov.
References
1. Duda, J. R. and A. B. Yost II: 1995. "DOE/Fossil Energy's Drilling, Completion, and Stimulation RD&D: A Technologies/Product Overview," SPE 30993 presented in Morgantown (September)2. U.S. Department of Energy/METC: 1995. "Natural Gas RD&D Contractors Review Meeting," Agenda, Abstracts, and Visuals, Section 7.4 (April)
3. Product Facts Brochure-Natural Gas Research: 1995. "Drilling, Completion, and Stimulation Product Area Overview," available from Morgantown Energy Technology Center, Morgantown, WV (June)
Drilling RD&D Solicitation Forthcoming from METC
The Morgantown Energy Technology Center will be releasing a Commerce Business Daily announcement for advanced drilling research in the near future. Currently, a description of the forthcoming CBD announcement is available in the September 9th Federal Register on page 47505. Additional information is available from Thom Martin, of the contracting office, at (304) 285-4087. Also, Al Yost and Bill Gwilliam of the drilling program are available for information at (304)-385-4479 and -4401, respectively.