Earlier today, my colleagues at Dexter Magnetic Technologies announced the launch of an innovative downhole generator tool, which we have developed for some pretty extreme drilling conditions. This new high pressure – high temperature (HPHT) tool could lead the way to drilling deeper and more productive oil, gas and geothermal wells in the world’s most demanding drilling environments.
The tool was developed by the magnetics engineering group at Dexter, specifically by a team led by my colleague Chris Ras, Dexter’s Product Development Manager, and with the support of the U.S. Department of Energy’s National Energy Technology Laboratory (NETL). The tool, shown in Figure 1, is approximately 67 inches (170 cm) long and provides over 200 watts of high density electrical power at a regulated 24 VDC, for a variety of downhole drilling, measurement and logging systems, in environments up to 250 °C (480 °F) of temperature and greater than 20,000 psi (140 kPa) of pressure. As we drill ever-deeper into the earth, the temperature and pressure inside the resulting wells generally increase with depth.
- Figure 1: Downhole permanent magnet-based turbine generator tool for providing electrical power in extreme drilling conditions. Image courtesy of Dexter Magnetic Technologies (2009).
This type of turbine generator works by drawing energy from the drilling fluid that is pumped down under pressure from the surface, which is used to lubricate the drill bit and to remove the rock cuttings as drilling proceeds. This fluid passes through a set of turbine blades in the generator tool [shown in the cutaway schematic in Figure 2], which connects with a special permanent magnet generator that then generates power.
The new generator system can replace disposable lithium and rechargeable lithium ion batteries, which are commonly used in these systems. Because these batteries do not operate above 200 °C (390 °F), they limiting the cycle time and depth of drilling for systems that use them. Using the turbine generator means that in addition to oil & gas well drilling, the tool could also have applications for geothermal drilling, which can experience even more demanding conditions.
- Figure 2: Cross-section of multi-turbine blade section of downhole generator tool. Image courtesy of Dexter Magnetic Technologies (2009).
My colleague Tim Price, Dexter’s Business Development Manager for the oil & gas industry, said:
“The development of HPHT measurement and logging tools has outpaced the availability of safe and reliable HPHT power supplies. Dexter’s HPHT downhole generator was developed specifically to fill that void. We have a downhole power supply that provides regulated power from subzero surface temperatures to 250 °C (480 °F) bottom hole formation temperatures. No other single commercially-available technology can provide power over that operating range as of this date.”
Tim went on to say that:
“The need for such HPHT power supplies appears to be greater now more than ever, with the high temperature, extended reach horizontal drilling experienced in plays such as the Haynesville Shale.”
Performance data on the HPHT downhole generator products can be acquired directly from Courtney Stone, Marketing Manager at Dexter, or from me. We are now actively looking for partners in the well drilling industry, to participate in field trials and qualification of the new HPHT downhole generator tool, in wells with formation temperatures expected to exceed 175 °C (350 °F).
Get in touch with me if that describes you or your company!
Thu, Dec 3, 2009
Applications, Technology