Ultra-High Pressure Down Hole Pump for Jet-Assisted Drilling

An ultra-high pressure (UHP-30,000 psi) downhole pump (DHP{trademark}) is being developed for jet-assisted drilling. With this technology, drilling penetration rates in gas and oil wells can be increased 1.5 to 2.5 times. The prototype downhole pump was built for laboratory and field experimentation under a program with the Gas Research Institute. A second generation prototype is being supported by the US Department of Energy-Morgantown. Current development is focused on the DHP system that develops the UHP fluid stream used to assist the drill bit. The pump is located just above the drill bit. Its rated output is 22 gpm at 35,000 psi. The DHP is about the same size as and is handled like a conventional drill collar. Power to drive the DHP is taken from the conventional mud stream. Surface mud pump pressure is elevated approximately 1,500 to 2,000 psi while maintaining conventional flow rates downhole. Five field experiments were conducted with the first prototype. Observed ROP ratios varied from 1.1 to about 3.5 times conventional rates. The second prototype is currently being tested in the laboratory.