Generators: HPHT Turbine

The HPHT Turbine Generator is a device used to generate power in harsh environment downhole applications for the Oil & Gas industry.  The tool utilizes turbine blades as the prime mover to generate voltage as drilling fluid is forced through the inlets.  This voltage is produced as the turbine blades spin a permanent magnet rotor about a copper wound lamination stack.  

                                                                           Click on image to enlarge

The current specifications of the HPHT Turbine Generator are:

Maximum Tool Diameter = 3.60”

Maximum Length = 96”

Maximum Pressure = 20,000 psi

Maximum Temperature = 250 °C

Voltage = 24 VDC

Maximum Bend Radius = 10° / 100 ft

Flow Rate = 150 – 275 USGPM (350 USGPM short durations)

Shock & Vibration = 20 g’s @ 5-1000 hz

Power Output = 200 watts @ 250 °C

Turbine Blade Life = 200 hrs

Maximum Sand Content = 2%

Tool Life = 4000 hrs

The HPHT Turbine Generator incorporates Samarium Cobalt magnets within the permanent magnet rotor.  The samarium is necessary to operate at high temperatures with minimal degradation to the field strength.  Due to the extreme pressures, the mechanical components of the HPHT Turbine Generator are made of super alloys including 718 Inconel and Monel.  All of the bearings in the tool have been made from fully dense carbide.

1. Can the tool be used in the middle of a drill string?
2. Is the tool serviceable?
3. Can the tool voltage be changed?
4. What happens if the tool is exposed to a flow rate higher than specified?

1. Yes, the HPHT Turbine Generator has two “through wires” to allow signals to be sent through the tool.
2. Yes, the turbine blades can and must be replaced after 200 hours.  The bearings should be inspected every 200 hours and replaced when the thickness of the bearing is below recommendation.  All electronics issues should be repaired by the supplier. 
3. Yes, the tool voltage may be changed if a customer’s requirements warrant a modification.  A fee may apply.
4. The tool will experience increased wear as well as excess heat.  It is recommended that the tool remain within the specified flow rates.

The HPHT Turbine Generator is in the prototype stage and is not ready for industry use.  It is expected that lead times for a single unit will be 16 to 20 weeks when in production.