Fuel cell apparatus and method for downhole power systems

• US 10,113,398 B2
• Filed: 03/23/2016
• Issued: 10/30/2018
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Zhang, Wenlin, Ramakrishnan, Terizhandur S., Walter, Joseph, Perez, Jr., Albert
• Primary Examiner(s): Walls, Cynthia K
• Application Number:
  US15/078,186
• Publication Number:
  US 20160201436A1
• Time in Patent Office: 951 Days
• CPC Class Codes: E21B 4/04 Electric drives E21B4/12 takes precedence
• CPC Class Codes: E21B 41/0085 Adaptations of electric power generating means for use in boreholes
• CPC Class Codes: H01M 8/0273 with sealing or supporting means in the form of a frame
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04104 Regulation of differential pressures
• CPC Class Codes: H01M 8/04365 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04388 of anode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04395 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/186 by electrolytic decomposition of the electrolytic solution or the formed water product
• CPC Class Codes: H01M 8/2425 High-temperature cells with solid electrolytes
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A rechargeable power system comprising: a drill string configured to operate in a well bore, the drill string comprising: a fuel cell system; a generator in electrical communication with the fuel cell system; a turbine, configured to rotate due to an impingement of drilling mud on one or more turbine blades, the turbine in operable communication with the generator; and where the fuel cell system is configured to provide power at least when drilling mud is not circulating in the well bore, and further configured to be recharged by the generator when drilling mud is circulating in the well bore. A method for operating a rechargeable downhole fuel cell. The method comprises: monitoring a fluid supply pressure; determining whether the fluid supply pressure is below a threshold value; and stopping a fuel cell discharge if the fluid supply pressure is below the threshold value.

Claims

1. A method for generating electricity in a drill string disposed within a wellbore, wherein the drill string comprises a turbine, a generator, and a fuel cell system, the method comprising:

(i) generating electricity using the fuel cell system, wherein the fuel cell system generates electricity by producing an electrochemical reaction between hydrogen and oxygen within a fuel cell stack, wherein the fuel cell stack comprises;

a first electrode;

a second electrode;

a proton exchange membrane located between the first electrode and the second electrode; and

at least one water storage medium located between the proton exchange membrane and the second electrode;

(ii) retaining water produced by the electrochemical reaction within the fuel cell stack;

(iii) stopping the electrochemical reaction within the fuel cell stack;

(iv) circulating drilling mud through the wellbore;

(v) generating electricity using the generator, the turbine, and the circulating drilling mud; and

(vi) generating hydrogen and oxygen within the fuel cell stack by using the electricity generated in process (v) to electrolyze the water produced in process (i) and retained in process (ii).

2. The method of claim 1, further comprising:

drilling the wellbore while the drilling mud is circulating in process (iv).

3. The method of claim 1, further comprising:

(vii) stopping the electrolysis within the fuel cell stack;

(viii) generating electricity using the fuel cell system, wherein the fuel cell system generates electricity by producing an electrochemical reaction between the hydrogen and the oxygen generated by the electrolysis in process (vi).

4. The method of claim 3, wherein process (viii) is performed while circulation of the wellbore mud has stopped.

5. The method of claim 1, wherein, in process (i), the first electrode acts as an anode and the second electrode acts as a cathode;

and wherein, in process (vi), the first electrode acts as a cathode and the second electrode acts as an anode.