Power system for downhole toolstring
A downhole power system includes an energy storage adapted to operate at high temperatures, and a modular signal interface device that serves to control the energy storage component as well as offer a means of data logging at high temperatures. The controller is fabricated from pre-assembled components that may be selected for various combinations to provide desired functionality. The energy storage may include at least one ultracapacitor.
1 . A downhole power system comprising:
a first energy storage device (ESD) positioned within a toolstring to provide power to one or more instruments within the toolstring;
wherein the first ESD is configured to operate at a temperature range of −40 degrees C. to 250 degrees C. to:
receive power from a power source at a first power level that is lower than a power requirement of a first tool in the toolstring, and
output power to the tool at a second power level that is at or above the requirement of the first tool in the toolstring;
wherein the ESD comprises an ultracapacitor comprising an advanced electrolyte system (AES) and the AES comprises a salt of the following formula:
wherein R 1 is straight-chain or branched alkyl comprising 1 to 4 carbon atoms, R 2 is methyl or ethyl, and X − is [B(CN) 4 ]— or [BF n (CN) 4-n d]— where n=0, 1, 2 or 3;
wherein the AES comprises less than 500 ppm of chloride ions, less than 50 ppm of fluoride ions, and less than 50 ppm of water.
2 . The system of claim 1 , wherein the ESD receives power from the power source through a tool string power bus configured to provide power to one or more tools in the toolstring.
3 . The system of claim 2 , wherein the first tool comprises at least one selected from the list consisting of: a nuclear magnetic resonance tool, a coring tool, a sonic tool, a neutron density tool, a gamma detector tool, a seismic measurement tool, a telemetry tool, a resistivity tool, and a formation tester.
4 . The system of claim 2 , wherein the first ESD has an energy storage capacity in the range of 100 J to 100 kJ of energy.
5 . The system of claim 4 , wherein the first ESD is configured to provide an output voltage in the range of 30 V to 200 V.
6 . The system of claim 4 , wherein the first ESD is configured to provide an output power in the range of 50 W to about 100 kW.
7 . The system of claim 6 , wherein the first ESD has a peak output power of about 100 W.
8 . The system of claim 6 , wherein the first ESD has a peak output power of about 1 kW to about 100 kW.
9 . The system of claim 6 , wherein the first ESD has an operational temperature range of −40 degrees C. to 210 degrees C.
10 . The system of claim 6 , wherein the first ESD comprises a rechargeable energy storage device (HTRESD).
11 . The system of claim 10 , wherein the ultracapacitor has a volumetric power density of at least 50 kW/L to about 120 kW/L.
12 . The system of claim 11 , wherein the ultracapacitor has a volumetric power density of at least 100 kW/L to about 120 kW/L.
13 . The system of claim 6 , wherein the HTRESD is the ultracapacitor.
14 . The system of claim 13 , wherein the ultracapacitor is configured to operate at temperatures above 210 degrees Celsius to about 250 degrees Celsius for about 10,000 charge/discharge cycles at a voltage of about 0.5V while exhibiting an increase in equivalent series resistance (ESR) of less than about 100% to about 85%.
15 . The system of claim 2 , wherein the first ESD has an energy storage capacity of at least 1 kJ to 100 kJ.
16 . The system of claim 1 , wherein the first ESD is located adjacent to the first tool in the toolstring.
17 . The system of claim 1 , wherein the power source comprises a downhole generator or downhole battery.
18 . The system of claim 1 , further comprising:
a second ESD positioned within a toolstring to provide power to the one or more instruments within the toolstring;
wherein the second ESD is configured to operate at temperatures at about 210 degrees C. to about 250 degrees C. to:
receive power from a power source at a first power level that is lower than a power requirement of a second tool of the one or more instruments in the toolstring, and
output power to the tool at a second power level that is at or above the requirement of the second tool in the toolstring.
19 . The system of claim 1 , further comprising:
a modular signal interface device (“MSID”) module for controlling at least one of the power provided to a downhole tool connected to the downhole power system and the charge discharge cycles of the first ESD, wherein the MSID is adapted to connect to the power source.
20 . A method comprising:
providing a first energy storage device (ESD) positioned within a toolstring to provide power to one or more instruments within the toolstring;
operating the first ESD at a temperature range of −40 degrees C. to 250 degrees C. to:
receive power from a power source at a first power level that is lower than a power requirement of a first tool in the toolstring, and
output power to the tool at a second power level that is at or above the requirement of the first tool in the toolstring;
wherein the ESD comprises an ultracapacitor comprising an advanced electrolyte system (AES) and the AES comprises a salt of the following formula:
wherein R 1 is straight-chain or branched alkyl comprising 1 to 4 carbon atoms, R 2 is methyl or ethyl, and X − is [B(CN) 4 ]— or [BF n (CN) 4-n ]— where n=0, 1, 2 or 3;
wherein the AES comprises less than 500 ppm of chloride ions, less than 50 ppm of fluoride
ions, and less than 50 ppm of water.