Downhole Fluid-Powered Electrical Discharge for Pulse Rock Fracture
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Solution Overview
Problem
Existing downhole drilling technologies face inefficiencies in supplying sufficient electrical power for pulse power drilling, which requires high internal pressure to fracture rock, and transmission losses are significant when electrical power is transmitted from the surface.
Innovation Solution
A drill string configuration that generates electrical power downhole using hydraulic energy from drilling fluid flow, converting it into mechanical energy with a downhole motor and generator, and conditions the power before storage in capacitors for controlled discharge into the formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If electrical power is transmitted from the surface to downhole operations, then downhole devices can be powered, but transmission losses are significant
Solution Approach 1:
The downhole drilling system generates its own electrical power using a generator coupled to a downhole motor, eliminating the need for power transmission from the surface. The system serves itself by converting hydraulic energy from drilling fluid flow into electrical energy right at the drilling location, thereby eliminating transmission losses entirely.
Solution Approach 2:
The patent replaces the electrical power transmission system with a hydraulic-to-mechanical-to-electrical energy conversion system. Instead of transmitting electrical power through conductors, the system uses the hydraulic energy of drilling fluid flow to drive a motor-generator assembly that produces electrical power locally at the downhole location.
2Power
If high electrical power is supplied for pulse power drilling, then rock fracture capability is improved, but transmission losses increase
Solution Approach 1:
The system performs preliminary energy conversion by converting hydraulic energy to mechanical energy and then to electrical energy before the actual drilling operation. The generator is coupled to the downhole motor to produce electrical power that is stored in capacitors, ensuring high power is available exactly when needed for rock fracture without transmission losses.
Solution Approach 2:
The patent introduces hydraulic energy from drilling fluid flow as an intermediary energy source. This hydraulic energy serves as a mediator that is converted into electrical energy through the motor-generator system, providing the necessary high power for pulse power drilling while avoiding the problems of electrical power transmission from the surface.
3Duration of action of moving object
If continuous power is supplied to downhole operations, then operational continuity is improved, but energy efficiency decreases due to transmission losses
Solution Approach 1:
The system uses periodic discharge of stored electrical energy from capacitors to power the pulse power drilling operation. The generator continuously converts hydraulic energy to electrical energy, which is stored and then discharged in controlled pulses, achieving both operational continuity and energy efficiency by eliminating continuous transmission losses.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces transmission losses and improves electrical efficiency by generating power on-site, allowing for effective pulse power drilling operations with controlled electrical discharges.
Implementation Method 1
a downhole motor configured to convert the hydraulic energy to mechanical energy
Implementation Method 2
a generator configured to convert the mechanical energy into electrical energy
Implementation Method 3
electrocrushing drills and methods for operating electrocrushing drills
Data Source
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AI summary
A method for supplying, via an electrical interface, an output electrical power to an electrical load that is downhole in a borehole formed in a subsurface formation, includes generating mechanical energy from a flow of a fluid being delivered into the borehole; converting the mechanical energy into an input electrical power; storing the input electrical power into a primary capacitor, wherein the input electrical power has a variance that is greater than a variance threshold. The method includes performing the following operations while continuing to generate the mechanical energy generated from the flow of the fluid, in response to determining that at least one load criteria is satisfied, discharging the input electrical power from the primary capacitor to the electrical load to power a downhole operation by the electrical load.