Hybrid Drillstring Conveyance for High-Voltage Plasma Drilling

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Solution Overview

Problem

Traditional drilling methods face challenges in efficiently recovering dry gas reserves from tight, hard rock formations due to low rate of penetration and high costs associated with running electrical cables, particularly in deep and extended-reach wells, where coiled tubing limitations restrict pump rate and increase the risk of helical lockup.

Innovation Solution

The implementation of a hybrid drillstring conveyance system that combines coiled tubing and jointed pipe to efficiently transport high-voltage power to downhole plasma drilling tools, allowing for extended reach and improved safety by housing electrical conductors within the coiled tubing section, enabling pulsed-power and energy injection drilling techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If coiled tubing is used to convey electrical conductors, then ease of deployment and cost are improved, but the reach is limited and pump rate is restricted due to smaller diameter requirements

Engineering Contradiction:

Improveease of deploymentVSAvoidreach

Core Design Contradiction:

Ease of manufactureVSLength of stationary object

Solution Approach 1:

The drillstring is divided into two functional segments: coiled tubing for conveying electrical conductors and jointed pipe for extending reach. This segmentation allows each component to optimize its specific function while working together as an integrated system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Electrical conductors are nested within the coiled tubing section, allowing the conductors to be conveyed through the tubing to the downhole tools without requiring external routing, thereby simplifying deployment.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of operation

If coiled tubing is used, then ease of operation is improved, but reliability deteriorates due to increased risk of helical lockup

Engineering Contradiction:

Improveease of operationVSAvoidreliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The drillstring is segmented into coiled tubing and jointed pipe sections, with the jointed pipe section providing structural stability to prevent helical lockup while the coiled tubing section maintains ease of operation for conductor conveyance.

Inventive Principle:

Principle #1Segmentation

3Length of stationary object

If jointed pipe is used to extend reach, then reliability is improved, but cost and time increase due to section-by-section assembly

Engineering Contradiction:

ImprovereachVSAvoidtime

Core Design Contradiction:

Length of stationary objectVSLoss of time

Solution Approach 1:

The drillstring is segmented into coiled tubing and jointed pipe, where the coiled tubing section can be deployed continuously from a reel, significantly reducing the time required compared to assembling jointed pipe sections one by one.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The coiled tubing is pre-loaded onto a reel in a compact form, allowing for rapid deployment without the need for on-site section-by-section assembly, thereby reducing time loss.

Inventive Principle:

Principle #10Preliminary action

4Strength

If jointed pipe is used, then strength is improved, but weight increases

Engineering Contradiction:

ImprovestrengthVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The drillstring is divided into coiled tubing and jointed pipe sections, with the jointed pipe providing necessary strength for deep well applications while the coiled tubing being lighter, thus optimizing the overall weight-strength ratio.

Inventive Principle:

Principle #1Segmentation

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

This approach enhances drilling efficiency and safety by allowing deeper well penetration, optimizing cost, and reducing the frequency of electrical conductor reconnections, while maintaining high-voltage power delivery and fluid circulation efficiency.

Implementation Method 1

plasma channel drilling

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

applying pulses of electric current to detach formation material

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 3

electrical conductors within the hybrid drillstring and convey power to the bottomhole assembly or bit

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS10407993B2High-voltage drilling methods and systems using hybrid drillstring conveyance

Publication Date: 2019.09.10 HALLIBURTON ENERGY SERVICES INC

AI summary

In at least some embodiments, a high-voltage drilling system includes a a power supply to output high-voltage power to an electrical conductor, a bit that extends a borehole based on the high-voltage power, and a hybrid drillstring that transports a fluid flow from the bit to convey detached formation material out of the borehole. At least part of the electrical conductor resides within the hybrid drillstring to convey power to the bit. The hybrid drillstring includes a coiled tubing section and a jointed pipe section.