Downhole Controller Sub Device Order Determination

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Solution Overview

Problem

Existing drilling systems face challenges in automatically determining the order of downhole tools and devices attached to a drill string or wireline before or after insertion into a borehole, leading to ambiguity in identifying the orientation of weight-on-bit (WOB) measuring devices connected via busses, which affects drilling operations.

Innovation Solution

The system employs a controller sub with rotation direction detection and bus orientation determination techniques, including 'who's there' messages, current and voltage measurements, and switch operations to identify device order on busses, resolving ambiguity by determining bus directions and device connections, and using unique serial numbers or time measurements to establish device sequences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If downhole tools and devices are assembled into a string and inserted into a borehole, then drilling operations can be performed, but the order of devices cannot be automatically determined leading to ambiguity in identifying device orientation

Engineering Contradiction:

Improvedevice order informationVSAvoidautomatic device identification

Core Design Contradiction:

Loss of informationVSExtent of automation

Solution Approach 1:

The system performs preliminary actions by having devices transmit their serial numbers and by measuring current flow characteristics before finalizing the device order determination. This allows the controller to establish the complete sequence of devices on the bus before drilling operations begin, eliminating ambiguity about device orientation and positioning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback mechanisms where devices respond to controller inquiries by transmitting their serial numbers, and the controller measures current flow characteristics that provide feedback about device positions. This feedback loop enables automatic determination of the device order on the bus, resolving the information loss problem.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If devices are connected via busses without orientation determination, then system complexity is reduced, but measurement precision of WOB devices is affected

Engineering Contradiction:

ImproveWOB measurement accuracyVSAvoidbus orientation determination system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system replaces complex mechanical orientation determination methods with electrical measurements. By measuring current flow characteristics and analyzing voltage drops across devices, the system automatically determines bus orientation and device positions without requiring complex mechanical markers or manual identification procedures, thus maintaining measurement precision while avoiding excessive complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system introduces an intermediary measurement approach by using current flow as an intermediate indicator to infer device order and orientation. Instead of directly measuring physical positions or orientations, the system measures electrical current characteristics that indirectly reveal the device sequence, simplifying the overall system while maintaining accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 allows for accurate determination of device order and orientation, enhancing flexibility and efficiency in drilling operations by clarifying WOB measurements and optimizing drilling mechanics, thereby improving drilling precision and decision-making.

Implementation Method 1

a property that varies with distance from the bus controller and uses those measurements to determine the order of devices on the bus

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

controller sub with rotation direction detection and bus orientation determination techniques

Methodology Applied

Scientific EffectRotation direction detection:

Data Source

PatentEP2569603B1Determining the order of devices in a downhole string

Publication Date: 2017.01.18 HALLIBURTON ENERGY SERVICES INC

AI summary

A string of subs includes a controller sub. The controller sub includes a first end, a second end, a controller, a first controller bus coupled to the controller, the first controller bus exiting at the first end of the controller sub, and a second controller bus coupled to the controller, the second controller bus being separate from the first controller bus, the second controller bus exiting at the second end of the controller sub. The string of subs also includes a first measuring sub and a second measuring sub. A process, running on a computer, discovers that the first measuring sub is connected to the first controller bus, discovers that the second measuring sub is connected to the first controller bus, determines that the first measuring sub is physically closer to the controller sub than the second measuring sub, and use the fact that the first measuring sub is physically closer to the controller sub than the second measuring sub in controlling the operation of the string of subs.