Rig Engine Control via Exhaust Temperature Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional wellbore rig generator engines, particularly those running on natural gas, face inefficiencies due to sluggish throttle response and intermittent power demands, leading to excessive fuel consumption and emissions, with issues of low-quality power supply and potential generator overload, resulting in operational disruptions and increased emissions.

Innovation Solution

A system comprising a controller that maintains constant exhaust temperature by adjusting power load on the rig engine, coupled with energy storage apparatuses like flywheels and batteries to manage power demand and supply, ensuring efficient engine operation and high-quality power distribution across the rig.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If natural gas powered engines are operated at high load capacity (70% or higher) to maintain fuel efficiency and catalytic converter function, then fuel efficiency improves and emissions are reduced, but the engine response to transient power demands becomes sluggish and operational flexibility deteriorates

Engineering Contradiction:
Improvefuel efficiencyVSAvoidengine response speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The system maintains the engine at a constant high load (70-90% capacity) in advance to ensure optimal fuel efficiency and catalytic converter operation. Energy storage devices are charged beforehand during periods of low power demand, so when transient power demands occur, the stored energy can be immediately discharged to meet the demand without requiring the engine to change its operating load.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Energy storage devices (flywheels, batteries, capacitors) are introduced as intermediary components between the engine and the power demand. These devices absorb excess energy when demand is low and release energy when demand spikes, decoupling the engine's operating load from the transient power demands and allowing the engine to maintain optimal efficiency while meeting variable power requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If artificial loads (resistor banks) are added to maintain high engine loading, then fuel efficiency improves, but total fuel consumption increases and carbon dioxide emissions increase

Engineering Contradiction:
Improvefuel efficiencyVSAvoidcarbon dioxide emissions
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

Instead of wasting energy as heat in resistor banks, the system captures and stores the energy that would otherwise be wasted during braking and lowering operations. The energy storage devices accumulate this regenerative energy, which can then be reused during hoisting operations, converting what was previously a harmful waste product into a useful resource that reduces overall fuel consumption and carbon dioxide emissions.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system recovers energy during braking and lowering cycles by directing it to charge energy storage devices instead of dissipating it in resistor banks. This recovered energy is then available for reuse during subsequent hoisting operations, reducing the total energy that must be produced by the engine and thereby reducing fuel consumption and carbon dioxide emissions.

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If standby generators are maintained to compensate for sluggish throttle response, then operational reliability improves, but fuel consumption increases and nitrous oxide emissions increase

Engineering Contradiction:
Improvepower supply reliabilityVSAvoidnitrous oxide emissions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

Energy storage devices serve as intermediary power sources that can immediately respond to transient power demands without requiring additional standby generators. When power demand spikes, the controller directs the load to the energy storage devices, which can deliver power instantly without the delay associated with generator throttle response, thereby maintaining reliability while avoiding the emissions from running additional generators.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If engine load is reduced to match intermittent power demands, then operational flexibility improves, but fuel efficiency deteriorates and emissions increase

Engineering Contradiction:
Improvepower demand adaptabilityVSAvoidemissions
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The system performs preliminary action by maintaining the engine at a constant optimal load (70-90% capacity) regardless of transient power demands. Energy storage devices are charged in advance during low-demand periods, so when power demands increase, the stored energy is already available to meet the demand immediately, eliminating the need to adjust engine load and maintaining both adaptability and emissions control.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2126268B1Rig engine control
Publication Date: 2012.02.22 NAT OILWELL VARCO LP
  • EP2126268B1 patent drawingFigure 1
  • EP2126268B1 patent drawingFigure 2
  • EP2126268B1 patent drawingFigure 3A

AI summary

A system for controlling power load on a rig engine of a wellbore rig, the system comprising: a controller for controlling said rig engine; and a sensor for sensing an exhaust temperature of said rig engine, the sensor in communic ation with the controller for providing to the controller signals indicat ive of the exhaust temperature, the arrangement being such that, in use, said controller maintains power load on said rig engine based on said exhaust temperature.