Iterative Bisection for Sucker Rod Pump Damping Factors

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Solution Overview

Problem

Existing methods for determining the downhole performance of sucker rod pumps in oil wells face inaccuracies due to energy losses not being directly transmitted from the surface, requiring compensation for system losses to achieve accurate pump card calculations.

Innovation Solution

A method involving iterative bisection to adjust damping factors for upstroke and downstroke calculations, using error tolerance checks and Riemann Sums to refine the downhole card calculations, ensuring accurate representation of energy losses and system performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If damping factors are adjusted to account for energy losses in the rod string, then measurement precision of downhole performance improves, but device complexity increases due to iterative calculation requirements

Engineering Contradiction:
Improvedownhole performance measurement accuracyVSAvoidcalculation system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The damping factors are made dynamic and adjustable rather than fixed, allowing them to be optimized for different rod string conditions. The iterative bisection method dynamically adjusts damping values to achieve convergence, transforming a static calculation into an adaptive process that improves precision while managing complexity through systematic iteration.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The calculation system incorporates feedback mechanisms where the difference between calculated and measured downhole performance is used to adjust damping factors in subsequent iterations. This feedback loop continues until convergence criteria are met, ensuring high measurement precision while providing a structured approach to managing calculation complexity.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If iterative bisection method is used to calculate optimal damping factors, then downhole card calculation accuracy improves, but calculation time increases

Engineering Contradiction:
Improvedownhole card calculation accuracyVSAvoidcalculation time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The iterative bisection method applies partial action by performing a limited number of iterations until convergence criteria are satisfied. Rather than exhaustively searching all possible damping factor values, the method stops when the difference between successive iterations falls below a threshold, achieving sufficient accuracy without unnecessary time expenditure.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The method systematically changes the damping factor parameter through bisection iterations, adjusting it from initial estimates toward optimal values. By changing this key parameter in a controlled manner and monitoring convergence, the system achieves high calculation accuracy while managing computation time through efficient parameter exploration.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20240376814A1Automatic Iteration of Upstroke and Downstroke Damping Factors with Iterative Bisection Method
Publication Date: 2024.11.14 WELLWORX ENERGY SOLUTIONS LLC
  • US20240376814A1 patent drawing
  • US20240376814A1 patent drawing
  • US20240376814A1 patent drawing

AI summary

A method for calculating a downhole card for an oil and gas well includes setting a damping factor to an initial value, calculating a downhole card using the initial load value, and determining whether the difference between a true load value and an effective load value is within a desired error tolerance. If not, the method can also include setting a new damping factor to a value equal at a mid-point between the initial damping factor and a damping factor bound, recalculating the downhole card using the new damping factor, and determining whether the difference between a new true load value and a new effective load value is within a desired error tolerance. If not, the method can also include setting the new damping factor to a value equal at a mid-point between the previous damping factor and a damping factor bound.