Dual Completion Linear Rod Pump with Rack and Pinion Actuation
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Solution Overview
Problem
Conventional sucker-rod pumping systems face challenges due to rod string stretching and contraction, inherent damping, and the complexity and cost of walking beam-type pumping mechanisms, which affect efficiency and require significant site preparation and removal efforts.
Innovation Solution
A dual completion linear pumping apparatus with a single housing and two linear mechanical actuator systems, each with a rack and pinion gearing arrangement, driven by a reversible motor, allowing independent operation of two sucker-rod pumps at different depths and completion zones, with electronic control and sensors for optimized motion control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional walking beam-type pumping mechanism is used, then the pump can operate reliably, but the device complexity and site preparation requirements increase significantly
Solution Approach 1:
The patent divides the pumping system into modular components: a simplified linear actuator mechanism, separate rod strings for different zones, and independent control systems. This segmentation allows each component to be optimized independently, reducing overall system complexity while maintaining reliability through modular design.
Solution Approach 2:
Instead of using a conventional walking beam mechanism that converts rotational motion to linear motion through complex linkages, the patent inverts the approach by directly applying linear actuation to the rod strings. This eliminates the intermediate mechanical conversions and reduces device complexity while preserving the essential pumping function.
2Reliability
If a conventional walking beam-type pumping mechanism is used, then the pump can operate reliably, but the ease of manufacture and installation deteriorates due to heavy foundation requirements
Solution Approach 1:
The patent extracts and eliminates the heavy concrete foundation requirement from the conventional walking beam system. By replacing the walking beam mechanism with a linear actuator system, the patent removes the need for massive stationary structures, allowing the pump to be installed on lighter, more adaptable foundations that are easier to manufacture and install.
Solution Approach 2:
The patent employs a simplified linear actuator mechanism that can be manufactured more economically and installed faster than conventional walking beam systems. The design accepts that certain components may have reduced service life but compensates through easier replacement and lower installation costs, improving overall ease of manufacture and deployment.
3Device complexity
If a single pump is used, then the device complexity is reduced, but the adaptability to pump from multiple completion zones simultaneously deteriorates
Solution Approach 1:
The patent implements a universal pumping platform where a single dual-actuator system can pump from multiple completion zones simultaneously. The system uses independent rod strings that can be configured for different zones, allowing one apparatus to perform multiple pumping functions that would otherwise require separate pumps, thereby maintaining low complexity while achieving high adaptability.
Solution Approach 2:
The patent adds the dimension of vertical zonation by implementing independent rod strings at different depths within the same wellbore. This allows the system to access multiple completion zones vertically while maintaining a single horizontal footprint and control system, effectively multiplying the system's adaptability without proportionally increasing complexity.
4Adaptability or versatility
If the rod string is made longer to reach deeper zones, then the adaptability to access different completion zones improves, but the loss of energy due to rod stretch and damping increases
Solution Approach 1:
The patent segments the rod string into separate, shorter sections for different completion zones, each driven by its own actuator. This segmentation reduces the effective length of each rod string, minimizing stretch and damping losses in each segment while maintaining the ability to access deep zones through coordinated operation of multiple segmented systems.
Solution Approach 2:
The patent applies preliminary action by pre-tensioning or pre-positioning the segmented rod strings to optimize their mechanical properties before operation. This allows each segment to operate more efficiently with reduced energy losses to stretch and damping, while the coordinated control of multiple segments maintains adaptability to access different completion zones.
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 solution enables efficient and flexible operation of sucker-rod pumps, reducing site preparation and removal costs, allowing simultaneous extraction of hydrocarbons and water from different zones without the need for additional constraints, and improving pumping efficiency by controlling rod motion and force distribution.
Implementation Method 1
Each linear mechanical actuator system has a rack and pinion gearing arrangement. The rack is configured to impart a reciprocating motion along a pumping axis. The rack is operatively connected in a gear-mesh relationship with the pinion to establish a fixed relationship between the rotational position of the rotatable element and the vertical position of the vertically movable member.
Implementation Method 2
The rod string, which may be about 305 meters (1000 feet), or longer, acts much like an extension spring, which is stretched during the portion of the pump stroke in which the rod string is drawing the fluid upward within the well, and which then contracts back to an essentially un-stretched state as the rod string moves downward during a return portion of the pump stroke.
Data Source
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AI summary
A dual completion linear rod pumping apparatus for imparting reciprocating vertical motion to a pair of rods for respective sucker-rod pumps. The dual completion linear rod pumping apparatus includes first and second linear mechanical actuator systems disposed in a single housing. These linear mechanical actuator systems impart and control vertical motion of the pair of rods. Each linear mechanical actuator system includes a rack and pinion gearing arrangement. The rack is operatively connected in a gear-mesh relationship with the pinion. The pinion is operatively connected to a rotating output of a motor. Rotation of the motor in a first direction results in an upward motion of the rack and connected sucker rod pump. Rotation of the motor in a second direction opposite the first direction results in a downward motion of the rack and connected sucker rod pump. An electronic controller is operatively connected to the motor.