Hydraulically Actuated Reciprocating Pump for Drilling Fluid
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Solution Overview
Problem
Conventional reciprocating pumps generate pressure pulsations due to the direct contact between the piston and drilling fluid, which can interfere with downhole instrumentation and communication devices, and cause fatigue damage to drill string components.
Innovation Solution
A hydraulically driven reciprocating pump system with a housing containing multiple subchambers and a hydraulic system that adjusts the volume of hydraulic fluid to control the piston's motion, minimizing direct contact and pressure fluctuations by using a combination of pistons and bladder pistons to manage fluid pressure and volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional reciprocating pump uses direct piston contact with drilling fluid, then the pump can effectively pressurize and deliver drilling fluid, but pressure pulsations are generated that interfere with downhole instrumentation and cause fatigue damage
Solution Approach 1:
A hydraulic fluid intermediary system is introduced between the piston and drilling fluid. The piston moves within a hydraulic chamber, actuating a piston that adjusts the volume of hydraulic fluid in a hydraulic chamber, which in turn actuates a second piston to pressurize drilling fluid. This intermediary hydraulic system eliminates direct contact between the reciprocating piston and drilling fluid, thereby reducing pressure pulsations while maintaining effective fluid delivery.
Solution Approach 2:
The patent replaces the direct mechanical connection between the piston and drilling fluid with a hydraulic actuation system. Instead of mechanical direct contact, the system uses hydraulic fluid pressure transmission to achieve piston actuation and fluid pressurization, substituting mechanical interaction with hydraulic interaction to reduce harmful pressure pulsations.
2Power
If a reciprocating pump piston directly contacts drilling fluid, then fluid pressurization is achieved, but wear and fatigue damage to components occurs over time
Solution Approach 1:
The hydraulic fluid serves as an intermediary medium that transmits power from the piston to the drilling fluid without direct contact. This intermediary system protects the piston and associated components from wear and fatigue damage caused by direct contact with drilling fluid, thereby extending component lifespan while maintaining pressurization capability.
Solution Approach 2:
The patent substitutes the mechanical direct-contact system with a hydraulic actuation system, replacing mechanical friction and contact wear with hydraulic fluid interaction. This substitution reduces wear and fatigue damage to components while preserving the essential power transmission and fluid pressurization functions.
3Productivity
If a reciprocating pump operates at high cyclic rates, then drilling fluid is continuously delivered at constant rate, but pressure pulsations increase and interfere with downhole communication devices
Solution Approach 1:
The hydraulic fluid intermediary system acts as a buffer that smooths out pressure variations during high-rate reciprocating operation. The hydraulic chamber volume adjustment mechanism modulates the transmission of pressure pulses, allowing continuous fluid delivery at high cyclic rates while reducing the amplitude of pressure pulsations that would otherwise interfere with downhole communication and measurement devices.
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
The system effectively reduces pressure pulsations, improving the accuracy of downhole measurements and communication, while also reducing wear and extending the lifespan of pump components by minimizing direct contact between the piston and fluid.
Implementation Method 1
deliver hydraulic fluid to the second subchamber, whereby the second subchamber is pressurized and the first piston translates in a first direction
Implementation Method 2
the hydraulic system is actuatable to adjust a volume of hydraulic fluid within the third subchamber to translate the first piston in either the first direction or the second direction
Data Source
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AI summary
A hydraulically driven reciprocating pump. In some embodiments, the pump includes a housing including a hydraulic chamber, a cylinder coupled to the housing, a piston assembly adapted for reciprocal motion within the housing and the cylinder, the piston assembly separating the hydraulic chamber into three subchambers, and a hydraulic system fluidicly coupled to each of the subchambers. The hydraulic system is actuatable to deliver hydraulic fluid to a first of the subchambers, whereby the piston assembly strokes back and a working fluid is drawn into the cylinder, to deliver hydraulic fluid to a second of the subchambers, whereby the piston assembly strokes out and the working fluid is exhausted from the cylinder, and to adjust a volume of hydraulic fluid within a third of the subchambers, whereby the piston assembly translates to bring a pressure of the working fluid in the cylinder to within a pre-selected range.