Segmented Gas Piston Dampener for High-Pressure Pulsations
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Solution Overview
Problem
High-pressure hydraulic fracturing operations face significant costs due to equipment failures caused by pulsating flows, which existing pulsation dampeners cannot effectively manage safely and efficiently, especially at pressures above 3,000 psig, due to safety concerns and design limitations.
Innovation Solution
A pulsation dampener design that segments high-pressure gas volumes into discrete cylinders with pistons, housed in a specially constructed dampener with eccentric reducers and flanged for easy removal, allowing the gas cylinders to absorb pressure pulses and maintain containment, using hardened stainless steel for durability and incorporating a flow-through design to manage suspended solids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas-cushioning is used in pulsation dampeners for high-pressure applications, then pulsation dampening effectiveness is improved, but safety risks increase due to explosion threats from highly compressed gas
Solution Approach 1:
The patent divides the gas containment system into multiple separate cylinders (first cylinder, second cylinder, etc.) rather than using a single large gas reservoir. Each cylinder contains high-pressure gas at controlled volumes, segmenting the overall gas-cushioning function while reducing the explosion risk associated with any single container. The dampening effect is achieved through the combined action of multiple gas springs.
Solution Approach 2:
The patent applies different material properties to different parts of the system: hardened stainless steel is used for the cylinders and piston rods to provide erosion and corrosion resistance in the high-pressure fluid environment, while the gas chambers use controlled-volume design to manage safety risks. Each component is optimized for its specific functional requirements.
2Reliability
If conventional material containers are used to contain high-pressure gas, then gas containment is achieved, but wall thickness and device weight increase significantly
Solution Approach 1:
The patent employs hardened stainless steel for the cylinder construction, combining the properties of stainless steel (corrosion resistance, toughness) with surface hardening treatment to achieve both lightweight design and high-strength containment. This composite material approach allows thinner walls compared to conventional materials while maintaining containment integrity at high pressures.
3Reliability
If gas cylinders are placed in high-pressure pulsatile flow systems, then pulsation absorption is improved, but pressure differentials cause wall distortion and seal integrity issues
Solution Approach 1:
By using multiple separate cylinders instead of a single large chamber, the patent reduces the wall area exposed to high pressure differentials in any one location. Each cylinder wall experiences reduced stress, minimizing distortion and maintaining seal integrity while collectively providing the required pulsation absorption.
Solution Approach 2:
The gas springs are pre-charged to specific pressures to provide cushioning force before pressure pulses arrive. This beforehand cushioning allows the system to absorb incoming pressure pulses more gently, reducing the peak pressure differentials that would otherwise cause wall distortion and seal failure.
4Productivity
If positive displacement pumps are used for hydraulic fracturing, then fluid delivery capability is improved, but equipment failure increases due to high-pressure pulsating flow
Solution Approach 1:
The patent extracts the pulsation-dampening function from the pump system itself and places it downstream in a dedicated dampener assembly. The gas springs are positioned to absorb pressure pulses after they are generated by the pump, isolating the pump from the harmful effects of pulsations while maintaining the pump's high fluid delivery capability.
Solution Approach 2:
The gas springs act as an intermediary element between the high-pressure pump and the downstream piping system. They absorb and dampen pressure pulses, serving as a mediator that protects downstream equipment (couplings, joints, fittings) from the harmful pulsating forces while allowing the pump to continue operating at full productivity.
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 solution effectively reduces pulsation magnitudes, maintains safety by containing high-pressure gas within stress-free cylinders, and extends equipment life through erosion and corrosion resistance, reducing downtime and costs associated with equipment failures.
Implementation Method 1
a piston assembly (70) including a piston head (74) having a gas pressure surface (75a) and a fluid pressure surface (75b) with a gas-cushioned dampener canister (50) disposed above the piston assembly (70) in the non-flow fluid chamber (24)
Implementation Method 2
incorporating a flow-through design to manage suspended solids
Implementation Method 3
using hardened stainless steel for durability and incorporating a flow-through design to manage suspended solids
Data Source
AI summary
Disclosed is an in-flow pulsation dampening system for high-pressure (e.g., 10K psi and higher) fluid lines. At high fluid flow pressures, the dampening system is a dual stage dampening system, responsive to low (e.g., when first charging the fluid line) and to very high-pressure pulsations. An external containment shell handles the full fluid flow pressures. One or more internal shells contain and handle the internal gas dampening system. The in-flow relationship of the gas dampening component assures that pressure differences between the internal gas handling system and the high-pressure fluid flow is always relatively small. This enables the gas handling components to be constructed of less robust material than the external shell (even though the gas system's internal pressure can equal that of the fluid flow), and be less susceptible to pressure failure.