Inverted Shroud for Submersible Well Pump Gas Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing submersible pump systems face challenges in effectively positioning shrouds in wells with perforations that extend over a great distance or have horizontal sections, making it difficult to install and operate electrical submersible pumps (ESPs) efficiently, especially when casing perforations are in a horizontal section with a smaller diameter.
Innovation Solution
The well pump assembly features a shroud with an open upper end and a tubular member extending downward from the motor, allowing well fluid to flow upward and then downward, with optional components like a gas anchor sleeve, recirculation tube, and baffle to enhance fluid flow and separation, and a debris chamber for collecting debris, while maintaining efficient operation across varying well geometries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a closed upper end shroud is used to force all well fluid to flow downward alongside the shroud, then gas separation is improved, but the system cannot be effectively positioned in wells with perforations extending over great distance or horizontal sections
Solution Approach 1:
The shroud is divided into multiple sections: an open upper end portion, a closed middle portion, and an open lower end portion. This segmentation allows the shroud to adapt to different well configurations while maintaining gas separation functionality in the closed middle section.
Solution Approach 2:
The shroud design inverts the traditional closed upper end configuration by placing the closed section in the middle and having open ends at both top and bottom, allowing fluid to enter from above while maintaining gas separation in the closed section.
2Ease of operation
If the shroud is positioned above perforations to allow upward fluid flow, then installation is simplified, but gas separation efficiency decreases
Solution Approach 1:
Dividing the shroud into open upper end, closed middle section, and open lower end allows the device to be installed above perforations while maintaining gas separation capability in the closed middle section.
Solution Approach 2:
The closed middle section acts as an intermediary chamber that receives fluid from the open upper end and forces it to flow downward, creating the necessary conditions for gas separation without requiring the entire shroud to be positioned below perforations.
3Temperature
If a tubular member extends below the motor to divert well fluid for cooling, then motor cooling is improved, but device complexity increases
Solution Approach 1:
The tubular member extending below the motor serves multiple functions: it provides structural support, creates a pathway for cooling fluid circulation, and helps define the lower boundary of the closed middle section, thereby reducing the need for separate cooling system components.
4Adaptability or versatility
If the shroud is used in horizontal sections with smaller diameter casing, then well coverage is improved, but positioning accuracy decreases
Solution Approach 1:
The shroud design allows for flexible positioning along the wellbore, adapting to both vertical and horizontal sections. The open ends and flexible length allow the device to be installed in various configurations while maintaining functional effectiveness.
Solution Approach 2:
The shroud can be positioned to extend in multiple spatial dimensions, accommodating both vertical well sections and horizontal lateral sections, thereby expanding the range of applicable well architectures without sacrificing positioning precision.
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 configuration enables effective gas separation and fluid flow management, ensuring efficient operation of ESPs in wells with complex perforation layouts, improving the positioning and performance of submersible pumps by optimizing fluid flow paths and reducing recirculation and pressure losses.
Implementation Method 1
The shroud has an open upper end in fluid communication with the pump intake for drawing well fluid along an upper flow path down the shroud into the pump intake
Implementation Method 2
A gas anchor sleeve may surround the lower portion of the tubular member. The gas anchor sleeve has a closed lower end and an open upper end, requiring well fluid flowing up along a lower flow path to flow around the gas anchor sleeve then down between the gas anchor sleeve and the tubular member
Implementation Method 3
The recirculation tube diverts a portion of the well fluid being pumped by the pump to below the motor... The diverted well fluid flows back alongside the motor to the pump intake, thereby cooling the motor
Implementation Method 4
The baffle is positioned to be struck by the well fluid flowing down the recirculation tube and direct the well fluid back upward
Data Source
AI summary
A well pump assembly includes rotary pump and a submersible motor. A shroud surrounds the pump intake and the motor. The shroud has an open upper end in fluid communication with the pump intake. A tubular member of smaller diameter is secured to and extends downward from a lower end of the shroud. The tubular member may have an open lower end for drawing well fluid along a lower flow path up the tubular member to the pump intake. An upper flow path at the upper end of the shroud may have a minimum flow area that is smaller than a minimum flow area of the lower flow path. The tubular member has a smaller outer diameter than an outer diameter of the shroud. The tubular member may have a closed lower end to define a debris collection chamber with a drain valve.