Axial Flow ESP Pump Stage for Gas Lock Mitigation
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Solution Overview
Problem
Electric submersible pumps (ESPs) face performance degradation due to gassy two-phase flow mixtures, which can lead to gas lock issues, preventing the intake of well fluid.
Innovation Solution
A novel centrifugal pump stage with a high volume, axial flow impeller and diffuser structure, featuring a larger inlet and outlet area and a reduced number of impeller vanes, is introduced to enhance fluid flow rates and reduce the risk of gas lock.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional centrifugal pump design is used, then the pump can operate with standard flow rates, but gas accumulation occurs on the suction side leading to gas lock and performance degradation
Solution Approach 1:
The pump is divided into multiple stages with each stage containing an impeller and diffuser. The suction side is segmented into multiple inlet channels that distribute gas-liquid mixture uniformly across the impeller eye, preventing gas accumulation in a single location and eliminating gas lock conditions
Solution Approach 2:
The patent transitions from traditional radial flow impellers to axial flow impellers with three-dimensional vane configurations. This dimensional change creates a through-flow pattern where gas and liquid move axially through the impeller, preventing gas accumulation on the suction side and eliminating gas lock while maintaining high flow rates
2Productivity
If the pump intake area is increased to handle higher flow rates, then productivity improves, but the pump becomes more susceptible to gas lock due to larger suction side volume
Solution Approach 1:
The enlarged pump intake is segmented into multiple smaller inlet channels distributed around the pump perimeter. Each channel independently feeds a specific region of the impeller eye, ensuring uniform gas-liquid distribution and preventing gas accumulation even with large total intake area, thus maintaining high productivity without gas lock risk
Solution Approach 2:
Different regions of the pump intake are designed with locally optimized characteristics. The inlet channels are positioned and sized to create uniform local flow distribution across the impeller eye, ensuring that each local region handles gas-liquid mixture appropriately, preventing gas accumulation while maintaining overall high flow capacity
3Ease of manufacture
If the number of impeller vanes is reduced to simplify manufacturing, then ease of manufacture improves, but the pump efficiency decreases due to poorer fluid guidance
Solution Approach 1:
The impeller vanes are designed with optimized three-dimensional parameters including twisted profiles, variable pitch angles, and specific curvature radii. These parameter changes compensate for the reduced number of vanes by improving fluid guidance and energy transfer efficiency, maintaining high pump performance while simplifying manufacturing through fewer vane components
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 high volume, axial flow centrifugal pump stage effectively homogenizes gas and liquid phases, reducing the likelihood of gas lock and enabling ESPs to handle well fluids with higher gas-to-liquid ratios.
Implementation Method 1
axial flow centrifugal pump stage... The impeller is a high volume, axial flow impeller with a larger inlet and outlet area
Implementation Method 2
The high volume, axial flow centrifugal pump stage effectively homogenizes gas and liquid phases
Data Source
AI summary
An electrical submersible pump (ESP) assembly. The ESP assembly comprises an electric motor having a first drive shaft; a seal section having a second drive shaft that is coupled to the first drive shaft; a third drive shaft that is coupled to the second drive shaft; and an axial flow centrifugal pump stage, wherein the centrifugal pump stage comprises an impeller coupled to the third drive shaft and a diffuser, wherein the impeller defines a plurality of impeller vanes attached between an impeller hub and an impeller shroud, wherein the impeller shroud is a straight-walled cylindrical shape, wherein the diffuser defines a plurality of diffuser vanes attached between a diffuser hub and a diffuser shroud, and wherein the diffuser shroud is a straight-walled cylindrical shape.