Torque Absorption Anchor System for ESP Startup
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Solution Overview
Problem
The startup of electric submersible pumps (ESPs) generates substantial torque that can cause cracking or breaking at coupled joints in tubing strings, especially when made of weaker materials like fiberglass, limiting the horsepower and size of ESP systems, which restricts their use in deeper wells.
Innovation Solution
A torque absorption anchor system comprising an annular sleeve and collar with a torsional spring that compresses and unwinds during ESP rotation, reducing the transfer of rotational inertia to the production string, thereby alleviating torsional stresses on threaded connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If ESP motor horsepower is increased to handle deeper wells, then pumping capability is improved, but torsional forces during startup increase causing cracking or breaking at threaded connections
Solution Approach 1:
A torque absorption device is introduced as an intermediary component between the ESP motor and the production tubing string. This device includes a torque absorption member with a torque absorption element that can rotate relative to the production tubing, absorbing startup torque through friction or mechanical deformation. The intermediary device allows the motor to generate high horsepower while preventing excessive torsional forces from being transmitted to the threaded connections in the production tubing string.
2Weight of moving object
If fiberglass tubing is used in the production string, then weight is reduced, but resistance to torsional forces during ESP startup decreases
Solution Approach 1:
The torque absorption device serves as a protective intermediary that decouples the motor's rotational inertia from the production tubing string. By placing the torque absorption member between the motor and the fiberglass tubing, the device absorbs the harmful torsional forces during startup while allowing the lightweight fiberglass tubing to maintain its weight advantages. The torque absorption element prevents cracking or breaking at threaded connections by limiting the transmission of torsional forces to the vulnerable fiberglass sections.
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 reduces the risk of early failure in coupled joints, allowing for higher horsepower and larger ESP systems by minimizing torsional stresses during startup, enabling their use in deeper wells with greater pumping heads.
Implementation Method 1
a torsional spring in the annulus that has a portion coupled to the sleeve and another portion coupled to the collar so that when the ESP rotates with respect to the production tubing, the torsional spring is compressed
Data Source
AI summary
An electric submersible pump (ESP) torque absorbtion anchor system (TAS) and a method to assemble the same are disclosed. The TAS includes a collar having an uphole end coupled to a production string and a flange formed on an outer diameter of the collar. The TAS also includes a sleeve having a rim extending radially inward from an uphole end of the sleeve. The collar is positioned in a cavity of the sleeve so that oppositely facing shoulders of the collar and the sleeve contact and transfer axial loads between the sleeve and the collar. A spring is positioned in an annulus between the sleeve and the collar and mounts to the collar and the sleeve so that rotational loading of the sleeve relative to the collar transfers to the spring.