Shearable Control Line Connectors for Downhole Retrieval
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Solution Overview
Problem
Severed control lines in the oil and gas industry often obstruct downhole equipment, preventing successful reconnection and retrieval, as the remaining portions can bunch up and bind during ascent to the surface.
Innovation Solution
A shearable control line connector system that includes upper and lower coupling elements secured by a connector cap, designed to separate upon application of an axial force, ensuring controlled disconnection and preventing obstruction of downhole equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If control lines are severed by pulling on upper portions until control line fails in tension at a random location, then control lines can be severed to allow retrieval of upper portions, but the severed control line portions may obstruct downhole equipment and prevent successful reconnection
Solution Approach 1:
The control line connector is divided into separate upper and lower coupling elements that can be disconnected from each other. The shearable connector allows the control line to be segmented into upper and lower portions at a predetermined location, preventing obstruction of downhole equipment while enabling successful retrieval and reconnection operations.
Solution Approach 2:
The connector is pre-configured with a predetermined failure location and shear strength characteristics before being installed in the wellbore. This preliminary design ensures that when axial force is applied, the connector will fail at the intended location rather than at a random position, thereby preventing obstruction issues and ensuring reliable downhole equipment reconnection.
2Reliability
If control lines are severed using a shearing device located downhole, then control lines can be severed in a controlled manner, but the device complexity increases
Solution Approach 1:
The shearing function is extracted from a complex downhole shearing device and integrated directly into the connector cap itself. The connector cap incorporates a predetermined failure location with reduced wall thickness, eliminating the need for separate shearing devices and reducing overall system complexity while maintaining controlled severing capability.
Solution Approach 2:
The connector cap is designed to perform its own shearing function through its inherent structural weakness at the predetermined failure location. When axial force is applied, the connector cap automatically fails at the intended location without requiring external shearing devices or additional mechanisms, thereby simplifying the overall system.
3Ease of operation
If connector cap is designed to shear upon axial force application, then controlled disconnection is achieved, but the strength of the connector is reduced
Solution Approach 1:
The connector cap has non-uniform wall thickness, with a predetermined failure location featuring reduced wall thickness compared to other portions. This local quality variation creates a weak point that fails first under axial load, enabling controlled disconnection while the rest of the connector maintains full strength for normal operation.
Solution Approach 2:
The connector cap is segmented into regions of different strength characteristics. The predetermined failure location is designed with reduced strength to facilitate controlled failure, while other portions maintain full strength. This segmentation allows the connector to be strong enough for normal use but capable of controlled disconnection when needed.
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
Enables reliable disconnection of control lines at a predetermined location, allowing for unobstructed reconnection and retrieval of downhole equipment by keeping the severed control line portions below the remaining equipment, preventing binding issues during ascent.
Implementation Method 1
a connector cap securing the upper coupling element to the lower coupling element, the connector cap being configured to shear upon being subjected to an axial force
Data Source
AI summary
Disclosed are shearable control line connectors. One control line connector includes an upper coupling element, a lower coupling element communicably coupled to the upper coupling element, and a connector cap securing the upper coupling element to the lower coupling element and being configured to shear upon being subjected to an axial force, thereby effectively separating the upper coupling element from the lower coupling element.