Downhole Tool Retaining Cementing Plugs
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Solution Overview
Problem
In oil and gas well cementing operations, there is a challenge in preventing the inadvertent discharge or escape of plugs or balls used to define the cement volume, which can lead to inefficiencies and inaccuracies in cement placement.
Innovation Solution
A downhole tool with a tool body having a main flow bore and internally and externally threaded sections, equipped with a check valve and enlarged diameter sections to catch and retain plugs or balls, preventing their discharge and allowing controlled cement flow around them.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a plug or ball is dispensed into the well during cementing operations, then the cement volume can be defined, but the plug or ball may inadvertently discharge or escape leading to inaccuracies in cement placement
Solution Approach 1:
The patent introduces a catching mechanism as an intermediary component between the plug/ball and the wellbore. This mechanism includes a catching member with an opening that allows the plug or ball to pass through during dispensing, but then closes to retain it. The intermediary catching mechanism prevents inadvertent discharge while maintaining the ability to define cement volume accurately.
Solution Approach 2:
The catching mechanism employs dynamic movement to resolve the contradiction. The catching member transitions from an open state during plug dispensing to a closed state for retention. This dynamic transformation allows the system to first allow passage of the plug/ball for cement volume definition, then securely retain it to prevent escape and ensure placement accuracy.
2Reliability
If a catching mechanism is added to retain plugs or balls, then reliability of plug retention improves, but device complexity increases
Solution Approach 1:
The patent merges the catching mechanism with the existing downhole tool body, integrating multiple functions into a single apparatus. The catching member is incorporated as part of the tool assembly, combining the cementing function with the plug retention function. This merging reduces the need for separate components and minimizes overall device complexity while maintaining high reliability.
Solution Approach 2:
The downhole tool is designed with multi-functionality, serving both as a cementing device and a plug retention device. The catching mechanism is integrated into the universal tool assembly that can handle both cement dispensing and plug retention operations. This multi-functional design eliminates the need for separate specialized devices, reducing overall system complexity.
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
Ensures accurate placement of cement by retaining plugs or balls, preventing their unintended release and allowing fluid to bypass them, thereby maintaining a defined cement volume and ensuring effective well cementing operations.
Implementation Method 1
equipped with a check valve and enlarged diameter sections to catch and retain plugs or balls, preventing their discharge and allowing controlled cement flow around them
Data Source
AI summary
An improved method and apparatus for catching and holding a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured tool body that accepts a ball or a plug or a dart that flows downwardly into the tool body but disallows escape or discharge of the ball, plug or dart upwardly. The tool body has first and second flow channels or passages, one being generally axially aligned with the tool body. The other flow channel or passage is a second channel or passage that enables fluid flow around a cavity that contains one or more captive plugs (or ball or dart(s)).