Shear-Disconnect Toe Sleeve Prevents Cement Plugging in Cased Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional toe sleeves in directional drilling often get plugged due to cementation or limited opening areas, hindering effective communication with the formation during frac operations in horizontal wells.
Innovation Solution
A toe sleeve design that allows disconnection from the casing by pumping fluid to create a dynamic opening, preventing cementation and ensuring ports remain unobstructed, utilizing a lower body that can shear from an upper body to expose communication ports directly to the formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional toe sleeves are used with cement pumping, then the toe sleeve can be installed in cased hole, but the toe sleeve ports get plugged by cement sheath
Solution Approach 1:
The toe sleeve transitions from a static cemented structure to a dynamic disassemblable structure. The lower body is initially held by shear pins but can be disconnected when fluid pressure exceeds the shear strength, transforming the system from fixed to movable state to prevent plugging
Solution Approach 2:
The toe sleeve is divided into separate components (upper body and lower body) connected by shear pins. This segmentation allows the lower body to disconnect and move independently, creating a dynamic opening that prevents cement from plugging the ports while maintaining structural integrity during installation
2Ease of manufacture
If wipers are used to clean cement from casing, then cement removal is attempted, but the geometric properties of wipers and casing prevent effective cleaning
Solution Approach 1:
Fluid is pumped into the casing before launching the tail wiper plug to create a wet chamber that prevents cement from adhering to the toe sleeve outer diameter in advance. This preliminary wetting action ensures the toe sleeve remains uncemented even though wiper cleaning is ineffective
3Device complexity
If toe sleeve opening area is limited, then the toe sleeve structure is compact, but the opening area gets plugged during pressure up
Solution Approach 1:
The toe sleeve opening transitions from a limited static area to an expanded dynamic area. When the lower body disconnects and moves downward, it creates a larger dynamic opening that prevents plugging during pressure up, while maintaining a compact structure during installation through the shear pin connection
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 effective communication with the formation by preventing plugging, allowing for efficient fluid flow and frac operations without cement obstruction, enhancing the productivity of horizontal wells.
Implementation Method 1
The lower body may be configured to shear from an upper body
Data Source
AI summary
A toe sleeve that is configured to disconnect from casing. More specifically, a toe sleeve that is configured to shear from casing creating a dynamic opening that does not get plugged.