Frac Plug Setting Sleeve to Eliminate Shear Pin Debris
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional frac plugs require shear pins to connect with wire line adapter kits, leaving behind debris that needs to be milled out, complicating the process and increasing operational complexity.
Innovation Solution
A frac plug design that uses a setting sleeve to radially expand slips without shear pins, utilizing a collapsible collet and adapter kit to minimize downhole debris, and a lower cone geometry that prevents interaction with slips, allowing for stress-induced slip expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shear pins are used to connect the wire line adapter kit to the frac plug, then the frac plug can be set and held in place, but shear pins remain downhole after setting requiring milling operations
Solution Approach 1:
The invention extracts the harmful function of shear pins by replacing them with a collapsible collet mechanism. The collet is collapsed during setting operations and then expanded to grip the casing, eliminating the need for shear pins that leave debris downhole. This resolves the contradiction by removing the source of harmful factors while maintaining setting reliability.
Solution Approach 2:
The collet is designed to be collapsed during the setting operation and then recovered in its expanded state to provide gripping function. This allows the setting tool to be removed while the frac plug remains securely set, discarding the temporary connection need while recovering the permanent gripping function without leaving debris.
2Reliability
If conventional slips interact with the lower cone fins, then the slips can be held in place, but the fins shear the slips causing failure
Solution Approach 1:
The invention introduces asymmetry in the interaction between the lower cone and slips by providing a ramp surface on the lower cone that interfaces with the slips at an angle. This asymmetric ramp geometry allows the slips to be held in place through friction and normal forces without the symmetric fin configuration that causes shearing, resolving the contradiction between holding capability and slip integrity.
3Ease of operation
If the setting rod has sufficient stroke length to set the frac plug, then the setting operation can be completed, but the setting rod must be pulled out requiring the adaptor kit to be removed
Solution Approach 1:
The collet is designed with dynamic collapse and expansion capabilities. During setting, the collet is collapsed to allow passage of the setting rod. After setting is complete and the rod is pulled out, the collet expands to grip the casing and hold the frac plug in place. This dynamic behavior simplifies the removal operation by eliminating the need to manually remove the adaptor kit while maintaining the necessary setting function.
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 solution enables frac plug setting without leaving shear pins or other materials downhole, simplifying the operation and reducing the need for milling, while ensuring reliable grip and expansion of slips.
Implementation Method 1
The lower cone may include a ramp configured to interface with an inner surface of the lower slip. The lower slip may include an inner surface that interfaces with the ramp of the lower cone. Responsive to the inner surface of the lower slip interfacing with the ramp, the lower slip may radially expand.
Data Source
AI summary
An adaptor kit is configured to limit the amount of shear pins/metal/material left downhole after the frac plug is set and the setting tool is removed from the hole. More specifically, embodiments may utilize a setting sleeve that is configured to set the frac plug.