Dual Hydrostatic Piston Packer for Redundant Interventionless Setting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing packer setting technologies, particularly bottom-up hydrostatic setting modules, are inadequate for applications where simultaneous wellbore annulus and production tubing pressure cannot be applied, leading to incomplete packer setting due to limited annular regions and the need for interventionist methods.
Innovation Solution
A packer assembly with dual hydrostatic pistons that can be set without requiring both tubing and annulus pressure, featuring a first and second piston with activation assemblies that allow pressure differences to radially expand a seal assembly, and a slip assembly to ensure effective sealing without the need for a plug or simultaneous pressure application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a bottom-up hydrostatic setting module is used to set a packer above another sealing device, then the packer can be set interventionlessly using available hydrostatic pressure, but the limited annular region between the packer and lower sealing device becomes closed off and cannot communicate with the upper annular area, causing the trapped pressure to dissipate and the packer to not fully set
Solution Approach 1:
The packer assembly is divided into two independent hydrostatic piston systems: an upper hydrostatic piston and a lower hydrostatic piston. Each piston operates in its own chamber and can be actuated independently or simultaneously. This segmentation allows the upper piston to be actuated by tubing pressure while the lower piston is actuated by annulus pressure, ensuring reliable setting even when annular communication is limited or blocked.
2Reliability
If traditional hydraulic setting with a tubing plug is used, then the packer can be reliably set by creating pressure differential, but the rig time required to run and retrieve the plug negatively impacts project economics and adds complications
Solution Approach 1:
The packer assembly uses self-service hydrostatic setting where the setting force is generated automatically by available hydrostatic pressure in the wellbore and applied surface pressure, without requiring external intervention devices like tubing plugs. The dual piston system with activation assemblies allows the packer to set itself by utilizing the natural pressure differentials present in the wellbore environment.
3Device complexity
If a single hydrostatic piston is used, then the device complexity is reduced, but the system lacks redundancy and cannot operate reliably when annular pressure communication is blocked
Solution Approach 1:
The packer assembly incorporates a backup or contingency piston system that provides redundancy against failure modes. The activation assemblies are designed with frangible members that can break to allow pressure communication, providing a fail-safe mechanism. This beforehand cushioning ensures that if one piston system fails to actuate or if annular communication is blocked, the alternative pathway remains available to achieve reliable packer setting.
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
A packer for use in a wellbore includes a packer mandrel. First and second pistons are slidably disposed about the packer mandrel defining first and second chambers therewith. A first activation assembly initially prevents movement of the first piston. A second activation assembly initially prevents movement of the second piston. A seal assembly is disposed about the packer mandrel between the first and second pistons such that actuation of the first activation assembly allows a force generated by a pressure difference between the wellbore and the first chamber to shift the first piston in a first direction toward the seal assembly to radially expand the seal assembly and actuation of the second activation assembly allows a force generated by a pressure difference between the wellbore and the second chamber to shift the second piston in a second direction toward the seal assembly to radially expand the seal assembly.