Shiftable Packer Assembly for Independent Steam Zone Isolation
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Solution Overview
Problem
Existing packers in steam-assisted gravity drainage (SAGD) wells are typically set simultaneously or in close sequential order, lacking the ability to be independently set or unset, which limits flexibility in creating isolated steam zones.
Innovation Solution
A coil shiftable packer assembly with a mandrel, push sleeve, and shift sleeve mechanism that allows for independent setting and unsetting of packers using a hydro-mechanical shifting tool, enabling selective isolation of steam zones by actuating each packer individually.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If all packers are set simultaneously or in close sequential order using hydraulic pressure, then the injection tubing string can be quickly established, but the ability to independently set or unset individual packers is lost, limiting flexibility in creating isolated steam zones
Solution Approach 1:
The packer assembly is segmented into independent controllable units, where each packer can be set or unset individually through separate shifting tools. The shift sleeve and push sleeve are divided into discrete components that can be manipulated independently, allowing selective isolation of steam zones without affecting other packers in the string.
Solution Approach 2:
The packer mechanism transitions from a static hydraulic setting system to a dynamic mechanically shiftable system. The shift sleeve can be moved to different positions (running position, set position, released position) to dynamically control the packer state, enabling flexible creation and modification of isolated steam zones during well operations.
2Adaptability or versatility
If a hydro-mechanical shifting tool is used to independently actuate each packer, then selective isolation of steam zones is enabled, but the operational complexity and time required for setting packers increases
Solution Approach 1:
The packer components (shift sleeve, push sleeve, collet, ratchet ring) are pre-configured and assembled in a ready-to-deploy state. The shift sleeve is pre-positioned with the ability to engage the collet and compress the packer element, eliminating the need for complex sequential adjustments during the setting operation.
Solution Approach 2:
The hydraulic setting mechanism is extracted and replaced with a mechanical shifting system. The shifting tool engages directly with the shift sleeve profile, removing the intermediate hydraulic fluid transmission step and enabling more direct and potentially faster actuation of individual packers.
3Reliability
If the push sleeve and shift sleeve are designed to slide on the mandrel with collet retention, then reliable packer expansion is achieved, but the mechanism requires multiple components increasing assembly complexity
Solution Approach 1:
The collet acts as an intermediary component between the shift sleeve and mandrel, providing a simple yet reliable retention mechanism. The collet engages with the mandrel to hold the shift sleeve in the running position and releases to allow movement to the set position, simplifying the overall retention system while maintaining reliability.
Solution Approach 2:
The ratchet ring and shear pin mechanism provides self-locking functionality. Once the push sleeve is moved to the set position, the ratchet ring automatically engages with the mandrel ratchet section to maintain the position without requiring additional active retention components, allowing the system to service itself.
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 flexible creation of multiple steam injection zones with independent control over steam distribution, enhancing operational efficiency and flexibility in SAGD operations.
Implementation Method 1
compressing the packer element longitudinally to expand radially outwards
Implementation Method 2
the push sleeve and push sleeve has returned to its running position by shearing the at least one shear pin connecting the push sleeve and the ratchet ring
Data Source
AI summary
A packer assembly includes (a) a mandrel bearing an expandable packer element, the mandrel having a ratchet section, a lower collet retaining shoulder, and defining a plurality of longitudinal slots; (b) a push sleeve connected to a ratchet ring by at least one shear pin, wherein the ratchet ring is disposed between push sleeve and the mandrel and engages the mandrel ratchet section; (c) a shift sleeve comprising an inner shift sleeve slidingly disposed within the mandrel and having a lower collet, the inner shift sleeve defining a profile for engaging a shifting tool, and an outer shift sleeve slidingly around the mandrel and connected to the inner shift sleeve with a plurality of bolts, wherein each bolt passes through a longitudinal slot defined by the mandrel; (d) wherein the shift sleeve and push sleeve is moveable between a running position and a released position. Also disclosed are methods of using a packer actuated by a sliding sleeve.