Casing Hanger Wedge System for Well Installation
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Solution Overview
Problem
The existing methods for hanging casing in hydrocarbon wells are time-consuming and expensive due to the need to remove and reinstall blowout preventer stacks and lock the casing top into the wellhead, which can lead to casing collapse and increased rig time.
Innovation Solution
A hanger system with interengaged wedge surfaces that allow lateral expansion and adjustment, enabling the casing to be suspended without locking into the wellhead, allowing for the removal of the blowout preventer stack and reducing the need for rigid locking, facilitating easier installation and removal of the hanger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the casing is locked into the wellhead to prevent collapse, then the casing stability is improved, but the rig time and expense increase due to the need to remove and reinstall blowout preventer stacks
Solution Approach 1:
The landing system is divided into separate functional components: a wellhead assembly and a casing hanger assembly. The casing hanger can be independently installed and removed without affecting the wellhead, allowing the blowout preventer stack to remain in place throughout the cementing operation. This segmentation eliminates the time-consuming process of removing and reinstalling the blowout preventer while maintaining casing stability through the hanger's locking mechanism.
Solution Approach 2:
The casing hanger is pre-installed on the casing string before cementing operations begin. This preliminary action allows the hanger to be in position and ready to support the casing weight immediately, eliminating the need for subsequent wellhead modifications or blowout preventer removal. The hanger's internal shoulder is prepared in advance to receive and lock the casing, ensuring stability without additional rig intervention.
2Ease of manufacture
If the blowout preventer stack is removed to install the wellhead, then the wellhead can be attached, but the rig must sit idle for hours increasing expense
Solution Approach 1:
The casing hanger integration merges the functions of wellhead attachment and casing support into a single component. The hanger is designed to be attached to the wellhead internally, combining the support function with the wellhead structure. This integration allows the blowout preventer stack to remain externally attached to the wellhead throughout the operation, eliminating the need to remove it for wellhead installation and maintaining continuous rig productivity.
3Reliability
If the casing is hung in tension to prevent collapse, then the casing stability is improved, but the hanger must be permanently installed increasing equipment cost
Solution Approach 1:
The casing hanger employs a dynamic locking mechanism with movable locking elements that can engage or disengage from the wellhead's internal features. The hanger's body can move axially to allow the locking elements to engage with the wellhead's internal shoulder or grooves, creating a secure connection. This dynamic design provides stable casing support when engaged, while allowing the hanger to be removed and reused when disengaged, eliminating the need for permanent installation and reducing overall equipment costs.
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
This solution reduces the time and expense associated with well completion by eliminating the need for locking the casing into the wellhead and allows for the removal of the blowout preventer stack after cementing, thereby saving rig time and equipment costs.
Implementation Method 1
interengaged wedge surfaces that interengage to induce lateral expansion of the hanger portion
Data Source
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AI summary
The method of installing a plurality of casing sections in a well, that includes providing a hanger supporting the casing sections to extend longitudinally in the well, landing the hanger on structure in the well, whereby weight of the casing sections longitudinally compresses the hanger, cementing the casing sections in position in the well, below the hanger, adjusting the hanger to provide for controllable longitudinal shortening of hanger length, thereby removing exertion of casing weight on the hanger, and removing at least part of the hanger away from the well head.