Wellhead Sleeve for Cement Control and Seabed Stability
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Solution Overview
Problem
During the construction of hydrocarbon wells, controlling the return cement in the initial stages of well construction is challenging, leading to increased cement usage, longer operational time, and potential interference with equipment or other operations. Additionally, there is a need to minimize movement of the seabed around the installed foundation to avoid interfering with the support of the well and drilling operation.
Innovation Solution
A wellhead assembly is provided with a foundation having at least one well slot, where a sleeve is vertically movable and can be locked in place. The sleeve is positioned in the receptacle and can move between two positions, allowing for the installation of a well pipe and subsequent cementing in place, while minimizing seabed movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement is injected between the earth formation and the outermost pipe during initial well construction, then the wellbore is sealed and stabilized, but cement control becomes difficult leading to increased cement usage and longer operational time
Solution Approach 1:
A controllable valve system is introduced as an intermediary device between the cement injection system and the wellbore annulus. This valve acts as a mediator that regulates cement flow, allowing precise control over cement placement and preventing uncontrolled cement return, thereby reducing operational time while maintaining wellbore sealing reliability
2Reliability
If cement is injected during initial well construction, then the wellbore is sealed, but cement may flow out below or around the foundations causing interference with equipment and operations
Solution Approach 1:
A controllable valve system is installed in advance during foundation installation to preemptively prevent cement from flowing out below or around the foundations. The valve is positioned and configured before cement injection begins, creating a barrier that stops harmful cement flow before it can interfere with equipment or operations
3Ease of operation
If the seabed is disturbed during wellbore preparation, then the well pipe can be installed, but movement of the seabed around the foundation interferes with well support and drilling operation
Solution Approach 1:
The controllable valve system is installed and configured in advance during foundation installation, before any seabed disturbance or well pipe installation occurs. This preliminary setup ensures that when wellbore preparation and seabed disturbance are necessary for well pipe installation, the valve is already in place to control any resulting seabed movement and prevent interference with well support
Data Source
AI summary
A wellhead assembly comprises a foundation having at least one well slot. The at least one well slot comprises a receptacle having an internal profile for holding a well pipe and a sleeve arranged in the receptacle. The sleeve is vertically movable and has a top end, which in a first position of the sleeve is located above the internal profile and in a second position of the sleeve is located below the internal profile. There is also provided a method of installing a wellhead assembly at a seabed.