Riserless Single Trip Hanger Running Tool
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Solution Overview
Problem
Current methods for pressure testing annulus seal assemblies in subsea oil and gas production systems require a blowout preventer and riser, which are weight-limited, especially in deep water, and often necessitate multiple trips, limiting well depth and reservoir accessibility.
Innovation Solution
A running tool that lands a tubular hanger, installs, and pressure tests an annulus seal assembly in a single trip without a riser or blowout preventer, using an inner and outer mandrel system with pressure chambers and locking mechanisms to communicate pressure and secure the seal assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a riser and blowout preventer are used for pressure testing annulus seal assemblies, then the sealing integrity can be verified, but the weight limitations of the surface vessel are exceeded and multiple trips are required
Solution Approach 1:
The patent extracts the pressure testing function from the traditional riser-BOP system and integrates it directly into the running tool. The testing assembly includes a packer, setting tool, and pressure testing device that can be lowered through the tubing string to test the annulus seal without requiring a BOP or riser, thereby eliminating the weight limitation constraint while maintaining sealing integrity verification capability
Solution Approach 2:
The patent combines multiple functions (hanger setting, seal installation, and pressure testing) into a single integrated running tool. The tool includes an upper body with a setting tool, a lower body with a packer, and a testing assembly that can all be deployed together in one trip, merging what were previously separate operations into a unified system that eliminates the need for multiple trips and heavy BOP equipment
2Reliability
If a riser and blowout preventer are used for pressure testing, then the annulus seal can be tested, but multiple trips from the surface vessel are required
Solution Approach 1:
The patent combines hanger setting, seal installation, and pressure testing operations into a single integrated running tool that can be deployed in one trip. The tool includes a setting tool for securing the hanger, a packer for sealing the annulus, and a testing assembly with pressure sensor and communication device that can all be deployed together, eliminating the need for separate trips required by traditional methods
Solution Approach 2:
The patent performs preliminary actions by pre-assembling the testing assembly with the packer and setting tool before deployment. The testing device is prepared in advance with the packer positioned to seal the annulus and the pressure sensor ready to measure, allowing all operations to be executed in a single continuous operation without requiring multiple trips or intermediate setup steps
3Length of stationary object
If slim bore wellhead systems are used to eliminate riser requirements, then water depth capability is improved, but the maximum well depth below sea floor is reduced
Solution Approach 1:
The patent creates a universal running tool that can be used with both standard and slim bore wellhead systems. The tool is designed to accommodate different wellhead configurations while maintaining the capability to set hangers and test seals in both shallow and deep water environments, eliminating the need to choose between water depth capability and well depth capability based on wellhead system selection
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 pressure testing of annulus seal assemblies in deep water environments without the weight limitations of risers and BOPs, allowing for single-trip operations and maintaining maximum well depth capability.
Implementation Method 1
pressure is applied to the first pressure chamber to thereby force the outer mandrel and the lower body axially downward and move the seal assembly into the sealing annulus
Implementation Method 2
pressure is applied to a second pressure chamber defined between the seal assembly, the wellhead housing, the inner body and the upper body to test the sealing ability of the seal assembly
Data Source
AI summary
A running tool for landing a tubular hanger in a subsea wellhead housing or the like, installing an annulus seal assembly into a sealing annulus between the tubular hanger and the wellhead housing, and then pressure testing the seal assembly. The running tool includes an inner mandrel which comprises an upper end that is connectable to a running string, a generally cylindrical inner body which is movably connected to the inner mandrel and releasably connectable to the tubular hanger, a generally cylindrical lower body which is positioned around the inner body above the tubular hanger and connectable to the seal assembly, a generally cylindrical upper body which is positioned above the lower body and is connected to the inner body, an outer mandrel which is slidably supported on the upper body and is connected to the lower body, and a first pressure chamber.