Managed-Pressure Casing Installation Assembly for Borehole Lining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for installing casing in subterranean boreholes face challenges in maintaining desired positive pressure while allowing selective fluid flow for casing insertion and cementing operations, particularly when using Managed Pressure Drilling (MPD) systems.
Innovation Solution
A casing installation assembly with a downhole isolation sub featuring a closable valve assembly that selectively prevents or allows fluid communication between the borehole and the surface, facilitating both casing insertion and subsequent cementing operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a valve assembly is closed to maintain pressure containment during casing insertion, then pressure control is improved, but fluid flow for cementing operations is blocked
Solution Approach 1:
The system divides the fluid flow path into multiple segments using separate valves: a first valve controls flow between the borehole and annular space, while a second valve controls flow between the tubular string and annular space. This segmentation allows independent control of different fluid paths, enabling pressure containment in one region while allowing fluid flow in another region during cementing operations.
2Productivity
If casing is inserted quickly to improve productivity, then installation time is reduced, but pressure control and fluid flow management become more difficult
Solution Approach 1:
The system performs preliminary actions by pre-positioning the diverter sub with its bypass flow path and valves before casing insertion begins. The bypass flow path is prepared in advance to provide an alternative route for fluid flow, and the valve assembly is ready to be activated at critical moments. This preliminary preparation enables fast casing insertion while maintaining pressure control, as the fluid diversion mechanism is already in place and requires only activation rather than installation during the high-speed insertion phase.
3Adaptability or versatility
If a bypass flow path is added to allow fluid diversion, then fluid flow flexibility is improved, but device complexity increases
Solution Approach 1:
The diverter sub serves multiple functions: it provides a bypass flow path for fluid diversion, houses the valve assembly for controlling fluid flow, and integrates with the casing installation assembly. The bypass flow path can be used during both casing insertion and cementing operations, and the valve assembly can control flow in different directions. This multi-functionality reduces the need for separate dedicated components for each function, thereby limiting the increase in overall device complexity despite the added versatility.
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 efficient and controlled casing insertion and cementing processes by maintaining pressure containment during casing installation and allowing fluid flow as needed, thereby improving operational efficiency and safety.
Implementation Method 1
a pump fluidly coupled to the borehole and configured to circulate a fluid within the borehole... applying a positive pressure to the borehole
Implementation Method 2
closing a valve assembly of the isolation sub and preventing the fluid from flowing into the tubular string
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Casing installation assemblies for installing a casing within a borehole, as well as systems and methods related thereto are disclosed. In an embodiment, the casing installation assembly includes a tubular string, an isolation sub coupled to a downhole end of the tubular string, and a diverter sub coupled to and positioned downhole of the isolation sub. In addition, the casing installation assembly includes a landing string coupled to the diverter sub and configured to be coupled to the casing. The isolation sub includes a valve assembly that is configured to selectively prevent fluid communication between the tubular string and the diverter sub.