Downhole Safety Valve Sectional Maintenance via Ball-Actuated Flappers
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Solution Overview
Problem
Conventional oil and gas drilling methods face challenges in efficiently maintaining and repairing tools and drill strings along the length of the drill string, particularly due to the need for costly and time-consuming tripping and wire-line operations to address well control losses and tool malfunctions upstream of the bottomhole assembly.
Innovation Solution
Deployment of a valving system along the drill string, utilizing Flapper-tool-DSV combinations and profile nipple-DSV setups, allows for section-by-section inspection, maintenance, repair, and replacement of tools and string sections without the need for tripping or running a wire line, by using plugs or balls to control fluid flow and isolate sections for repair.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tools are deployed along the drill string upstream of the BHA, then tool functionality and well control are improved, but maintenance and repair become more complex and time-consuming due to the need for tripping and wire-line operations
Solution Approach 1:
The drill string is divided into multiple sections with individual valves (first valve and second valve) at different locations. This segmentation allows isolated maintenance of specific sections without requiring complete string tripping, reducing maintenance complexity while maintaining well control reliability.
Solution Approach 2:
The invention introduces an intermediary valve system with flow diverter mechanisms that can redirect fluid flow between different string sections. This intermediary system enables maintenance operations without requiring wire-line specialists or complete tripping, simplifying the maintenance process while preserving well control.
2Reliability
If conventional plug and profile nipple systems are used for well control, then well control is achieved, but maintenance and repair require time-consuming tripping operations
Solution Approach 1:
The valve system is pre-configured with flow diverters and bypass mechanisms before deployment. This preliminary configuration allows rapid isolation and maintenance of specific sections without time-consuming tripping operations, reducing maintenance time while maintaining well control reliability.
Solution Approach 2:
The invention employs dynamic valve mechanisms that can be opened or closed remotely to redirect fluid flow during maintenance operations. This dynamic control eliminates the need for complete string tripping, significantly reducing maintenance time while preserving well control capabilities.
3Adaptability or versatility
If tools with smaller inner diameter than drill pipe are deployed, then tool functionality is improved, but plug passage is blocked requiring wire-line operations
Solution Approach 1:
The invention extracts the flow control function from the traditional plug system and implements it through dedicated valves positioned at strategic locations. This extraction allows plugs to pass through tool sections while maintaining well control, eliminating the need for wire-line operations and improving ease of operation.
Solution Approach 2:
The valve system utilizes hydraulic or pneumatic actuation mechanisms to control flow diversion remotely. This allows plugs to pass through the system while valves remotely control fluid direction, resolving the conflict between tool deployment adaptability and plug passage ease of operation.
4Reliability
If the entire drill string is tripped for maintenance, then complete inspection is achieved, but operational time and cost increase significantly
Solution Approach 1:
The drill string is segmented into multiple controllable sections with individual valves. This segmentation enables targeted inspection and maintenance of only the necessary sections, achieving sufficient reliability without the productivity loss associated with complete string tripping.
Solution Approach 2:
The invention applies local quality control through section-specific valves that can be operated independently. This allows maintenance personnel to focus on specific problem areas with local interventions, maintaining adequate inspection quality while significantly improving operational efficiency compared to complete string tripping.
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 approach enables cost-effective and efficient maintenance and repair of drill strings and tools along the length of the drill string, reducing operational expenses and time by allowing section-by-section operations without the need for extensive tripping or wire-line usage.
Implementation Method 1
A ball is pumped down the drill string to seal against a flapper valve and close a flow path
Implementation Method 2
plugs, which are pumped down from the surface and arrested and set by the first nipple profile they encounter in the string
Data Source
AI summary
Disclosed is a cost-effective remedy to loss of well control caused by a defective string section upstream of the BHA, and more cost-effective inspection, maintenance, repair and replacement of any tools placed upstream of the BHA. The solution is to deploy one or more tools along the length of the string, either: (i) each tool below a profile nipple, and where each tool is upstream from an adjacent downhole safety valve (“DSV”); or (ii) one or more Flapper-tool-DSV combinations each below a profile nipple, and where the tool is positioned between each Flapper and DSV in the combination. If desired, the valving system described may be deployed along the string without a tool, to allow section-by-section inspection, maintenance, repair and replacement of string sections.