Electronically Controlled Downhole Valves for Wellbore Pressure Management
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Solution Overview
Problem
Conventional downhole valves in the oil and gas industry face challenges such as complex wellhead setups, limited control over individual valves, unequal pressure distribution, and safety hazards due to high surface pressure requirements, particularly in deep wells, and lack selective and incremental control over fluid flows during gas-lift operations.
Innovation Solution
A system of electronically controlled downhole valves along a tubing string that measures pressure differentials and allows for selective actuation, enabling incremental opening or closing of valves to maintain desired pressure distributions and control slug flows, with the ability to operate remotely and automatically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional hydraulic valves are used with separate control lines from the wellhead to each downhole valve, then valve control capability is provided, but the number of downhole valves is practically limited and wellhead complexity increases
Solution Approach 1:
Multiple hydraulic control lines are merged into a single control line that serves all downhole valves. The system uses a single pressure source at the wellhead that distributes hydraulic pressure through one control line to multiple valves, eliminating the need for separate control lines to each valve while maintaining full control capability.
Solution Approach 2:
The single control line performs multiple functions by serving all downhow valves simultaneously. The control line acts as a common hydraulic pathway that can actuate any or all valves independently through pressure modulation, making the system universally applicable to multiple valves without requiring dedicated infrastructure for each.
2Ease of operation
If deep wells are operated with conventional hydraulic valves, then valve actuation is achieved, but increased surface pressure is required which becomes a safety hazard
Solution Approach 1:
A compressible gas (such as nitrogen) is introduced as an intermediary medium in the hydraulic control system. The gas is injected into the control line to provide cushioning and reduce peak pressure requirements during valve actuation. This intermediary allows deep well valves to be actuated without requiring excessively high surface pressures, thereby eliminating the safety hazard while maintaining actuation capability.
3Ease of manufacture
If typical gas-lift valves are used with predetermined pressure settings, then valve operation is simplified, but selective and incremental control over each valve is not provided and pressure distribution becomes unequal
Solution Approach 1:
The valve system transitions from static predetermined pressure settings to dynamic, adjustable pressure control. Each valve's opening pressure can be modified in real-time based on downhole conditions and production requirements. The system allows incremental adjustments and selective actuation of individual valves, enabling adaptive pressure distribution throughout the wellbore while maintaining operational simplicity through automated control.
Solution Approach 2:
Pressure sensors and control systems provide feedback on actual downhole pressure conditions to the surface control unit. Based on this feedback, the system automatically adjusts the hydraulic pressure signals to each valve to achieve the desired pressure distribution. This closed-loop control enables selective and incremental valve operation while maintaining simplicity through automated decision-making rather than complex manual configuration.
4Device complexity
If a single return line is used for all downhow valves, then system complexity is reduced, but if it fails all lines fail and all valves become inoperable
Solution Approach 1:
The hydraulic control system incorporates a cushioning gas (such as nitrogen) that is pre-injected into the control line to provide pressure buffering and system resilience. This cushioning medium absorbs pressure shocks and maintains minimum pressure levels even during partial system failures, ensuring that a single point failure does not cause complete system collapse and all valves become inoperable.
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 provides precise control over fluid flows, reduces operational costs, enhances oil and gas production efficiency, and minimizes slug flows by maintaining uniform pressure distribution within the wellbore, allowing for bi-directional flow management without the need for hydraulic control lines.
Implementation Method 1
measuring a pressure differential at each of a plurality of downhow valves coupled to a tubing string in a wellbore
Implementation Method 2
in a gas-lift oil well, natural gas produced in the oil field is compressed and injected in an annular space between the casing and tubing and is directed from the casing into the tubing to provide a 'lift' to the tubing fluid column for production of oil out of the tubing
Data Source
AI summary
Disclosed is a method and system for fluid flow optimization within a wellbore for gas-lift operations and control of slug flows within the wellbore by utilizing a plurality of electronically controlled valves coupled to a tubing string. Selective actuation of the valves includes incremental opening or closing of an individual valve between a fully open, fully closed, or partial opening of a particular valve. Pressure measurements inside and outside of the tubing string are measured in real-time near the valve to help maintain the desired pressure distribution within the wellbore and to measure and control a pressure differential at a selected valve. Actuation of the valves may be electronically controlled at a remote location by electronic command signals or may be performed automatically by the downhole valves with or without input by a remote system.