Adjustable Orifice Choke Valve Control for Fast Well Pressure Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing well drilling systems with adjustable orifice choke valves have a relatively slow response to pressure variations, which can lead to uncontrolled pressure fluctuations and potential blowouts, as they rely on iterative processes to adjust the choke valve positions.
Innovation Solution
A well drilling system with a choke manifold and a controller that determines the appropriate choke position based on flow coefficient values (Cv) calculated from pressure differences, fluid density, and volumetric flow rates, allowing for rapid adjustment of the choke valve to maintain optimal annular pressure within the pressure window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an iterative process is used to adjust the choke valve translating member, then the pressure across the choke can be changed, but the response time is relatively slow
Solution Approach 1:
The system pre-calculates and stores the relationship between Cv values and choke positions in a lookup table before operation. When pressure control is needed, the controller directly queries this pre-established table to determine the required choke position, eliminating the need for iterative adjustments and achieving immediate response to pressure variations.
Solution Approach 2:
The patent replaces the manual iterative mechanical adjustment process with an automated electronic control system. The controller calculates the required Cv value based on pressure differential and flow rate, then directly actuates the choke valve to the corresponding position using motorized control, substituting the slow iterative mechanical process with rapid electronic computation and actuation.
2Adaptability or versatility
If a variable orifice choke is used instead of a fixed orifice, then pressure control flexibility is improved, but the system complexity increases
Solution Approach 1:
The patent implements a dynamically adjustable choke valve with a translating member that can continuously vary the orifice size. This dynamic structure allows the choke to adapt to different pressure and flow conditions in real-time, providing flexible pressure control while the control algorithm manages the complexity through automated Cv calculation and position determination.
Solution Approach 2:
The system changes the flow coefficient parameter (Cv) of the choke valve dynamically based on calculated requirements. By computing the needed Cv value from pressure differential and flow rate measurements, and then adjusting the choke position to achieve that Cv, the system achieves adaptable pressure control without requiring complex manual intervention for each parameter change.
3Reliability
If iterative adjustment of the choke valve is performed, then pressure control can be achieved, but time is lost in the adjustment process
Solution Approach 1:
The system continuously monitors the actual pressure differential across the choke and the flow rate, then uses this feedback to calculate the required Cv value. The controller compares the calculated Cv with the current choke position and automatically adjusts the valve to maintain the correct pressure, providing reliable closed-loop control without iterative manual adjustments and minimizing response time through automated real-time correction.
Solution Approach 2:
The controller pre-establishes the relationship between operating conditions (pressure differential and flow rate) and the required choke position through Cv calculations. This preliminary computational preparation allows the system to immediately determine the correct choke position when pressure control is needed, eliminating the time-consuming iterative adjustment process while maintaining reliable pressure control through direct positioning.
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 enables quick and precise control of annular pressure, reducing the risk of blowouts and improving drilling efficiency by eliminating the need for iterative processes, thus maintaining pressure within the desired fracture and pore pressure boundaries.
Implementation Method 1
The choke valve (28) has a flow coefficient value (Cv) for each choke position... determine a first Cv value using the ΔP, the value representative of the density of the drilling fluid, and the value representative of a volumetric fluid flow
Data Source
AI summary
A well drilling system is provided that includes a choke manifold and a controller. The choke manifold includes at least one choke valve. The choke valve is actuable between fully open and closed choke positions. The choke valve has a Cv value for each choke position. The controller is in communication with the choke valve and a non-transitory memory storing instructions. The instructions relate Cv values to choke positions for the choke valve. The instructions when executed cause the controller to: a) determine a difference in pressure (ΔP); b) input or determine a density value; c) input or determine a Q value; d) determine a first Cv value using the ΔP, the density value, and the Q value; and e) actuate the choke valve to a first choke position associated with the first Cv value.