Well Bore Pressure Control via Model Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional well bore pressure control techniques fail to maintain safe and precise pressure control during well drilling, especially in complex structures, leading to increased risks and costs, as they rely on manual throttle adjustments and are unable to accurately predict and manage overflow or leakage.
Innovation Solution
A method using model prediction control theory and systems theory to detect and adjust well bore pressures by simulating single-phase or multi-phase flow dynamics, optimizing control parameters to maintain well bottom pressure within a safe range, and adjusting the wellhead casing pressure based on real-time monitoring and prediction algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional manual OBD pressure control technique is used, then operation simplicity is maintained, but pressure control precision deteriorates resulting in wide pressure fluctuations
Solution Approach 1:
The patent replaces manual mechanical throttle valve adjustment with an automated electronic control system that uses sensors to detect pressure and flow rates, processes data through a controller, and automatically adjusts the throttle valve position. This substitution of manual mechanical operation with an automated control system resolves the contradiction by maintaining operational simplicity through automation while achieving precise pressure control through electronic regulation and real-time monitoring.
2Adaptability or versatility
If repeated throttle valve adjustment is performed to control well bottom pressure, then adaptability to pressure changes is improved, but system stability deteriorates preventing relative steady state
Solution Approach 1:
The patent implements a closed-loop feedback control system where sensors continuously monitor well bottom pressure and flow rates, the controller processes this data to determine the current state, and automatically adjusts the throttle valve to maintain pressure within the safety window. This feedback mechanism provides adaptability to pressure changes while ensuring system stability by making controlled, incremental adjustments rather than repeated manual adjustments, preventing oscillations and achieving a stable steady state.
3Ease of operation
If wellhead constant pressure control is applied, then ease of control is maintained, but reliability of well bore pressure control deteriorates causing accidents
Solution Approach 1:
The patent applies different control strategies to different locations in the well system. Instead of uniform constant pressure control at the wellhead, the system specifically targets and controls well bottom pressure within a safety window by adjusting wellhead pressure dynamically. This localized quality approach focuses control efforts where they are most needed (at the well bottom) while allowing flexibility at the wellhead, thereby improving reliability of well bore pressure control while maintaining ease of operation through automated control.
4Measurement precision
If conventional pressure control methods focusing on well bore flow are used, then measurement capability is maintained, but prediction capability deteriorates unable to ensure safe pressure control
Solution Approach 1:
The patent incorporates prediction functionality that uses current pressure and flow rate measurements to forecast future well bottom pressure trends. This preliminary action allows the system to anticipate pressure changes before they occur and proactively adjust the throttle valve to prevent pressure from exiting the safety window. By combining real-time measurement with predictive capability, the system ensures reliable safe pressure control while maintaining accurate measurement of current well bore conditions.
Data Source
AI summary
A method for controlling well bore pressure based on model prediction control theory and systems theory, includes: detecting a well bottom pressure, a stand pipe pressure, a casing pressure, an injection flow rate and an outlet flow rate during the drilling operation process and determining the presence of overflow or leakage; if there is no overflow or leakage, then fine-adjusting the wellhead casing pressure according to the slight fluctuations of the well bottom pressure, the stand pipe pressure or the casing pressure; if there is overflow or leakage, simulating and calculating the overflow or leakage position and starting time of the overflow or leakage, predicting the variation over a future time period of the well bore pressure in the well drilling process, and utilizing an optimization algorithm to calculate the control parameter under a minimum of an actual well bottom pressure difference during the future period.