Patent EA-005278-B1 (EA)
Title: Method for detecting and correcting sensor failure in oil and gas production system
Inventor: VAN DER GEEST ROBERT ANTON BER
IPC: G01D1/18
Filed: 2002-04-26
Abstract: 1. A method for detecting sensor failure in an oil and gas production system, comprising performing in a data processing system: generating from a process model of the oil and gas production system using measurements from one or more sensors an expected value for a sensor measurement; comparing the expected value with an actual measurement obtained from a first sensor in said oil and gas production system; if the expected value is within acceptable specified limits of the actual measurement confirming the validity of the actual measurement obtained; and if the expected value is not within acceptable specified limits of the actual measurement, indicating the failure of the sensor and replacing the value of the actual measurement with the expected value. 2. A method for detecting sensor failure in an oil and gas production system, comprising the steps performed in a data processing system: generating an expected value for a sensor measurement from a process model of the oil and gas production system, by means of one (or more) generated back-up value(s), primarily being generated by means of the process model; comparing the expected value with an actual measurement obtained from a first sensor; if the expected value is within acceptable specified limits of the actual measurement confirming the validity of the actual measurement obtained; and if the expected value is not within acceptable specified limits of the actual measurement, indicating the failure of the sensor and replacing the value of the actual measurement with the expected value. 3. The method of Claim 1 or 2, wherein the step of generating an expected value for a sensor measurement comprises the step performed in a data processing system of: obtaining a probability distribution of expected values for the sensor measurement. 4. The method of claim 3 wherein said obtaining of a probability distribution of expected values comprises performing in a data processing system multiple simulations of the oil and gas production system using sensors in the production system other than the first sensor over a range of possible sensor readings from the other sensors. 5. The method of claim 4 wherein said obtaining of a probability distribution of expected values comprises performing in a data processing system multiple simulations of the oil and gas production system using a range of model parameters for the production system. 6. The method of claim 1 or 2, wherein a probability distribution of measured sensor values is available and said comparing comprises performing in a data processing system obtaining a probability distribution of the difference between the expected value and the actual measurement obtained from the sensor. 7. The method of claim 6, wherein said comparing comprises performing in a data processing system obtaining the acceptable specified limits for the difference between the expected value and the actual measurement by means of said probability distribution of the difference between the expected value and the actual measurement. 8. A computer program product for causing a data processing system to monitor for sensor failure in an oil and gas production system, the computer program product comprising: computer-readable instructions on the storage device for causing the data processing system to monitor for sensor failure in the oil and gas production system by performing the steps of: generating from a process model of the oil and gas production system using measurements from one or more sensors an expected value for a sensor measurement; comparing the expected value with an actual measurement obtained from a first sensor; if the expected value is within acceptable specified limits of the actual measurement confirming the validity of the actual measurement obtained; and if the expected value is not within acceptable specified limits of the actual measurement, indicating the failure of the sensor and replacing the value of the actual measurement with the expected value. 9. A computer program product for causing a data processing system to monitor for sensor failure in an oil and gas production system, the computer program product comprising: computer-readable instructions on the storage device for causing the data processing system to monitor for sensor failure in the oil and gas production system by: generating an expected value for a sensor measurement from a process model of the oil and gas production system, by means of one (or more) generated back-up value(s), primarily being generated by means of the process model; comparing the expected value with an actual measurement obtained from a sensor in said oil and gas production system; if the expected value is within acceptable specified limits of the actual measurement confirming the validity of the actual measurement obtained; and if the expected value is not within acceptable specified limits of the actual measurement, indicating the failure of the sensor and replacing the value of the actual measurement with the expected value. 10. The computer program product of claim 8 or 9, wherein the computer-readable instructions further include instructions for causing the data processing system to perform obtaining a probability distribution of expected values for measurement from the sensor. 11. The computer program product of claim 8, wherein the computer-readable instructions further include instructions for causing the data processing system to perform multiple simulations of the oil and gas production system using sensors in the production system other than the first sensor over a range of possible sensor readings from the other sensors. 12. The computer program product of claim 8, wherein the computer-readable instructions further include instructions for causing the data processing system to perform multiple simulations of the oil and gas production system using a range of model parameters for the production system. 13. The computer program product of claim 8 or 9, wherein the computer-readable instructions further include instructions for causing the data processing system to perform multiple simulations of the oil and gas production system to perform obtaining a probability distribution of the difference between the expected value and the actual measurement obtained from the sensor. 14. The computer program product of claim 13, wherein the computer-readable instructions further include instructions for causing the data processing system to perform obtaining the acceptable specified limits for the difference between the expected value and the actual measurement by means of said probability distribution of the difference between the expected value and the actual measurement.