System for monitoring pipelines

• US 4,796,466 A
• Filed: 02/17/1987
• Issued: 01/10/1989
• Est. Priority Date: 02/17/1987
• Status: Expired due to Term

• Current Assignee: Farmer John F
• Original Assignee: Farmer John F
• Inventors: Farmer, Ed
• Primary Examiner(s): Chapman, John
• Assistant Examiner(s): WILLIAMS, HEZRON
• Application Number:
  US07/015,739
• Time in Patent Office: 693 Days
• Field of Search: 73/40, 73/49.1, 73/40.5 R, 73/49.5, 364/507, 364/510, 364/558, 340/605
• US Class Current: 73/40.50R
• CPC Class Codes: F17D 5/02 Preventing, monitoring, or locating loss
• CPC Class Codes: G01M 3/2807 for pipes G01M3/2892, G01M3/30 take precedence

Abstract

A system for monitoring pipelines through which fluids, be they gases or liquids flow using conventional readily available monitoring equipment, that determines the probability of a leak as opposed to the actuality of a leak using a moving average of statistical information gained from a plurality of monitoring stations that monitor either pressure or flow.

Claims

1. A system for monitoring fluid pipelines or pressure vessels to determine the probability of a break, leak or rupture therein using a procedure in which two or more different sets of pressure or velocity measurements, each of said different sets containing a different number of readings, are compared statistically to detect a trend in the readings that would be indicative of a break, leak or rupture, which system comprises:

(a) a fluid characteristic measuring means for monitoring a characteristic of a fluid in the pipeline, and which measuring means provides an output signal that is proportional to the characteristic being monitored;

(b) statistical analyzer means receiving the output signal from a measuring means and providing a statistical analysis of the data from a transducer means to determine by a statistical analysis the probability of a break, leak, or rupture in said pipeline, said probability being expressed as an output signal to a display device.

2. The system of claim 1 wherein the characteristic being monitored is pressure and the characteristic measuring means is a transducer.

3. The system of claim 1 wherein the characteristic being monitored is fluid velocity and the characteristic measuring means is a fluid velocity meter.

4. The system of claim 1 further including additional qualifying logic means interposed between the statistical analyzer and the display device, for receiving the output signal from the statistical analyzer and nullify the value of the said signal upon the occurrence of prespecified events along the pipeline or the like thereby avoiding false alarms, and providing a qualified signal to the display device.

5. The system of claim 1 wherein the display device is a CRT screen.

6. The system of claim 4 wherein the display device is a CRT screen.

7. The system of claim 1 wherein the display device is a recorder.

8. The system of claim 4 wherein the display device is a recorder.

15. The system of claim 1 further including an actuation device adapted to take corrective action along the pipeline or pressure vessels upon the determination of the probability of a break, leak or rupture to the pipeline or the like.

16. The system of claim 4 further including an actuation device adapted to take corrective action along the pipeline or pressure vessels upon the determination of the probability of a break, leak or rupture to the pipeline or the like.

9. A method for detecting the probability of a break, leak or rupture of fluid from a pipeline which comprises the steps of:

(a) monitoring a characteristic of the fluid in the pipeline from a single data collection site,

(b) providing a signal proportional to the characteristic being monitored, from said site,

(c) analyzing the data from the monitoring step for a predetermined quantity of the most recent data measurements, (n₂) by comparing the statistical properties of the n₂ measurements with the statistical properties of a second predetermined quantity of data measurements (N₂) said second quantity of measurements being made during a second period of time,

wherein one of two conditions exists;

(a) said second period of time is different from the time period of the most recent measurement period;

(b) the number of measurements of the most recent time period differs from the number of measurements of the second time period, if the two time periods are of the same length, and wherein n₂ <

n₁, and

(d) displaying the analysis on a display device.

10. The method of claim 9 wherein the monitoring step comprises measuring one of the characteristics of pressure and velocity in the pipeline at a data collection site and providing an output signal proportional to the characteristic thereto.

11. The method of claim 9 wherein the monitoring step comprises measuring the fluid velocity of fluid in a pipeline or pressure vessels at a data collection site and providing an output signal proportional thereto.

12. The method of claim 9 further including the step of qualifying the data from the monitoring step to avoid false alarms.

13. The method of claim 9 further including the step of actuating a device to cause action to be taken along the pipeline or pressure vessels upon the determination of the probability of a break, leak or rupture, of the pipeline or the like.

14. The method of claim 12 further including the step of actuating a device to cause action to be taken along the pipeline or pressure vessels upon the determination of the probability of a break, leak or rupture, of the pipeline or the like.

17. An apparatus for determining the probability of a break, leak or rupture of a pipeline which comprises:

(a) means for monitoring the pressure, P, of fluid in a pipeline and providing an output signal proportional to the measurement of the pressure,

(b) statistical analysis means for receiving the output signal of the means for monitoring the pressure, and for providing an output signal to a display device, for determining the probability that a change of pressure in the pipeline is indeed a break, leak or rupture, by applying a statistical analysis to the output signal of the means for monitoring the pressure according to the procedure recited below, and using the formulae set forth;

##EQU12## and further wherein n₂ is the quantity of the most recent measurements of the pressure and n is a different quantity of pressure measurements, which quantity is greater than the n₂ quantity of measurements;

(a) based upon a series of readings of the pressure, compute the average value of the most recent n₂ readings of the pressure thus yielding a value for y;

(b) determining the average value of the n₁ readings of the pressure, which n₁ readings preceded the n₂ readings taken for use in step (a), thereby yielding a value for μ

;

(c) determining the standard deviation of the entire set of pressure readings as computed above using known statistical procedures;

(d) determine statistically whether the pressure readings that gave rise to the value calculated for y are statistically different from the pressure readings that gave rise to the value calculated for μ and

if so,

(e) conclude that an event that could have been a break, leak or rupture, was statistically more than likely a break, leak or rupture; and

if not, was statistically less than likely a break, leak or rupture.

18. The apparatus of claim 17 further including a display device and an actuation device to take appropriate action to the pipeline upon the determination of a break, leak or rupture.

19. The apparatus of claim 17 further including additional qualifying logic to review the output of the statistical analysis means to avoid false alarms, prior to sending the signal to a display device.

20. The apparatus of claim 18 further including additional qualifying logic to review the output of the statistical analysis means to avoid false alarms, prior to sending the signal to a display device.

21. An apparatus for determining the probability of a break, leak or rupture of fluid from a pipeline which comprises:

(a) means for monitoring velocity, V, of fluid in a pipeline and providing an output signal proportional to the measurement of the velocity,

(b) statistical analysis means for receiving the output signal of the means for monitoring the velocity, and for providng an output signal to a display device, for determining the probability that a change of velocity in the pipeline is indeed a break, leak or rupture, by applying an analysis to the output signal of the means for monitoring the velocity according to the procedure recited below and using the formulae set forth;

##EQU13## and further wherein n₂ is the quantity of the most recent measurements of the velocity, and n₁ is a different quantity of velocity measurements, which quantity is greater than the n₂ quantity;

(a) based upon a series of readings of the velocity, compute the average value of the most recent n₂ readings of the velocity thus yielding a value for y;

(b) determining the average value of the n₁ readings of the velocity, which n₁ readings preceded the n₂ readings taken for use in step (a), thereby yielding a value for μ

;

(c) determining the standard deviation of the entire set of velocity readings as computed above using known statistical procedures;

(d) determine statistically whether the velocity readings that gave rise to the value calculated for y are statistically different from the velocity readings that gave rise to the value calculated for μ and

if so;

(e) conclude that an event that could have been a break, leak or rupture, was statistically more than likely a break, leak or rupture; and

if not, was statistically less than likely a break, leak or rupture.

22. The apparatus of claim 21 further including a display device and an actuation device to take appropriate action to the pipeline or pressure vessels upon the determination of a break, leak or rupture.

23. The apparatus of claim 21 further including additional qualifying logic to review the output of the statistical analysis means to avoid false alarms, prior to sending the signal to a display device.

24. The apparatus of claim 22 further including additional qualifying logic to review the output of the statistical analysis means to avoid false alarms prior to sending the signal to a display device.