Method and system for measuring displacement of buried fluid transmission pipelines
AssigneeAtlantic Richfield Company
InventorRichard A. Behr
Life of this patent
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Abstract
The vertical and lateral displacement of sections of fluid transmission pipelines due to earth subsidence or heaving is determined using vertical and horizontal arrays of magnetometer sensors located spaced apart on a boom or support member for providing multiple readings of the earth's magnetic field intensity and the anomaly caused by the presence of the pipeline. True position of the sensors may be measured using stadia techniques or electromagnetic radiation signals transmitted from a reference point. The sensor array may be mounted on a landbased vehicle or suspended from a rotary wing aircraft to provide access to remote regions which may not be accessible to conventional equipment and techniques.
Claims13
A method for determining the position of a section of fluid transmission pipeline which is disposed beneath the earth's surface in such a way as to generally preclude visual inspection, comprising the steps of:
- providing magnetometer means including sensor means for recording the intensity of the earth's magnetic field at a predetermined point in space and means for receiving a signal generated by said sensor means;
- positioning said sensor means with respect to a generally known location of said section of pipeline and taking readings with said sensor means of the magnetic field intensity at a selected number of positions of said sensor means spaced apart in the vicinity of said generally known location wherein the position of said section of pipeline is indicated by a magnetic anomaly in the magnetic field measured by said sensor means;
- determining the location of said sensor means with respect to a predetermined known lateral position of said section of pipeline;
- determining the elevation of said sensor means with respect to a reference point generally removed from the immediate vicinity of said section of pipeline;
- and
- determining the vertical distance from said sensor means to said section of pipeline by measuring the magnetic intensity of the magnetic field at said selected number of positions for establishing the elevation of said sectin of pipeline with respect to said reference point for successive measurements of any change in position of said pipeline or for determining any change in position of said section of pipeline from a previous known elevation of said section of pipeline with respect to said reference point.
A method for determining the position of a section of fluid transmission pipeline which is disposed in such a way as to generally preclude visual inspection, comprising the steps of:
- providing magnetometer means including a vertically spaced array of sensors for recording the intensity of the earth's magnetic field at a predetermined point in space and means for receiving signals generated by said sensors, respectively;
- positioning said sensors with respect to a generally known location of said section of pipeline;
- determining the elevation of said sensors with respect to a reference point generally removed from the immediate vicinity of said section of pipeline;
- measuring the magnetic intensity sensed by at least two vertically spaced apart sensors of said array of sensors and measuring the vertical spacing between said two vertically spaced apart sensors;
- and
- calculating the vertical distance from the lower one of said two vertically spaced apart sensors to said section of pipeline for establishing the elevation of said section of pipeline with respect to said reference point for successive measurements of any change in position of said section of pipeline or for determining any change in position of said section of pipeline from a previous known elevation of said section of pipeline with respect to said reference point.
Apparatus for determining the location of a section of fluid transmission pipeline disposed beneath the earth's surface including;
- a vehicle including sensor means mounted thereon for providing a plurality of readings of the earth's magnetic field intensity at spaced apart points;
- means for determining the elevation of said vehicle with respect to a reference point so as to determine any changes in elevation of the earth's surface generally directly over said section of pipeline;
- and
- means for recording said plurality of signals generated by said sensor means for determining the point of maximum magnetic field intensity based on measurements of magnetic field intensity made by said sensor means whereby the vertical distance between said sensor means and said section of pipeline at the point of measurement of said maximum magnetic field intensity may be determined.
A method for determining the position of a section of fluid transmission pipeline which is disposed in such a way as to generally preclude visual inspection, comprising the steps of:
- providing magnetometer means including a horizontally spaced array of sensors for recording the intensity of the earth's magnetic field at a predetermined point in space and means for receiving signals generated by said sensors, respectively;
- positioning said sensors with respect to a generally known location of said section of pipeline and taking readings with said sensors of the magnetic field intensity;
- determining the true position of said sensors with respect to a reference point generally removed from the immediate vicinity of said section of pipeline;
- and
- calculating the vertical distance between the one of said sensors indicating the maximum value of magnetic intensity resulting from the perceived presence of said section of pipeline and said section of pipeline for establishing the elevation of said section of pipeline with respect to said reference point for successive measurements of any change in position of said section of pipeline or for determining any change in position of said section of pipeline from a previously known position of said section of pipeline with respect to said reference point.
Dependencies are inferred from the claim text.