System for monitoring the condition of a pipeline

• US 4,162,635 A
• Filed: 01/03/1978
• Issued: 07/31/1979
• Est. Priority Date: 01/03/1978
• Status: Expired due to Term

• Current Assignee: Triad & Associates Incorporated
• Original Assignee: Triad & Associates Incorporated
• Inventors: Burke, Robert, Morrow, Richard, Brauer, Walter H., Triplett, William C.
• Primary Examiner(s): Gill, James J.
• Application Number:
  US05/866,486
• Time in Patent Office: 574 Days
• Field of Search: 73/622, 73/623, 73/432 R, 33/178 F
• US Class Current: 73/623
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 29/2481 Wireless probes, e.g. with transponders or radio links
• CPC Class Codes: G01N 29/265 by moving the sensor relative to a stationary material
• CPC Class Codes: G01N 29/40 by amplitude filtering, e.g. by applying a threshold or by gain control

Abstract

Apparatus for scanning the interior of pipelines. The apparatus comprises a pig having an elongated body, a bogie assembly adapted to maintain the body in the center of a pipeline, and a seal assembly extending radially from the body and adapted so that the pig may be propelled by fluid flow through a pipeline. The pig further includes an on-board power supply coupled to the bogie assembly to provide and store electrical power for the pig. In addition, the pig includes an odometer, sensor and recording device powered by the power supply. The odometer is coupled to the bogie assembly and provides a motion signal representative of motion of the pig through a pipeline. The sensor includes a scanning ultrasonic surface wave exciter/transponder which generates a data signal representative of the interior condition of the pipeline. The recording device records the motion and data signals for subsequent analysis.

Claims

1. Apparatus for scanning the interior of a pipeline having a radius R, comprising:

A. an elongated body member having a longitudinal axis,

B. bogie assembly including means for maintaining the longitudinal axis of said body member substantially coaxial with the central axis of said pipeline,

C. sealing means extending radially from said body member, and including means for establishing a fluid-tight seal between regions in a pipeline ahead of said apparatus and regions behind said apparatus, whereby said apparatus is responsive to the pressure differential across said sealing means to move at a velocity V along said pipeline axis from regions of relatively high pressure to regions of relatively low pressure,

D. sensor means powered by said power supply for detecting one or more physical characteristics of portions of said pipeline adjacent to said apparatus, and for generating sensor data signals representative of said conditions, said sensor means including;

ultrasonic surface wave transponder including;

i. means for transmitting an ultrasonic surface wave excitation beam at an angle θ

with respect to said pipeline axis, where θ

is measured from said pipeline axis ahead of said body member and is less than π

/2 radians, and for receiving an oppositely directed wave disturbance, said transmitted beam being adapted to excite ultrasonic waves on the interior surface of said pipeline, and having a beam width at least equal to L in the direction of said pipeline axis at a distance R from said axis, and a beam width Δ

which is small compared with 2π

R in the direction transverse to said axis at a distance R from said axis,

ii. means for rotating said transmitting and receiving means at an angular velocity equal to 2π

V/L radians per second, and

iii. means for generating an ultrasonic surface wave sensor data signal representative of said received wave disturbance, said surface wave sensor data signal being representative of the interior surface condition of said pipeline at the point of incidence on said pipeline of said transmitted excitation beam,

wherein said sensor means further includes an inner diameter (ID) sensor means for generating ID sensor data signals representative of the inner diameter of portions of said pipeline adjacent to said apparatus,

wherein said ID sensor means includes a yoke assembly fixed to said body member and extending about the circumference thereof, and a plurality of elongated, resilient whisker members, each of said whisker members extending radially with respect to said longitudinal axis from said yoke member and adapted for engaging a portion of the inner surface of said pipeline adjacent to said apparatus, and each of said whisker members being coupled to an associated piezoelectric transducer at said yoke member, said piezoelectric transducers including means for generating said ID sensor data signals from motions of said whisker members resulting from the interaction of said whisker members with said inner surface portions.

2. Apparatus according to claim 1 wherein adjacent ones of said whisker members are interconnected by a coupling member, and wherein each coupling member includes a plurality of elongated, resilient secondary whisker members extending radially outward with respect to said longitudinal axis from said yoke member and adapted for engaging a portion of the inner surface of said pipeline adjacent to said pipeline.

3. Apparatus according to claim 2 wherein said front and rear seals are adapted to maintain a liquid phase medium in said interior region, and wherein said sensor means further includes a pressure transducer means for generating a pressure sensor data signal representative of the pressure within said interior region.

4. Apparatus according to claim 1 wherein said front and rear seals are adapted to maintain a liquid phase medium in said interior region, and wherein said sensor means further includes a pressure transducer means for generating a pressure sensor data signal representative of the pressure within said interior region.

5. Apparatus for scanning the interior of a pipeline having a radius R, comprising:

A. an elongated body member having a longitudinal axis,

B. bogie assembly including means for maintaining the longitudinal axis of said body member substantially coaxial with the central axis of said pipeline,

C. sealing means extending radially from said body member, and including means for establishing a fluid-tight seal between regions in a pipeline ahead of said apparatus and regions behind said apparatus, whereby said apparatus is responsive to the pressure differential across said sealing means to move at a velocity V along said pipeline axis from regions of relatively high pressure to regions of relatively low pressure,

D. an odometer coupled to said bogie assembly including means for generating a motion signal representative of said apparatus movement,

E. a power supply disposed within said body member and coupled to said bogie assembly, said supply including a generator means responsive to the motion of said bogie apparatus with respect to said pipeline to generate and store electrical energy,

F. sensor means powered by said power supply for detecting one or more physical characteristics of portions of said pipeline adjacent to said apparatus, and for generating sensor data signals representative of said conditions, said sensor means including;

an inner diameter (ID) sensor means for generating ID sensor data signals representative of the inner diameter of portions of said pipeline adjacent to said apparatus, said ID sensor means including;

a yoke assembly fixed to said body member and extending about the circumference thereof, and a plurality of elongated, resilient whisker members, each of said whisker members extending radially with respect to said longitudinal axis from said yoke member and adapted for engaging a portion of the inner surface of said pipeline adjacent to said apparatus, and each of said whisker members being coupled to an associated piezoelectric transducer at said yoke member, said piezoelectric transducers including means for generating said ID sensor data signals from motions of said whisker members resulting from interaction of said whisker members with said inner surface portions, G. recording means disposed within said body member and powered by said power supply for recording said motion signal and said sensor data signals with a predetermined relationship.

6. Apparatus according to claim 5 wherein adjacent ones of said whisker members are interconnected by a coupling member, and wherein each coupling member includes a plurality of elongated, resilient secondary whisker members extending radially outward with respect to said longitudinal axis from said yoke member and adapted for engaging a portion of the inner surface of said pipeline adjacent to said pipeline.

7. Apparatus according to claim 6 wherein said front and rear seals are adapted to maintain a liquid phase medium in said interior region, and wherein said sensor means further includes a pressure transducer means for generating a pressure sensor data signal representative of the pressure within said interior region.

8. Apparatus according to claim 5 wherein said front and rear seals are adapted to maintain a liquid phase medium in said interior region, and wherein said sensor means further includes a pressure transducer means for generating a pressure sensor data signal representative of the pressure within said interior region.