Marine surveying apparatus and method for locating pipelines buried under the seabed

• US 4,574,241 A
• Filed: 08/22/1983
• Issued: 03/04/1986
• Est. Priority Date: 08/22/1983
• Status: Expired due to Fees

• Current Assignee: Stelly C L Jack
• Original Assignee: Stelly C L Jack
• Inventors: Stelly, C. L. Jack
• Primary Examiner(s): Strecker, Gerard R.
• Application Number:
  US06/525,017
• Time in Patent Office: 925 Days
• Field of Search: 324/326, 324/345, 324/346, 324/200, 114/264-266, 166/65 M, 175/19, 175/21, 175/23, 175/40, 175/50, 175/5, 175/7, 175/10, 405/195, 405/201-203, 405/227
• US Class Current: 324/326
• CPC Class Codes: E21B 41/0014 Underwater well locating or reentry systems
• CPC Class Codes: E21B 7/128 from floating support with independent underwater anchored guide base
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 9/00 Prospecting or detecting by methods not provided for in groups G01V1/00 - G01V8/00

Abstract

A marine pipeline surveying apparatus useful for locating buried pipelines includes a barge having a work deck with a dolly mounted on the work deck for movement on the deck upon a provided track. A slot in the barge can be provided so that workers can move completely around the dolly. The dolly provides a gimbal type articulating support for supporting a hollow casing during operation. The gimbal support allows the articulating movement to compensate wave action on the barge so that the wave action is not transmitted to the casing. During operation a magnetometer placed in the casing bore can be used to "roughly" position the barge and casing above the pipeline to be located. Then the barge can be anchored in position over the pipeline as dictated by the magnetometer "rough" positioning. The magnetometer is then removed from the casing bore and the casing provides a guide for a probe rod such as a jet probe which is placed within the casing. The probe can then repeatedly penetrate the seabed to locate the buried pipeline by physically contacting the pipeline thereby giving both plan and profile position of the pipeline.

Claims

1. A marine surveying apparatus for locating hidden pipelines buried a distance under the seabed, comprising:

a. a barge having a work deck which can be supported above the pipeline to be located;

b. a transverse track mounted on the barge work deck;

c. a dolly movably supported on the track so that the dolly can move transversely upon the track and with respect to the barge;

d. a casing supported during operation in a generally vertical position by the dolly for transverse movement with the dolly and with respect to the barge;

e. surveying means positioned adjacent the casing for preliminarily determining the location of the pipeline so that both the barge and the casing can be positioned close to the undersea pipeline to be located;

f. probe means vertically movable within and laterally supported by the casing so that the casing guides the probe means;

g. and means supported at least in part by said barge and connected to said probe means allowing repeated lifting and lowering of said probe means so that the probe means can repeatedly penetrate the seabed to locate the buried pipeline by physical contact with the hidden pipeline.

2. The marine surveying apparatus of claim 1, wherein the barge has a generally vertical slot in its deck and the track is positioned at the slot.

3. The marine surveying apparatus of claim 1 further including connection means for forming an articulating support between the dolly and the casing.

4. The marine surveying apparatus of claim 1, wherein the positioning means is a magnetometer removably positioned in the casing preliminarily until the casing is positioned vertically above the buried pipeline to be located.

5. The marine surveying apparatus of claim 1, wherein the probe means is an elongated jetting probe.

6. The marine surveying apparatus of claim 3, wherein the connection means is a gimbal mounted upon the dolly.

7. A method of marine surveying for hidden pipelines that are buried under the seabed, comprising the steps of:

a. preliminarily determining the approximate location of the pipeline;

b. vertically positioning a casing above the pipeline to be located with a marine vessel having a laterally adjustable support that holds the casing in a vertical position;

c. movably supporting an elongated probe rod with the casing so that the probe rod can be elevated and lowered along a generally vertical path defined by the casing;

d. thrusting the probe rod downwardly through the casing and into the underlying seabed while the casing laterally supports the probe rod;

e. sequentially moving the casing position with the adjustable support into a number of laterally spaced preselected prospective sites to be probed until the pipe is contacted by the probe so that the pipeline horizontal elevation and the location at the probe site can be measured, each prospective site being surveyed by thrusting the probe rod downwardly through the casing and into the underlying seabed.

8. The method of claim 7 wherein in step "a" the casing is supported by a marine vessel using an articulating support connection between the vessel and the casing so that wave action upon the vessel has a minimized effect upon the casing.

9. The method of claim 7 wherein in step "a" a dolly on the vessel supports the casing and in step "c" the casing position is laterally adjusted by movement of the dolly with respect to the vessel.

10. The method of claim 7, wherein in step "a" an electronic instrument carried by the casing locates the pipeline so that the casing can be positioned above it.

11. The method of claim 10, wherein in step "a" the casing is hollow and the electronic instrument is placed inside the casing during positioning of the casing above the buried pipeline.

12. The method of claim 10 or 11 wherein the electronic instrument is a magnetometer.

13. The method of claim 9, wherein in step "a" an articulated connection carried by the dolly supports the casing.