APPARATUS FOR ATTACHING A TOOL TO A CONDUIT IN A BOREHOLE

• US 3,670,566 A
• Filed: 12/10/1970
• Issued: 06/20/1972
• Est. Priority Date: 12/10/1970
• Status: Expired due to Term

• Current Assignee: Edward R. Basham, William D. Smith
• Original Assignee: Edward R. Basham, William D. Smith
• Inventors: Basham, Edward R., Smith, William D.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/096,864
• Time in Patent Office: 558 Days
• Field of Search: 73/151 166/255
• US Class Current: 73/152.59
• CPC Class Codes: E21B 17/1021 with articulated arms or arcuate springs
• CPC Class Codes: E21B 47/09 Locating or determining the position of objects in boreholes or wells , e.g. the position of an extending arm; Identifying the free or blocked portions of pipes

Abstract

Apparatus for attaching to a conduit at a depth in a borehole, as in free point indicator tools, characterized by a plurality of aspects. In a first aspect, the apparatus has individual, nonflow restricting attachment members that are operable to engage the conduit any number of times on a trip into the well with a force sufficient to bear the weight of the tool and any sinker bars and cable resting thereon. In a second aspect, the force is controlled electrically from the surface with a current limiter and a downhole electric motor is run to stall. In a third aspect, the attachment members are connected with the downhole motor via a shear pin so the pin can be sheared to release the attachment members in the event of power failure. In a fourth aspect, the downhole, or borehole tool has a sensor section with an automatic centralizer for effecting a neutral position of the two movable portions for detecting small rotational or longitudinal movement therebetween. Also disclosed are specific structures and methods that are advantageously employed in measuring the depth at which a conduit such as drill pipe is stuck in the borehole.

Claims

1. Apparatus for attaching to a conduit in a borehole comprising:

a. surface equipment including attachment monitor means and attachment control means;

b. cable means connected with said surface equipment for traversing into said borehole;

said cable means having at least one electrical conductor and electrical ground means;

c. borehole tool means physically and electrically connected with said cable means and adapted for traveling longitudinally of said conduit in said borehole;

said borehole tool means including attachment means that is operable to engage and disengage attachment members with said conduit at predetermined depths any number of times on a single trip traversing said conduit;

said attachment means being remotely controlled electrically by said attachment control means in said surface equipment and adapted to provide an attachment force when engaging said attachment members with said conduit that is sufficient to effect movement of the portion of said borehole tool means in which said attachment members are located responsive to any movement of said conduit with which said attachment members are engaged regardless of the weight of said borehole tool, and apparatus bearing thereon and suspended therefrom;

said attachment members being substantially nonrestrictive to flow of fluids therepast;

said attachment means including a downhole electric motor means supplying force to said attachment members;

said attachment control means comprising a current limiter means for limiting current to said downhole motor means for supplying a regulated force to said attachment members.

2. The apparatus of claim 1 wherein said motor means is adapted to run to stall on both the setting of said attachment members in engagement with said conduit and on retraction of said attachment members into said borehole tool means.

3. The apparatus of claim 1 wherein said current limiter means is settable to a first current to provide a first force to move said attachment members against said conduit without structural damage to said attachment means and to a second current to provide a second force that is greater than said first force for setting and holding said attachment members in engagement with said conduit.

4. Apparatus for measuring the point at which a conduit is stuck in a borehole penetrating subterranean formations comprising:

a. surface equipment including attachment monitoring means and attachment control means;

b. cable means connected with said surface equipment and traversing via a depth measuring means into said borehole;

said cable means having at least one electrical conductor and an electrical ground means;

c. borehole tool means physically and electrically connected with said cable means and suspended within said conduit and adapted for being traversed lonGitudinally of said conduit in said borehole;

said borehole tool means including upper and lower attachment means carried by respective upper and lower portions, said attachment means being operable to frictionally engage attachment members with said conduit with a force sufficient to effect responsive movement of the respective upper and lower portions concomitantly with movement of said conduit;

said borehole tool means having a sensing means disposed intermediate said upper and lower portions, said sensing means also including a detector means that is responsive to stress induced in said conduit;

at least one of said attachment means comprising an improved attachment means that is operable to engage and disengage said attachment members with said conduit at predetermined depths any number of times on a single trip traversing said conduit;

said improved attachment means being remotely controlled electrically by said attachment control means in said surface equipment and adapted to provide an attachment force when engaging said attachment members with said conduit that is sufficient to effect movement of the portion of said borehole tool means in which said attachment members are located responsive to any movement of said conduit with which said attachment members are engaged regardless of the weight of said borehole tool, and apparatus bearing thereon and suspended therefrom;

said attachment members being substantially nonrestrictive to flow of fluids therepast;

said improved attachment means including a downhole electric motor means supplying force to said attachment members;

said attachment control means comprising a current limiter means for limiting current to said downhole motor means for supplying a regulated force to said attachment members.

5. The apparatus of claim 4 wherein said motor means is adapted to run to stall on both the setting of said attachment members in engagement with said conduit and on retraction of said attachment members into said borehole tool.

6. The apparatus of claim 4 wherein said current limiter means is settable to a first current to provide a first force to move said attachment members against said conduit without structural damage to said improved attachment means and to a second current to provide a second force that is greater than said first force for setting and holding said attachment members in engagement with said conduit.

7. The apparatus of claim 4 wherein said upper attachment means comprises said improved attachment means and said lower attachment means comprises a bow spring.

8. The apparatus of claim 4 wherein both said upper and lower attachment means comprise said improved attachment means.