Well tool apparatus and method
AssigneeHomco International, Inc.
InventorAustin S. Rogers
Life of this patent
Estimating the term…
Abstract
A new and improved well tool apparatus and method for sensing and testing conditions in a well, such as stuck drill pipe, temperature, metal creep, and the like, and for performing certain operations in the well, such as backing off, or loosening, the stuck pipe.
Claims26
An apparatus for testing pipe in a well bore at a test location therein, comprising:
- a. sensor means for sensing whether the pipe is stuck at the test location in the well bore;
- b. reference means for moving said sensor means into a reference position from which movement of the pipe when stressed indicates whether the pipe is stuck at the test location;
- and
- c. means for causing a time delay during which said reference means moves said sensor means into the reference position after said sensor means is at the test location, wherein said sensor means is in proper reference position for accurate sensing operations.
An apparatus for sensing the location of stuck pipe in a well bore, comprising:
- a. means for mounting the apparatus at a test location between first and second spaced portions of the pipe;
- b. sensor means for detecting movement of the pipe when forces are applied thereto, said sensor means comprising:
- 1. stator core means operably connected with a first spaced portion of the pipe, said stator core means comprisng an annular ferromagnetic core;
- 2. rotor core means operably connected with a second portion of the pipe spaced from said first portion, said rotor core means comprising a ferromagnetic core mounted within said annular ferromagnetic core and being longitudinally and rotatably movable with respect to said stator core means in response to movement of the pipe;
- 3. inductive coil means;
- 4. said stator core means and said rotor core means forming a ferromagnetic circuit whose parameters change in response to relative movement between the first and second spaced portions of the pipe, varying the inductance of said inductive coil means;
- and
- c. means for transferring movement of the pipe to said sensor means when forces are applied to the pipe, wherein movement of the pipe indicates that the pipe is not stuck at the test location.
A method of testing pipe at a test location in a well bore to determine whether the pipe is stuck in a well bore, comprising the steps of:
- a. mounting a sensor at the test location in the well bore;
- b. moving the sensor up to a reference position in the test location from which movement of the sensor in response to movement of the pipe indicates whether the pipe is stuck;
- c. causing a time delay to elapse during movement of the sensor to the reference position so that the sensor may assume the proper reference position for sensing operations;
- d. applying force to the pipe;
- and
- e. sensing with the sensor whether the pipe moves when the force is applied thereto.
A method of locating the point where pipe is stuck in a well bore with a sensor portion of a free point/back-off apparatus and loosening the pipe above such stuck point with a backoff position of the apparatus comprising the steps of:
- a. moving the apparatus to a first operating position for sensing operations;
- b. sensing whether the pipe is stuck;
- c. moving the apparatus to a second operating position for backoff operations;
- d. loosening the stuck pipe;
- and
- e. preventing rapid movement from the second operating position to the first operating position during said step of loosening wherein the sensor is protected against shock and damage during loosening operations.
Dependencies are inferred from the claim text.