Apparatus and methods for well-bore proximity measurement while drilling
First Claim
1. A method of determining a distance between a first borehole and a second borehole, the method comprising:
- rotating a magnet of a tool disposed in the second borehole to generate a primary magnetic field at a position of a magnetic object in the first borehole, wherein the magnet is disposed on a sleeve that rotates independently of the tool;
detecting a secondary magnetic field generated by the magnetic object responsive to a current induced by the primary magnetic field in the magnetic object using a sensor in the second borehole that is stationary with respect to the tool; and
determining the distance between the first borehole and the second borehole from the detected secondary magnetic field.
1 Assignment
0 Petitions
Accused Products
Abstract
In one aspect an apparatus for determining a distance between a first borehole and a second borehole during drilling of the second borehole is disclosed that in one embodiment includes a magnet on a drilling tool that rotates in the second borehole to induce a primary magnetic field in a magnetic object in the first borehole, a substantially stationary sensor on the drilling tool that detects a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field, and a controller that determines the distance between the first borehole and the second borehole from the detected magnetic field. In another aspect a method of determining a distance between a first borehole and a second borehole, the in one embodiment includes inducing a primary magnetic field in a magnetic object in the first borehole using a rotating magnet in the second borehole, detecting a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field using a substantially stationary sensor in the second borehole, and determining the distance between the first borehole and the second borehole from the detected magnetic field.
-
Citations
20 Claims
-
1. A method of determining a distance between a first borehole and a second borehole, the method comprising:
-
rotating a magnet of a tool disposed in the second borehole to generate a primary magnetic field at a position of a magnetic object in the first borehole, wherein the magnet is disposed on a sleeve that rotates independently of the tool; detecting a secondary magnetic field generated by the magnetic object responsive to a current induced by the primary magnetic field in the magnetic object using a sensor in the second borehole that is stationary with respect to the tool; and determining the distance between the first borehole and the second borehole from the detected secondary magnetic field. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An apparatus for determining a distance between a first borehole and a second borehole during drilling of the second borehole, comprising:
-
a magnet on a drilling tool in the second borehole, wherein the magnet rotates independently of the drilling tool to induce a primary magnetic field in a magnetic object in the first borehole; a sensor on the drilling tool that detects a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field, wherein the sensor is stationary with respect of the drilling tool; and a controller that determines the distance between the first borehole and the second borehole from the detected secondary magnetic field. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
-
-
16. A method of determining a distance between a first borehole and a second borehole, the method comprising:
-
rotating a magnet of a tool in the second borehole at a first rotational speed to generate a primary magnetic field in a magnetic object at the first borehole, wherein the magnet rotates independently of the tool; detecting a secondary magnetic field from a current induced in the magnetic object by the primary magnetic field using a magnetometer in the second borehole stationary with respect to the tool; and determining the distance between the first borehole and the second borehole from the detected secondary magnetic field.
-
-
17. An apparatus for determining a distance between a first borehole and a second borehole, the apparatus comprising:
-
a drilling tool in the second borehole having a magnet configured to rotate with respect to the drilling tool to generate a primary magnetic field from the second borehole into a magnetic object in the first borehole to induce a current in the magnetic object; a sensor on the drilling tool stationary with respect to the drilling tool for detecting a secondary magnetic field from the magnetic object responsive to the induced current; and a controller that determines the distance between the first borehole and the second borehole from the detected secondary magnetic field. - View Dependent Claims (18, 19, 20)
-
Specification