SU60917A1 - Apparatus for determining the curvature and azimuth of the borehole curvature - Google Patents

Description

A device for determining the curvature and azimuth of the curvature of boreholes is designed as a camera lowered into the well, where a light source is installed and the illuminated photocells included in the electrical measuring device circuit differ from the known instruments in that the camera in which the light source and photocells are placed partially filled with an opaque liquid, which, depending on the inclination of the chamber to the axis of the well, closes the light source and the photo cells located around it.

To determine the azimuth of curvature, two of the photoelectric cells that are opposite to the light source are mounted on a magnetic needle, positioning it in the direction of the magnetic meridian of the earth.

FIG. 1 shows a vertical section of the proposed device; in fig. 2 — camera arrangement with photocells suspended on a magnetic needle to determine the azimuth of the curvature of the well.

The device is suspended on the cable 1. The photocells placed in the device are connected by a multicore cable 2 to a galvanometer circuit located on the surface.

The cable 2 with sealing mastic 3 is embedded in the upper tip of the device 4 connected to the cylindrical case 8 on a screw thread. The same tip 14 is attached by welding to the lower part of the case 8.

Four radial holes are drilled crosswise in the tips, into which the nuts 6 are screwed with pins 7 passed through them from under the action of pressure springs 5. These pins serve to center the instrument in the well. In the upper part of the device there is a slot 12, into which a cylindrical tightly closed chamber 11 is screwed. In the center of this chamber there is an electric light bulb 9, and around it are two pairs of photo cells 10 connected through a cable 2 into a galvanometer circuit located on the surface.

No. 60917-2 -

The chamber 11 is filled with an opaque liquid 13 to the middle of the light source 9 and the surrounding photocells 10. The light bulb 9 is placed inside a closed cartridge 14, equipped with glasses 15 against each of the photo cells 10. A dry battery 16 is provided in the chamber 11 to power the light bulb 9. cartridge 14 is made in the form of a binder 17 for the pin of magnet 18 made of magnetized steel, which plays the role of a magnetic needle. At the ends of the magnet 18 on thin, for example aluminum strips, two photocells are reinforced

10, from which the wires lead through the seal 19 in the cover 20 of the camera

11. The other two photocells are perpendicular to the first and also fixed rigidly on the magnet 18 using a thin aluminum strip. Each pair of photocells 10 is included towards each other. In the vertical position of the device, the opaque liquid 13 closes each photocell exactly halfway and the arrow of the galvanometer stands by zero.

If, when lowering into the well, the device receives a certain inclination, then one of the photo cells opposite to each other will be illuminated more strongly than the other, and in the galvanometer peaks, according to the voltage emf, the deflector of the galvanometer. The divisions of the latter can be graduated in units of the angle of inclination of the axis of the instrument.

The direction of the axis of the housing of the device 8 coincides (with a slight deviation) with the direction of the axis of the well at a given location, and the cylinder // and the housing 8 are coaxial, then the curvature of the well at a given depth can be determined from the angle of inclination of the axis of the cylinder 11. And by switching the galvanometer to one or another pair of photocells, determine how well the curved.

The definition of the azimuth of curvature is based on the use of a magnetic field of the earth. But the deviation of the arrow of the galvanometer, included in the circuit of each of the two pairs of photocells, determines how well the well is twisted in each of the two directions.

When the cS light bulb is turned on in alternating current, a pulsating current is formed in the circuits of both pairs of photo elemets, which can be enhanced and, using an automatic recording device, draw a curve about the change in the curvature of the well non-continuously during the drilling process.

Subject invention

Claims (2)

1. An instrument for determining the curvature and azimuth of the borehole curvature, lowered into the well and containing a chamber with a light source and photocells illuminated by it, connected to an electrical measuring circuit, characterized in that the chamber is partially filled with an opaque liquid intended to cover the light source and located around it photocells depending on the inclination of the chamber to the axis of the well. 2. The form of the device according to claim 1, wherein in order to determine the azimuth of curvature, two of the oppositely located relative to the light source of the photocell are mounted on a magnetic needle that sets them in the direction of the magnetic meridian of the earth.