US-12624632-B2 - Down hole measurement system

Abstract

A bore hole measurement system includes a cable with spaced apart embedded elements along a length of the cable, a sensor for detection of the elements as they move relatively past the sensor, and a processor for determining the distance that the cable has travelled based on the detections of elements that have moved past the sensor. A method includes detecting the elements moving past a sensor, and determining the distance that the cable has travelled based on the detections of elements that have moved past the sensor.

Inventors

• Nicholas Bodley

Assignees

• MTI GROUP PTY LTD

Dates

Publication Date

20260512

Application Date

20211206

Priority Date

20190606

Claims (18)

1. 1 . A blast hole measurement system comprising: a cable comprising equally spaced apart embedded elements along a length of the cable and comprising an outer protective layer of polyurethane or poly tetrafluoroethylene for protecting against wear damage from a blast hole, the cable comprising electrical wires surrounded by a fiber-glass layer being resistant to stretching over a depth of the blast hole; a sensor for detection of the elements as the elements move relatively past the sensor; and a processor for determining a distance that the cable has travelled into the blast hole based on the detections of elements that have moved past the sensor.
2. 2 . A system according to claim 1 , wherein the cable comprises a probe at an end of the cable electrically connected to the electrical wires forming a wire core for transmitting a plurality of signals from the probe, the wire core being suitable for communication over a distance substantially the length of the blast hole, wherein the probe is configured to be lowered into the blast hole for measurement of parameters of the blast hole.
3. 3 . A system according to claim 2 , wherein the stretch resistance fiber-glass layer comprises reinforced plastic so as to stretch less than 0.05 m per 20 m of cable length.
4. 4 . A system according to claim 3 , wherein the probe comprises a water detector for detecting that the end of the probe is in contact with water.
5. 5 . A system according to claim 4 , wherein the probe comprises an accelerometer and the processor is configured to determine the depth of the water based on the number of elements that have moved past the sensor between when the water detector detects that the end of the probe is in contact with water and when the accelerometer detects that the probe encounters the bottom of the blast hole.
6. 6 . A system according to claim 2 , wherein the probe comprises a temperature sensor for measuring the air a temperature in the blast hole.
7. 7 . A system according to claim 2 , wherein the probe comprises a distance sensor for detection of a void laterally extending from the blast hole.
8. 8 . A system according to claim 2 , wherein the processor is configured to compare the parameters of the blast hole to requirements of a blast pattern and to determine whether the blast hole meets the requirements of the blast pattern.
9. 9 . A system according to claim 1 , wherein the sensor is a magnetic or induction sensor.
10. 10 . A system according to claim 1 , wherein the elements are metallic crimps around the fiber-glass layer, and underneath the outer protective layer.
11. 11 . A system according to claim 1 , wherein the outer protective layer is in the form of a single piece extending along the length of the cable.
12. 12 . A method of making a measurement of a blast hole comprising: providing a cable comprising equally spaced apart embedded elements along a length of the cable; detecting the elements moving past a sensor; determining a distance that the cable has travelled based on the detections of elements that have moved past the sensor, without needing to account for substantial stretching of the cable when deployed in the blast hole; determining whether a probe at an end of the cable is in contact with water using a water detector at the end of the probe; determining when the probe encounters a bottom of the blast hole using an accelerometer in the probe; and wherein, in the event that the water detector detects the end of the probe is in contact with water, determining a depth of the water by a number of detections of elements that have moved past the sensor between when the water detector detects the end of the probe is in contact with water and when the probe encounters the bottom of the blast hole.
13. 13 . A method according to claim 12 , further comprising recording a temperature at the bottom of the blast hole.
14. 14 . A method according to claim 13 , further comprising determining whether the temperature exceeds the expected temperature threshold.
15. 15 . A method according to claim 12 , further comprising recording whether there is a void laterally extending from the blast hole.
16. 16 . A method according to claim 15 , further comprising determining whether the recorded void in the blast hole meets the requirements of a blast pattern.
17. 17 . A method according to claim 12 , further comprising comparing the depth of the blast hole and the depth of the water in the blast hole with requirements of a blast pattern and determining whether the blast hole meets the requirements of the blast pattern.
18. 18 . A blast hole measurement system comprising: a cable comprising spaced apart embedded elements along a length of the cable, the cable being resistant to stretching; a sensor for detection of the elements as the elements move relatively past the sensor; and a processor for determining a distance that the cable has travelled based on the detections of elements that have moved past the sensor; wherein the cable comprises a probe at an end of the cable and an electrical wire core for transmitting a plurality of signals from the wire core, the wire core being suitable for communication over a distance substantially the length of a blast hole, wherein the probe comprises a water detector for detecting that the end of the probe is in contact with water; wherein the probe comprises an accelerometer and the processor is configured to determine a depth of the water based on a number of elements that have moved past the sensor between when the water detector detects that the end of the probe is in contact with water and when the accelerometer detects that the probe encounters the bottom of the blast hole.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of PCT/AU2020/050583, filed Jun. 8, 2020, which claims priority to AU patent application No. 2019901972, filed Jun. 6, 2019, the disclosures of which are incorporated herein by reference in their entireties. FIELD The present invention relates to a tool for measuring properties, such as the depth, of a drilled blast hole. BACKGROUND A known method of drilling and blasting a volume of earth to extract mineral bearing material is to generate a blast pattern which describes a number of holes to be drilled, such as in pit. A drill rig drills these holes. A quality control step takes place to measure the drilled holes to ensure they are as designed and redrilled as required. Following this the holes are loaded with explosives and stemming ready to blast. A blast pattern may comprise many hundreds of holes. Many factors may cause the hole to not match that required in the blast pattern. These factors may include water in the hole, cave-ins due to ground conditions, drill rig inaccuracy, voids present in the ground and other reasons. Drilled patterns may be left on shot for many days between drilling and loading, which allows weather to cause issues in the holes. As such, quality control is a necessary step before blasting to minimise explosives use and ensure the blast matches the plans. A typical quality control process utilises a tape measure with a weight on the end of it. The responsible person throws the weight down the hole and uses the tape to measure the depth of the hole. Water depth is inferred by “bobbing” the weight which, depending on the operator, can lead to inaccurate results. If the recorded measurements vary from the designed blast pattern, the hole will be redrilled. The blast pattern is an extremely high-risk environment, and personnel responsible for this process are highly paid. Innovations such as autonomous drills and camera operated MMU's have resulted in improved efficiency and less workers on pattern in the drill and blast space, but no technological solution has been successful in improving the efficiency of measuring the depth of a blast hole for quality control. SUMMARY According to the present invention there is provided a bore hole measurement system comprising: a cable comprising spaced apart embedded elements along a length of the cable;a sensor for detection of the elements as they move relatively past the sensor;a processor for determining the distance that the cable has travelled based on the detections of elements that have moved past the sensor. In an embodiment the cable comprises an electrical wire core for communication with instruments downhole for measurement of the bore hole. In an embodiment the sensor is a magnetic or induction sensor. Preferably the sensor is an induction sensor. In an embodiment the sensor comprises a hole through which the cable passes. In an embodiment the sensor comprises a toroid. In an embodiment the elements are ferrous. Preferably the elements are metallic. In an embodiment the elements evenly spaced along at least a portion of the length of the cable. In the preferred embodiment the elements are spaced 0.1 m, 0.2 m, 0.25 m or 0.5 m apart, most preferably 0.2 m apart. In an embodiment the cable is resistant to stretching. Preferably the cable is fibre reinforced and stretches less than 0.05 m over a 20 m length. In an embodiment the cable comprises an outer layer of a polyurethane or poly tetrafluoroethylene. In an embodiment the cable comprises probe at an end of the cable and at least one wire for transmitting a plurality of signals from the probe. In an embodiment the probe comprises multiple sensors for detection of the end of the cable encountering an event. In an embodiment the probe comprises a water detector and the event is the detection of water. In an embodiment the processor is configured to determine the depth of the water based on the number of elements that have moved past the sensor between when the probe encounters water and when the probe encounters the bottom of the hole. In an embodiment the probe comprises a temperature sensor. In an embodiment the sensor comprises an infrared temperature measurement sensor. In an embodiment the probe comprises distance sensor and the event is the detection of a void laterally extending from the bore hole. The distance sensor could utilise radar, laser, ultrasonic, mechanical or a combination of these to detect and/or measure the void. In an embodiment the probe comprises of an electronic instrument, such as, for example, a gyrometer, magnometer or accelerometer, for detection of tilting and in the event of the probe touching the bottom of the bore hole. The preferred embodiment includes both a gyrometer and accelerometer. In an embodiment the probe comprises an accelerometer for measuring a change in speed of decent of the cable into the bore hole. In an embodiment the event is detection of the probe stopping or