Electro-hydraulic drilling with shock wave reflection
Shock waves produced during electro-hydraulic drilling can be reflected into a rock body where the reflected shock waves are converted from compression waves to tension waves, which are more efficient at breaking down the rock body. A system configured for electro-hydraulic drilling where shock waves produced during drilling are reflected into the rock body includes two electrodes and a shock wave reflector disposed at an electro-hydraulic drill head. The two electrodes are configured to (1) facilitate formation of a spark along a spark path spanning the two electrodes and (2) facilitate a pulse of electricity being passed through the spark to form a primary shock wave emanating from the spark path. The shock wave reflector is configured to reflect a portion of the primary shock wave such that the reflected shock wave is concentrated to a focal region within the rock body.
1. A system configured for electro-hydraulic drilling where shock waves produced during drilling are reflected into a rock body, the system comprising:
two electrodes disposed at an electro-hydraulic drill head, the two electrodes being configured to (1) facilitate formation of a spark along a spark path spanning the two electrodes and (2) facilitate a pulse of electricity being passed through the spark to form a primary shock wave emanating from the spark path; and
a shock wave reflector disposed at the electro-hydraulic drill head, the shock wave reflector being configured to reflect a portion of the primary shock wave that emanated from the spark path such that the reflected shock wave is concentrated to a focal region within the rock body, the reflected shock wave being converted from a compression wave to a tension wave when the reflected shock wave propagates beyond the focal region.
2. The system of claim 1 , wherein a portion of the shock wave reflector is shaped as a portion of a cylinder.
3. The system of claim 1 , wherein the reflected shock wave is temporally coordinated with a subsequent spark.
4. The system of claim 1 , wherein the shock wave reflector is shaped so as to concentrate more of the reflected shock wave to the focal region proximate to each of the two electrodes relative to a midpoint between the two electrodes.
5. The system of claim 1 , wherein the shock wave reflector includes one or more passages through the shock wave reflector, the one or more passages being configured to allow fluid and/or particulate communication through the shock wave reflector.
6. An apparatus configured to reflect shock waves into a rock body during electro-hydraulic drilling, the apparatus comprising:
a shock wave reflector disposed at an electro-hydraulic drill head, the electro-hydraulic drill head having two electrodes disposed thereat, the two electrodes being configured to (1) facilitate formation of a spark along a spark path spanning the two electrodes and (2) facilitate a pulse of electricity being passed through the spark to form a primary shock wave emanating from the spark path,
wherein the shock wave reflector is reflects a portion of the primary shock wave that emanated from the spark path such that the reflected shock wave is concentrated to a focal region within the rock body, the reflected shock wave being converted from a compression wave to a tension wave when the reflected shock wave propagates beyond the focal region.
7. The apparatus of claim 6 , wherein a portion of the shock wave reflector is shaped as a portion of a cylinder.
8. The apparatus of claim 6 , wherein the reflected shock wave is temporally coordinated with a subsequent spark.
9. The apparatus of claim 6 , wherein the shock wave reflector is shaped so as to concentrate more of the reflected shock wave to the focal region proximate to each of the two electrodes relative to a midpoint between the two electrodes.
10. The apparatus of claim 6 , wherein the shock wave reflector includes one or more passages through the shock wave reflector, the one or more passages being configured to allow fluid and/or particulate communication through the shock wave reflector.
11. A method for reflecting shock waves into a rock body during electro-hydraulic drilling, the method comprising:
forming a spark between two electrodes disposed at an electro-hydraulic drill head, the spark following a spark path spanning the two electrodes;
passing a pulse of electricity through the spark to form a primary shock wave emanating from the spark path; and
reflecting a portion of the primary shock wave that emanated from the spark path such that the reflected shock wave is concentrated to a focal region within the rock body, the reflected shock wave being converted from a compression wave to a tension wave when the reflected shock wave propagates beyond the focal region.
12. The method of claim 11 , further comprising temporally coordinating the reflected shock wave with a subsequent spark.
13. The method of claim 11 , wherein reflecting the portion of the primary shock wave is performed using a shock wave reflector.
14. The method of claim 13 , wherein a portion of the shock wave reflector is shaped as a portion of a cylinder.
15. The method of claim 13 , wherein the shock wave reflector is shaped so as to concentrate more of the reflected shock wave to the focal region proximate to each of the two electrodes relative to a midpoint between the two electrodes.
16. The method of claim 13 , further comprising facilitating fluid and/or particulate communication through one or more passages through the shock wave reflector.