Claims
- 1] A drill bit, comprising:
a bit body having a plurality of ports therein arranged to provide a flow path between an interior of a drill string and the exterior of the bit body; and at least one flow relief disposed in one of the ports, the at least one flow relief adapted to change a total flow area of the drill bit upon application of a selected fluid flow condition to the drill bit.
- 2] The drill bit as defined in claim 1 wherein the selected flow condition comprises a predetermined differential pressure across the drill bit.
- 3] The drill bit as defined in claim 1 wherein the selected flow condition comprises a predetermined total flow volume across the drill bit.
- 4] The drill bit as defined in claim 1 wherein the at least one flow relief comprises a rupture disk.
- 5] The drill bit as defined in claim 1 wherein the at least one flow relief comprises a biased pressure relief valve.
- 6] The drill bit as defined in claim 5 wherein the biased pressure relief valve is adapted to open above a selected differential pressure.
- 7] The drill bit as defined in claim 5 wherein the biased pressure relief valve is adapted to open within a selected range of differential pressure.
- 8] The drill bit as defined in claim 1 wherein the at least one flow relief comprises an orifice in an orifice body having an erodible material disposed therein, the erodible material adapted to be work away after a selected volume of fluid has passed therethrough.
- 9] The drill bit as defined in claims 8 wherein the erodible material comprises mild steel.
- 10] A method for changing a total flow area of a drill bit, comprising:
pumping drilling fluid through the drill bit; and operating a flow relief disposed in the bit to change the total flow area of the bit.
- 11] The method as defined in claim 10 wherein operating the flow relief comprises increasing a differential pressure across the drill bit to at least a predetermined value.
- 12] The method as defined in claim 10 further comprising decreasing the total flow area of the bit by causing the differential pressure to drop below the predetermined value.
- 13] The method as defined in claim 10 wherein the operating the flow relief comprises maintaining a differential pressure across the drill bit within a predetermined range.
- 14] The method as defined in claim 10 wherein the operating the flow relief comprises causing a selected total volume of fluid to flow through the flow relief.
- 15] A drill bit, comprising:
a bit body having a plurality of ports therein arranged to provide a flow path between an interior of a drill string and the exterior of the bit body; at least one cutting element operatively coupled to the bit body; and at least one rupture disk disposed in one of the ports.
- 16] A drill bit, comprising:
a bit body having a plurality of ports therein arranged to provide a flow path between an interior of a drill string and the exterior of the bit body; at least one cutting element operatively coupled to the bit body and at least one biased pressure relief valve disposed in one of the ports.
- 17] The drill bit as defined in claim 16 wherein the biased pressure relief valve is adapted to open above a selected differential pressure.
- 18] The drill bit as defined in claim 16 wherein the biased pressure relief valve is adapted to open within a selected range of differential pressure.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This invention claims priority from U.S. provisional application serial number 60/304,555, filed on Jul. 11, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60304555 |
Jul 2001 |
US |