# US 2013/0153301 A1 · Lubrication system for a drilling apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153301 A1 - Document ID: US20130153301A1 - Status: Published application - Kind: A1 - Application number: 13/714,847 - Filed: 2012-12-14 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Drill Rigs Australia Pty Ltd - Inventors: Edgar John Banner - Web page: https://patentgrep.com/patent/US20130153301A1 ## CPC - E21B 4/003: {Bearing, sealing, lubricating details (for roller bits E21B10/22)} - E21B 4/14: Fluid operated hammers - E21B 7/00: Special methods or apparatus for drilling - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract The present invention provides a lubrication system for a drilling apparatus. The drilling apparatus includes a drill string and a drill bit, and it is driven by a working fluid circulated through a working fluid circuit. The lubrication system uses a reservoir of a lubricating fluid for supply to a drilling apparatus during a drilling operation; and a pump for supplying lubricating fluid from said reservoir to the drilling apparatus during the drilling operation. The pump is controlled to supply lubricating fluid from the reservoir at a determined rate to a lubrication circuit formed by the working fluid circuit of the drilling apparatus. ## Claims ### Claim 1 A lubrication system for a drilling apparatus including a drill string and a drill bit, said drilling apparatus being driven by a working fluid circulated through a working fluid circuit, said system comprising: a reservoir of a lubricating fluid for supply to a drilling apparatus during a drilling operation; and a pump for supplying lubricating fluid from said reservoir to said drilling apparatus during said drilling operation, wherein said pump is controlled to supply lubricating fluid from the reservoir at a determined rate to a lubrication circuit formed by said working fluid circuit of said drilling apparatus. ### Claim 2 (depends on 1) A lubrication system according to claim 1, wherein said drilling apparatus is operated from a surface located drilling rig, said pump and the reservoir also being surface located, preferably on a deck of the drilling rig. ### Claim 3 (depends on 2) A lubrication system according to claim 2 wherein said working fluid is compressed air. ### Claim 4 (depends on 2) A lubrication system according to claim 2 wherein said drilling apparatus comprises an assembly of said drill bit and a drive sub, said drill bit and drive sub being provided with a plurality of respective and complementary spline portions formed about their perimeter, said spline portions interlocking to form said assembly with spaces between said interlocking spline portions acting as channels through which both working fluid and entrained lubricating fluid pass. ### Claim 5 (depends on 4) A lubrication system according to claim 4 wherein said pump delivers lubricating fluid at sufficient rate to form a film on surfaces of the complementary interlocking spline portions of said assembly of drill bit and drive sub. ### Claim 6 (depends on 2) A lubrication system according to claim 2, wherein the lubricating fluid creates an oil seal between a piston reciprocable in a working chamber within said drill string for driving said drill bit and the wall of the working chamber. ### Claim 7 (depends on 2) A lubrication system according to claim 2, wherein the determined rate of supply of lubricating fluid to said working fluid circuit depends on at least one parameter selected from the group consisting of drill string or hammer diameter, working fluid pressure and formation type. ### Claim 8 (depends on 2) A lubrication system according to claim 2 wherein said pump is a hydraulically operated pump, having hydraulic fluid pressure within the pump controlled by a timer or a control valve device for controlling hydraulic fluid pressure within the pump. ### Claim 9 (depends on 8) A lubrication system according to claim 8 including pressure regulator(s) for reducing pressure of hydraulic fluid from the drill rig to pressure suitable for operating said pump. ### Claim 10 (depends on 8) A lubrication system according to claim 8 wherein said pump is a piston pump. ### Claim 11 (depends on 10) A lubrication system according to claim 10, wherein the piston pump draws a predetermined quantity of lubricating fluid from the reservoir during intake stroke, and expels the drawn lubricating fluid during a delivery stroke to the drilling apparatus. ### Claim 12 (depends on 11) A lubrication system according to claim 11, wherein the piston pump includes a working chamber comprising two variable volume chambers, one variable volume chamber being on a delivery side of the pump, and the other variable volume chamber being on a pump side of the pump. ### Claim 13 (depends on 12) A lubrication system according to claim 12, wherein the pump side chamber is pressurised by a hydraulic fluid for operating the pump during delivery stroke. ### Claim 14 (depends on 13) A lubrication system according to claim 13, wherein length of travel of the piston of the pump is controlled to control rate of intake of hydraulic fluid into hydraulic side chamber and supply of lubricating fluid to the drilling apparatus. ### Claim 15 (depends on 14) A lubrication system according to claim 14 wherein hydraulic fluid operating the hydraulic pump is the lubricating fluid contained in the reservoir. ### Claim 16 (depends on 13) A lubrication system according to claim 13 including at least one non-return valve to prevent return of lubricating fluid to the reservoir when the lubricating fluid is intended to be supplied to the drilling apparatus, or the drilling apparatus when supply to the pump is required. ### Claim 17 (depends on 1) A lubrication system according to claim 1 wherein the drilling apparatus is a rotary drilling apparatus or a percussive drilling apparatus. ### Claim 18 A method of drilling a formation with an earth drilling apparatus including a drill string and a drill bit, said drilling apparatus being driven by a working fluid circulated through a working fluid circuit, said method comprising lubricating the drilling apparatus during a drilling operation wherein said drilling apparatus comprises a lubrication system having a reservoir of a lubricating fluid for lubricating the drilling apparatus; and a pump for supplying lubricating fluid from said reservoir to said drilling apparatus during said drilling operation, said pump being controlled to supply lubricating fluid from the reservoir at a determined rate to a lubrication circuit formed by said working fluid circuit of said drilling apparatus.