# US 6,293,356 B1 · Method of and system for optimizing rate of penetration in drilling operations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,293,356 B1 - Document ID: US6293356B1 - Status: Granted - Kind: B1 - Application number: 09/398,674 - Filed: 1999-09-17 - Granted: 2001-09-25 - Earliest claimed: 1998-04-02 - Assignees: Noble Drilling Services Inc. - Inventors: Charles H. King; Mitchell D. Pinckard - Web page: https://patentgrep.com/patent/US6293356B1 ## CPC - E21B 44/00: Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions - E21B 3/02: Surface drives for rotary drilling - E21B 44/02: Automatic control of the tool feed ({E21B44/005,} E21B44/10 take precedence) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A method of and system for optimizing bit rate of penetration while drilling substantially continuously determine an optimum weight on bit necessary to achieve an optimum bit rate of penetration based upon measured conditions and maintains weight on bit at the optimum weight on bit. As measured conditions change while drilling, the method updates the determination of optimum weight on bit. ## Claims ### Claim 1 A method of optimizing bit rate of penetration while drilling, which comprises the steps of: substantially continuously determining an optimum drilling control variable value to achieve an optimum bit rate of penetration; and maintaining said drilling control variable at said optimum drilling control variable value. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein said step of substantially continuously determining an optimum drilling control variable value to achieve an optimum bit rate of penetration includes the steps of: (a) substantially continuously determining bit rate of penetration and said drilling control variable value while drilling; (b) periodically computing an optimum drilling control variable value based upon said determined rate of penetration and said determined drilling control variable value; and, (c) repeating steps (a) and (b) while drilling. ### Claim 3 (depends on 2) The method as claimed in claim 2, wherein said step of maintaining said drilling control variable at said optimum drilling control variable value includes the steps of: displaying a currently determined drilling control variable value to a human driller; and, displaying said optimum drilling control variable value to said human driller to enable said human driller to match said displayed currently determined drilling control variable to said displayed optimum drilling control variable. ### Claim 4 (depends on 2) The method as claimed in claim 2, wherein said step of maintaining said drilling control variable at said optimum drilling control variable value includes the steps of: inputting a currently determined drilling control variable value to an automatic drilling machine; and, inputting said current optimum drilling control variable value to said automatic drilling machine. ### Claim 5 (depends on 2) The method as claimed in claim 2, wherein said step of substantially continuously determining bit rate of penetration and said drilling control variable value while drilling includes the step of: making surface measurements of drilling parameter values. ### Claim 6 (depends on 5) The method as claimed in claim 5, wherein said drilling control variable is weight on bit. ### Claim 7 (depends on 6) The method as claimed in claim 6, wherein said step of determining said drilling control variable and bit rate of penetration includes the steps of: measuring weight on hook; measuring hook rate of penetration; computing weight on bit based upon measured weight on hook; and, computing bit rate of penetration based upon measured weight on hook and measured hook rate of penetration. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein said step of substantially continuously determining an optimum drilling control variable to achieve an optimum bit rate of penetration includes the steps of: building a mathematical model of bit rate of penetration as a function of drilling control variable value; substantially continuously updating said mathematical model while drilling; and, computing an optimum drilling control variable value based upon said mathematical model. ### Claim 9 A method of optimizing bit rate of penetration in drilling operations, which comprises the steps of: substantially continuously determining bit rate of penetration as function of a drilling control variable value for a set of conditions; periodically, while drilling, calculating a target drilling control variable value to produce a desired bit rate of penetration for said set of conditions; and, maintaining a current drilling control variable value equal to said target drilling control variable value during drilling. ### Claim 10 (depends on 9) The method as claimed in claim 9, maintaining a current drilling control variable value equal to said target drilling control variable value during drilling includes the steps of: displaying said current drilling control variable value and said target drilling control variable to a human driller. ### Claim 11 (depends on 10) The method as claimed in claim 10, wherein said drilling control variable is weight on bit. ### Claim 12 (depends on 11) The method as claimed in claim 11, wherein said step of maintaining said current drilling control variable value equal to said target drilling control variable during drilling includes the step of controlling a brake to attempt to match said displayed current bit weight to said displayed target bit weight. ### Claim 13 (depends on 10) The method as claimed in claim 10, wherein said drilling control variable is weight on bit, and said step of maintaining said current drilling control variable equal to said target drilling control variable during drilling includes the step of inputting said target weight on bit to an automatic driller. ### Claim 14 A method of optimizing bit rate of penetration in drilling operations, which comprises the steps of: (a) substantially continuously determining weight on bit and bit rate of penetration; (b) periodically, while drilling, determining an optimum weight on bit to achieve said optimum rate of penetration. ### Claim 15 (depends on 14) The method as claimed in claim 14, including the step of: (c) maintain weight on bit at said optimum weight on bit while drilling. ### Claim 16 (depends on 15) The method as claimed in claim 15, including the step of repeating steps (a)-(c) while drilling. ### Claim 17 (depends on 14) The method as claimed in claim 14, wherein said step of determining an optimum weight on bit includes the steps of: periodically computing bit rate of penetration as a function of weight on bit. ### Claim 18 A drilling system, which comprises: means for displaying current weight on bit; means for displaying a target bit weight; and, means for controlling weight on bit so that a driller can attempt to match said displayed current bit weight to said target bit weight. ### Claim 19 (depends on 18) The system as claimed in claim 18, wherein said target bit weight is selected to produce an optimum bit rate of penetration. ### Claim 20 (depends on 18) The system as claimed in claim 18, including: means for determining said current weight on bit; and, means for determining a current bit rate of penetration. ### Claim 21 (depends on 20) The system as claimed in claim 20, including: means for determining said target bit weight based upon determined current weights on bit and determined current rates of penetration. ### Claim 22 A drilling system, which comprises: means for substantially continuously determining current weight on bit while drilling; means for substantially continuously determining current bit rate of penetration while drilling; and means for periodically determining a target weight on bit while drilling. ### Claim 23 (depends on 22) The system as claimed in claim 22, including: means for maintaining current weight on bit equal to said target weight on bit while drilling. ### Claim 24 (depends on 22) The system as claimed in claim 22, wherein said target weight on bit is selected a achieve an optimum bit rate of penetration. ### Claim 25 A drilling method, which comprises the steps of: substantially continuously determining current weight on bit while drilling; substantially continuously determining current bit rate of penetration while drilling; and periodically determining a target weight on bit while drilling based upon determined weights on bit and bit rates of penetration. ### Claim 26 (depends on 25) The method as claimed in claim 25, including the step of: maintaining current weight on bit equal to said target weight on bit while drilling. ### Claim 27 (depends on 25) The method as claimed in claim 25, wherein said target weight on bit is selected a achieve an optimum bit rate of penetration.