System and method for controlling drill bit usage and well plan

A method of controlling drill bit usage comprising the steps of:

• drilling at least a portion of a given oil or gas exploration or production well with a given drill bit;
• continually measuring drilling data from the well and producing outputs indicative of the drilling data;
• converting the outputs indicative of the drilling data into electrical drilling data signals and inputting the electrical drilling data signals to a computer;
• continually processing the drilling data signals to produce at least one signal indicative of the lithology which has been most recently drilled with said bit;
• continually applying said signal indicative of said recently drilled lithology to adjust a wear coefficient signal;
• continually processing the wear coefficient signal to calculate current abrasive wear of the bit and produce a wear calculation signal;
• and
• contining use of the bit or retiring the bit in accord with said wear calculation signal.

A data processing system comprising:

• memory means for storing a set of bit data signals, including signals indicative of parameters of a drill bit, and a set of drilling data signals, including signals indicative of parameters of an oil or gas exploration or production well drilling operation being performed with said bit;
• means for processing said data signals to produce a variable signal indicative of an abrasive-wear-affecting variable;
• means for processing said variable signal to calculate abrasive wear of said bit as a function of said variable signal and produce a wear calculation signal;
• and
• an output device for providing a visual indication of said wear calculation signal.

A method of controlling the execution of a well drilling plan, comprising the steps of:

• drilling at least a portion of a given oil or gas exploration or production well with a given drill bit;
• continually measuring drilling data from the well and producing outputs indicative of the drilling data;
• converting the outputs indicative of the drilling data into electrical drilling data signals and inputting the electrical drilling data signals to a computer;
• continually processing the drilling data signals to produce a drilling signal indicative of the drilling strength of the lithology which has been drilled by said bit, relative to said bit, and closely adjacent said bit;
• continually processing the drilling strength signal to calculate pore pressure as a function of said drilling strength;
• and
• continuing or modifying said well drilling plan as a function of said pore pressure calculation.