Well drilling method utilizing real time response to ahead of bit measurements

Abstract

A well drilling method utilizing real time response to ahead of bit measurements. A well drilling method includes measuring a property of a portion of the earth prior to drilling a wellbore into the earth portion; and varying a drilling parameter in real time while drilling the wellbore, in response to measuring the property.

1 . A well drilling method, comprising:
 collecting ahead-of-bit measurements while drilling;   determining a desired value of at least one drilling parameter based at least in part on the ahead-of-bit measurements; and   providing an adjustment to the drilling parameter to match the desired value, wherein said providing includes using a rate-of-penetration measurement to determine timing for said adjustment.   
     
     
         2 . The method of  claim 1 , wherein the at least one drilling parameter comprises bottom hole pressure. 
     
     
         3 . The method of  claim 2 , further comprising estimating a formation pore pressure based at least in part on the ahead-of-bit measurements. 
     
     
         4 . The method of  claim 3 , further comprising estimating a formation fracture pressure based at least in part on the ahead-of-bit measurements. 
     
     
         5 . The method of  claim 2 , further comprising verifying that the desired value of the drilling parameter is suitable for previously penetrated formations. 
     
     
         6 . The method of  claim 5 , further comprising activating an alarm if the desired value is not suitable for previously penetrated formations. 
     
     
         7 . The method of  claim 1 , wherein the ahead-of-bit measurements include formation resistivity. 
     
     
         8 . The method of  claim 1 , wherein the ahead-of-bit measurements include at least one of acoustic velocity, acoustic impedance, and formation density. 
     
     
         9 . The method of  claim 1 , wherein the ahead-of-bit measurements include at least one of natural gamma radiation, prompt gamma response to neutron radiation, and formation porosity. 
     
     
         10 . The method of  claim 1 , further comprising processing the ahead-of-bit measurements to identify a position of at least one of a bed boundary, a formation fluid interface, a fracture, and a borehole. 
     
     
         11 . The method of  claim 10 , wherein the drilling parameter comprises a steering direction. 
     
     
         12 . A well drilling system that comprises:
 a drillstring having at least one tool that collects look-ahead measurements; and   a control system that regulates a drilling parameter based at least in part on the look-ahead measurements.   
     
     
         13 . The system of  claim 12 , wherein the control system further regulates the drilling parameter based at least in part on timing information derived partly from rate of penetration measurements. 
     
     
         14 . The system of  claim 13 , wherein the drilling parameter comprises bottomhole pressure. 
     
     
         15 . The system of  claim 14 , wherein the control system determines formation pore pressure based at least in part on the ahead-of-bit measurements. 
     
     
         16 . The system of  claim 14 , wherein the control system determines formation fracture pressure based at least in part on the ahead-of-bit measurements. 
     
     
         17 . The system of  claim 14 , wherein the control system verifies that a desired value of the drilling parameter is suitable for previously penetrated formations and activates an alarm if the desired value is not suitable for previously penetrated formations. 
     
     
         18 . The system of  claim 12 , wherein the look-ahead measurements include at least one of formation resistivity and dielectric constant. 
     
     
         19 . The system of  claim 12 , wherein the look-ahead measurements include at least one of acoustic velocity, acoustic impedance, and formation density. 
     
     
         20 . The system of  claim 12 , wherein the look-ahead measurements include at least one of natural gamma radiation, prompt gamma response to neutron radiation, and formation porosity. 
     
     
         21 . The system of  claim 12 , wherein the drilling parameter comprises a steering direction, and wherein the control system further processes the look-ahead measurements to identify a position of at least one of a bed boundary, a formation fluid interface, a fracture, and a borehole.