Earth surveying for improved drilling applications

Abstract

Methods and apparatuses for geophysical surveying are disclosed. In one embodiment, a marine vehicle may obtain magnetic measurements in a location around a drilling site. The magnetic measurements may be used to calculate a localized disturbance magnetic field resulting from, for example, solar flares. The localized disturbance magnetic field may be used to calculate a declination value and, thus, a wellbore position with improved accuracy.

What is claimed is: 
     
         1 . A system, comprising:
 a processing system configured to receive magnetic measurements from a magnetic measurement device, the processing system comprising at least one processor configured to perform steps comprising:
 determining a crustal field based on the received magnetic measurements; 
 calculating a localized magnetic disturbance field in an area local to a location corresponding to the received magnetic measurements, 
 wherein the localized magnetic disturbance field is related to solar activity and independent of a main field and independent of the crustal field, and 
 wherein the localized magnetic disturbance field is calculated by subtracting one of the received magnetic measurements from the determined crustal field; and 
 calculating a wellbore position based, at least in part, on the calculated localized magnetic disturbance. 
   
     
     
         2 . The system of  claim 1 , further comprising at least one marine vehicle in which the magnetic measurement device is attached to the at least one marine vehicle. 
     
     
         3 . The system of  claim 1 , wherein the wellbore position is in the area local to the magnetic measurement. 
     
     
         4 . The system of  claim 1 , wherein the received magnetic measurements correspond to magnetic measurements at a plurality of coordinates corresponding to a grid pattern. 
     
     
         5 . The system of  claim 4 , further comprising receiving second data corresponding to geophysical measurements for the plurality of coordinates. 
     
     
         6 . The system of  claim 1 , in which the received magnetic measurements are received in real-time. 
     
     
         7 . The system of  claim 1 , in which the processing system is further configured to perform the steps of:
 calculating a main field;   calculating a crustal field; and   calculating the localized magnetic disturbance based on the main field and the crustal field.   
     
     
         8 . The system of  claim 1 , wherein the step of determining the crustal field comprises monitoring the location by fitting a spline with knot separations, wherein the spline is the sum of the main field and the crustal field. 
     
     
         9 . The system of  claim 1 , wherein the step of calculating the wellbore position comprises calculating a declination value to direct drilling operations to reach an underground reservoir. 
     
     
         10 . The system of  claim 1 , wherein the processing system comprises a plurality of computing systems organized in a distributed computing system. 
     
     
         11 . A computer program product, comprising:
 a non-transitory computer readable medium comprising code to perform steps comprising:
 receiving magnetic measurements; 
 determining a crustal field based on the received magnetic measurements; 
 calculating a localized magnetic disturbance field in an area local to a location corresponding to the received magnetic measurements, 
 wherein the localized magnetic disturbance field is related to solar activity and independent of a main field and independent of the crustal field, and 
 wherein the localized magnetic disturbance field is calculated by subtracting one of the received magnetic measurements from the determined crustal field; and 
 calculating a wellbore position based, at least in part, on the calculated localized magnetic disturbance, wherein the wellbore position is in the area local to the magnetic measurement. 
   
     
     
         12 . The computer program product of  claim 11 , wherein the received magnetic measurements correspond to magnetic measurements at a plurality of coordinates corresponding to a grid pattern, and the medium further comprises code to perform steps comprising receiving second data corresponding to geophysical measurements for the plurality of coordinates. 
     
     
         13 . The computer program product of  claim 11 , wherein the step of determining the crustal field comprises monitoring the location by fitting a spline with knot separations, wherein the spline is the sum of the a main field and the crustal field. 
     
     
         14 . The computer program product of  claim 11 , wherein the step of calculating the wellbore position comprises calculating a declination value to direct drilling operations to reach an underground reservoir. 
     
     
         15 . A method, comprising:
 receiving magnetic measurements;   determining a crustal field based on the received magnetic measurements;   calculating a localized magnetic disturbance field in an area local to a location corresponding to the received magnetic measurements,   wherein the localized magnetic disturbance field is related to solar activity and independent of a main field and independent of the crustal field, and   wherein the localized magnetic disturbance field is calculated by subtracting one of the received magnetic measurements from the determined crustal field; and   calculating a wellbore position based, at least in part, on the calculated localized magnetic disturbance.   
     
     
         16 . The method of  claim 15 , wherein the wellbore position is in the area local to the magnetic measurement. 
     
     
         17 . The method of  claim 15 , wherein the received magnetic measurements correspond to magnetic measurements at a plurality of coordinates corresponding to a grid pattern, and the method further comprising receiving second data corresponding to geophysical measurements for the plurality of coordinates. 
     
     
         18 . The method of  claim 15 , wherein the step of determining the crustal field comprises monitoring the location by fitting a spline with knot separations, wherein the spline is the sum of the a main field and the crustal field. 
     
     
         19 . The method of  claim 15 , wherein the step of calculating the wellbore position comprises calculating a declination value to direct drilling operations to reach an underground reservoir.