Automatic Wellbore Survey Evaluation

Abstract

A method for automatically evaluating a survey of a subterranean wellbore includes receiving downhole navigation sensor measurements and automatically evaluating surface sensor data obtained at substantially the same time as the navigation sensor measurements to determine whether or not the navigation sensor measurements were obtained during satisfactory wellbore survey conditions. The navigation sensor measurements are evaluated to determine whether or not they meet certain predetermined conditions necessary for obtaining a satisfactory survey. A survey recommendation is automatically generating based on the automatic evaluations performed.

What is claimed is: 
     
         1 . A method for surveying a subterranean wellbore, the method comprising:
 (a) deploying a drill string in the subterranean wellbore, the drill string including one or more navigation sensor sets;   (b) performing survey preparation operations to promote satisfactory wellbore survey conditions based upon a position of the drill string within the wellbore and specific requirements of the navigation sensor sets for taking and communicating a survey;   (c) causing the downhole navigation sensor sets to obtain navigation sensor measurements;   (d) automatically evaluating surface sensor measurements obtained at substantially the same time as the navigation sensor measurements to determine whether or not the navigation sensor measurements were obtained during satisfactory wellbore survey conditions;   (e) automatically evaluating the navigation sensor measurements to determine whether or not the navigation sensor measurements meet certain predetermined conditions necessary for obtaining a satisfactory survey; and   (f) automatically generating a survey recommendation based on said automatic evaluations performed in (d) and (e).   
     
     
         2 . The method of  claim 1 , wherein the survey preparation operations comprise (i) lifting the drill string such that the drill bit is off bottom and (ii) holding the drill string rotationally stationary with respect to the subterranean wellbore. 
     
     
         3 . The method of  claim 1 , wherein the navigation sensor measurements comprise accelerometer measurements and magnetometer measurements. 
     
     
         4 . The method of  claim 1 , wherein the surface sensor measurements comprise at least one of hook load sensor measurements, traveling block position and velocity measurements, surface torque and rotation rate measurements of the drill string, and bit and hole depth measurements. 
     
     
         5 . The method of  claim 4 , wherein the surface sensor measurements verify satisfactory wellbore survey conditions when (i) at least one of the hook load sensor measurements and the bit and hole depth measurements indicate that the drill bit is off-bottom, (ii) the traveling block position and velocity measurements indicate that a velocity of the traveling block is about equal to zero, and (iii) the drill string torque and rotation rate measurements indicate that a rotation rate of the drill string is about equal to zero. 
     
     
         6 . The method of  claim 4 , wherein the surface sensor measurements verify satisfactory wellbore survey conditions when the bit and hole depth measurements indicate that a distance between the navigation sensors and magnetically hot casing components is greater than a predetermined threshold. 
     
     
         7 . The method of  claim 1 , wherein said automatic evaluation in (e) comprises at least one of the following: (i) processing the navigation sensor measurements to compute a total acceleration and comparing the total acceleration with a reference value of earth's gravitational field, (ii) processing the navigation sensor measurements to compute a total magnetic field and comparing the total magnetic field with a reference value of the earth's magnetic field, (iii) processing the navigation sensor measurements to compute a magnetic dip angle and comparing the magnetic dip angle with a reference value of earth's magnetic dip angle, (iv) co-processing the total acceleration, the reference value of the earth's gravitational field, the total magnetic field, the reference value of the earth's magnetic field, the magnetic dip angle, and the reference value of the earth's magnetic dip angle to obtain a survey confidence value. 
     
     
         8 . The method of  claim 7 , wherein the automatic evaluation in (e) verifies that the predetermined conditions were met for obtaining a satisfactory survey when (i) the total acceleration is substantially equal to the reference value of earth's gravitational field, (ii) the total magnetic field is substantially equal to the reference value of the earth's magnetic field, and (iii) the magnetic dip angle is substantially equal to the reference value of earth's magnetic dip angle. 
     
     
         9 . The method of  claim 1 , wherein the survey recommendation comprises an automatic survey acceptance when the automatic evaluation in (d) verifies that the navigation sensor measurements were obtained during satisfactory wellbore survey conditions and the automatic evaluation in (e) verifies that the navigation sensor measurements meet the predetermined conditions necessary for obtaining a satisfactory survey. 
     
     
         10 . The method of  claim 1 , further comprising:
 (g) automatically employing measurement correction processes to improve quality of the navigation sensor measurements.   
     
     
         11 . A method for automatically evaluating a survey of a subterranean wellbore, the method comprising:
 (a) receiving downhole navigation sensor measurements;   (b) receiving surface sensor measurements made at substantially the same time as the navigation sensor measurements;   (c) automatically evaluating the surface sensor measurements to determine whether or not the navigation sensor measurements were obtained during satisfactory wellbore survey conditions;   (d) automatically evaluating the navigation sensor measurements to determine whether or not the navigation sensor measurements meet certain predetermined conditions necessary for obtaining a satisfactory survey; and   (e) automatically generating a survey recommendation based on said automatic evaluations performed in (c) and (d).   
     
     
         12 . The method of  claim 11 , wherein the navigation sensor measurements comprise tri-axial accelerometer measurements and tri-axial magnetometer measurements. 
     
     
         13 . The method of  claim 11 , wherein the surface sensor measurements comprise at least one of the following: hook load sensor measurements, traveling block position and velocity measurements, surface torque and rotation rate measurements of the drill string, and bit and hole depth measurements. 
     
     
         14 . The method of  claim 13 , wherein the surface sensor measurements verify satisfactory wellbore survey conditions when (i) at least one of the hook load sensor measurements and the bit and hole depth measurements indicate that the drill bit is off-bottom, (ii) the traveling block position and velocity measurements indicate that a velocity of the traveling block is about equal to zero, and (iii) the drill string torque and rotation rate measurements indicate that a rotation rate of the drill string is about equal to zero. 
     
     
         15 . The method of  claim 13 , wherein the surface sensor measurements verify satisfactory wellbore survey conditions when the bit and hole depth measurements indicate that a distance between the navigation sensors and magnetically hot casing components is greater than a predetermined threshold. 
     
     
         16 . The method of  claim 11 , wherein said automatic evaluation in (c) comprises at least one of the following: (i) processing the navigation sensor measurements to compute a total acceleration and comparing the total acceleration with a reference value of earth's gravitational field, (ii) processing the navigation sensor measurements to compute a total magnetic field and comparing the total magnetic field with a reference value of the earth's magnetic field, and (iii) processing the navigation sensor measurements to compute a magnetic dip angle and comparing the magnetic dip angle with a reference value of earth's magnetic dip angle. 
     
     
         17 . The method of  claim 16 , wherein the automatic evaluation in (c) verifies that the predetermined conditions were met for obtaining a satisfactory survey when (i) the total acceleration is substantially equal to the reference value of earth's gravitational field, (ii) the total magnetic field is substantially equal to the reference value of the earth's magnetic field, and (iii) the magnetic dip angle is substantially equal to the reference value of earth's magnetic dip angle. 
     
     
         18 . The method of  claim 11 , wherein the survey recommendation comprises an automatic survey acceptance when the automatic evaluation in (b) verifies that the navigation sensor measurements were obtained during satisfactory wellbore survey conditions and the automatic evaluation in (c) verifies that the navigation sensor measurements meet the predetermined conditions necessary for obtaining a satisfactory survey. 
     
     
         19 . The method of  claim 1 , further comprising:
 (e) automatically employing measurement correction processes to improve quality of the navigation sensor measurements.   
     
     
         20 . A system for automatically evaluating a wellbore survey, the system comprising:
 a plurality of surface sensors deployed on a drilling rig;   a computer processor in electronic communication with the surface sensors, the processor configured to automatically (a) receiving downhole navigation sensor measurements, (b) receive sensor measurements from the surface sensors; (c) evaluate the surface sensor measurements to determine whether or not the navigation sensor measurements were obtained during satisfactory wellbore survey conditions; (d) evaluate the navigation sensor measurements to determine whether or not they meet certain predetermined conditions necessary for obtaining a satisfactory survey, and (e) generate a survey recommendation based on said automatic evaluations performed in (c) and (d).