METHOD OF AUTOMATICALLY CONTROLLING THE TRAJECTORY OF A DRILLED WELL

• US 20110213601A1
• Filed: 05/05/2011
• Published: 09/01/2011
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Dimitrios K. Pirovolou
• Original Assignee: Dimitrios K. Pirovolou
• Inventors: Pirovolou, Dimitrios K.
• Granted Patent: US 8,676,558 B2
• Time in Patent Office: Days
• US Class Current: 703/10
• CPC Class Codes: E21B 2200/20 Computer models or simulations, e.g. for reservoirs under production, drill bits
• CPC Class Codes: E21B 7/04 Directional drilling

Abstract

Steering behavior model can include build rate and/or turn rate equations to model bottom-hole assembly behavior. Build and/or turn rate equations can be calibrated by adjusting model parameters thereof to minimize any variance between actual response 118 and estimated response produced for an interval of the well. Estimated position and orientation 104 of a bottom-hole assembly along a subsequent interval can be generated by inputting subsequent tool settings into the calibrated steering behavior model. Estimated position and orientation 104 can be compared to a well plan 106 with a controller 108 which determines a corrective action 110. Corrective action 110 can be converted from a build and/or turn rate to a set of recommended tool settings 114 by using an inverse application 112 of the steering behavior model. As additional data 118 becomes available, steering behavior model can be further calibrated 102 through iteration.

Claims

1. A method of controlling the trajectory of a drill string comprising:

providing a steering behavior model of a bottom hole assembly having at least a build rate component or a turn rate component;

determining a first estimated position of the bottom hole assembly by inputting the first tool setting into the steering behavior model; and

utilizing an inverse of the steering behavior model to generate a second tool setting that is predicted to result in a second estimated position.

2. The method of claim 1 further comprising calibrating the steering behavior model by minimizing any variance between an actual build rate and an actual turn rate of the bottom hole assembly generated by the first tool setting and a first estimated build rate and turn rate.

3. The method of claim 2 further comprising comparing the first estimated position to a well plan to determine any deviation of the bottom-hole assembly from the well plan.

4. The method of claim 3 wherein the second estimated position is closer to the well plan the first estimated position.

5. The method of claim 1 further comprising calibrating the steering behavior model by minimizing any variance between the actual build rate or the actual turn rate of the bottom hole assembly generated by the first tool setting and the first estimated build rate or the first estimated turn rate generated by inputting the first tool setting into the steering behavior model

6. The method of claim 1 further comprising automatically generating a signal to a control means of the drill string to accomplish the second tool setting.

7. A method of controlling the trajectory of a drill string comprising:

providing a steering behavior model having a build rate equation or a turn rate equation;

calibrating the steering behavior model by minimizing any variance between an actual build rate or an actual turn rate of the drill string generated by a first tool setting and a first estimated build rate or a first estimated turn rate generated by inputting the first tool setting into the steering behavior model; and

determining a second estimated build rate or a second estimated turn rate by inputting a second tool setting into the steering behavior model.

8. The method of claim 7 further comprising comparing the second estimated build rate or the second estimated turn rate to a well plan to determine a deviation of the bottom-hole assembly therefrom.

9. The method of claim 8 further comprising determining with a controller a corrective action to correct the deviation.

10. The method of claim 9 further comprising determining a recommended tool setting for the corrective action.

11. The method of claim 10 wherein the recommended tool setting is determined with an inverse application of the calibrated steering behavior model.

12. The method of claim 9 further comprising automatically transmitting the recommended tool setting to a component in the drill string.

13. The method of claim 7 wherein the calibrating step further comprises adjusting a model parameter of at least one of the build rate equation and the turn rate equation to minimize the any variance.

14. The method of claim 7 wherein the tool setting is selected from the group consisting of weight on bit, mud flow rate, rotational speed of the drill string, rotational speed of a drill bit, toolface angle, steering ratio, and drilling cycle.

15. A method of controlling the trajectory of a drill string comprising:

providing a steering behavior model having a build rate equation and a turn rate equation of a bottom-hole assembly;

providing an actual azimuth and inclination at a first interval of drilling;

determining an actual build rate and an actual turn rate at the first interval;

calibrating the steering behavior model by minimizing any variance between the actual build rate and the actual turn rate and a first estimated build rate generated by inputting a first set of tool settings into the steering behavior model; and

determining a second estimated build rate and a second estimated turn rate with the calibrated steering behavior model for a subsequent second interval drilled with a subsequent second set of tool settings.

16. The method of claim 15 further comprising integrating the second estimated build rate and the second estimated turn rate over the subsequent second interval to produce a second estimated azimuth and inclination for the second interval.

17. The method of claim 15 further comprising integrating the second estimated azimuth and inclination data set over the second interval to produce an estimated position of the bottom-hole assembly.

18. The method of claim 16 further comprising:

providing an actual azimuth and inclination data set for the second interval drilled with the second set of tool settings; and

further calibrating the steering behavior model by minimizing any variance between the actual build rates and turn rates of the first and subsequent second intervals and the first and second estimated build rates and the estimated turn rates generated by inputting the first and second sets of tool settings into the calibrated steering behavior model.

19. The method of claim 15 wherein the build rate equation and the turn rate equations comprise at least one of drilling parameters, drilling tool settings, position and orientation of the drill string, properties of the formation, geometry of the bottom-hole assembly, and model parameters.

20. The method of claim 15 wherein the at least one of the build rate equation and the turn rate equation has a model parameter and further wherein the calibrating step further comprises adjusting the model parameter of at least one of the build rate equation and the turn rate equation to minimize the any variance.