Simulating the dynamic response of a drilling tool assembly and its application to drilling tool assembly design optimization and drilling performance optimization

• US 7,139,689 B2
• Filed: 05/24/2004
• Issued: 11/21/2006
• Est. Priority Date: 10/11/2000
• Status: Active Grant

• Current Assignee: Smith International Incorporated (Schlumberger NV)
• Original Assignee: Smith International Incorporated (Schlumberger NV)
• Inventors: Huang, Sujian
• Primary Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US10/852,574
• Publication Number:
  US 20040211596A1
• Time in Patent Office: 911 Days
• Field of Search: 703/7, 175/45, 175/50, 702/6, 702/9
• US Class Current: 703/7
• CPC Class Codes: E21B 10/00 Drill bits specially adapted for deflecting the direction of boring E21B7/064; with means for collecting substances E21B27/00
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions

Abstract

A method for simulating a drilling tool assembly having a drill string and a drill bit. The method includes simulating a dynamic response of the drill string; simulating a dynamic response of the drill bit; and resolving the dynamic response of the drill string and the dynamic response of the drill bit into a dynamic response of the drilling tool assembly.

Claims

1. A method for simulating a drilling tool assembly having a drill string and a drill bit, comprising:

simulating a dynamic response of the drill string;

simulating a dynamic response of the drill bit; and

resolving the dynamic response of the drill string and the dynamic response of the drill bit into a dynamic response of the drilling tool assembly.

2. The method of claim 1, wherein the simulating comprises,

solving for the dynamic response of the drill string to an incremental rotation using a first part of a two-part mechanics analysis model of the drilling tool assembly that represents the drill string;

and

repeating said solving for a select number of successive incremental rotations.

3. The method of claim 1, wherein the simulating comprises,

solving for the dynamic response of the drill string to an incremental rotation using a second part of a two-part mechanics analysis model of the drilling tool assembly that represents the drill bit;

and

repeating said solving for a select number of successive incremental rotations.

4. The method of claims 2 or 3, wherein said solving comprises,

constructing the two-part mechanics analysis model of the drilling tool assembly using selected drilling tool assembly design parameters;

determining well bore constraints from well bore trajectory parameters, a specified bottom hole geometry, and a specified hook load,

determining loads on the drilling tool assembly for a position of the drilling tool assembly in the well bore using at least the two-part mechanics analysis model and the well bore constraints; and

calculating the dynamic response of the drilling tool assembly under the loads to the incremental rotation using the two-part mechanics analysis model.

5. The method of claim 1, wherein said resolving comprises,

applying a convergence algorithm to said simulating the dynamic response of the drill string and said simulating the dynamic response of the drill bit.

6. A new method of claim 1, further comprising:

converting the dynamic response of the drilling tool assembly into a visual presentation of drilling characteristics of the drilling tool assembly.

7. A method for designing a drill string of a drilling tool assembly, comprising:

defining initial drilling tool assembly design parameters;

simulating a dynamic response of the drill string of the drilling tool assembly;

simulating a dynamic response of a drill bit of the drilling tool assembly;

resolving the dynamic response of the drill string and the dynamic response of the drill bit into a dynamic response of the drilling tool assembly;

adjusting a value of at least one of the drill string design parameters;

repeating the simulating and the adjusting a selected number of times;

evaluating the dynamic responses of the drilling tool assembly; and

based on the evaluating, selecting desired drill string design parameters.

8. A method for designing a drill string of a drilling tool assembly, comprising:

defining initial drilling tool assembly design parameters;

simulating a dynamic response of the drill bit of the drilling tool assembly;

simulating a dynamic response of a drill string of the drilling tool assembly;

resolving the dynamic response of the drill string and the dynamic response of the drill bit into a dynamic response of the drilling tool assembly;

adjusting a value of at least one of the drill bit design parameters;

repeating the simulating and the adjusting a selected number of times;

evaluating the dynamic responses of the drilling tool assembly; and

based on the evaluating, selecting desired drill bit design parameters.