发明名称 |
Alternating frequency time domain approach to calculate the forced response of drill strings |
摘要 |
A method for estimating a steady state response of a drill string in a borehole includes calculating a first displacement of the drill string in a frequency domain for a first excitation force frequency and a number of multiples of this frequency using an equation of motion of the drill string. The equation of motion has a static force component, an excitation force component, and a non-linear force component with respect to at least one of a deflection and a derivative of the deflection of the drill string. The method further includes: transforming the first displacement from the frequency domain into a time domain; calculating a non-linear force in the time domain; calculating a frequency domain coefficient derived from the calculated non-linear force in the time domain; and calculating a second displacement of the drill string in the frequency domain using the equation of motion and the frequency domain coefficient. |
申请公布号 |
US9000941(B2) |
申请公布日期 |
2015.04.07 |
申请号 |
US201313771749 |
申请日期 |
2013.02.20 |
申请人 |
Baker Hughes Incorporated |
发明人 |
Hohl Andreas;Schuberth Frank;Reckmann Hanno |
分类号 |
G01V3/00;E21B23/00;E21B17/10;E21B17/00 |
主分类号 |
G01V3/00 |
代理机构 |
Cantor Colburn LLP |
代理人 |
Cantor Colburn LLP |
主权项 |
1. A method for estimating a steady state response of a drill string disposed in a borehole penetrating at least one of the earth and another material, the method comprising:
calculating a first displacement of the drill string in a frequency domain for a first excitation force frequency and a number of multiples of this frequency using an equation of motion of the drill string that is solved by a processor, the equation of motion having a static force component, an excitation force component, and a non-linear force component with respect to at least one of a deflection and a derivative of the deflection of the drill string; transforming the first displacement from the frequency domain into a time domain using the processor; calculating a non-linear force in the time domain based on at least one of the calculated displacement and a derivative of the calculated displacement using the processor; calculating a frequency domain coefficient derived from the calculated non-linear force in the time domain using the processor; and calculating a second displacement of the drill string in the frequency domain using the equation of motion and the frequency domain coefficient using the processor. |
地址 |
Houston TX US |