STOCHASTIC ANALYSIS OF THE FRICTIONAL FORCES OF A DRILL-STRING ON HORIZONTAL DRILLING

THIAGO RITTO; MARIO R. ESCALANTE; RUBENS SAMPAIO; MARTA B. ROSALES

Maresias

Simposio; UNCERTAINTIES 2012; 2012

The aim of this paper is to analyze uncertainties on the frictional forces of a drill-string performing horizontal drilling. There are few articles treating the dynamic modeling of a horizontal drill-string. In the present numerical analysis, the drill-string is modeled using the bar model (tension/compression), and is discretized by means of the finite element method. An oscillatory force is imposed on one side and the bit-rock interaction occurs on the other side. The frictional forces are modeled by two random fields: (1) a constant one and (2) one with exponential autocorrelation function. Finally, the Monte Carlo method is used to approximate the statistics of the response and to analyze the input and output power.