Abstract

The stick-slip vibration in deep hard formation is a technical bottleneck restricting the efficient use of PDC bit. In order to combat the stick-slip phenomenon during drilling in deep hard formations, we introduced the high frequency self-excited torkbuster. Based on the analysis of the working principle of the torkbuster, a nonlinear dynamic three-dimensionalmodel of PDC bit is established by using the finite element software (ANSYS/LS-DYNA). The wear conditions and themotioncharacteristicsof the PDC bit as well as the failure of the rock are simulated with and without the action of the high frequency torsional impact, and several field experiments are conducted. The results show that the high frequency torsional impact force generated by the torkbuster can effectively improve the uniformity of the force on the PDC bit and rock, and restrain the stick-slip vibration and the damage of the cutters. The experimental results show that the torkbuster can improve the rock breaking efficiency and shorten the drilling cycle, and provide an important technical reference for the torsional impact technology applying in deep hard formations.

Highlights

  • At present, the development of oil and gas reservoirs in the world has entered the middle and late stages, Thedevelopment proportion of deep wells or ultra-deep wells has gradually increased

  • The energy stored in the drill strings was suddenly released and the angular velocity of the drill bit was increased several times

  • Simulation and field tests, it was found that the rock breaking mechanism of PDC bit with and without torkbuster is different, and it has obvious effect on ROP improvement [7,8,9,10]

Read more

Summary

Introduction

The development of oil and gas reservoirs in the world has entered the middle and late stages, Thedevelopment proportion of deep wells or ultra-deep wells has gradually increased. The failure of PDC bits in deep-hard formations is a technical difficulty faced by fast drilling. The energy stored in the drill strings was suddenly released and the angular velocity of the drill bit was increased several times. At this time, the drill bit was in a slip state. In order to reduce the stick-slip vibration and failure of PDC bit in the drilling process [1,2,3,4,5,6], a new type of self-excited high-frequency torkbuster (abbreviated as torkbuster) was introduced. Simulation and field tests, it was found that the rock breaking mechanism of PDC bit with and without torkbuster is different, and it has obvious effect on ROP improvement [7,8,9,10]

Working Principle and Rock Breaking Mechanism of Torkbuster
Modeling
Definition of Element Type
Model Material Definition
Loading Constraints
Simulation Analysis
Comparison of Bit Motion
Analysis of Drill Bit Motion Characteristics
Field Experiment
Findings
Conclusion and Suggestion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call