Research on Cepstrum Analysis of Drill String Vibration and Extraction of Bit Source Signals

2010 ◽  
Vol 53 (4) ◽  
pp. 684-692
Author(s):  
He-Zhen WU ◽  
Hong-Kui GE ◽  
Ding-Hui YANG ◽  
Bin LU ◽  
Lai-Ju HAN ◽  
...  
1968 ◽  
Vol 90 (4) ◽  
pp. 671-679 ◽  
Author(s):  
D. W. Dareing ◽  
B. J. Livesay

This paper discusses longitudinal and angular drill-string vibrations and supporting field measurements taken with a special downhole recording instrument. Computer programs based on the theory are used to calculate longitudinal and angular vibrations (caused by periodic bit motions) along the drill string; field measurements made during actual drilling operations are used to check computer calculations. The main difference between this and other theory on the same problem is the inclusion of friction, which acts along the length of a drill string and impedes longitudinal and angular vibrations. For the sake of simplicity, the effect of different types of friction, such as fluid, rubbing, and material, which act along the string, is approximated by the effect produced by viscous friction. This approximation is generally accepted and appears to give adequate results for the drill-string vibration problem.


2013 ◽  
Author(s):  
Abdolali Esmaeili ◽  
Behzad Elahifar ◽  
Rudolf Konrad Fruhwirth ◽  
Gerhard Thonhauser

2013 ◽  
Vol 318 ◽  
pp. 27-32
Author(s):  
Hao Cheng Wu ◽  
Yong Shou Dai ◽  
Wei Feng Sun ◽  
Li Gang Li ◽  
Ya Nan Zhang

Periodic noise is an important manifestation of the drill string vibration signal noise. In order to extract the characteristics of the signals which reflect the situation of the tools in drilling, the periodic components which influence the original drill string vibration signal in the well field were researched and the independent component analysis algorithm which is on the basis of negative entropy for periodic vibration noise separation was adopted. At the same time, the effect of algorithm demixing was improved where periodic noise components which existed in three directions of drill string vibration signals were used, combining with the improved particle swarm optimization algorithm to seek the optimal mixed matrix by which the multi-channel mixed-signal of independent component analysis algorithm could be structured. This method in operation was fast. And after separation each signal was of high similarity. Through the experimental simulation, the method was proven effective in the drill string vibration periodic noise signal separation.


2012 ◽  
Author(s):  
Abdolali Esmaeili ◽  
Behzad Elahifar ◽  
Rudolf Konrad Fruhwirth ◽  
Gerhard Thonhauser

2014 ◽  
Vol 535 ◽  
pp. 597-601 ◽  
Author(s):  
Peng Wang ◽  
Hong Jian Ni ◽  
Zhi Na Li ◽  
Rui He Wang

Drill-string vibration excitation longitudinally is a potential drilling method for reducing friction between drill-string and borehole rock. This article assumes that borehole rock surface is composed of elliptical asperities, based on elastic-plastic contact theory, a modified model for friction reduction by vibrating drill-string longitudinally is developed. The results show that the tangential stiffness of borehole rock surface decreased with increasing ovality of asperity. Further, at the same ovality, thin and tall asperity has bigger tangential stiffness than short and fat asperity. Only when the tangential stiffness of borehole rock is greater than a certain threshold, the friction force calculated by proposed model in this paper can appear reverse phenomenon. When the tangential stiffness tends to infinity, the result tends to Coulomb model. The conclusions provide basis for research and application of drill-string vibration longitudinally friction reduction technology.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yongwang Liu ◽  
Zhichuan Guan ◽  
Hongning Zhang ◽  
Bo Zhang

It is a hot topic for deep/ultradeep wells to improve rock-breaking efficiency and drilling speed by available downhole energy. Based on different downhole energies and working conditions, specialized plunger pump is proposed to convert longitudinal vibration of drilling string into rock-breaking energy. Technical design is developed to generate high-pressure water jet. And then a simulation model is built to verify feasibility of the technical design. Through simulation, the influence law of key factors is obtained. On this basis, this device is tested in several wells. The result indicates this device can increase drilling speed as much as 136%. Meanwhile the harmful vibration can be absorbed. The energy from drilling string vibration is of high frequency and increases as well depth and formation anisotropy increase. By reducing adverse vibration, this device is able to increase the drilling speed and the service life also meets the demand of field application. The longest working time lasts for more than 130 hours. The performance of this device demonstrates great application prospect in deep/ultradeep resources exploration. To provide more equipment support for deep/ultradeep wells, more effort should be put into fundamental study on downhole drill string vibration and related equipment.


Sign in / Sign up

Export Citation Format

Share Document