State Dependent Delayed Drill-string Vibration : Theory, Experiments and New Model

L.J. Pei would like to acknowledge NNSF of China (No. 11372282) and China Scholarship Council.Peer reviewedPublisher PD

3D and 4D Seismic Technics Today

Years ago, exploration was done through surface observations and divining rods now, it is done by satellites, microprocessors, remote sensing, and supercomputers. In the 1970´ s, the exploration success rate was 14 percent, today, it is nearly 29 percent. Not so long ago, three dimension (3D) seismic diagnostic techniques helped recover 25-50 percent of the oil in place now, 4D seismic helps recover up to 70 percent of the oil in place. 3D and 4D seismic and earth imaging systems also help in understanding the subsurface flow of other fluids, such as groundwater and pollutants.Seismic surveys a technique in which sound waves are bounced off underground rock struktures to reveal possible oil and gas bearing formation are now standard fare for the modern petroleum industry. But todays seismic methods are best at locating structural traps where faults or folds in the underground rock have created zones where oil can become trapped

Bifurcation scenarios in helical buckling of slender rods using new FE

The authors would like to acknowledge the use of the Maxwell High Performance Computing Cluster of the University of Aberdeen IT Service and various industrial projects sponsored by Oil & Gas Innovation Centre (OGIC), which stipulated these studies.Peer reviewedPostprin

Helical buckling of thin rods : FE modelling

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Suppression of drill-string stick–slip vibration by sliding mode control : Numerical and experimental studies

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Complex dynamics of drill-strings : Theory and experiments

Peer reviewedPublisher PD

Experimental studies of forward and backward whirls of drill-string

The authors wish to thank BG Group plc for the financial support to this research.Peer reviewedPostprin