Drilling is one of the most challenging and expensive processes in hydrocarbon extraction
and geothermal well development. Dysfunctions faced during drilling can increase the non …

A stable rotational speed of the marine propeller shaft is essential to minimize the friction of
the supporting bearings and to improve the efficiency of the power system. While, the friction …

Optimization of drilling processes for oil and gas and geothermal wells requires the effective
use of mechanical energy for the destruction of rocks. When constructing a well, an …

A stable operating state of the marine shaft-bearing system is essential to minimize the
vibration level and improve the transmission efficiency of the ship power system. A semi …

In this paper, the surface morphology method is improved and the bit-rock interaction model
between the rock and the PDC bit is studied, considering the influence of blades' shape and …

In this study, a resonant bending fatigue test rig, designed and implemented by the
University of Pisa, is presented, providing a detailed description of the set-up of the machine …

The role of time delay in the control processes aimed at mitigating stick-slip vibration in drill-
strings, is of paramount importance. Its influence on the controlled system's settling time …

Severe torsional vibration of the drill string is referred to as stick–slip. Although it is widely
believed that drill string vibration can affect drilling efficiency, there have been no detailed …

In the exploitation of subsurface hydrocarbon and geothermal energy, more than 50% of
total expenses are typically attributed to drilling and well completion. Coupled triaxial …

Pneumatic down-the-hole (DTH) hammer drilling technology has been used extensively in
the fields of heat reservoir exploitation and geological exploration owing to its advantages of …