Drilling operations in the oil and gas industry present a highly complex dynamic. In this
paper, the coupled lateral–torsional vibrations of a drill string are investigated in order to …

Large high-power gear transmission systems, especially complex gear systems, have
problems such as high processing costs, long manufacturing cycles, and difficult testing …

In this study, we investigate the dynamic scaling laws of geometrically similitude models and
systems for predicting their vibration characteristics accurately. A determination method of …

The formation of boreholes in tectonically deformed coal (TDC) seams is challenging,
hindering the efficient exploitation of coalbed methane (CBM) resources. The reciprocating …

Drillstring vibrations are a dynamic response of the drillstring to a combination of external
forces and initial conditions. Such response is can be measured and recorded by various …

Motion states of bottom hole assembly (BHA) have a great effect on the trajectory control and
drilling efficiency while rotary drilling. In order to study the motion states of BHA in horizontal …

Conventional kick detection methods mainly include monitoring pit gains, surface flow data
(flow in and flow out), surface and down-hole pressure variations, and outputs from physics …

Abstract The development of Integrated Enset processing technology is significant for the
easy availability of stable food in the current condition for fulfilling the pangs of hunger in …

This paper treats the nonlinear problem of a coupled lateral-torsional drill string. A simplified
3 DOF system is used to model the system. The nonlinearity has two main sources:(1) the …

The drill string used in drilling is in a complex motion state downhole for several kilometers.
The operating attitude and eccentricity of the downhole drill string play important roles in …