Abstract: Bottom-hole assemblies control the vibration response of drill strings because they are much heavier and stiffer than drill pipe. The length of bottom-hole assemblies is also a factor and the ...

Abstract: The paper evaluates different soft metal coatings for use in conjunction with teflon transfer films. The work was directed at angular contact bearings. The overall goal was to reduce friction ...

Abstract: Drillstring vibrations are generally considered to be detrimental to downhole drilling equipment because they produce cyclic or fatigue loading. Tool joint failures, tubular washouts, and bit ...

Abstract: Critical buckling loads and natural frequencies of lateral vibration modes are determined for a long vertical pipe, suspended in a fluid, simply supported at the top and vertically guided at ...

Abstract: Marine riser response calculations are usually based on finite element or finite difference methods. This paper outlines the modal analysis method as an alternate approach for calculating marine ...

Abstract: This paper presents stability data for a very long vertical pipe transmitting torque in a viscous medium. In addition to these factors, distributed pipe weight and hydrostatic-fluid pressure ...

Abstract: As a pair of gears is loaded, the minimum oil-film thickness between the gear teeth decreases and can approach a magnitude equal to the magnitude of the surface roughness. Metal-to-metal contact ...

Abstract: This paper is concerned with the load carrying capacity of thermohydrodynamic lubricating films in sector pad thrust bearings; it combines the effects of the thermal wedge and fluid film inertia ...

Abstract: 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 ...

Abstract: This paper gives a method of analysis for determining drill string weight required to develop a given bit force while drilling through and out of high-curvature well bores. The analysis is ...