Unconventional gas includes tight sandstone gas, shale coalbed methane, and natural hydrate. With huge reserves, unconventional has become the most important resource successor after end of “Easy Oil era.” The drilling fluid is an indispensable wellbore working for with multiple functions. polymer (PDF) common, longest developed, diverse type. advantages easily controlled rheology, convenient o...

There are essentially three main categories of drilling fluids: oil based fluids (OBF’s), synthetic based fluids (SBF’s) and water based fluids (WBF’s). OBF’s have been traditionally been used for their high performance drilling characteristics but tend to have a poor environmental performance in terms of their ecotoxicity and their tendency to persist in cuttings piles on the seafloor. More re...

Conditions of work on offshore drilling platforms are particularly hard due to extreme environmental situations created both by nature and technological processes. Oil drilling workers employed on the open sea are potentially exposed to permanently high stress. Apart from the obvious objective factors affecting drilling platform employees, a great role in the general work-related stress level i...

INTRODUCTION The purpose of this study was to compare the influences of different implant modalities on orthodontic microimplants and surrounding tissues biomechanically and histologically. METHODS Fifty-six titanium alloy microimplants placed on the buccal side of the maxillae and the mandibles in 2 dogs were divided into 2 groups of 28; one group of microimplants was self-drilling, and the ...

The past decade has seen increased focus on nanoparticle (NP) based drilling fluid to promote wellbore stability in shales. With the plugging of NP into shale pores, the fluid pressure transmission can be retarded and wellbore stability can be improved. For better understanding of the interaction between shale and NP based drilling fluid based on previous pressure transmission tests (PTTs) on A...

[1] Thermal records from boreholes in young oceanic crust, in which water is flowing up or down, are used to assess formation and borehole flow properties using three analytic equations that describe the transient thermal and barometric influence of downhole or uphole flow. We link these calculations with an iterative model and apply Markov chain Monte Carlo (MCMC) analysis to quantify ranges o...

Hybrid composite-metal stacks (HCMS) combine metal alloys and composite materials are used in the manufacturing maintenance of aircrafts. Drilling is an important process necessary for installing rivets fuselages. This work sought to identify influence cooled compressed air high-speed cutting (HSC) on drilling multi-material joints with different configurations. Among factors observed type (car...

K e y w o r d s F o u r t h g r a d e fluid, Unsteady flow, Lie symmetries. 1. I N T R O D U C T I O N In recent years, considerable efforts have been usefully devoted to the s tudy of flow of nonNewton ian fluids. This is ma in ly due to their m a n y appl icat ions in pe t ro leum drilling, manufactu r ing of food and paper, and other similar activities. A vast a m o u n t of l i te ra ture i...

This paper examines the diverse nature of user reactions to information technology (IT) within the social-historical context of its organizational use. Employing activity theory as a conceptual framework, we conduct an interpretive analysis of physicians work, perceptions, and IT usage experience at a large community hospital to understand why some of these physicians were favorably disposed to...