An approach to the optimization of drilling tools which is based on the analysis of dependence of drilling cost on the tool shape is presented. The effect of tool shape on the energy consumption in rotatory drilling and on the lifetime of tool is studied analytically. It is shown that the main part of drilling energy is consumed not for the rock removal, but rather by the microfracture, shearin...

Pore pressureis defined as the pressure of the fluid inside the pore space of the formation, which is also known as the formation pressure. When the pore pressure is higher than hydrostatic pressure, it is referred to as overpressure. Knowledge of this pressure is essential for cost-effective drilling, safe well planning, and efficient reservoir modeling. The main objective of this study is to ...

The sound produced by a dental air turbine handpiece (dental drill) can markedly influence the sound environment in a dental clinic. Indeed, many patients report that the sound of a dental drill elicits an unpleasant feeling. Although several manufacturers have attempted to reduce the sound pressure levels produced by dental drills during idling based on ISO 14457, the sound emitted by such dri...

Received: April 29, 2017 Revised: July 01, 2017 Accepted: August 30, 2017 Abstract: Introduction: Unloading phenomenon happens in the beginning of drilling and is able to change stress state around borehole. This change of stress state causes impact on rock structure and strength, thus affecting the evaluation of wellbore stability. Especially for determining initial mud pressure, unloading is ...