the narrow operating window between pore pressure and fracture pressure makes drilling difficult in some operations. a feasibility study of managed pressure drilling (mpd) is carried out on iran darquain oil field. the previous wells drilled in this field showed that mud returns were lost during drilling gadvan formation. the present work addresses this problem by means of surface back pressure...

Coiled tubing (CT) is widely used in drilling, workover, completion, fracturing and stimulation the field of oil gas exploration development. During CT operation, will present a gas–liquid two-phase flow state. The prediction frictional pressure drop for fluid tube an important part hydraulic design, its accuracy directly affects success technique. In this study, we analyzed effects void fracti...

Propulsion of a bolus through the upper esophageal sphincter (UES) is driven by a pressure drop in the direction of flow against frictional resisting force. Basic mechanics suggest that the axial rate of drop in intrabolus pressure (IBP), i.e., the intrabolus pressure gradient (IBPG), should be locally sensitive to abnormal constriction. We sought to quantify space-time patterns of IBP and IBPG...

Environmental concerns have urged a search for eco-friendly refrigerants in the refrigeration industry to overcome ozone depletion and global warming problems. Therefore, current research emphasizes frictional pressure drop during flow boiling of environment-friendly (GWP<150), isobutane, HFC-152a, HFO-1234yf were tested against commonly reported HFC-134a. The data presented here was collected ...

Magnetohydrodynamic(MHD) peristaltic flow of a Couple Stress Fluid through a permeable channel is examined in this investigation. The flow analysis is performed in the presence of an External Magnetic Field. Long wavelength and low Reynolds number approach is implemented. Mathematical expressions of axial velocity, pressure gradient and volume flow rate are obtained. Pressure rise, frictional f...

electrospinning is a method of nanofiber filter media production. by this method, it is possibleto produce media with nanofiber in the range of nanometer to micrometer. nanofibrous media provide a large specific surface area in a finite volume thus they are suitable for filtration applications. in this study, nanofiber non-woven membranes production of nylon-6 by electrospinning method is inves...

Measurement of the pressure-flow relationships of the human respiratory tract is basic to the study of ventilatory mechanics. The relationship of respiratory air flow to the total pressure drop along the respiratory tree (alveolus to mouth) has been extensively studied and been shown to depend on lung inflation (1-3) and the type and degree of airway disease (4). Recently the total pressure dro...