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...

introduction air pollution as one of the most important technological risks of contemporary era is mainly resulted from the emergence of large cities and fast growing industries. one of the main objectives of climatic and environmental studies is to survey atmospheric pollutions. tabriz is one of the metropolises where air pollution is a problem in it. of course, what is essential regarding the...

this paper criticizes the model and the new definition for osmotic pressure given by parsafar et al. [j. sci. i. r. iran, vol. 10, no. 4, 233 (1999)]. the model is a closed system containing 1 kg of solvent plus m mole of solute at constant temperature and under pressure p0 + ? where p0 is the standard pressure and ? is the osmotic pressure of the corresponding m molal solution. while the total...

open-celled foams are capable to allow the passage of fluids through their structure, because of interconnections between the open cells or bubbles and therefore these structures can be used as a membrane and filter. in thiswork, we have studied the production of polystyrene open-celled microcellular foam by using co2 as blowing agent. to achieve such structures, it is necessary to control the ...

the excess accumulation of water in lung interstitial or alveolar is called pulmonary edema which is caused by factors that upset the normal starling balance in micro-circulation. pulmonary edema disturbs the alveolar gas exchanges which are normally regulated by the respiratory system. mathematical modelling of pulmonary edema may help to predict the lung conditions and the mechanisms involved...

Computational Fluid Dynamics (CFD) simulations of gas-solid flow through a positive low-pressure pneumatic conveyor were performed using Eulerian-Eulerian framework. Pressure drop in pneumatic conveying pipelines, creation and destruction of plugs along the horizontal and vertical pipes, effect of 90° elbows and U-bends on cross-section concentrations, and rope formation and dispersion were...

a synthesis of well logs was carried out and drilling mud weight data were analyzed to figure outanomalous high fluid pressure within the triassic evaporitic cap rock (the dashtak formation) andstudy its impact on the geometry of anticlinal traps in the gas rich gavbandi province located in thesoutheast part of the zagros mountains. the results indicated that the location of anticlinal traps at...