Concepts.for.GATE

Important Forces before starting: Reference : Internet Reynolds number  : Ratio of inertial forces to viscous forces. (dimensionless) Reynold number = (density)*(velocity)*(Diameter)/(Dynamic viscosity) The ratio ν = µ/ρ is termed the kinematic viscosity. Reynold number is used to categorize the fluids systems in which the effect of viscosity is important in controlling the velocities or the flow pattern of a fluid. Flow  in a pipe is  laminar  if the  Reynolds Number  (based on diameter of the pipe) is less than 2100 and is turbulent if it is greater than 4000.  Transitional  Flow  prevails between these two limits. Ca pillary number : Ratio of viscous force to interfacial force . It is used while flooding or EOR. More the capillary number, higher the oil recovery.   Capillary number = (Dynamic viscosity)*(Velocity)/(interfacial tension) For a flowing liquid, if  N C  >>1, then viscous forces dominate over interfacial forces; however  if  N C  <<1, then viscous forces ar

For  part one of separation principles click here . For  part two of separation principles click here .  For  part three of separation principles click here. Next thing is, something related to electricity. Yes, we can use electricity to separate fluids, because different fluids have different different electrical properties. So, based upon their electric behaviour, we can use electricity for separation of fluids. First property which differs is, electric conductivity. We all know that formation water which come along with oil is brine water, and brine is conductive to electricity. And crude oil is not that much conductive in nature, and gas is very very poor in conductivity. So, Conductivity vice, Gas<oil<brine and pure. (Gas has very less amount of free ions). brine water (we all know after great ranchhod das of 3 idiot). So, if we apply current to mixture of fluid, then it will pass through water. (Current will find least resistant path to flow, because he is lazy). So, what

(this post will be always under construction, things will be added) Look at previous year PE GATE papers, you will find one quetion per year, which is directly based on comparison. So it is better, we compare things while study.  This is sum of some lf comparisons for revision. (** ##<##<## means in increasing order and  ##>##>## means in decreasing order) Conductivity vice, Gas<oil<brine (Resistivity wise is opposite of conductivity wise ) Depth of penetration (of acid) wise, Acid fracturing > Matrix acidization > Acid wash . For separators, for GOR wise, Spherical Separators< Vertical Separators< Horizontal Separators for Surge capacity  wise, Spherical Separators<Horizontal  Separators< Vertical  Separators Cost wise, Spherical Separators<Horizontal  Separators< Vertical  Separators liquid level criticality, Spherical Separators>Horizontal  Separators> Vertical  Separators Space wise, Spherical Separators<Horizontal  Separators<

Porous Formation A Formation can be damaged mainly while one of following activities (ordered in timely manner). 1) During Drilling and Completions 2) During and after production and workover operations 3) During Injection  Formation Damage Mechanisms: 2) During  and after production and workover operations. (This is part 2 of this topic, for part one of this topic click here .) This kind of formation damage is divided into following types. 1) Due to increase in relative permeability of fluid other than desired fluid. 2) Due to viscosity increase 3) Due to precipitations. 3) Formation Damage Due to precipitations: Main precipitation problems on field during production: 1) Inorganic scales, 2)  Precipitation related to acidizing In stimulation jobs ( Sludge formation) , 3)  Paraffin 4)  Asphaltene We have aqueous formation water is already present inside reservoir rock pores along with oil, and during Workover or other activities, when other fluid enter into formation, which is not comp