Posts

Joule Thomson effect

Image
Joule - Thomson Effect . ... The  Joule - Thomson  (JT)  effect  is a thermodynamic process that occurs when a fluid expands from high pressure to low pressure at constant enthalpy (an isenthalpic process) .   The cooling occurs because work must be done to overcome the long-range attraction between the gas molecules as they move farther apart. The frequency of atomic collisions decrease as air  expands , therefore the air gets cooler . Temperature is just the average heat of a substance. As the energy needed to increase it's temperature must be supplied from somewhere, and the  gas  does not takes the energy from the surrounding system giving the effect of cooling. Most of the real gases need more work downstream at ambient temperature, due to the effects of compressibility. P   1  × V  1  < P   2  × V   2 The indicates that the internal energy decreases when the gas passes through the restriction . It ca...

Type of Conventional oil wells

Image
Exploration wells are tentative ventures that drill in new areas with the hope of discovering untouched resources.  These tend to be the highest risk wells in terms of failure versus success. Exploratory Well (Succeed) Appraisal wells are used to evaluate the characteristics of existing hydrocarbon accumulation. An oil and gas company will typically go on to drill an appraisal well once a discovery has been made. The wells, which have a higher chance of success and are more expensive than exploration wells, are used to determine the size of an oil gas field (both physically and in terms of its reserves) and its expected production rate.  Appraisal wells can offer the best risk/reward ratios when speculating on drill outcomes.  Appraisal wells Wildcat wells are projects located outside of already established oil and gas fields. Wildcat wells are usually drilled to find out if there is any oil or gas present in an unproven location. However, they can also be used to extend ...

SRP : Air balanced

Image
This is not a conventional Sucker Rod Pumping unit. This is special type of Pumping unit which is, Air balanced SRP. The air-balanced unit is a * rear mounted, class III lever system with Air Counter balance machine first built by Lufkin in early 1950’s.   (*Gear reducer and all accessories will be mounted at rear side of SRP). This machine uses the pitman to both push the walking beam up and pull the beam down to make a pumping cycle. The air-balanced unit uses an air tank fitted with an opened ended cylinder and piston to counterbalance the pumping unit. On the down stroke, air in the tank is further compressed thus storing energy in the compressed air.  Then on the up stroke the stored air energy is used to help lift part of the rod and fluid load. The piston uses piston rings to seal a pool of oil on top of the piston.  The pool of oil, in turn, seals the air from escaping from the tank and lubricates the piston/cylinder interface.    Click on icons ...

PE GATE Syllabus : Petroleum Subjects

Image
Petroleum Exploration:  Classification and description of some common rocks with special reference to clastic and nonclastic reservoir rocks.  Origin, migration and accumulation of Petroleum.  Petroleum exploration methods.  Oil and Gas Well Drilling Technology:  Well planning.  Drilling method.  Drilling rigs Rig operating systems.  Drilling fluids function and properties.  Drilling fluid maintenance equipment.  Oil & gas well cementing operations.  Drill bit types and their applications.  Drill string & Casing string  function,  operations,  selection & design.  Drilling problems, their control & remedies.  Directional drilling tools.  Directional survey.  Application of horizontal, multilateral, extended reach, slim wells.  Reservoir Engineering:  Petrophysical properties of reservoir rocks.  Coring and core analysis.  Reservoir fluid properties.  Ph...

PE gate : Aptitude

Image
Verbal Ability:   English grammar,  sentence completion,  verbal analogies,  word groups,  instructions,  critical reasoning and  verbal deduction.  Numerical Ability:   Numerical computation,  numerical estimation,  numerical reasoning and data interpretation    Click on icons to follow Us.

PE GATE Syllabus : Mathemaics

Image
Mathematics Petroleum Engineering GATE syllabus Linear Algebra:  Matrix algebra,  Systems of linear equations,  Eigen values and eigenvectors.  Calculus:  Functions of single variable,  Limit, continuity and differentiability,  Taylor series,  Mean value theorems,  Evaluation of definite and improper integrals,  Partial derivatives,  Total derivative,  Maxima and minima,  Gradient, Divergence and Curl,  Vector identities,  Directional derivatives,  Line, Surface and Volume integrals,  Stokes, Gauss and Green’stheorems.  Differential equations:  First order equations (linear and nonlinear),  Higher order linear differential equations with constant coefficients,  Cauchy’s and Euler’s equations,  Initial and boundary value problems,  Laplace transforms,  Solutions of one dimensional heat and wave equations and Laplace equation.  Complex variables:  Complex numbe...

Graph explaination : Klickenberg Effect

Image
At infinite average or mean pressure, gas molecules will be as closer as liquid, So gases will behave like liquids at higher mean pressure. So, high mean pressure means less inverse of mean pressure (1/Pm). So, at zero inverse pressure, there should be minimum absolute permeability.amd that's callled liquid permeability. So, according to klinkenberg, it follows straight line rule and we can express it like, Gas permeability = liquid permeability *(1 + (b/Pm)) Pm is mean pressure. So, at infinity mean pressure, (zero inverse mean pressure), Gas permeability is equal to liquid permeability. Now, in lab, we can not go for infinitiy pressue (zero inverse pressure),so we obtain data which are possible (shown in continuous line in graph) and as we know it is straight line, we extrapolate it to zero inverse of mean pressure. (Intercept of line). And get liquid or Absolute  Permeability of that rock. For low molecular weight gases, it will be easier to slip through pores that's why the...