As a geoscientist i would like to thank you. Very simple and understandable explanation, learned alot from this lecture which does NOT include any formulas, numbers etc...
I am trying to pick up some ESP application skills. I feel more confident understanding PVT diagrams after watching your video. Thank you for posting this!
Thanks for this presentation. Still to come, wish if you kindly add your insight to the controversial "retrograde condensation" zone inside the PT two-phase envelope. How you present it to your students?
This is discussed in this video and the subsequent lecture 6. Retrograde condensation - the formation of a liquid from a gas when the pressure is dropped - is what happens in a gas condensate field. It is not controversial, but a consequence of the phase behaviour. I tend not to use the expression retrograde condensation as it usually causes confusion. I simply explain what happens for different types of hydrocarbon field.
In the Dry Gas example, How can we have the surface condition as low P and high T? Low P i can understand because no pressure but how is it possible that we have high T at the surface? Whwre is the high T coming from? Sorry, didn't get it there...
It seems that you misunderstood. The surface temperature is the same. It is just a problem with having one diagram and showing wet and dry gas conditions together. It is not high T for dry gas, but a rescaling of the temperature axis! See the second figure I show, where the reservoir and surface conditions remain fixed on the graph.
Thank you for the presentation Mr. Martin. This is so helpful content. I have a question sir, i still did not understand about the critical point term, i understand that when the reservoir pressure hits the bubble point line there is a small bubble of gas appears from the liquid. In my mind, when the reservoir pressure hits the bubble point line and the small bubble of gas appears, the liquid and the bubble of gas have different density, so that why the term of critical point is the properties of liquid and gas are similar? Whether they merge so that the properties of liquid and gas are similar? I am sorry for my bad English Sir, i hope you understand what my question. Once more, thank you for advance.
The way of thinking about this is to consider the transition from the bubble point line to the dew point line. So the bubble of the second phase is first less dense than the surrounding fluid (bubble point) and then more dense (dew point). The only way this happens is a point where the properties of the two phases are similar.
Good evening mr. Martin My name is WADERO MARTIN from Uganda a student of kyambogo University requesting for your help. We know the bubble point of natural gas is -162°C, the question is what happens to natural gas if u heat it above that value ?
This refers to the temperature and pressure at the surface - once the oil and gas is produced. Traditionally this is considered to be 1 atmosphere pressure (around 100 kPa) and a temperature of 60 degrees F (15.6 degrees Celsius).
