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Sunday, December 13, 2015

Black Oil vs Compositional Modeling

We often hear the Reservoir Engineers talking about Black-Oil model and Compositional Model. What are these? How do they compare? 

All these are different fluid model or the part of numerical simulation model that handles how the fluids, that is, oil, water, gas and any other substances would behave at different pressure and temperature.

Black Oil model is relatively simpler model with only three fluids - oil, water and gas. 

An extended version of Black-Oil model, called Extended Black Oil model takes are of volatile oil in gas and dissolved gas in oil.

A Compositional Model  on the other, tracks any number of components the fluid might actually has - like different hydrocarbons (C1, C2, C3, C4. C5, C6, C7,... etc), H2S, CO2, Water etc. These models are complex and takes lot more computing time than Black-Oil models.  

Brain Deposit !!

In the recent visit to the USA while addressing a large crowd of the Indian diaspora of the Silicon Valley, Indian Prime Minister Sri Narendra Modi mentioned an interesting term - "Brain Deposit". For him, the flow of talents from India to other countries is not "Brain Drain", rather "Brain Deposit", that he hopes that one day will return to "Mother India" with interest, i.e. with enhanced expertise. That`s what he calls "Brain Gain With Interest". According to him, that day is perhaps now or in the very near future.

Does it apply only to the IT sector or to our Oil&Gas sector as well? The Indian E&P companies including Oil India and ONGCL have experienced "Brain Drain" for quite a long time. These companies groomed talents in various fields like geosciences, reservoir engineering, production engineering, drilling etc from the very nascent stage. They hire fresh graduates, often with degrees with no direct relevance to the industry and spends time, money and man-hours to train them. After working and gaining experience for few years, many of them leave the company and the country in search of better opportunities. The time, money and man-hours spent apparently goes down the drain. The expertise and skills imparted by the Indian companies are utilized later by the foreign companies. Are these "Brain Drain"  or "Deposit" ?  

Tuesday, June 2, 2015

Volumetric Method of Reserves Estimation

The volumetric method of reservoir is a very simple and yet elegant mathematical tool that gives a fairly accurate idea about the volume of hydrocarbons in the reservoir. Its accuracy depends upon a correct estimation of certain physical properties of the reservoir viz. Porosity , Reservoir thickness .

In the simplest mathematical terms , the volume is determined as 

Where , V is the volume of the hydrocarbon in reservoir
              A is the area over which the reservoir is spread
              h is the thickness of the reservoir
              phi is the reservoir porosity
              Swc is the connate water saturation
              Bo is the formation volume factor