Article 1: What is saturation modelling?

Date of publication: May 1^st 2018, by Matthew Meyer

Knowing the distribution of fluids within hydrocarbon producing reservoirs is of fundamental importance; without it, correctly calculating the hydrocarbon volume of a field is impossible.

Over geological time, fluids in a reservoir will stratify according to density, with oil above water and, gas overlying oil. Determining the saturation of each fluid and the nature of the transition between each fluid phase throughout the reservoir is the primary objective of saturation modelling.

The industry standard way of evaluating fluid distribution is through the construction of a saturation height function. A saturation height function is a way of visualising and predicting the distribution of fluids through a reservoir relative to the saturation percentage of water.

Many factors control the distribution of fluids within hydrocarbons reservoirs from fluid density, porosity, permeability, rock type and more; and as many different methods have also been developed to determine reservoir fluid saturation.

Saturation modelling is a complex, and sometimes daunting, subject. We've only provided a brief introduction here. Check back regularly for more resources which will shed more light on saturation modelling and the fundamentals which underpin it.