Why and How Petro-elastic Modelling - PEM

The FMU pem workflow calculates elastic parameters based on input from reservoir simulator results, model selections and constant parameters. pem is an important step in the FMU sim2seis workflow, see sim2seis documentation.

Whilst pem can be run as an independent tool, its primary use is as part of the sim2seis workflow. This is described in a chapter below.

pem performs of the following tasks:

1. Read and validate parameter file in YAML format
2. Import reservoir simulator results
3. Estimate effective mineral properties
4. Estimate effective fluid properties for each date
5. Estimate effective pressure for each date
6. Estimate effective properties for saturated rock
7. (Optional) estimate difference properties
8. Save intermediate (optional) and final estimates

Each step is described in some detail in the links.

As a general user of FMU, how much do I need to know?

Calibration of a petro-elastic model is considered to be a specialist task, but it should be carried out in close cooperation with asset teams who has the detailed field knowledge. Without interaction with most disciplines from the asset, it is highly likely that wrong assumptions are made. The main responsibility lies with geophysics. Table 1 below shows topics that must be coordinated with other disciplines.

Topic	Discipline(s) Involved	Description
Reservoir properties	Reservoir Engineering	Input on static and dynamic reservoir properties
Mineralogy	Geology, Petrophysics	Data on mineral composition and volume fractions
Fluid properties	Petrophysics, Reservoir Engineering, Production Engineering	Details on fluid types, composition, properties, and phase behavior
Pressure and stress regime	Geomechanics, Operation Geology	Information on in-situ stresses and pressure changes
Seismic data calibration	Geophysics	Alignment of model outputs with seismic observations, wavelet selection
Well data integration	Petrophysics	Selection of well logs for model calibration
Production history	Reservoir Engineering, Production Engineering	Historical production data for model validation

Table 1: Topics that should be coordinated between disciplines during PEM calibration.