Our rock physics approach:

Inverse Rock Physics Modelling (IRPM)

To help our customers, we apply a range of cutting edge methods and technologies to our products and services, including forward modelling-techniques, Inverse Rock Physics Modelling (IRPM), the Rock Physics Template and our own AVO Rock Physics Template.

Key features:

  • Use fit-for-purpose rock physics models, not limited to a specific theory.
  • Honour complex, non-linear relationships between properties.
  • Capture non-uniqueness in relationship between rock properties and elastic properties.
  • Integrate uncertainties in data and model parameters.
  • Predict uncertainties in reservoir properties and model quality

Inverse Rock Physics Modelling (IRPM) is a rock physics based inversion method for predicting reservoir properties such as porosity, lithology and fluid saturation. The method was developed at University of Bergen by Prof. Johansen and Dr. Jensen, and has been published in several peer-review journals.

As inversion of seismic data to reservoir properties is a problem with non-unique solutions, IRPM provides a stochastic and probabilistic method which honors the ambiguity of the problem.

The method is highly generic, and can be used with various rock physics models e.g. representative of siliciclastic rocks or carbonates, and with various types of inputs; well log data, seismic inversion data (Bredesen et al., 2015) or even AVO data (Jensen et al., 2016).

Additionally, a priori probabilities can be defined when using a Bayesian type of inversion with IRPM that allows . At its core, IRPM is an exhaustive search in a library of forward modelled rock physics constraints which has been done before initiating the inversion process.

Because the inversion problem has non-unique solutions, we typically produce several different solution types using the ENTERTM software when performing an IRPM. Below we provide a brief overview of the most common solution types: (see next slide for all the different solutions)

Apply IRPM to a range of data types

IRPM on well log data

  • Explore the information content in the well log data
  • Feasibility for predicting porosity, lithology and fluid from seismic data
  • Sensitivity to parameter combinations and uncertainties

IRPM on seismic inversion data

  • Quantify layer properties on seismic scale –  go beyond rock physics templates
  • Analyze prediction ambiguities in the data
  • QC your seismic interpretation

IRPM on seismic AVO data

  • Quanitfy reflector properties – go beyond AVO classes and fluid factor
  • Analyze prediction ambiguities in the data
  • Make interpretations for various interfaces