Stratigraphic prediction based on limited subsurface data

Sedbase was developed to help you make geologically sound decisions about depositional architecture when working with limited subsurface data.

Misinterpretation of depositional architecture and excessive reliance on automated algorithms can impact modeling decisions and jeopardize project success.

The limited subsurface data problem

Predicting fluid flow in the subsurface relies on accurate estimates of the distribution of rock properties.

This task is challenging because:

• Wells sample only a tiny fraction of the full 3D volume on of an interval.

• Flow units and important heterogeneities often fall below seismic resolution.

• Facies sample density from wells is often insufficient for robust geostatistical modeling

• Inter-well areas may contain unexpected rock properties, including such as low-permeability barriers and baffles, that may not have been sampled by available data

  

Rather than relying solely on geostatistical methods to assign properties between wells, addressing these challenges often requires geoscience-driven solutions grounded in a sound understanding of the underlying depositional environments.

A required geological solution

One of the most effective strategies for stratigraphic prediction in data-limited settings is to relate rock properties to the environments in which they were deposited.

This process involves interpreting depositional environments from available data and predicting stratigraphy in inter-well areas through a combination of data analysis, application of depositional models, use of analogues, and calibration with dimensional and geometric constraints.

Working with sparse data means identifying valid depositional scenarios that not only honor well control, but also provide geologically reasonable predictions in the inter-well areas.

To effectively address subsurface predictions in data-limited settings, it is essential to:

Accurately interpret depositional environments at well locations while capturing a reasonable degree of interpretation uncertainty.

Develop sound depositional conceptual models that explain well observations and provide a framework for possible solutions for areas between wells.

Translate geological concepts into static geocellular model design choices, informing decisions about deterministic and stochastic parts of models.

Focus your decisions on the practical subsurface problems at hand and the stratigraphic architectures that most influence fluid flow.

Great economic impact

It is important to note that environmental prediction for areas between wells is not a trivial task and should be guided by appropriate depositional concepts, suitable analogues, and well-reasoned assumptions about the likely spatial dimensions of the identified units.

Decisions made during early facies interpretation and depositional architecture prediction propagate through later static and dynamic modeling, economic forecasting, and ultimately influence the success or failure of projects.

Sedbase offers a range of tools and databases to help you making such geology-driven decisions.