The oil industry is at the brink of the "perfect storm." Easy-to-find oil is gone. In its place are harder-to-find reservoirs that are structurally and geologically more complex and more difficult to understand. Even existing fields must be accurately characterized to extract bypassed hydrocarbons.

While data is being collected at historically fast rates, the challenge is to find software and personnel to properly analyze it or add it to a model completed years ago. The E&P industry is awash in interpretation and modeling applications that are difficult to use, poorly integrated and fall short of providing satisfactory solutions for ever-deeper and more complex reservoirs.

Add to this equation the shortage of qualified talent and the ever-decreasing time allocated to support reservoir-management decisions, and the "perfect storm" emerges.

To meet the challenge, start with the premise that ultimate integration can exist between the geosciences and reservoir engineering, based on the concept of shared-earth modeling.

The central piece is the reservoir model resulting from the integration of geophysical (interpretation and attribute), petrophysical (logs), geological (conceptual, sedimentary) and engineering (production) data. It can be used to predict reservoir behavior.

A current drawback is that constructing such a model can be too time-consuming. It often must be done by the few modeling software experts with multidisciplinary knowledge, for whom there is unfortunately no obvious training or career track either in industry or in universities. The cost of training geoscientists and engineers during the course of a project is often too large to support the effort. As a result, tools that enable anyone to construct accurate reservoir models for fast decisions are needed.

On the technical side, current state-of-the-art reservoir-modeling technology revolves around the construction of a 3-D corner-point geometry stratigraphic grid. This grid is used by geologists for geostatistical property modeling and volumetric analysis, and by reservoir engineers for flow simulation and reserve assessment. Their construction is dictated by the pillar, or extrusion, approach that works well in simple, vertically faulted, layer-cake topologies.

However, when even a small amount of structural complexity, such as multi-z, reverse or y faults, is added, currently available modeling applications create severe distortion of cells near faults. Very often the reservoir grid simply cannot be constructed.

Common solutions include simplifying or removing the offending interpreted fault data so the modeling application can be accommodated. The application can then proceed, but the resulting model is simplified, often beyond recognition.

Furthermore, deciding on which faults to remove or verticalize can be extremely time-consuming. As a result, the reservoir model no longer accurately reflects the interpreted underlying geology or the data that supports it. Fault blocks are not adequately represented, which affects the compartmentalization and connectivity of the reservoir model.

Also, geological distances and constant volume assumptions of geostatistical algorithms are violated due to the deformation of the cells as soon as faults are not sub-vertical. The correlations imposed on the facies, porosity and permeability models will be wrong. With a bad model going into the reservoir flow simulator, history-matching results can only be erroneous and non-predictive.

The large amount of money spent collecting and interpreting the data has thus been marginalized. Difficult data was ignored due to time constraints. Updating the models with new information or changes in interpretation is a long process, requiring rework by the consulting modeling expert and starting the model building again. Wonder why production forecasts are wrong?

There is a new approach. Instead of calling on an expert, any geoscientist or engineer should be able to construct models without being overwhelmed by the idiosyncrasies of the modeling software. They need to focus on the science, not the buttons. Users should be guided through mostly automated processes, focusing at each step on decisions re­quiring geological and engineering judgments.

Instead of removing or simplifying data, all available interpretation data, even when hundreds of faults are involved, should be used. Using all information available ensures confidence in the accuracy of the model and the answers extracted from it and provides better support for decision-making.

Instead of using the same grid format for both geostatistical property modeling and reservoir-flow simulation, one should be adapted for each case, honoring all available data, and also the constraints of each discipline should be used. This way, the geological grid is no longer a victim of the pillar nightmare, and geological distances are respected.

A simulation grid satisfies this discipline's requirements, yet still accounts for the total complexity of the structural geology. These two grids are intrinsically linked, ensuring an accurate upscaling of reservoir properties.

New, integrated subsurface imaging, interpretation and modeling technologies make it possible for such projects to be completed in hours. Recent benchmarks found reductions in modeling time by factors of 50 to 100 times using every piece of data available.

Such new-generation technology eliminates repetitive tasks and error-prone manual steps. Fully 3-D systems can enable fast remodeling when additional field and production data are captured, while removing distortion introduced by 2.5-D modeling technologies. Also, adaptive output capabilities can be used for both reservoir modeling and flow simulation.

With modeling so easily available to all geoscience domains, the earth model can become a true, live document that engineers and geoscientists can together share, edit, refine or derive into several alternatives. 3-D reservoir modeling must become a commodity, a foundation piece to the shared-earth model, and should be key to any reservoir management decision. It should not be the reserved playground of a select few.