The last phase of the project is the final integration of all the previously described inputs and calibrated 1-D models with the depositional and history heat flow of the basin.  The result is the final petroleum system interpretation and includes a description of identified organofacies, present day maturity of source rocks, likely migration pathways and relationship of hydrocarbon accumulations to source kitchens, and a discussion of PVT conditions and expected hydrocarbon phases (See Figure 4 for example migration map).  Additionally, an estimate of volume of hydrocarbon generated and expelled can also be provided, as well as a high-level ranking of identified opportunities. 

How is the basin model different than just gridded maps of data sets as described above?  Measured properties describe the present-day condition of the sample but does not describe the history that resulted in that outcome.  If we rely on present day maturity measurements, our assumptions about fluid properties and things such as kerogen conversion may be inaccurate.  A case in point is the modern resource play in the Bakken Formation of the Williston Basin.  Direct maturity estimates indicate that the source rock is immature, causing many investors to look elsewhere in the early days of resource plays.  Petroleum System modelling that can account for varied kerogen types, depositional history and the potential for charge focus confirm what is known today through decades of production: the Bakken source rock generated significant hydrocarbons and is clearly not immature.  A calibrated petroleum system model confirms this and highlights the best places to operate in the basin.  Properties that are affected by change over time, such as maturity, overpressure, fetch, and erosion are best captured through petroleum system modeling.

A key aspect of petroleum system modeling is understanding the heat flow history of the source rocks in the basin of interest.  When there is limited calibration data available, as is the case in many exploration projects, GeoMark believes in “bottoms up” temperature modelling, starting at the base of the lithosphere and initial formation of the basement, followed by an understanding of the depositional history up to present day, including key geologic events related to erosion, uplift, and thermal anomalies.     Fortunately, in many of the most prolific basins, there is ample calibration data and more of a “top down” approach to temperature and pressure modeling can be applied.  Integrating available PVT and fluid phase data when available is critical to understanding and predicting fluid at reservoir conditions.

Based on previous experience, it’s important to note that the best petroleum system models come from integrating of the modeling team with the subsurface interpretation team.  GeoMark excels in open communication with to ensure that all available data and ranges are best captured  in the model and that the end-user fully understands the model content and results.  Prior to the final report and project conclusion, GeoMark will submit a draft review that should allow for additional feedback and improvement.  The final report should not only address the project goals of completing a geochemical evaluation of the petroleum system but also provide the project team with confidence in its understanding of how to use the report to develop and pursue petroleum opportunities in the region.  The most successful project will be a living project that the can referenced and expanded for years to come.