GEOLOGICAL PROBLEM SOLVING USING INTEGRATED BIOSTRATIGRAPHY: EXAMPLES FROM INDUSTRY QUANTITATIVE CHARTS, AN ESSENTIAL TOOL

Biostratigraphy is the element of stratigraphy that deals with the distribution of fossils in the stratigraphic record and the organization of strata into units on the basis of the contained fossils. It is one of very few methods available for precise, real-time age dating of sediments, paleoenvironmental interpretation and regional correlation.

Pioneered by the oil industry, marine and non-marine microfossils have been continuously developed as precise tools for dating Paleozoic through Cenozoic sediments, from onshore to the deep sea. Biostratigraphy in the oil industry relies heavily on extinction events (“tops”) of select species called “index fossils” or “markers” to determine age. While this is an invaluable application, modern capabilities are extensive owing to increased computing capability and specialized software programs. Supplemental to age determination, biostratigraphy can aid in understanding and interpreting sediment source, depositional environments and reservoir extent. With sufficient data, biostratigraphy can help identify subtleties in accompanying datasets that may go unnoticed as well as identify and anticipate geohazards. Ultimately, it can aid in target characterization and increase drilling precision and success.

Our standard methodology is to chart biostratigraphic data to display various components of each microfossil group examined, including total abundance of observed microfossil groups, abundances of select marker species and abundances of species groups with particular environmental affinities. In addition to biological data, electric logs, bathymetry and pore pressure measurements are included if the data are available. In some cases, traditional biostratigraphic methods and applications can be rendered ineffective by complicated geology, but biostratigraphy is a dynamic tool that, regardless, can be developed and tailored for powerful application.

Ultimately, biostratigraphy, like any geologic discipline, is stronger when integrated with data sets of complementary disciplines. Building a comprehensive geologic picture by incorporating micropaleontology is the best way to understand your objective and achieve success.