Classically, basin modeling is done with the intention of modeling oil and gas generation and migration for a specific existing basin of interest. Data that is available to the modeler is incorporated to create a comprehensive and holistic model, which is typically calibrated using vitrinite reflectance data. When a model is created, it follows a specific geologic history that is known. A key question here is how each geologic event in the history of a basin affects hydrocarbon generation and migration. To address this question, we would like to explore the influence of changes in the geologic history, such as the introduction of an erosion event and variations in heat flow. In order to do this we have created a synthetic basin model through which we can compare the same basin, for example, with constant heat flow and with variations in heat flow. The two models can then be compared side by side after simulation for differences to help us understand the significance of changing such a parameter in the geologic history.
Through the use of this benchmark basin model, we plan to expand on traditional analyses by exploring new ways to incorporate data that isn’t commonly used during the basin modeling process. Petroleum engineers and geophysicists collect both well log and seismic data for reservoirs of interest. In addition, information about the spatial distributions of rock properties is studied by geostatisticians. While this data typically does not cover an entire basin, it is still possible to calibrate the basin model at locations where this kind of data is available. We would like to start by creating a corresponding seismic volume to go with the basin model and compare this with a version of the model that includes spatial distributions of porosity for the reservoir layers of interest.
For this project, we have created a synthetic, or “benchmark,” basin model based on realistic geology. The model is a rectangle and has been simulated with a base set of parameters. The model is roughly 180 by 100 km in size, with a grid spacing of 500 x 500 x 500 m. It includes one main shale source rock, and twenty-four rock formations. Five of these formations are reservoir layers of interest. After simulation, we obtain velocity and density volumes for the model. Based on these, we can obtain a near and far stack seismic volume. The synthetic model provides us both with a base case as well as an experimental environment in which we can explore the influence of key inputs for basin modeling.
A number of topics we plan to explore include the following: using seismic to calibrate basin models, exploring the influence of spatial heterogeneities in rock properties, variations in heat flow, and the effect of having multiple source rocks.