Integrating Advanced Geochemistry into Basin Modeling: Applications for Exploration and Production Risk Analysis

Yongchun Tang and Qisheng Ma
Power, Energy and Environmental Research Center, California Institute of Technology, Covina, CA

Conventional basin modeling techniques generally attempt to predict the timing and volume of hydrocarbon generation within a basin. Due to the increasingly cost of deepwater oil production, it is extremely important also to predict fluid properties such as pour points, wax and asphaltene content, fluid viscosity and etc. In recent years, significant progresses have been made for fluid property prediction by using more complex mathematical models describing the kinetics of hydrocarbon generation (Figure 1). Integration of these kinetic models into a standard basin model allows for the prediction of key physicochemical properties of (1) the liquid phase such as gas-to-oil ratios (GORs), wax content, oil composition, API gravity, and viscosity (Figure 2); (2) the gas phase including the volume, timing, and migration pathways of gas as well as the gas composition (e.g., condensate yield, H₂S formation via TSR, CO₂ generation, etc.); and (3) the stable isotopic composition of the generated gases. The ability to predict these critical parameters "ahead of the drill" provides enormous benefit for prospect evaluation. Equally as important as the forward predictive capabilities of this tool is its application to geochemical inversion. Incorporation of geochemical field data into the kinetic model can place important constraints on the basin model, thereby significantly reducing the uncertainty associated with the model. Ultimately, the kinetic and basin models can be run interactively such that they converge on a single solution.

Figure 1. Complicated reaction network of gas generation from Kerogen. The solid lines represent the primary cracking and the dished lines represent the secondary reactions.