Gulf of Mexico
About the basin
There are very few places on Earth where you can find reservoirs that rival the structural complexity that you find in the Gulf of Mexico. The basin itself is an oceanic rift basin, which began formation soon after the initiation of the breakup of Pangea in the late Triassic. Throughout the Middle Jurassic, the basin saw intermittent seawater influx, which would in turn evaporate leaving the massive Louann Salt.
Later Mesozoic sediments included a combination of both fluvial and marine clastics as well as carbonate reef successions; though most carbonates were snuffed out by the Middle Cretaceous due to shelf deepening and an influx in clastic deposition.
Throughout the Cenozoic, the Gulf of Mexico accommodated huge volumes of clastic sediments, which added a good 30-35 thousand feet of sediment in areas. Increasing sediment load atop the Louann Salt caused the salt to begin migrating both vertically and laterally, forming an extensive network of diapiers, salt welds, stratigraphic pinch outs, salt tongues, growth faults, shear zones, etc. While this provides a plethora of hydrocarbon trap opportunities in the basin, it also provides a challenge in properly characterizing said traps (especially in 3D!)
Projects
Integrated Rock and Fluid Workflow to Optimize Geomodeling and History Matching (2021)
This is an ongoing project involving the integration of insights from Geology and Reservoir Fluid Geodynamics (RFG). RFG in its most general sense is the study of the evolution of reservoir fluids over geologic time. These studies can place additional interpretive constraints on a reservoir and its behavior- for instance, it can indicate connectivity/compartmentalization, gas/oil ratio gradients, and even the relative timing of fault block migration and other tectonic events. For a full discussion of this topic, see Oliver C. Mullins’s textbook on the subject, available for free here.
I joined the project team for an RFG study on the Tornado Field where the challenge was to integrate RFG based constraints on a 3D geomodel. I constructed a geomodel using depth converted seismic horizons and inversion data to create the framework and initial geologic trends. These trends were then modified to incorporate RFG data, which indicated the existence of a regionally extensive shale of sub-seismic resolution existed between two reservoir sands. We then incorporated fluid properties into the model and performed a successful history match. Subsequent well data appeared consistent with the new interpretations. This project acted as the next step in carrying RFG from single well studies to a 3D framework. The project is ongoing, and has so far resulted in a conference paper and a patent application, with another paper forthcoming. For details on the RFG side of this project, see case study #3 in Oliver Mullins’s textbook, link above.
Pilot Discrete Fracture Network model for a carbon storage project (2016)
This project involved building a Discrete Fracture Network to ascertain the next steps in the development of a gas storage facility targeting a limestone reservoir. To date, the client has used a single matrix pore system for numerically simulating the behavior of the reservoir. However, image logs showed numerous vugs, partially healed fractures, and open fractures, necessitating the use of a dual permeability simulation model. My project team interpreted FMI and tied the interpretation results to seismic attributes. We then generated and QCed an artificial neural network model to invert seismic attributes into fracture driver properties, distributed a discrete fracture network using stochastic geostatistical methods, and upscaled a dual permeability property for purposes of dynamic simulation.