Integrated Characterization and Simulation of the Fractured Tensleep Reservoir at Teapot Dome for CO2 Injection Design

Abstract

This paper describes a workflow that fully utilizes the post-stack seismic attributes to derive reliable geologic and fracture models that are validated with multiple blind wells and reservoir simulation. The first step in the workflow is to run post-stack seismic processes, which includes volumetric curvature, post-stack inversion and spectral imaging. The second step consists of using the various post-stack seismic attributes to derive 3D geologic and fracture models. The third step is to use the derived models in a reservoir simulator to verify the validity of the models.This workflow was applied to the Tensleep reservoir at Teapot Dome in Wyoming. A large number of post-stack seismic attributes were generated in time and then depth converted within a 3D geocellular grid. These seismic attributes were used as input in REFRACT TM , Prism Seismic fracture modeling software, to create geologic and fracture models. An effective permeability was estimated by using a linear combination of the scaled fracture density and the matrix permeability. Two reservoirs unknowns were estimated by history matching in a black oil simulator: the strength of the aquifer and the scaling factor used to convert fracture density to fracture permeability. Water cut was matched at all the wells, confirming the reliability and accuracy of the derived geologic and fracture models and the usefulness of the workflow. With the derived dynamic model, a compositional simulator was used to test various CO 2 injection rates and their effects on the breakthrough time.

Dual‐Porosity Flow Diagnostics for Spontaneous Imbibition in Naturally Fractured Reservoirs

“…The Pennsylvanian Tensleep formation forms the main reservoir. The formation consists of aeolian sands, interbedded with sabkha and marine dolomites (Ouenes et al., 2010). The Teapot Dome is considered to be predominantly a Type II fractured reservoir according to Nelson ’ s classification (Nelson, 2001), meaning that the reservoir is a dual‐porosity system where fractures provide the essential permeability and the matrix only contributes to flow.…”

The effect of natural fractures on CO2storage performance and oil recovery from CO2and WAG injection in an Appalachian basin reservoir

“…In the single equivalent continuum model, the fracture properties are incorporated through changing the porous media (i.e., matrix) permeability 103–105 . The single continuum modeling approach has been used to evaluate CO 2 ‐EOR and storage in fractured reservoirs 106 . Simulation of fractured reservoirs using dual continuum (e.g., the dual‐porosity, dual‐permeability) approach involves discretization of the solution domain into two continua, called the matrix and the fracture 107,108 .…”

Developing a model discrete fracture network, drilling, and enhanced oil recovery strategy in an unconventional naturally fractured reservoir using integrated field, image log, and three-dimensional seismic data

“…Smith (2008) used ant tracking (Pedersen et al, 2002) to control the distribution of fracture intensity in her model. Ouenes et al (2010) employed a continuous fracture modeling approach that used lithology, structure, proximity to faults, and other geologic factors to control the location and intensity of fracturing. They used a neural network approach to model fracture trends throughout the field.…”