Fracture intensity attribute for the Tensleep reservoir at Teapot Dome, Wyoming, USA

Abstract

The Tensleep oil reservoir at Teapot Dome, Wyoming, USA, is a naturally fractured tight sandstone reservoir that has been considered for carbon dioxide enhanced oil recovery ([Formula: see text]-EOR) and sequestration. Interpretation of open fractures identified in wireline image logs from the field suggests that the reservoir fracture network is dominated by early formed structural hinge-oblique fractures with interconnectivity enhanced by hinge-parallel and hinge-perpendicular fracture sets. Previous studies show that 3D seismic scale discontinuity attributes are dominated by more recent hinge-parallel and strike slip trends. The most negative curvature attribute that we used highlights concave features attributed to subtle traveltime delay through fracture zones and small faults or flexures associated with the fracture swarms. The poststack discontinuity extraction workflow incorporated seismic spectral blueing (SSB) to enhance the resolution of the seismic data. The SSB process is followed by computation of the short-wavelength most negative curvature. Subsequently, the minimum similarity attribute is applied to accentuate regions with minimum similarity of curvature. An edge-illumination process is then applied to the minimum similarity of the most negative curvature output. Discontinuities extracted through edge illumination locate regions of minimal similarity in curvature along fracture zones or small fault boundaries. This workflow enhances hinge-oblique discontinuities without azimuthal filtering and provides a fracture intensity attribute, which is used as an input to distribute the fracture intensity through the model discrete fracture network. Qualitative correlation of production data to extracted discontinuities suggests that wells located on hinge-oblique discontinuities are more productive than other wells in the field.

Structures Controlling Hydrocarbon Migration and Retention: Effective Seismic DHI

“…Here we take care about it, once this inclusion can be critical for secondary migration, as the development of complex heterogeneous fractures occurs within the Tensleep eolian sandstone. To understand the relationship between hydrocarbon carrier zones and juxtaposition of faults and fractures, Ghahfarokhi and Wilson (2015) mention that in Teapot Dome exists a qualitative correlation between production data and extracted discontinuities, and suggest that the wells located in the articulated oblique discontinuities are more productive than other wells in the field. Retention in such regions are enhanced, and impedance variation in traps increases.…”

“…Schneider et al (2016) carry out important studies and build Discrete Fracture Network (DFN) from seismic attributes of coherence. Ghahfarokhi and Wilson (2015) use seismic attributes of samples similarity to extract discontinuities in intensely fractured or flexural zones in the Tensleep reservoirs in the Teapot Dome.…”

Reservoir Characterization and Flow Simulation for CO 2-EOR in the Tensleep Formation Using Discrete Fracture Networks, Teapot Dome, Wyoming

“…Wireline image logs, outcrop studies, core observations, and seismic data analysis provide direct and indirect measurements of fracture properties at different scales. Observations made at these different scales must be integrated to provide a representative model of the reservoir DFN Kavousi and Wilson 2015). Fracture spacing, aperture, and length distributions can be incorporated in the reservoir model using wireline image logs, core data, and field studies .…”

“…The history matching effort is followed by evaluation of two CO2-EOR models. CO2 is injected in the B1 Tensleep Sandstone from the end of the production history (December, 2005) Observations made at these different scales must be integrated to provide a representative model of the reservoir DFN Kavousi and Wilson, 2015). Fracture spacing, aperture, and length distributions can be incorporated in the reservoir model using wireline image logs, core data, and field studies .…”

“…Fracture Model Framework: A model discrete fracture network (DFN) is generated using the fracture aperture and length distributions proposed by and a fracture intensity attribute proposed by Kavousi and Wilson (2015). used wireline image logs and statistically showed that fracture apertures are log-normally distributed with the mean log electrical aperture of -1.805 (corresponding to 0.01568mm).…”