Re-processing and True-Amplitude and Acoustic-Impedance Inversion of the Teapot Dome 3-D Seismic Dataset
Date
2022-05-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Masters
Abstract
The reflection seismic method provides the most complete and detailed images of the subsurface and allows characterization of economically important targets like hydrocarbons and stored CO2. However, obtaining a correct and accurate seismic image requires application of an extensive and elaborate data processing and interpretation, particularly when dealing with three-dimensional (3-D) seismic data and when true-amplitude imaging and inversion is desired. This thesis presents a complete reprocessing of the 3-D Teapot Dome seismic dataset (Wyoming, USA) from raw field records to a stacked and migrated 3-D image. This dataset represents a well-known example for development and testing of innovative imaging and interpretation methods.
By visualizing the 3-D post-stack migrated seismic dataset, I performed ten seismic-to-well ties and identified the target zone between 500 ms and 1500 ms of reflection times. Within this zone, I picked detailed shapes of two horizons and interpreted major faults. In the vicinities of these horizons, potential hydrocarbon indicator was identified.
Variations of the densities and seismic velocities for different rocks are the principal physical properties revealed by seismic methods. However, post-stack imaging does not allow differentiation between velocity and density variations. This uncertainty can be constrained by deriving empirical velocity-density relations from well logs. In this thesis, I derive Gardner’s average relations between rock densities and velocities for six depth intervals and created a 3-D model of the density-velocity relations within the Teapot Dome area.
By using the 3-D seismic image and velocity-density relations, an innovative procedure for true-reflectivity and acoustic-impedance inversion is performed. Volumes of recorded reflection amplitudes and interval velocities determined from seismic data processing are combined with average reflectivity and reflectivity spectra from well logs. The resulting images give most accurate representations of seismic reflection amplitudes within the subsurface. By using such true-reflectivity and impedance images, detailed and accurate interpretation for physical properties of reservoir rocks can be performed. Several directions for enhancing the methodologies and extending the results of this thesis are also proposed.
Description
Keywords
3D Seismic refraction and reflection Processing, 3-D VISUALIZATION AND INTERPRETATION, Density-Velocity Relations, INVERSION FOR TRUE REFLECTIVITY AND ACOUSTIC IMPEDANCE, Teapot Dome oilfield Wyoming
Citation
Degree
Master of Science (M.Sc.)
Department
Geological Sciences
Program
Geology