SEISMIC PROCESSING OF TEAPOT DOME SURVEY

Abstract

Seismic method of data acquisition is one of the most widely used geophysical techniques for delineating the subsurface and exploration purposes. Processing of seismic reflection data and imaging provides a detailed insight about the subsurface, the major formations and their structural setting. In the current study, seismic reflection method is applied to the Teapot Dome in Wyoming, USA to delineate and obtain its structural information. The Teapot Dome field is located in central Wyoming on the southwest flank of the Powder River Basin and is a doubly plunging anticline which is asymmetrical and has a curvilinear fold hinge in map view. Along the eastern limb of the teapot dome, NE-striking normal oblique faults, striking predominately perpendicular to the curvilinear fold hinge are common whereas the structure is bound on the west side by a large thrust fault zone with a series of reverse faults. With the increasing demand of both renewable and non-renewable sources of energy, the Teapot Dome, being an extensively deformed dome and serving as a structural trap, holds great potential in terms of energy. With the ongoing developments of increasing renewable technology alongside more wells and exploration activity, this current study aims to target the seismic dataset collected over the Teapot Dome and process it so as to provide an insight through the process of seismic reflection data processing. In the present study, seismic reflection methods for imaging the formations of Teapot Dome was applied. The 3D dataset of Teapot Dome made available through SEG was used, which had a group interval of 220 ft, source interval of 220 ft, sampling interval of 2 ms, data length of 3 s, along with total 345 inlines and 188 crosslines. The study area had undergone thrusting and faulting and therefore pre-stack time migrated (PSTM) processing steps were used for processing and imaging. The study identified seven formation tops A through G by observing cross sections of PSTM sections. From available documentation regarding Teapot dome from SEG, it is known iv that the proper sequence of bed exists as Lakota, Sundance, Crow Mtn., Red Peak, Tensleep, Madison, Precambrian. However, one cannot correlate these to the identified beds A to G without integrating the results from seismic to any other means of interpretation. The study also helped identify faults and folds present on the limbs of Teapot Dome. The study produced better, improved and higher resolution images of the seismic dataset as a result, as seen in the 3D interval velocity model cube or the filtered migrated image obtained after completion of processing. These 3D images are better capable for the purpose of interpretation and provide high-resolution cross-section images as well, at whichever inlinecrossline pair required.