Crosswell seismic imaging in the Permian Basin, West Texas, USA

Abstract

Crosswell seismic imaging technology has advanced rapidly over the last three years as the processing methods have become more robust, the cost of data acquisition has fallen, and the interwell distances of operation have increased. The Permian Basin of west Texas, USA is proving to be an ideal environment in which to develop this technology because of the relatively low seismic attenuation of the carbonate-dominated lithology, the moderate well spacings in the large number of mature fields, and the unusually high number of reflecting horizons. Current technology permits us to operate in carbonates at well spacings on the order of 2000 ft (650 m) and to image P- and S-wave reflecting horizons on a scale of 8 to 25 ft (2.4 to 7.6 m). Crosswell technology is not limited to carbonates, although the majority of recent applications have been in this environment. We are involved in three separate crosswell experiments in the Permian Basin, each with unique objectives. The first experiment involves a CO{sub 2} pilot project in a Grayburg Formation reservoir on the eastern edge of the Central Basin Platform. Here we are attempting to characterize the reservoir at a scale unobtainable from 3-D surface seismic data and tomore » image CO{sub 2} fronts directly. The second experiment deals with a waterflood in a Middle Clearfork Formation reservoir on the Eastern Shelf, where we are trying to explain the erratic response of adjacent wells to water injection. In the third project we are trying to image the structure and stratigraphy of subtle {open_quotes}anomalies{close_quotes} in 3-D surface seismic images of the Wolfcamp Formation.« less