ABSTRACT: Stratigraphic Heterogeneity from Dipmeter Logs, Ferron Sandstone, Central Utah

Jeffrey B. Hulen, M. L. Allison, Susan J. Lutz, C. A. Bengston, Marjorie A. Chan, Dennis L. Nielson

New methods for interpreting dipmeter data show great promise of revealing subtle stratigraphic heterogeneities critical in the search for and development of petroleum reservoirs. Stratigraphic statistical curvature analysis techniques (Strat-SCAT) developed by one of us (Bengston) theoretically can yield not only the facies, orientation, internal characteristics, and extent of a sedimentary body, but also the position of that body within a sedimentary sequence. Initial results of field studies of the Cretaceous Ferron Sandstone in central Utah support these contentions. For example, dip-vs.-azimuth plots (one type of Strat-SCAT) for outcropping, fluvial-channel, and distributary-mouth-bar sandstone sequences display different configurations, yet in rotary-drilled wells, sing conventional logging technology, these rocks would be virtually indistinguishable.

These field investigations represent the initial phase of a multicomponent research program sponsored jointly by the Gas Research Institute and the petroleum industry. Based on results of these studies, shallow-depth coreholes will be completed adjacent to the measured Ferron outcrops; a full suite of dipmeter and other well logs (including televiewer and microscanner as well as electrical and density logs) will be obtained for each hole. Dipmeter data then can be correlated directly with corresponding features both in core and outcrop. Basic SCAT techniques have been extremely successful for interpretation of large-scale structures. Confirmation and refinement of Strat-SCAT by means of the Ferron Sandstone study and similar investigations will furnish a powerful new tool for characte izing smaller-scale stratigraphic features in increasingly complex geologic settings.

AAPG Search and Discovery Article #91002©1990 AAPG Rocky Mountain Section Meeting, Denver, Colorado, September 16-19, 1990