ABSTRACT: Morrow Channel Case Histories Using a New Exploration Approach
Seven Morrow channel-sand, oil, and gas traps in eastern Colorado and western Kansas have been investigated using the deep induction exploration (DINEX) method. This deep sounding technique is capable of measuring the resistivity of the complete sedimentary section as a function of depth well into the basement with a high degree of accuracy. All of the oil and gas traps surveyed showed well-defined, robust, and deep-seated resistivity anomalies very closely associated with the traps. Two areas where the Morrow sands were in the log had very little to no resistivity anomalies.
The methodology for doing deep induction soundings and processing is inexpensive and rapid. A high-power transmitter and grounded-wire antenna are used to induce the received magnetic fields. The receiver system is backpackable, making data acquisition discrete and ideal in sensitive and rugged areas.
According to Archie's law, the resistivity of a porous rock varies with the volume and arrangement of the pores and even more with the conductivity and amount of contained water. During the development of an oil and gas trap, large volumes of water migrate through the trap, resulting in a number of diagenetic changes in the section associated with the trap. As a result of cementation, mineralization, and increased hydrocarbon content, the resistivity of the rocks in close proximity to the oil and gas deposits is altered.
AAPG Search and Discovery Article #90991©1993 AAPG Mid-Continent Section Meeting, Amarillo, Texas, October 10-12, 1993.