Correlation and Implications of Results from Recent Wildcat Wells in Mid-Continent Rift in Northeastern Kansas: ABSTRACT

Abstract

Three recent wildcat wells, the Texaco 1 Poersch (Sec. 31, T5S, R5E), the Producers Engineering et al 1 Finn (Sec. 4, T4S, R7E), and 1 Freiderich (Sec. 8, T7S, R5E), respectively, penetrated 8,455, 1,848, and 1,781 ft of Precambrian rocks in the Mid-Continent rift system (MRS) in Kansas. The Producers Engineering et al 1 Finn, which is 18 mi northeast of the Texaco 1 Poersch, encountered mostly arkosic sandstones and shales. The Producers Engineering et al 1 Freiderich, 7 mi south of the Texaco 1 Poersch, penetrated mafic igneous and volcanic clastic rocks. In contrast, the Poersch well drilled approximately 90% mafic igneous rocks and 10% arkosic sandstones in the upper 4,584 ft of the Precambrian section. In the lower 3,871 ft of the well, the proportions of these rock-types were reversed. No Precambrian petroleum source rocks were found in the Poersch and Freiderich wells, but 300 ft of gray siltstone (approximately 0.5% TOC) were encountered directly below the Precambrian unconformity in the Finn well. The Finn well also has significantly more red siltstones than the Poersch well, thereby possibly indicating more distal lacustrine or low-energy marine environments of deposition. Alluvial fans and playas are probably responsible for most of more » the sedimentary deposition in the Poersch well. Geophysical and well data indicate the MRS in northeastern Kansas is divided into small subbasins that probably are only a few tens of square miles in areal extent. Abrupt facies changes and complicated structure make lithostratigraphic correlations difficult. « less