KING, CHARLES R., Associated Petroleum Consultants, Inc., Wichita, KA

ABSTRACT: Simpson Opportunities in the North Mid-Continent

Many production opportunities in Simpson sand (Middle Ordovician) still exist today in South Kansas, North Oklahoma, Colorado and Nebraska. Simpson tests are relatively sparse because of difficulty drilling (400' to 500' of hard Mississippi lime) in earlier days and undependability of seismic surveys more recently.

Many oil fields with recoveries exceeding 3,000,000 barrels have been discovered at depths less than 6000'.

The sand was deposited over most of Kansas by seas advancing northward fromwhat is now the Anadarko Basin. The great thickness of the Oklahoma Simpson diminishes to a pre-Chattanooga (Woodford) pinchout in the North Mid-Continent. This wedge edge is responsible, along with many pre-Pennsylvanian age structures, for excellent Simpson sand reserves.

Detailed isopachous, lithofacies and structural studies will result in significant Simpson discoveries. These studies are easier to accomplish today because of more geological control (open hole logs, cores and good sample descriptions) in the study area.

The Salina and Forest City Basins in Northeast Kansas, Southeast Nebraska and parts of Iowa and Missouri have Simpson production, but the potential isbarely "scratched."

The wedge edge from the Ozark Dome (Chautauqua arch area) westward across the Pratt anticline and into the Hugoton embayment produces Simpson oil inlarge quantities, but many favorable areas remain to be tested--talk about opportunity! The area has the added serendipity feature of four or more possible pays above the Simpson.

Presented structure, isopachous, lithofacies and production maps substantiate the belief that much Simpson oil is yet to be found at economic costs.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.