Application of Oil Gas-Chromatography Technique in Reservoir Continuity Studies, Zenith Peace Creek Field, Kansas

Wallace C. Dow, Suhas C. Talukdar, K. David Newell, Robert S. Sawin

The study investigates the applicability of high resolution, whole oil gas-chromatography in reservoir continuity of the Zenith pool located at the southwestern end of the Zenith Peace Creek field in central Kansas. The field is primarily a stratigraphic trap developed on a broad south-southwestward plunging anticlinal fold with a faulted eastern margin. Five separate reservoirs are known, Devonian-Mississippian Misener sandstone and Misener Limestone, Upper Ordovician Maquoketa dolomite, and two reservoirs within the Middle Ordovician Viola limestone.

A number of oil samples produced from individual reservoirs and a few commingled oils were analyzed with gas chromatography and the results were interpreted in relation to reservoir distribution and characteristics. The oils are all non-biodegraded, all except one are light oils, one is a condensate. Gas chromatographic data and detailed C₇ compositions indicate the oils were derived from a common marine Ordovician source rock and were expelled at the peak oil generation stage maturity (0.80-0.90% R₀). Detailed fingerprints of the oils shown by star plots and cluster analysis utilizing several naphthenic and aromatic peak height ratios in the carbon number C₉-C₁₉ range, show that most of the oils are very similar. This implies widespread cro s-stratigraphic reservoir continuity through fracture systems. Only one oil and one condensate produced from the Viola limestones are distinctly different. These oils occur in small isolated pools within the laterally extensive Viola limestone by porosity and permeability barriers. The conclusions drawn from the geochemical data agree with conventional engineering data on the field.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995