11 December, 2013

Mississippian Carbonates in Kansas: Integrating Log, Core & Seismic


The entire Middle Pennsylvanian–to–top Precambrian basement (500 m) interval was cored in early 2011 in the BEREXCO Wellington KGS #1-32 well in Wellington Field, Sumner County, KS.

The entire Middle Pennsylvanian–to–top Precambrian basement (500 m) interval was cored in early 2011 in the BEREXCO Wellington KGS #1-32 well in Wellington Field, Sumner County, KS. An exhaustive set of modern logs and routine and special core analyses on this well are being used to characterize the Mississippian tripolite oil reservoir in the field and the underlying Cambro-Ordovician Arbuckle saline aquifer as part of a regional 25,000 mi2 assessment for carbon storage potential under DOE-NETL contract (FE0002056).

Over 2.4 TCF gas and 278 MMBO have been produced in south-central Kansas from Mississippian reservoirs including 20 MMBO at Wellington Field. Reservoir strata consists of weathered and permeable chert-rich lithofacies that is referred to as tripolite. This lithofacies range from distinctly brecciated with abundant spiculitic and skeletal moldic pores and vugs to more dolomitized with intercrystalline porosity. The petrophysical properties of the brecciated chert are negatively impacted by increasing amounts of shale (Φ = 20-50%, k = 5-500 md, Sw 35-70%, BVW = 0.06-0.10). Vertically stacked tripolites reflect upward-shallowing, unconformity-bounded cycles consisting of argillaceous mudstone, dolo-siltites, and increasingly sponge-rich, skeletal wacke–packstones. Cycle tops are overlain by glauconitic, skeletal encrinites. Rock properties change systematically upward through each cycle reflecting variations in moldic and vug pores, pore size, and connectedness, Permeability was enhanced by meteoric diagenesis as recorded by an overlying subaerial-exposure surface.

Mississippian cycles appear to be deeper water equivalents at Wellington Field consisting of siliceous, often cherty dolomites that range from dark argillaceous dolo-siltites to lighter, cleaner, porous packstone lithofacies. Multicomponent 3D seismic (depth migrated and shear wave) interpretations are being incorporated with an extensive formation evaluation and reservoir characterization program and used to build an integrated 3D geocellular geomodel to evaluate suitability for CO2-EOR in Missississippian strata and CO2 sequestration in the underlying Arbuckle saline aquifer at Wellington Field.

Topics covered include:

  • Background to “Mississippi Lime” play in southern Kansas
  • Summarize near surface and subsurface geology or region
  • Stratigraphy and lithofacies
  • Reservoir rock, distribution, controls
  • Tripolite and siliceous dolo-siltite Ø
  • Key petrophysical observations
  • Introduction to the Wellington Field test site
  • Summary

Structure of the E-Symposium

Each e-symposium consists of one-hour live e-symposium, along with material for one full day of independent study. The live portion will be followed by a full day of independent study (not a live event). The one-hour live e-symposium can be accessed from any computer anywhere in the world using a high-speed internet connection. After the event is over, you will receive via email information about accessing the asynchronous segment (not live) which consists of your independent study materials, to be accessed and studied at any time. You will be able to email responses to the readings, along with your study question answers for CEU credit (if you sign up for the extended package).