In this project a consortium consisting of the U. S. Department of Energy, universities and industry partners will develop a comprehensive model for fractured carbonate reservoirs based on the "data cube" concept using the Michigan Basin as a prototype. This 3-year project will combine traditional historical data with 2D and 3D seismic data as well as data from modern logging tools in a novel way to produce a new methodology for characterizing fractured reservoirs in carbonate rocks.
Advanced visualization software will be used to fuse the data and to image it on a variety of scales, ranging from basin-scale to well-scales. Several new logging tools will be used in this study: (1) formation scanner logs will be used to delineate and quantify the fracture systems, and, (2) hydrocarbon logs, which are similar to traditional well logs except they are obtained by measuring hydrocarbon contents from fluid inclusions cuttings and core samples, will be used to identify and map diagenetic patterns. In addition to the logging tools, traditional geologic and engineering data will be used to define and interpret the reservoirs. These include: formation tops and reported hydrocarbon shows obtained from driller’s reports, scout tickets, well logs and seismic data. Engineering data will include porosity, permeability, drill stem tests, initial production, API gravity and cumulative production histories.
Carbonate rocks have been selected for this study because in many basins worldwide, fractured carbonate zones form important oil and gas reservoirs. Termed "dolomite chimneys", in the Michigan Basin, they have long been among the most prolific producers of hydrocarbons in the world. However, key aspects of their origin(s), distribution and architecture have been enigmatic. They have been difficult to find and once found, many have proven difficult to produce efficiently. The Michigan Basin is well suited to serve as a model for fractured reservoirs. It is a mature basin that contains almost 50,000 gas and oil wells with extensive data and rock samples. Over 150 million barrels oil has been produced from fractured carbonate reservoirs in Michigan and adjacent states. The Dundee Formation alone has produced over 350 million barrels, approximately 40-50 million from fractured, dolomitized reservoirs. It has been estimated that nearly this amount of hydrocarbons remains to be recovered.
The data collected and the data cube itself will be on the Internet in digital form together with the software packages required to display and manipulate the data. The software will permit visualization and interpretation on both large and small scales. The data cube for the Michigan Basin will include:
Detailed case histories and tutorials will be provided. Sponsoring organizations include: Marathon Oil Company, Chartwell Properties, L.. L. C., Advanced Hydrocarbon Stratigraphy, Newstar Energy, Dart Energy and Western Atlas Wireline Services.