Geologic and Engineering Analyses and Evaluation of Factors Affecting Widespread Development of Devonian Shale Oil Reservoirs: Final Report.

摘要

The objective of this study was an oil resource evaluation of Devonian Shale underlying a seven county area in Ohio and West Virginia near the Ohio River and the Burning Springs Anticline. This area contains about 200 square miles in which operators have drilled through or completed 2000 wells in the Devonian Shale. In spite of the high density of wells, only about four percent of the completed wells produced an excess of the 20,000 barrels needed to break even. The median production was 800 barrels and the mean was 4600 barrels. As a part of the reservoir study, data were collected from various sources, and a computer data management system was used to aid in the analysis. Engineering techniques, including material balance, a transient method for analysis of production data, and numerical simulation were employed, together with statistical methods, to complete the evaluation. These methods are believed to be applicable to other fractured tight matrix environments. Other findings of the study showed that the coexistence of natural fractures and matrix permeability and porosity are requisites for oil production from shale. These conditions are unique particularly to the lower Huron member of the Devonian Ohio Shale in and near this seven county area, but are by no means consistent over the area as evidenced by the few commercially successful wells. Matrix permeability and porosity are necessary for oil accumulation and production, because the permeability is extremely low, fractures are necessary to transmit oil from the matrix to the wellbore. 56 figs., 16 tabs. (ERA citation 14:012624)