Time Series Analysis and EROI of Shale Oil from the Bakken Formation

Abstract

The Bakken Formation has generated substantial attention due to an unprecedented surge in domestic oil production. The sheer size of the formation coupled with technological advances in the way of horizontal drilling and hydraulic fracturing have led some; most notably the former head of BP, the Wall Street Journal, and NY Times to speculate that domestic shale oil production will free the US from its dependence upon foreign oil entirely. Shale oil from the Bakken will provide a significant contribution to our domestic energy portfolio, but real problems to increased production exist in the form of physical limitations. Preliminary analysis indicates some of the largest fields are depleting rapidly. The decline is apparent in the Mountrail County’s two largest producing fields, hinting to evidence that much of production occurs in concentrated areas (i.e. sweet spots) and many of these fields with high profitability are undergoing rapid production declines. In order to maintain a consistent level of production and offset these growing declines, an increasing number of wells must be drilled throughout the lifetime of a field. Energy Return on Investment (EROI) is the ratio of energy outputs over energy inputs and is a useful metric for determining relations between, profits, price, disposable income and quality of life. Preliminary EROI analysis indicates that newly developed fields in the Bakken are less energetically profitable than their larger conventional predecessors as they yield far less energy per well.