Cross-Correlating Seismic Attributes With Cumulative Production from Horizontal Wells in the Middle Bakken Unconventional Reservoir

Abstract

The Middle Bakken reservoir is considered an unconventional play because the reservoir is relatively thin and tight. The reservoir also depends on hydraulic fracturing in laterally drilled wells to free commercial quantities of oil. The available 3-D seismic in the study area shows the reservoir to be seismically thin (i.e. below seismic resolution at the frequencies recorded). Additionally, the complex fracture network created by hydraulic fracturing contributing to the oil production cannot be measured by the existing 3-D seismic data that was acquired before the drilling and hydraulic fracturing took place. Analysis in one 3-D seismic survey in the North Dakota Middle Bakken play recognized 16 seismic attributes from 99 extracted that showed some degree of correlation with cumulative productions from 19 Middle Bakken H1 lateral wells within the seismic survey area. After statistical variable selection methods were employed, only one seismic attribute (relative acoustic impedance) was found to have statistical significance to productivity. Identical analyses were employed using available geologic attributes to correlate to IP90, as well as correlating IP90 to a combination of seismic and geologic attributes. This paper presents a seismic attribute based statistical methodology that has been used for productivity analysis, without the necessity of precisely knowing the mechanism, in the Hawkeye / Blue Buttes field area in the Middle Bakken reservoir in North Dakota. Examples of productivity analyses will be shown using seismic attributes and seismic attributes plus regional geology attributes.