Increased drilling and improved drilling efficiency have led to significant crude oil production increases in the Eagle Ford region in southern Texas. These increases have occurred despite the region's relatively high well decline rates. However, by offsetting the natural declines through the use of new recovery techniques, further production increases are possible.
Horizontal drilling combined with an increasing number of hydraulic fracturing stages in tight formations like the Eagle Ford typically enhance initial production rates when compared to past results. These higher initial production rates are often accompanied by initially larger decline rates, before gradually leveling off to a consistent level of decline for the remaining years of the well life.
While initial production rates have steadily increased since 2009, first-year decline rates in the Eagle Ford have fluctuated between 60% and 70%. Most notably, decline rates over the second year of production have steadily increased from 30% for wells drilled in 2009 to nearly 50% for wells drilled in 2011 and 2012. Since 2013, many producers have been using significantly more proppant (sand or other material designed to keep a hydraulic fracture open) when hydraulically fracturing new wells, which appears to have increased initial production rates, but which was followed by a steeper drop in production.
Principal contributors: Richard Yan, Jozef Lieskovsky, Sam Gorgen
Tags: drilling, Eagle Ford, efficiency, liquid fuels, oil/petroleum, states, Texas