Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Field Demonstration of Alkaline Surfactant Polymer Floods in Mature Oil Reservoirs Brookshire Dome, Texas
Layline Petroleum 1, LLC
The University of Texas at Austin
The largest onshore oil reserves in the US are the discovered mature oilfields that have been produced by primary and secondary recovery but still contain over 65% of the original oil in place. This represents 377 billion barrels of oil that is not recoverable by traditional methods. This proposal aims to demonstrate through a field pilot implementation that the use of alkaline surfactant polymer (ASP) flooding in appropriately selected reservoirs can result in an incremental oil production of 10 to 20% of the original oil [15 to 30% of the remaining oil].
Enhanced oil recovery (EOR) methods have been tested in the laboratory and in the field for over 50 years. Recent advances in alkali/ surfactant / polymer chemistry and our understanding of their application in oil reservoirs have made it possible to apply these methods at a cost far below originally possible. It is now estimated that ASP flooding is a commercially viable technology at oil prices in the range of $30-$50 per barrel. The incremental cost of chemicals is estimated to be in the range of $10-$15 per barrel of incremental oil recovered.
The Brookshire Dome field is located 20 miles west of Houston off I-10. It represents a typical candidate reservoir for ASP flooding. Laboratory phase behavior and core flood tests conducted with field crude oil suggests that the acidic nature of the oil combined with the low salinity and modest temperatures allow us to use moderate concentrations of alkali, surfactant and polymer so that the overall cost of chemicals can be kept at about $10 per incremental barrel of oil. In addition, the well spacing in the field varies from two to five acres allowing a field demonstration pilot to be conducted in a relatively short period of time.
It is proposed here that a field demonstration pilot be conducted in a portion of the Brookshire Dome field to prove or disprove the applicability of ASP flooding in shallow mature oilfields in the US. Should this field demonstration be successful it is anticipated that similar technologies and methodologies could be applied to a large number of mature oilfields that are temporarily abandoned in the US. Assuming that oil prices remain above $40 per barrel, it is anticipated that the findings from this field demonstration pilot would allow operators across the US to test and select candidate reservoirs for ASP flooding and apply this technology to increase recovery factors in candidate reservoirs by up to 50%.