Quantifying the potential for Jurassic oil EOR in Cooper/Eromanga Basins
Engineering Honours Degree 2009
University of Adelaide
The intentions of this study are to asses and quantify the potential of Enhanced Oil Recovery methods in the Cooper/Eromanga Basin Jurassic oil fields. A commercial screening software SelectEOR was used to identify these potential methods. A theoretical technique is considered to model a chemical flood and reservoir simulation is undertaken using Schlumberger’s ECLIPSE to model their performance. The Jurassic oil fields considered are given the general names Birkhead, Hutton and Namur according to the formation in which the oil was formed.
The properties of the three reservoirs in question were screened to reveal that chemical and gas injection processes were considered the most viable Enhanced Oil Recovery methods. Polymer and surfactant flooding techniques were seen as chemical flooding candidates. Carbon Dioxide, Nitrogen and Hydrocarbon immiscible flooding processes were also deemed applicable.
By constructing the fractional flow curves for each reservoir, it was possible to assess the potential incremental recovery on a theoretical basis of injection of a chemical slug in comparison to a waterflood. The increase in displacement efficiency obtained by this method was 7.3%, 1.3% and 3.4% for the Birkhead, Hutton and Namur reservoirs respectively.
A series of 2-dimensional models were developed in ECLIPSE to simulate the aforementioned Enhanced Oil Recovery methods. Polymer flooding was introduced at a concentration of 1lb/stb with the 200bbl/day injection water resulting in a displacement efficiency improvement of 0.92% for Birkhead requiring 167.1 lb of polymer per additional barrel of oil. When surfactant flooding was initiated at a concentration of 0.8lb/bbl, the Hutton reservoir resulted in 23.6% improvement in displacement requiring 6.74 lb of surfactant per additional barrel of oil. Immiscible Carbon Dioxide flooding exhibited a 10.8% improvement in recovery when preceded by a waterflood.
Consequently it was hypothesised that there is potential for Enhanced Oil Recovery in the Cooper/Eromanga Basin Jurassic oil reservoirs, however, more detailed study must be done to assess the viability on a more realistic scale.