Eagle Ford Shale Formation
Located approximately 10km west of Dallas, Texas, Eagle Ford is named after a Texas town in the area. It has become one of the most successful shale plays in the US, contributing to the ‘gas boom’ that has been experienced in the country. Eagle Ford is a sedimentary rock formation from the Late Cretaceous period, with three main areas of production: the northern part of the play is the ‘oil window’, with higher volumes of oil and lower pressures in the formations; the middle section is the wet gas window, and the southern section of the play contains dry gas. Permeability in the region is up to 0.13 md, with a porosity of 4% to 15%. Reservoirs are located at depths of between 1200m and 4300m.
ConocoPhillips was the first company to drill in Eagle Ford, at the Sugarkane field, with 600,000 hectares leased in 2008 to various other companies coming to the field. Contracting peaked in the second quarter of 2010, with over 350,000 hectares leased during the three-month period, with the vast majority of leases being awarded for the liquids areas in the region. The most active player since 2010 has been Chesapeake, with 322 permits awarded. Oil permits have grown year-on-year: there were 40 producing oil leases in 2009, 72 producing leases in 2010, 368 in 2011, and 1262 producing oil leases in 2012. It was Petrohawk’s first horizontal well, drilled at Eagle Ford in 2008, which exposed the true potential of shale gas production: after fracking, the well started producing at 7.6mcf/d. It is believed that the high carbonate content of the Eagle Ford shale makes it ‘brittle’, which means that fracking produces very good results.
Eagle Ford has serious implications for Pemex, as the field is extremely close to the US-Mexico border. It is expected that the shale formations in Mexico will share many similarities with the field that is already being exploited on the US side of the border: one of the most relevant facts for Pemex is that Eagle Ford produces much more oil than traditional shale plays. It will be interesting to see the method by which Pemex approaches production at its shale assets in the years to come. With the successes seen at Eagle Ford, it may simply be a case of applying the technology and the best practices used there in order to find success, in the same way that the NOC has approached deepwater exploration. However, it seems that Pemex may yet operate its shale assets in a new way: depending on the outcome of the energy reform, Pemex may look to develop its assets with deeper cooperation from the private sector. If this happens, then many of the companies operating just across the border in Texas might be very interested to participate, given the liquids-rich opportunities they have found on the US side of the border.