Discussing the Eagle Ford, Pearsall and Permian plays
SL - the EF and AC are pretty much one and the same as the productive zone is so thick. Many companies are now co-mingling from both on 60 acre spacing. The horizontals are often alternated between the two at different depths.
Look at p.16 of this presentation.
Attached is completion filing for the well. Not bad rates (986 BO & 899 MCF per day with 1573 BW (frac fluid) IP flowing @ 1110# pressure.
But production not great. First full month (Jan 2013) averaged 368 BOPD and Feb 2013 only 241 BOPD. Almost 35% decline from Jan to Feb.
Similar decline for the gas volume over same period.
COP has been completing a lot of their wells by drilling near the top of the EF and then fracking both the EF and the Austin Chalk.
The Edwards is a deeper target - about 750-1000' below the base of the Eagle Ford shale. Conventional reservoir with good porosity and permeabiity that is supplemented by natural fractures. Pretty dry gas (around 1000 Btu) that oftentimes contains H2S and CO2 in quantities that require gas processing on site and/or at processing plants.
Signficant formation water can be produced in some Edwards wells while the well is still economically producing gas if operator has the approprirate SWD capabilties. I know of one well (Homeyer #1 SW of Kenedy) that has produced over 1 Million BSW during its well life.
Edwards has different source than the Eagle Ford. There is probably some in situ source in the Edwards section. However, I believe that the primary source is from deeper horizons (e.g. Pearsall Shale).
I think the Edwards wells are verticals but I may be wrong. Also very little in the way of NGL's from Edwards due to dryness of the gas.
The Pearsall Shale organic members (Pearsall / Bexar and Pine Island) are probable source rocks through this entire area as are some of the interbedded carbonates. IMO at least some of the Edwards gas has migrated into the Edwards from the Pearsall section while some may be from much deeper source beds (e.g. Jurassic section).
The Pearsall section has hydrocarbons - the question lies with the volumes that can be extracted using horizontal drilling and frac technology. Comes down to economics which are going to be tied very closely to gas pricing and the $10 Million +/- drilling and completion costs for Pearsall wells.