Cotton Valley Lime (Oolitic Shoal) Play
The Cotton Valley Lime (CVL) gained notoriety as a 3D target in the mid-90s. The wells were deep and expensive, and the pinnacle reef reservoir was hard to find; but high rates overshadowed the more mature “shoal trend” along the east and west shelf of the East Texas Basin. Today rates are less dramatic, yet after fracture stimulation, rates as much as 4 million cubic feet per day (MMCFGPD) are not rare.
There are two reasons that the play was under-drilled: (1) Exxon controls most of the production, and (2) some hydrogen sulfide gas (H2 S) is produced. It may take as much as $1 per thousand cubic feet (MCFG) to process the H2 S out of the methane stream. If prices are low, the wells become uneconomic. This situation has not occurred since 1999. Ultimate recoveries for the wells are typically 3 billion cubic feet of gas (BCFG), and within the last 5 years, companies have discovered that it responds to large gelled-sand frac treatments. These factors, combined with the likelihood of shallow pay in the Cotton Valley Sand, are drawing a great deal of attention to the play. Prospects are once again in demand, and Energy Frontiers Partners has 10 high quality areas to lease, based on detailed geologic mapping. Energy Frontiers Partners recently sold one key prospect to a large independent energy company that has three drilling rigs, operating continuously in the area.