Arenosa Creek Prospect

Jackson County, Texas

The Arenosa Creek Prospect is located approximately 10 miles northwest of the town site of Edna in Jackson County, Texas. The prospect lies along a trend of Frio sand fields that produce hydrocarbons along the Texas Gulf Coast and into South Texas. Entrapment of hydrocarbons in the Frio trend is both structural and stratigraphic. These porous and permeable sands make excellent reservoirs.

In 1990, ATAPCO drilled their Kolle #1 well and discovered what they called Zodiac Field. They completed the well in the 3900’ Sand which produced 199 million cubic feet (MMcf) of gas in its three year lifetime. They drilled the Kolle #2 shortly after the Kolle #1 and completed it in the 3800’ Sand. The 3900’ Sand was not present in the Kolle # 2 showing that the 3900’ Sand was a stratigraphic trap. However, the 3800’ Sand is a channel sand across the area and is below the gas-water contact in the Kolle #1. The ATAPCO, Kolle #3 was drilled up-dip of the Kolle #2 and was also completed in the 3800’ Sand. The two wells produced over 721 MMcf of gas before watering-out after six years of production. Two other stratigraphic zones were completed in the Kolle #2 and #3 and made an additional 47 MMcf of gas.

The objective of the Arenosa Creek Prospect was to drill a well in an updip position from the ATAPCO, Kolle #2 and #3. This well was expected to encounter the 3800’ Sand structurally high and above the gas-water contact, thus enabling the completion of a successful producer. In addition to the 3800’ Sand, the 3900’ Sand in the Kolle #1 and other stratigraphic stray sands may be encountered at this location. These would be considered secondary objectives.

A 4,600 foot test, the Sibley Estate #1, was drilled in May 2009 to encounter the 3800’ Sand, the 3900’ Sand and other stray stratigraphic sands. Three reservoirs were discovered and tested productive: a 3' thick zone from 3898'-3901'; a second sand from 2536'-2577'; and a third sand at 2350'-2372'. All three sands core and formation tested natural gas and were present but thin in the Kolle #1, #2, and #3. A 1000' pipeline was constructed to tie into gas production and the well went into production in the last week of September, producing 220 Mcf/day. The well is currently producing consistently at 6 MMcf/month.

One to two additional wells could be drilled in 2011 to fully produce the field.