Carrizo's Eagle Ford Well Begins Flow-back

Carrizo O&G provided an operational update on the Company's activities in the Eagle Ford Shale and Niobrara Formation. Carrizo's initial two Eagle Ford Shale wells were drilled from a common surface location in central La Salle County, Texas. The Mumme Ranch 10H was drilled with a 5,493 foot horizontal leg and was completed with 15 frac stages. The Mumme Ranch 12H was drilled with a 5,455 foot horizontal leg and was completed with 19 frac stages. Following the flow-back of completion fluids, the two wells were tested for production potential beginning on November 20, 2010. The Mumme 10H had a 24-hour initial production rate of 1,011 barrels of oil per day ("Bopd") while the Mumme 12H had a 24-hour initial production rate of 1,220 Bopd. Production from this two-well pad appears to have stabilized at the current combined rate of approximately 1,125 barrels of oil per day. Approximately 2 million cubic feet per day of 1,367 btu per mcf natural gas is currently being flared pending connection to a gas gathering pipeline. Carrizo has a 100% working interest and a 75% net revenue interest in these two wells.

Hydraulic fracture stimulation activities have been completed on the Company's next Eagle Ford well, the Pierce 10H, located to the southwest of the Mumme wells, and the well has commenced flow-back today. It is currently anticipated that initial production results for this well should be available before the end of the year. Carrizo owns approximately 20,000 net acres in the Eagle Ford Shale play, the majority of which are located in the condensate window of La Salle, Dimmit, and McMullen Counties. In addition to the three wells mentioned in this announcement, Carrizo has drilled two other Eagle Ford horizontal wells in La Salle County which are currently waiting on completion, expected to begin in the first quarter of 2011.

On the Company's Niobrara Formation acreage located in Weld County, Colorado, fracture stimulation activities are scheduled to commence on the State 16-11-9-60H on December 1, 2010. Initial production results are expected to be available from this well before the end of this year. The drilling of the vertical portion of the Company's second Niobrara well, the Bob White 36-44-8-62H, has been completed and protective casing has been installed through the curve. The drilling of the horizontal leg is currently under way. Initial production results from this well are expected in January 2011. A third Niobrara well is planned to be drilled in Section 36, Township 9N, Range 61W of Weld County immediately following finalization of the drilling of the Bob White well. Carrizo owns approximately 59,000 net acres in the Niobrara play, all of which are located in Weld County.