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Industry Article: Multizone Treatment Saves Time

Shaving 4 days off a 5-day job helps independent Goodrich Petroleum save money and get its gas to market faster.

Publication: E&P
Volume: October
Issue: 2007
Publication Date: 10/01/2007

The tough-to-drill yet prolific Cotton Valley trend of East Texas and Northwest Louisiana doesn’t give up its prize easily, but Goodrich Petroleum has drilled 175 wells there with a 99.5% success rate. With 110,000 acres under lease, nine rigs working full-time, and a near-perfect record, one might wonder what else can be improved? The answer is efficiency. So what’s the problem? Most Cotton Valley and Travis Peak wells need a little help in the form of hydraulic fracturing to stimulate production and maximize reservoir contact. Many Travis Peak wells have multiple producing zones in the form of thin sand stringers spaced out over intervals of about 1,000 ft (305 m). While some of these stringer sands may deliver prolific production, it is critical to the well’s economic success to complete them as efficiently as possible. It would not be economic to complete them conventionally due to the relatively long completion time and high cost weighed against the lower productivity. Cotton Valley completions involve four frac stages of 250 ft to 350 ft (76 m to 107 m) per stage. The traditional process for completing these wells involved four steps: perforate an interval, stimulate it, flow the zone overnight to clean it up, and then set a composite bridge plug to protect the zone so the next shallower zone could be treated. After treating all zones, a coiled tubing unit would be mobilized to drill out the plugs to enable flowback and final completion. Typically, the process would take 5 days and cost more than USD 250,000. Although the traditional plan worked, it consisted of essentially the same steps repeated over and over. Usually when processes are repetitious, ways can be found to make them more efficient.



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