Traditional limits

Completion economics were critical to the success of a Chevron drilling program near Carthage in Northeast Texas. Many wells in the Deadwood field have multiple zones of interest, and conventional completion techniques were too time-consuming to justify treating all of them. However, bypassing zones would result in a reduction in potential recovery.

Traditional completions require a 5-day completion process on a lower prolific zone, including perforating, fracture stimulating, and flowback. If production during the flowback is sufficient, the well is turned over to production. If production is not sufficient, a composite bridge plug is run to isolate the lower zone, and an upper zone is completed through the same process of perforating, fracture stimulating, and flowback. When flowback is completed, the composite plug is milled out and the two zones are put on production.

This process is repeated until all zones of interest have been stimulated. Because the PerfFRAC approach requires no composite bridge plugs, there is no need for a coiled tubing unit to drill through the plugs.

Chevron compared the cost and time of the conventional completion process with the PerfFRAC process, which allowed completing two zones with minimal time and cost as compared to the conventional one-zone completion. The additional benefit of the PerfFRAC process enabled immediate production from and increased recoverable reserves in the second zone without the additional time, cost, and risks associated with the conventional two-zone operation.

Exceptional results

In the Deadwood project, the goal was to reduce time to market and cost without compromising reservoir contact and production efficiency. The entire process required a single wireline trip and was completed in less than a day as compared to 5 days using the conventional process. This resulted in significant cost savings for the client amounting to approximately 10% of the total completion costs.