A unique completion procedure has been developed to reduce the cost and time to hydraulically fracture wells. In the procedure, coiled tubing is used to replace conventional tubing in most of the operations. This procedure is made possible by a wellhead design that enhances safety and simplifies switching from one operation to the next.

Hydraulic fracturing costs comprise the majority of the total cost for new diatomite wells. Multiple stimulations can be completed in a single day by using coiled tubing to cleanout or place sand plugs which are used to isolate the perforated interval between hydraulic fracture stimulations. This allows significant savings to be realized by fully utilizing the service company's entire minimum daily charge. The coiled tubing also functions as a dead string during fracture stimulations which allows real time monitoring of downhole fracturing pressures.

The new wellhead incorporates two unique ideas: 1) a hammer union tree cap which replaces the conventional flanged tree cap. Integral to the tree cap is a blast joint that provides protection from sand erosion when using coiled tubing as the dead string. The wellhead design enables the tree cap (with attached blast joint) to be quickly and easily exchanged with a fullbore lubricator; 2) a full opening gate valve located between the casinghead and the fracture wellhead. The valve is a safety device that allows any part of the wellhead to be removed while ensuring a completely controlled condition.

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