Fracture stimulation fluids, desirable

Historically, the fracture stimulation fluids have been water or hydrocarbon-based. With respect to add stimulation, the base fluid has been hydrochloric add. As fluid technology developed, stimulation fluids have become more complex. However, the pursuit of the ideal stimulation fluid is an ongoing process. An ideal fluid would incorporate all of the desirable features of several stimulation fluids into one particular fluid. A few of the desirable features are the following ... 

In most air and gas drilling operations, open-hole well completions are common. This type of completion is consistent with low pore pressure and the desire to avoid formation damage. It is often used for gas wells where nitrogen foam fracturing stimulation is necessary to provide production. In oil wells drilled with natural gas as the drilling fluid, the well is often an open hole completed with a screen set on a liner hanger to control sand influx to the well. 

During well completion it is sometimes desirable or necessary to treat or stimulate the producing zone to improve permeability of the rock and to increase the flow of oil or gas into the casing. This may be accomplished by use of acid or by injection of fluid and sand under high pressure to fracture the rock. Such a trcatniciit usually improves the ability of the rock to allow fluid to flow through it into the well bore. At this point the drilling and completion phases have ended. 

Suspensions or slurries used for well stimulation are prepared by adding a known quantity of proppant to the carrier fluid of choice to obtain a desired proppant concentration. The proppant concentration is usually referred to as the amount of solids added in a gallon of carrier fluid. A 20-40 U.S. mesh size is the most commonly used proppant for hydraulic fracturing. However, other particle sizes such as 8-12, 8-16, 10-20, 12-20, and 40-60 mesh are also used. 

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