The introduction of a new technology is critical for operators to expand their completion options, increase efficiency, and drive profitably in challenging environments. For unconventional reservoirs, open-hole fracturing has been key for the economic success of new ventures. With the increase in activity of liquids rich plays, there is a growing need for new technology developments for open-hole fracturing systems that further optimize these completions.

Using a combination of open-hole packers and sliding sleeves, open-hole fracturing tools successfully segment horizontal sections of the reservoir to be stimulated individually. In order to achieve isolation, seats of increasing diameters are placed inside the completion at each fracturing sleeve. These seats catch a ball that performs the function of opening the sleeve for fracturing purposes and isolating the completion below the stage. After the stimulation job is performed, the balls should ideally flow back to surface. Unfortunately, as seen in the field and described in the literature, this is often not the case. Balls frequently remain in the completion without coming to surface. In some cases depending on ball and seat material, balls may actually get stuck in the ball seats completely isolating production from the stages below. Many operators have found this to be a root cause of production problems and they are forced to take the added cost and risk of milling out the balls and seats.

A new degradable material has been developed for use on frac balls that are used in said open-hole completions. Balls made of this material can handle pressure differentials beyond the current market offering without deformation. After fracturing, these balls degrade away opening up the flow path of the well without intervention. The degradation time is a function of temperature and water chemistry (including brine), but 1 to 4 days is a typical degradation time. No other requirements are needed for the degradation process to occur.

This paper discusses a new degradable metal technology and its application in open-hole fracturing.

Keywords:
drilling operation, pressure differential, field application, directional drilling, spe 166528, mechanism, completion equipment, production problem, hydraulic fracturing, alloy
Subjects:
Drilling Operations, Hydraulic Fracturing, Directional drilling, Completion Selection and Design, Completion equipment
Copyright 2013, Society of Petroleum Engineers
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