Disintegrating Frac BallsWed, 01/22/2014 - 10:53
Baker Hughes’ IN-Tallic disintegrating frac balls are composed of a controlled electrolytic metallic nanostructured material. As well as being lighter than aluminum and stronger than some mild steels, its most impressive feature is its ability to disintegrate when exposed to the appropriate fluid. The disintegration process results from electrochemical reactions controlled by nanoscale coatings within the composite grain structure. The INTallic balls retain their shape and strength throughout the fracturing process but disintegrate right away or shortly after the well reaches its production stage. They break down over time due to exposure to brine fluids, meaning that disintegration occurs with most fracturing and wellbore fluids without the need for additional special mixtures. Disintegration rates are dependent on temperatures and brine concentration levels. It is worth noting that acids disintegrate IN-Tallic balls at a much faster rate, providing the flexibility to pump acid on the balls after the fracturing is complete to speed up the breakdown process.
The IN-Tallic frac balls provide operators with different advantages, such as eliminating the risk of lost production associated with common frac balls. This lost production usually occurs when the pressure in the stage below the frac balls is lower than the pressure in the stage above. The differential pressure of the stages on either side of the frac ball causes it to remain sealed on the ball seat, blocking the production from all stages below that point. These are not the only risks that the IN-Tallic balls are designed to mitigate. When using a ball-activated frac sleeve system, standard frac balls have a tendency to pile up in low spots of the well if the production velocity is not high enough to bring them back to the surface. If they pile up and the formation starts producing sands or other debris, these can pile up alongside the frac balls and create a barrier.
This will mean a project has to incur additional expenses to fix the problem, usually involving acquiring a coiled tubing unit or a workover rig to mill out the balls and ball seats. A less desirable option consists of accepting the loss of production from all the stages below the obstruction. The use of IN-Tallic balls prevents either of these scenarios from occurring because the frac balls disintegrate before obstruction can happen. IN-Tallic disintegrating frac balls have also proven to be valuable in well-plugging and drilling applications. If operators cannot secure time to remove ball-activated composite plugs, they have the option of producing without removing the plugs. In this case, the balls trapped in the plugs cause obstructions in the wellbore, which hinder production rates below the obstruction. INTallic frac balls trapped in the wellbore will disintegrate, removing the obstruction that was hampering production.