Traditional ball-drop systems for multizone hydraulic-fracturing operations require deployment of balls and ball seats of successively smaller sizes, moving from heel to toe of a lateral. This process may require increased surface pressure and pumping horsepower to continue the necessary flow rate. Operators compensate by deploying additional casing and pumping larger volumes of proppant. Weatherford’s i-Ball Multizone Fracturing System (Fig. 2), which can be run as part of the ZoneSelect system, eliminates downhole-pressure buildup and associated logistics and storage concerns with the use of a single ball-and-seat size. The diameter of the system (close to that of the tubing) enables an unlimited number of zones to be stimulated, and the zones are fracture stimulated one at a time. Then, the sleeves retract to a size that is close to the inside diameter (ID) of the host tubing. This action reduces frictional force, enables a more-efficient fracture at each zone, allows for a smaller-ID fracturing string, and, in some cases, facilitates fracturing operations through the completion. The technology has been tested in openhole and cemented wellbores and is rated to 10,000 psi with a temperature envelope of 32 to 350°F. It is highly tolerant of downhole debris, such as lost-control material and fracturing sand and proppant. In April of this year, 400 of these sleeves will be run between four operators, running an average of 30 sleeves per well.
- For additional information, email Eric.Blanton@weatherford.com.