In recent years, there has been tremendous growth in multistage fracturing for unconventional plays employing multistage fracturing completion systems with openhole (OH) packers or cementing to isolate multiple stages and ball-activated frac sleeves with graduated seats (traditional graduated-seat frac sleeves) to divert the fracturing treatments. This phenomenon has developed primarily because these systems not only maximize production, but also save significant completion time and money with the ability to perform multiple stimulations in a single trip, with minimal or no thru-tubing intervention.
However, traditional ball-activated frac sleeves have graduated ball seat sizes for each additional zone, and therefore, each ball seat creates its own backpressure within the system. With the number of frac stages increasing, the ball seat sizes become smaller, leading to an increase in the surface pressure and hydraulic horsepower (HHP) required to generate a given net downhole pressure or flow rate. In order to solve these limitations, a revolutionary ball-activated fracturing system has been developed, which can be installed with an unlimited number of zones using a single size ball and ball seat for each zone. This new technology can greatly reduce frictional forces and enables a more efficient fracturing of each zone within the wellbore. Most importantly, this new frac sleeve is sized to achieve an inside diameter (ID) as close as possible to the host tubular string, thus requiring a much lower fracturing pressure on the surface compared with traditional graduated-seat frac sleeve.
This paper will present the operational mechanisms of this new frac sleeve, simulation of frac efficiency and financial analysis with quantitative comparisons between it and traditional graduated-seat frac sleeve. The analysis will indicate that this new frac sleeve technology can be used to optimize hydraulic fracturing operations in both HHP requirements and stimulated reservoir volume (SRV) while dramatically reducing operational time and overall completion costs.