Abstract
A new electronic sliding sleeve was developed for hydraulic fracturing that combines the best features of traditional sliding sleeves and plug-and-perf techniques. The electronic sliding sleeve combines the operational efficiency of sliding sleeves with the potential to perforate unlimited zones inherent to plug-and-perf operations. This tool helps improve the efficiency of multistage fracturing sleeve completions by enabling more zones to be perforated and therefore more of the formation to be fractured.
Traditional sliding sleeves use a series of progressivelysized fracturing balls that shift sleeves along with progressivelysized baffles. The number of zones is limited by the strength of the fracturing ball and the interference between the ball and the baffle. Traditional sliding sleeves, however, offer an operational efficiency advantage compared to traditional plug-and-perf fracturing techniques. The electronic sliding sleeve is of monobore construction, which helps eliminate pumping restrictions through a series of progressivelysized baffles. An electronic sliding sleeve helps eliminate the mechanical complexity of other monobore fracturing tools and enables access to an unlimited number of zones.
The electronic sliding sleeve operates by counting the passage of fracturing balls through the tool and then shifting the sleeve when the programmed number of balls has passed. The electronic sliding sleeve has an on-board sensor and processor equipped to count the fracturing balls. Once the programmed number of fracturing balls has been detected, an actuator releases stored energy to enable the sleeve to shift. The key to the electronic sliding sleeve is a newly developed electrohydraulic lock, which stores the actuation energy. The electronic assembly increases the reliability of the sliding sleeve because the key components of the tool are embedded within the casing string and are not subject to proppant erosion or becoming caught on proppant trapped within mechanical parts. The electronic sliding sleeves can be used in the stimulation of vertical, horizontal, and extended reach wellbores.
A newly developed electronic sliding sleeve presents a new method for performing multistage hydraulic fracturing and is especially applicable in extended reach applications by offering an unlimited number of zones with a simple monobore construction. The programmable electronics help enable increased flexibility, reliability, mechanical simplicity, and robustness.
