An Optimum Limited Entry for Multiple Zone Stimulation by Hydraulic Fracturing

In hydraulic fracturing, various diversion methods have been used to treat multiple zones with greater or lesser degree of effectiveness. Limited entry fracturing “LEF” is one of them. LEF could be very effective and can result in considerable savings in well completion costs. The process is not difficult to apply. The technique of limited entry perforations is used to achieve large frictional pressure drop across certain perforations to ensure fluid injection through each perforation in each interval. This study presents a new development in LEF. New relations were developed to optimize the perforations number that could not only increase the bottomhole pressure, but also, could result in the optimum fracture geometry in each zone which leading to several increase in post-fracture productivity. The validation of these relations was checked by hydraulic fracturing simulator “Frac-CADE™” utilizing data of a well which was treated before with hydraulic fracturing using an expensive isolation method. This study is the first-of-its-kind up to the author knowledge that considers the perforations erosion by proppant corrosive action in the design of this technique in order to prevent the perforation friction pressure loss and keep successful diversionof the fracturing fluid between different zones to the end of the treatment. Abstract In hydraulic fracturing, various diversion methods have been used to treat multiple zones with greater or lesser degree of effectiveness. Limited entry fracturing “LEF” is one of them. LEF could be very effective and can result in considerable savings in well completion costs. The process is not difficult to apply. The technique of limited entry perforations is used to achieve large frictional pressure drop across certain perforations to ensure fluid injection through each perforation in each interval. This study presents a new development in LEF. New relations were developed to optimize the perforations number that could not only increase the bottomhole pressure, but also, could result in the optimum fracture geometry in each zone which leading to several increase in post-fracture productivity. The validation of these relations was checked by hydraulic fracturing simulator “Frac-CADE™” utilizing data of a well which was treated before with hydraulic fracturing using an expensive isolation method. This study is the first-of-its-kind up to the author knowledge that considers the perforations erosion by proppant corrosive action in the design of this technique in order to prevent the perforation friction pressure loss and keep successful diversionof the fracturing fluid between different zones to the end of the treatment.