Probability-Statistical Models to Forecast Hydraulic Fracturing Efficiency Klara Fatkullinovna Gabdrakhmanova, Gulnara Rishadovna Izmaylova, Eldar Faritovich Samigullin and Rishat Sabirovich Gilmanov E3S Web Conf., 220 (2020) 01016 Published online: 16 December 2020 DOI: 10.1051/e3sconf/202022001016