Study of Channeling Mechanism between Sections and Anti-Channeling Methods for Horizontal Well Multi-Stage Fracturing

Abstract

During multi-stage fracturing of horizontal well, the key to successfully stimulating formation and improving fracturing effectiveness is ensuring no channeling between sections. Channeling frequently occur which decreases fracturing effectiveness. Cracks propagating mechanics model basing on cementing sheath second interface failure was established according to fracturing mechanics, and second interface failure length calculating model was established. Channeling conditions of different sections were calculated by using the model according to parameters of a certain multi-stage fracturing horizontal well. Calculated channeling conditions were same with actual ones, which prove that the model is reasonable and effective, and can be used to accurately calculate channeling conditions. Anti-channeling methods such as increasing Young's modulus and Poisson's ratio of cement sheath, improving cementing interface bond quality were proposed. The research achievements can provide theoretical basis for reasonable designing section interval and improving multi-stage fracturing effectiveness.