Plug-and-perf limited-entry fracturing treatments are commonly performed in horizontal wells. Recent presentations have indicated an occasional lack of containment within the targeted interval during these treatments. This issue was investigated during multi-stage treatment of a shale well. The well was instrumented with fiber-optic cable for obtaining DAS and DTS measurements and a downhole pressure/temperature gauge. The fiber measurements enabled allocation of treatment-volume outtake along the lateral, and the downhole gauge measurements enabled accurate calculation of pipe friction and bottomhole pressure at any point, when integrated with surface pressure. Injection rate step-downs were implemented early in the treatment during the pad-fluid stage and at the end of the treatment during the over-flush stage. Post-treatment ultrasonic imaging of the wellbore was conducted on an offset wellbore to measure perforation dimensions and wellbore abrasion.
Examples of three different cases will be covered in the presentation: 1) Excellent containment within the targeted section of lateral, 2) Frac-plug bypass resulting in communication to previously treated intervals and 3) A large-scale casing-breach incidence.