This presentation (SPE 194334) reviews a case study of plug-and-perf horizontal well treatments in an unconventional shale play in which various diagnostic methods were used to better understand and quantify the factors determining limited entry effectiveness.
Three diagnostic methods were implemented: 1.) injection step-down tests and pressure analysis of the fracturing treatments, 2.) video-based perforation imaging and 3.) distributed acoustic sensing (DAS).
Stress shadowing and perforation erosion were determined to have a significant impact on slurry allocation. Other undesirable effects such as heel side flow preference were also observed. Camera images readily confirmed proppant induced erosion at the scale of individual perforations. Measurements from the digital images provided comparison points for predictive software using surface pressure measurements. DAS results provided cluster level proppant distribution values. Correlations were also observed between treatment allocation values from DAS data and values derived from perforation friction calculated from Bernoulli’s equation using image-based entry hole diameter data.