This is believed to be the world's first two attempts, both successful, to replicate multi-cluster hydraulic fracturing at surface to better understand not only proppant transport and placement by cluster, but a host of other items of interest such as perforation erosion. With due recognition and compliments to all the good theoretical studies conducted and published by the academic community, it seemed that actual physical tests could be a valuable contribution to the industry activity. Both 8 cluster (6 shots per cluster) and 13 cluster (3 shots per cluster) tests were completed at 90 BPM injection rates at approximately 1,500 psi initial differential pressures. Both tests were conducted in 5.5" 23#, P-110 casing, with assembly lengths of 191 feet and 216 feet respectively. Water, Water plus Friction Reducer, 100 mesh sand and 40/70 mesh sand were utilized on these highly instrumented tests with each cluster having its own individual tank to capture fluids and proppants as they exited the perforation clusters. Perforation hole size changes, fluid level data, and proppant masses were captured after each test along with all the frac fleet data and pressure gauge data at each cluster. How the tests were safely and successfully executed will also be discussed. These tests led to subsequent tests with 15 perforation clusters with different charge designs and perforation orientations in a project with a larger number of operators participating. Predictive software based on computational fluid dynamics was also developed as an outcome of the project learnings and actual physical measurements. The key benefit of these tests is that all the data was physically measured and not subject to interpretation, therefore providing solid data for subsequent model calibration and predictions. Validity and shortfalls in the standardly used orifice flow equations was also the subject of the studies and will be discussed. Learnings about perforation erosion and impacts of different proppant sources as well as fluid velocities occurred.

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