The procedures of the Rate Step-down Test (RST) also referred to as "Step-Down Test" (SDT), and of Conventional Fracture Entry Friction (FEF) Analysis have been used worldwide for over 15 years to separate the Measured Total System Friction (MTSF) into constituent components. The magnitude of the FEF components has served as guidance to design and/or modify the placement procedure and treatment schedule, in order to reduce unplanned terminations (screenouts) of propped hydrofrac treatments.

Conventional FEF Analysis has inherent limitations which produce non-unique (somewhat erroneous) results that can only be overcome with Enhanced FEF Analysis methodology; which bypasses these limitations with innovative methods: appropriately corrected fluid friction factors, non-uniform perforation discharge coefficient, application of Maximum Drag Reduction (MDR) asymptote, and, matching of MTSF with Calculated Total System Friction (CTSF) at all rates of the RST. Several RST examples are analyzed with FEF Analyzer to illustrate and document the success in placing safe and effective propped hydrofrac treatments.

Real-world analogies are used as visual aids to explain the complex processes of FEF, along with RST design methodology, RST execution procedure, and detailed calculation procedures for performing Enhanced FEF Analysis.

Net-pressure history matching is significantly improved, due to the increased accuracy of calculating the magnitudes of the wellbore friction and of the FEF components.

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