Reservoir Engineering Consultants

DFIT Analysis – Diagnostic Fracture Injection Test Analysis

At IPT a Diagnostic Fracture Injection Test, DFIT, is used to discern both the reservoir aspects and hydraulic fracturing character. IPT analyzes both the pre-closure and post-closure pressure response and generally gets consistent permeability estimates from the two different analysis techniques. Furthermore, a detailed pre-closure analysis is performed to understand the fracturing character and integrate it into the upcoming stimulation treatment implementation.  In our integrated study approach, these DFITs are coupled with larger volume injections to discern the actual fracturing character of the formation.

The post-closure pressure data is analyzed with a classical pressure transient analysis approach. The flow regimes that occur as the pressure history transitions from an open to closed fracture response are identified and noted. The parameters derived from this approach are typically similar to that observed with post-treatment production and well test analysis.

The pre-closure pressure decline analysis and net pressure history match are used to discern unique fracturing characteristics such as near-well stress, pressure dependent leakoff, insufficient frac port opening, pressure depletion, fracture height recession, leakoff, fracture complexity, etc.  The associated implications are integrated into the main treatment design and communicated to IPT's hydraulic fracturing consultant as well as the client prior to treatment implementation.

An item of interest is that IPT's pre-closure derived permeability values are relatively accurate.  This is because we history match the pre-closure pressure response with a fracture model and have our own internal calibrations within FracproPT that have been derived from years of study and history matching of actual production responses.