Post-Frac Analysis Based on Flowback Results Using Chemical Frac-Tracers

Chemical frac tracing is used to evaluate flowback and cleanup efficiencies. The technique utilizes a family of<br>unique, environmentally-friendly, fracturing fluid compatible chemical tracers to quantify segment-by-segment<br>recovery for individual fracturing treatments and stage-by-stage recovery for multi-stage fracturing treatments.<br>These chemical tracers with their unique chemical characteristics are mixed at a known concentration into frac fluid<br>stages as the frac fluid is pumped downhole. Upon flowback, samples are collected and analyzed for tracer<br>concentration. With the use of the mass balance method the flowback efficiency for each stage is calculated.<br>These precise flowback calculations yield a more accurate assessment of cleanup efficiency. This paper presents<br>several case histories in which the technique was implemented. Results and fracture flowback prognoses are<br>presented. The results are also used to assess post-frac performance as a function of flowback efficiency.