The Eagle Ford Shale in South Texas is one of the top producing, yet complex unconventional plays in North America. Well-to-well production variability confounds a " factory" approach to field development, as preferred by many operators. Greater insight into sweetspot locations and optimal drilling and completions parameters is required to drive enhanced well production. While the breadth of engineering, geology and geophysics variables are daunting - modern analytic techniques provide a means to assimilate and comprehend massive amounts of disparate data.
In this study, over 3500 horizontal wells are modeled with non-linear analytics, to identify what geophysical and geologic properties define drilling sweetspots and what drilling and completions parameters drive better well production. Reservoir depth, related to pressure and thermal maturity; oil/gas mixture; thickness and proximity to faults are some of the major identified controls of Eagle Ford production sweetspots. Nominal well lengths of approximately 5500 feet with 20–25 fracture stages are some of the key drilling and completions parameters that correlate with optimal well production. Combining these results with current economics for oil, gas and liquids provides a unique perspective into targeting factory-based field development in unconventional plays.
With an expected industry capital expenditure of nearly $30 billion in 2013 - is this all that is required for an efficient and economic factory approach to development of the Eagle Ford? In our experience, across nearly a dozen projects, seismic data plays a key role in helping to reduce the complexity and risk of Eagle Ford development programs. Specifically, seismic data is essential for: infilling the structural picture between wells, identifying fault and other geologic hazards, and providing sweetspot trend indications, from a combination of elastic and structural attributes - that are calibrated with geology.
To quantify the impact of seismic data; we first extract seismic attributes at well locations; and then use the same non-linear analytic technique to predict well production - with and without seismic data. Seismic attributes used in this case study include: fault probability, incoherence, curvature, spectral deconvolution, elastic impedance and " fracability". We have also found that seismic waveform classification, in a zone above the Eagle Ford/Buda interface, is a useful diagnostic tools for tracking facies, thickness and fracture trends across the play. Model correlations are used to quantifying the impact of seismic data on " solving the Eagle Ford Puzzle".