Summary

From 2010 to 2014 horizontal drilling activity in the Wolfcamp was focused in the southern Midland Basin, primarily within western Irion, northern Crockett, and southeastern Reagan counties. Well results were extremely variable due to a variety of reasons such as matrix quality, hydrocarbon saturation, faulting, influx of carbonate debris flows, operator, etc, and to this day remain variable. Filtering the well results by operator, vintage, completion style, and target formation helps to explain much of the variation, yet when the above variables were controlled for, large differences in productivity still exist across small distances.

Tracker began this project with approximately 42 square miles (mi2) of 3D seismic data, and during the course of the next five years licensed an additional 88 mi2 of 3D seismic data from offset operators. Tracker worked with APEX Petroleum Engineering (APEX, formerly SIGMA3) to construct a 3D reservoir model that utilized core, wells with full log suites, and ~130 mi2 of prestack time migrated seismic to delineate target zones. While the Wolfcamp is almost entirely hydrocarbon charged, these volumes were used to map a sequence of stacked high-quality landing targets and clearly show the limit of the deep basin sediments to the east onto the basin margin slope. The seismic volumes also shed light on how our offset operators were targeting and drilling their horizontal wells.

While evaluating offset operator wellbore surveys against the reservoir model volumes we noticed large variations in wellbore paths and exposure to high porosity, hydrocarbon charged reservoir rock. These large variations in exposure to the preferred target interval played a large role in the statistical scatter of well results (Figure 1) as well as our model for drilling and completing a more economic well data set.

In early 2017 Tracker began drilling 16 horizontal Wolfcamp wells that were planned using the seismic depth volumes. Well paths were planned to minimize inclination/trajectory changes while avoiding hazards, with the goal of keeping 100% of the lateral in the targeted high-quality zone. Well performance thus far has been excellent when compared to the approximately 615 horizontal wells drilled in the immediate neighborhood. One aspect that has stood out from this analysis is the consistency/similarity in production from the Tracker wells, even though 3 distinct benches were tested. This consistency in results is likely due to the ability to stay in the target zone with minimal inclination changes, large high intensity engineered completions, and detailed flowback procedures which managed drawdown based on bottom hole flowing pressures.

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