Modeling of Horizontal Wells in Unconventional Reservoirs


NITEC continues to develop new simulation-based technologies to aid engineers and asset managers in understanding and developing increasingly complex reservoirs. This new technology addresses a better approach to modeling of horizontal wells in these reservoirs.

The use of horizontal wells and hydraulic fracture completion practices has become the norm today, particularly in unconventional reservoirs. These wells and their completions present unique challenges to engineers' efforts to optimize and forecast well performance. Where to drill wells is generally not the issue. The primary decisions are orientation of the lateral(s), length of the lateral(s), vertical placement of the lateral(s) in the formation, number and size of the hydraulic fracture treatments, and well spacing.

All of these decisions revolve around the stimulated rock volume (SRV) created by the hydraulic fracture treatment. Proper understanding of the SRV creation and its interaction with the reservoir matrix and natural fracture systems is paramount. The geometry, extent and complexity of fractures within the SRV impact the fracture surface area available for interaction with the matrix.

Reservoir simulation, if properly employed, is the best tool available for addressing these issues. NITEC has developed unique technologies to address the evaluation of hydraulically fractured horizontal wells. These technologies utilize assisted history matching (NITEC's MatchingPro®), and a dual porosity reservoir simulator (Coats Engineering's SENSOR®) with special geomechanical modifications to the simulator. (These simulator modifications are currently only available in SENSOR.)

Many of these operational decisions (well orientation, well spacing, well length, fracture treatment size and number of stages) cannot be properly addressed with statistical methods or "conventional" modeling approaches. NITEC's modeling approach provides knowledge about the reservoir behavior of the hydraulic fracturing process and the reservoir's natural fracture/matrix system for the well(s) being studied. Unlike the conventional approach this information can then be used to investigate operational decisions for future wells planned in the same reservoir.

Download the referenced pdf file to see how proper characterization of the SRV can impact the predicted EUR for a well and how the SRV is impacted by the number and size of the frac stages, the well orientation and spacing.