Abstract
In organic shales, hydraulic fracturing is an important parameter to optimize production of horizontal wells. For a lateral standalone, propped surface should be maximized to increase production (by increasing total proppant per well). While in the case of a pad, well spacing is an additional constrain for hydraulic fracture dimensions not to overlap with hydraulic fractures of neighboring offsets. Competition for production between laterals of a given pad should be minimized and is the result of both well spacing and hydraulic fracture design.
A numerical model coupling an explicit description of the hydraulic fracture geometry and reservoir simulation is proposed. Fracturing simulator accounts for material balance, geomechanics, interaction with natural fractures and stress shadowing within and in between fracturing stages.
Production interference is evaluated by comparing forecasted production of a lateral standalone (single well approach) against this same lateral while surrounded by offsets competing for production (multi well approach). Sensitivities are run assuming different completion and well spacing scenarios varying different parameters such as fluid and proppant volume, fracturing fluid type and staging.
Production interference between horizontal wells might reduce the final recovery of each individual well. However it provides an opportunity for simultaneous optimization of completion and well spacing to guide field development.
Hydraulic Fracture dimensions must match well spacing. Variation of fracture geometry along the lateral should be accounted for to evaluate well spacing and prevent the excessive growth of one single facture within a given stage. Completion design can be engineered by adjusting hydraulic fracture treatment volume, perforation cluster spacing or fracturing fluid viscosity to increase the overall consistency of the resulting fracture geometry and reduce effect of production interference between laterals of a given pad.
Novelty of the proposed methodology relies on the explicit description of the hydraulic fracturing geometry and direct coupling with reservoir simulation, not only for a single well, but considering a whole pad of horizontal wells as per a possible development of the Vaca Muerta shale.
