Abstract
Wide application of hydraulic fracturing especially in low permeability reservoirs becomes a successful approach in field development practice. Utilizing full potential of extensive fractures at production wells and water injection under induced fracturing conditions requires a new method of effective waterflood pattern design to be proposed. This paper describes a new general approach to optimization of well spacing and pattern geometry with account for hydraulic and induced fractures size and orientation.
It is shown that under specified conditions it is useful to present all regular well patterns as linear well systems with lines directed parallel to fracture orientation. This way of well systems description seems to be more consistent and applicable than traditional pattern description (five-, seven- or nine-spot patterns, etc.). It makes possible to increase water-free production period and sweep efficiency by stretching of well pattern along the fracture' direction while squeezing lines in perpendicular direction and keeping average well spacing intact. Semi-analytical model for calculation of pressure distribution, streamlines and field performance parameters for such waterflood systems with arbitrary fracture azimuth is also presented. Concept of effective well spacing is introduced and connected to average length of streamlines. Using proposed method it is shown that increasing of fracture length conform to denser well spacing when compared to regular (non-fractured) well patterns.
