Analyzing the Impact of Temperature Effects and Other Fracturing Parameters on Fracture Growth Propagation and Injectivity in Unconsolidated Sands

Abstract

Reservoir sands in the deepwater formations in West Africa are largely soft and unconsolidated based on data from producing fields and preliminary studies on upcoming developments. Studies have shown that fractured injection in unconsolidated sands is different from hard rock fracturing in which case a single dominant fracture is created during injection. For unconsolidated sands, smaller fractures are created to bypass impairment and much of the injection may be under matrix rather than fractured conditions. Given the importance of waterflood to most projects, it is imperative to understand the dynamics of fractured injection in this type of sands and all the factors that can impact on the effectiveness and efficiency of designed waterflood systems. This is even more important for upcoming projects whose viability may depend on the delivery of high rate – high ultimate recovery wells which can only be supported by an effective pressure maintenance /voidage replacement system. In this paper we present a study carried out on one of such developments (turbidite reservoirs in Deepwater West Africa) for which a water injection program is to be designed. The modeling work is highlighted and the effect of different parameters on fracture growth propagation and injectivity were analysed.