Abstract
Saudi Arabian nonassociated natural gas development programs are continuously expanding to meet the local energy demand. The challenges faced in the new development areas attributed to reservoir heterogeneity, high-pressure and high temperature, and low reservoir quality have been thoroughly evaluated and encountered with the application of fit-for-purpose novel technologies and the implementation of best practices. Drilling of horizontal wells and completing those with multistage fracturing (MSF) have been a preferred practice to obtain and maintain high and sustainable production and to help marginal wells become economical. One main focus area for the enhancement and improvement of stimulation efficiency is fracturing fluid additives. Regardless of the base gel and loading used, the additives play a major role in acid etching or proppant transport in heterogeneous reservoirs to attain uniform stimulation, maintain high fracture conductivity, and accelerate post-fracture cleanup.
Because of reservoir heterogeneity and the extent of permeability development and net pay sections that need to be stimulated in a horizontal well, ensuring uniform fracture propagation, acid penetration, and proppant placement, effective completion and stimulation design is necessary. The location of perforations is important and can impact fracture growth while the diversion additives in the fracturing fluid ensure that perforation clusters are all treated sequentially, assist and enhance acid interaction or proppant distribution inside the fracture, and increase the effective fracture geometry, contact area, and overall conductivity. The paper highlights the importance of perforation placement and discusses in detail a novel diversion technology and control pressure pumping (CPP) mechanism successfully applied in several high-pressure, high temperature condensate tight gas reservoirs to optimize breakdown, acid penetration, proppant transport, and maximize stimulated volume and well productivity.
Several wells have been acid fractured, matrix acidized, or proppant fractured using novel diversion materials and are discussed in this paper. Various diagnostics used to verify stimulation coverage include running production and temperature logs, conducting distributed acoustic and temperature measurements, as well as pumping nonradioactive tracers. Although these wells exhibited a wide range of porosity and permeability variation along the drilled section, each perforated interval was effectively stimulated using novel diversion materials. Compared to offset wells where diversion was not used, wells treated with novel diversion showed a distinct difference in acid etching or proppant placement profiles, thereby confirming their superiority. The total production rate observed was much higher in the novel diversion applied wells.
