Abstract
The South-Priobskoe Field is one of the largest oil pools in Western Siberia, with a unique category of reserves. Due to the low filtration properties of the productive formations AS10-AS12 (permeability of which is not more than 3 mD), the drilling of horizontal wells with subsequent multi-stage hydraulic fracturing (MSHF) completion is the most cost-effective way in this case. The use of highly viscous fracture fluids (at least 400 cP at 100 s-1) and 16/20 mesh proppant with a maximum concentration of 800-900 kg/m3 and the slurry rates are not exceeding 4.0 m3/min, became a kind of standard during the MSHF. However, a steady decline of permeability in the newly drilled areas of the field is observed (below 0.5 mD), because of this, an effective half-length of cracks begins to make an increasing contribution to oil production. This paper describes the introduction of non-standard methods of hydraulic fracturing for a traditional reservoir, and an idea was the use of low-viscous fluids with increased slurry rates, which resulted in an increase in well production rates by an average of 7%.
