Nowadays, hydraulic fracturing is one of the most effective ways of low-permeability layered reservoirs management. About half of the oil reserves, remained in Western Siberia today, are concentrated in such reservoirs. The field experience and engineering calculations show that without fracturing the largest part of this oil would be left in the Earth forever. That is why we can classify hydraulic fracturing as a method of oil recovery enhancement.
The reduction of multi-zone fracturing time cycle is an important part of asset management and cost optimization for the large multi-layer oil fields developing with the help of hydraulic fracturing.
The example of a typical low-permeability multi-layer oil field in Russia is the Priobskoe field. The main pay zones are ???12, ???11 and ???10 reservoirs (Fig.1) with permeability ranges of 1-1.7 mD, 1.5-4 mD, and 2-6 mD correspondingly. An important condition of efficient oilfield development is penetration of all formations simultaneously and with hydraulic fracturing, if possible. Thus, a large scope of fracturing treatments was performed. In year 2007, only on the Priobskoye oilfield 378 wells were drilled and 753 fracturing treatments were executed by RN-Yugansknefte gas. Most of the wells were fractured 1–3 times, and some of them — up to 5 times (Fig.2).