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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%.

Summary Integrated asset development project planning is based on delivering maximum effectiveness of hydrocarbon reserves development, formulating the concept of optimum development and operation of the asset in the long run. The fundamental of integrated asset development project planning is formation of integrated well intervention programs (hereinafter referred to as the well intervention) – commissioning of new wells, frac, side-tracking on the operating well stock, recompletion, etc. Relevance of well intervention planning process is evident – oil, water and gas production capacity and water injection are calculated based on the worked out well intervention programs, infrastructure development and construction is designed, and project efficiency is evaluated. The authors describe the process of formation of integrated well intervention programs, using digital information systems at the Priobskoye field (southern concession area). Remaining recoverable reserves of the field constitute 362 mn t of oil, the operating well stock of the field exceeds 2,000 wells, more than 500 well interventions are carried out annually. In 2015, a digital information system – IS Well Intervention Selection (algorithms are described in SPE- 176561) – was put in commercial operation; the engineers use this system to make calculations for selecting well intervention – frac and side-tracking, and align well interventions. The system is based on a web interface enabling vizualization of results, prompt computations and decision-making for all related specialists in the real time mode, while accumulating and saving the history. Technical support procedure is established; the interface is periodically upgraded in connection with functionality enhancement. Within 2015, the number of completed repeated frac activities has been increased to 180 operations p.a. (+50 wells) with startup increase to 14 tpd (+2 tpd), 76 tons of oil have been produced over the target. In 2016, according to the expert assessment of the activities potential, it is planned to increase the number of repeated frac activities to 260 operations per year (+100 wells to the business plan). In 2016, a new digital information system project – "New Well Drilling Rating" is to be launched. The project guideline has been elaborated, and the new well drilling rating template has been implemented. The system functionality for each new planned well by strata includes a block of geological and process information, computation modules for expert and probabilistic assessment of flowrates, reserves, production capacity with probability 10%, 50% and 90% (hereinafter referred to as P-10, P-50, P-90), a module of the financial economic model for estimation of all development scenarios.

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