OREANDA-NEWS. Gazprom Neft has used the recent St Petersburg International Gas Forum (SPIGF) to present proprietary software ensuring optimum efficiency in calculating key criteria in hydraulic fracturing (fracking) at unconventional reservoirs (the so-called “Bazhenov” formation). The new simulator was developed in conjunction with the Moscow Institute of Physics and Technology, and is currently the only IT product in the world developed specifically for the Bazhenov strata.
The programme developed helps assess how a crack or fissure will develop within the strata, and allows its form (length, thickness, width and other geometric characteristics) to be simulated, as well as allowing an assessment to be made of the amount of oil likely to be produced through such borehole. Highly complex mathematical and physical models are used to assess the impact of dozens of variables.
The Gazprom Neft Joint Scientific and Research Centre, together with leading Russian research institutes, is involved in developing technologies for the development of unconventional reserves. Work is being undertaken as part of a federal programme for extensive research into the Bazhenov formation.
The “Bazhenov formation” refers to a specific geological stratum identified in the centre of Western Siberia, running to depths of 2,000–3,000 metres. Estimates suggest that oil reserves at the Bazhenov reservoir could amount to as much as 100–170 billion tonnes in Western Siberia alone. The stratum covers an area of approximately one million square kilometres and is 10–100 metres thick.The Bazhenov formation is classified as unconventional type of reserves, comprising what is known as “shale oil”, development of which currently awaits the selection of technological solutions for its full-scale development.
Hydraulic fracturing is one of the most effective means of stimulating production, particularly in unconventional and hard-to-recover reserves, including shale oil, as is the case at the Bazhenov formation. Hydraulic fracturing, moreover — a technologically complex and rather expensive operation — requires intensive preparatory works. The outcomes of such modelling allow optimum criteria for fracking to be selected.
Alexey Vashkevich, Head of the Directorate for Geological Exploration and Resource-base development, Gazprom Neft, commented: “Our main job is to devise strategies for developing the Bazhenov formation that are as user-friendly as those used in traditional reserves. The Bazhenov formation differs from traditional strata in being practically impenetrable. The main purpose of the technologies we have developed is to create artificial conductive-fissure systems. The simulator we have developed allows us, in fact, to work out how to maximise coverage of strata through a fracture network and secure a viable oil inflow.”