OREANDA-NEWS. Gazprom Neft has begun investigating reserves at the Bazhenov formation* at Vyngayakhinskoye field, Yamalo-Nenets Autonomous Okrug (a project currently being implemented by Gazpromneft-Muravlenko). Marking the company’s first foray into the investigation of unconventional reserves (a category that includes the Bazhenov formation) Gazprom Neft has, hitherto, been concentrating on identifying the most viable technologies to develop the Bazhenov deposit, most of which is located within the Khanty Mansiysk Autonomous Okrug.**

Late 2015 saw Gazprom Neft undertake hydraulic fracking at Bazhenov strata of Vyngayakhinskoye field via two directional wells previously used for oil production from traditional reservoirs, albeit passing through the strata of the Bazhenov deposit. Hydraulic fracking undertaken at both wells saw oil inflow obtained. A prospecting directional well was also drilled, to allow the direct investigation and development of reserves at the Bazhenov formation, with a 90-metre well core sample obtained during drilling, for further laboratory analysis. This well is expected to be used for hydraulic fracking shortly.

Work on unconventional reserves is a priority area for strategic development within Gazprom Neft. The Bazhenov deposits are widely distributed throughout Western Siberia, and their development — within a region of already developed infrastructure — could, in the future, become a new area of production growth. Several initiatives in working with unconventional reserves are being implemented as part of Gazprom Neft’s Technology Strategy. Priorities here include the development of the first simulation software for the modelling of hydraulic fracking at the Bazhenov deposits, and the development of technology for forecasting hydrocarbon saturation (i.e., oil- and gas-bearing capacity) therein, allowing to identify the most promising blocks. Under the auspices of this initiative, Gazprom Neft is working on developing a map outlining the distribution and characteristics of unconventional reserves throughout Russia.

Vadim Yakovlev, First Deputy CEO and Head of Upstream Division, Gazprom Neft, commented: “We continue to build on our experience in investigating the Bazhenov formation. Starting this new project at the Vyngayakhinskoye field will give us a better understanding of how unconventional reserves can be better incorporated into commercial production. Opening up this formation — which, thus far, remains practically undeveloped — will, in the future, make a considerable contribution to oil production and extend the life of our fields. It is for this reason that work with unconventional resources remains one of the key areas of focus of our Technology Strategy.”

The Bazhenov formation is characterised by dense clay material, believed to have a high level of oil saturation (containing an anomalously high proportion of organic material, giving rise to the presence of oil). Practically no commercial development is currently ongoing at the Bazhenov formation, with work instead directed at identifying economically viable strategies for developing these reserves. A unique feature of the Bazhenov formation — and what determines its commercial value — is its high level of oil saturation, and, moreover, the high-quality of this — light and low-sulphur, making it easier to refine.

An initial exploration well was also drilled at the Archinskoye field (Tomsk Oblast) in 2015, again to allow investigation of the Bazhenov formation, with a well-core sample extracted, now under analysis at specialist institutions. Late 2015 also saw the company obtaining licences to three further concessions in the Khanty Mansiysk Autonomous Okrug, at which unconventional oil reserves are expected to be developed.

In addition to this, autumn 2015 saw a new specialist Gazprom Neft-supported faculty, “Technologies for Enhanced Oil Recovery in Tight Reserves” (including unconventional reserves), opened at the Gubkin Russian State Oil and Gas University, offering a two-year specialist master’s programme.

* 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. While the stratum covers an area of approximately one million square kilometres, it is comparatively thin, with an average thickness of about 40 metres. Estimates suggest that oil reserves at the Bazhenov reservoir could amount to as much as 100–170 billion tonnes in Western Siberia alone.

** Gazprom Neft is currently implementing two major projects directed at investigating the Bazhenov formation: at the Palyanovskaya deposit (Krasnoleninskoye field), and at the Yuzhno-Priobskoye field (both of which are located in the Khanty Mansiysk Autonomous Okrug). Several directional wells have been drilled at these fields to allow the development of unconventional deposits, with hydraulic fracking of the strata undertaken, and oil flow obtained. Two initial horizontal wells were also drilled last year at the Palyanovskaya deposit, and multi-stage fracking undertaken.