Gazpromneft Khantos has completed testing of an initial two wells, drilled to allow analysis of deposits in the Bazhenov formation, in the south of the Priobskoye oilfield. Hydraulic fracturing (fracking) was undertaken at both (directionally drilled) wells, and an inflow of hydrocarbons obtained; testing of a further two similar wells is to be undertaken in the nearest future.
Gazpromneft Khantos has, for many years, undertaken development of traditional oil reserves at the Southern Priobskoye field, before obtaining a licence for geological prospecting at promising deep oil-saturated strata (the Bazhenov and Tyumen formations) in March 2014. The strata lie at a depth of 2,000–3,000 metres, and the low filtration properties (flow capacity) of the underlying geology mean the reserves contained therein are hard-to-recover. The Bazhenov and Abalaksky formations are also categorised as unconventional (“tight”) reserves, or “shale oil”.
Analysis of geophysical data, specialist research of well-core data, and repeated analysis of 3D seismic data was undertaken at the Bazhenov-Abalaksky Southern Priobskoye field in 2014. The first stage in the prospecting programme for this category of reserves envisages the directional drilling of four prospecting and appraisal wells.
The key objective of the current phase of the prospecting programme at the Bazhenov strata will be the clarification of the nature of the geology, and the confirmation of the existence of mobile original oil in place (MOOIP). The next step will then be lateral extended-reach drilling, together with multi-stage hydraulic fracturing, in order to determine initial and subsequent changes in flow rates at individual wells and, subsequently, to evaluate volumes of recoverable reserves. Plans for 2016 include the continuation of 3D seismic and the drilling of horizontal wells.
Gazprom Neft’s second project in the independent prospecting of shale deposits involves work at the Palyanovsky reserves at the Krasnoleninsky field, Khanty-Mansiysk Autonomous Region. A new prospecting programme, initiated in autumn 2014, envisages the drilling of four horizontal wells, consistently increasing the length of the horizontal sections and the frequency of multi-stage fracking. Drilling of the first well (with a horizontal shaft of more than 200 metres in depth) has been completed, with multi-stage fracking expected to begin as soon as possible.