MULTIZONE ACID HYDRAULIC FRACTURING OF DOMANIK DEPOSITS IN THE BAVLY OIL FIELD
Contribution of oil-saturated shales to the World oil production rapidly grows. In a short period of time North America could overcome the tendency oil production decline owing to development of only two shale oil fields - the Bakken and Eagle Ford. Deterioration of the structure of reserves and acute problem of their renewal does make the development of similar deposits in Tatarstan extremely urgent. Analogs of the shale formations of the North American platform in Russia are as follows: the Bazhenov shales in West Siberia, Domanik deposits in the Volga-Ural and Timan-Pechora oil-and-gas provinces and Khadum suite in the Pre-Caucasus. Technologies of production of nonconventional HC are dictated not only by chemical-physical properties of the HC and geological and physical characteristics of the reservoir rocks, but also (and quite substantially) by their lithological properties. Each “shale” field of “tight” oil is known to require its own production technology, however in general all the technologies follow the scheme as follows: drilling wells terminated by a horizontal hole with e subsequent multistage hydraulic fracturing of the productive layer. In the first quarter of 2015 at the Novo-Bavlinsk part of the Bavly oil field a horizontal well (Well 2917г) was drilled with horizontal borehole in the Domanik layer of the Dankov-Lebedyansk (DDL) horizon. The horizontal hole 264,5 m long was designed and drilled based on geophysical and well logging data acquired in the pilot hole and results of special analyses of oriented core. To attain higher efficiency of the layer hydraulic fracturing, i.e. obtain a higher flow rate, at these particular geological conditions it is necessary to perform various versions of NBZT (near-borehole zone treatment) and MAHF with use of acid solutions at different operating conditions (varying pumping-in pressure, pumped volumes, concentrations, flow rates, etc.).