Development of Natural Bitumen Fields

APPLICATION OF NEW TECHNIQUES AND TECHNOLOGIES FOR THE DEVELOPMENT OF DEPOSITS OF NATURAL BITUMEN FIELDS

The Republic of Tatarstan possesses significant reserves of heavy and extra viscous bituminous oils (over 1.4 billion tonnes). About 450 deposits have been identified with majority of them confined to the depth of 50-250 m.

Since 2006, PJSC TATNEFT has initiated a pilot project at Ashalchinskoye field to test a modified heat stimulation technology through dual wellhead horizontal wells. (Patent of the Russian Federation No. 2287677). There are three pairs of dual wellbore wells at the site with a horizontal section length from 200 to 400 meters.

According to the Company's plans to develop extra-viscous oil fields, pilot works were carried out in the Sheshminsky horizon deposits of Ashalchinskoye heavy oil field.

Location of Horizontal Day Drift Wells

A method had been developed to control the process of steam assisted gravity stimulation using dual wellhead horizontal wells, providing for creation of a steam chamber and uniform heating of the interwell area, preventing steam breakthrough into producing wells from steam injectors and maximizing oil production at an optimal steam-oil ratio (RF patent №2340768). The site includes three pairs of dual head wells with a horizontal section of 200 to 400 m long.

Implementation of the technology demonstrated the works prospectivity: horizontal wells produce up to 20 tonnes per day (with an average production rate of conventional oil wells amounting to 4 tonnes per day), which is 8 to 10-fold higher than in case of vertical wells.

In 2015, the Company continued implementation of one of the most strategically important activities: the project of extra-viscous oil (EVO) development at Ashalchinskoye field: the production volume amounted to 376.4 thousand tonnes with the production growth compared to the previous year accounting for about 60%. Upon the whole, starting with the beginning of the pilot development operations the total production volume of EVO amounted to 930 thousand tonnes at the end of 2015. The plans for 2016 envisage the EVO production in the amount of at least 531 thousand tonnes.