Development of Natural Bitumen Fields

Application of New Techniques and Technologies for the Development of Deposits of Natural Bitumen Fields

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

Since 2006, OAO 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 Number 2287677). There are three pairs of double wellbore wells at the site with a horizontal section length from 200 to 400 meters.

Location of Horizontal Wells Reaching out to the Surface
A modified method of controlled steam assisted gravity drainage (SAGD) has been developed with application of dual wellhead horizontal wells, providing for forming of a steaming chamber and uniform heating of the interwell zone without breakthrough of the steam to the steam injector and receiving maximum oil production with the optimal rate steam/oil ratio. (Patent of the Russian Federation Number 2340768).

As of December 1, 2008 the oil production from two pairs of horizontal wells of the Ashalchinskoye field pilot area amounted to 18.3 thousand tons with the total amount of 141.1 thousand tons of the liquid produced. 78.2 thousand tons of steam have been injected. The aggregate production rates currently amount to 33-36 tons of oil per day. The average current steam/oil ratio is 3.2 t/ t.

Implementation of the technology showed promising results of work: horizontal wells yield up to 20 tons of oil per day (with an average rate for conventional oil amounting to 4 t/d), which is 8-10 times higher versus the rates of vertical wells.

There are plans to expand the operations throughout the Ashalchinskoye field: the plans provide for drilling 29 pairs of horizontal wells, 39 single horizontal wells and 69 vertical wells.