OVOCA Resources has secured an option in respect of a 50 per cent interest in four oilfields in western Siberia, Russia. The consideration involves the issue of 2.1 million Ovoca ordinary shares at 15p each. This places a value of £42,000 on the option. Quad Engineering, commissioned by Ovoca, has concluded that the four wells have proven and probable reserves of more than 500 million barrels of oil.