A replenishment oiler or replenishment tanker is a naval auxiliary ship with fuel tanks and dry cargo holds which can supply both fuel and dry stores during underway replenishment at sea. As the Soviet Navy began to more regularly operate in large areas of the world's oceans and because of the emergence of the Kiev-class aircraft carriers, demand for large surface supply ships increased. For these purposes, also were used civil tankers who transferred to the Navy. The Olekma class is a two civil fleet replenishment oilers (Olekma and Iman) built in 1960s for the USSR in Finland as part of a large series of civilian tankers of the Drogobych type.

The maximum length of the ship is 105,4 m, the maximum width 14,8 m and draft 6 m. When in standard load, the ship has displacement about 2,040 tons and 6,480 tons while fully loaded. Endurance of the ships is 20 days during which they can travel the distance about 4,000 nm. The oilers of this class are equipped with a device for the transfer of goods in move by the traverse method. This allows carrying out cargo operations during significant sea waves. Capacity -fuel tank for 1,500 t, 500 t of diesel fuel, 150 t of lubricants, 500 t of water, 50 t of food.

Replenishment Oiler Iman laid down at the Rauma-Repola Shipyard, Finland (yard No.155), launched 03 June 1966, commissioned 03 September 1966 and was assigned to the Black Sea Fleet.

Now in service.