Abstract: The oil controlled reserves conversion has become the main resource of the proven reserves in Jiyang depression. Increase of exploratory workload, reevaluation of the old wells and development of testing techniques are the main reasons of the oil controlled reserves conversion in Jiyang depression. Some factors such as reserves scale, reserves abundance, productivity and buried depth of the reservoirs are influencing the conversion of the controlled reserves blocks greatly. It is concluded that the oil controlled reserves block with reserves scale over 500×10⁴ t, reserves abundance over 50×10⁴ t/km², buried depth less than 3 500 m, steady productivity per 1 000 m footage over 2.8 t/km·d (on land) or 202.8 t/km·d (in shallow sea) can be converted into oil proven reserves on the whole.

Key words: Jiyang depression, oil controlled reserves, proven reserves, reservies conversion