Dolyna oil field
Dolyna oil field. One of the largest petroleum fields in Ukraine, located in Dolyna raion, Ivano-Frankivske oblast, in Subcarpathia. The field was discovered in 1949, and the first well began production in 1950. It covers an area of 32 sq km. The petroleum is found in sandstone of the Paleogene period at a depth of 1,600–3,000 m. The thickness of individual petroleum beds varies from a few meters to 120 m. The oil contains 6.1–10.1 percent paraffin and 17.0–23.8 percent tar, but practically no sulfur.