RESERVES AND RESOURCES OF THE DROHOBYCH AREA
Edyna Naftogazova Kompaniya performed a preliminary geological and economic assessment and approved the reserves in the State Commission for Reserves of Ukraine.
In the sedimentary strata involved:
- Paleozoic deposits that are exposed by the well Roliv 1 at a depth of 4200 m
- Mesozoic deposits that are explosed by the wells Grushiv 12 and 13, South Opary 1 and 2, Dovga 1 and Nezhukhiv 1
- Cenozoic formations are exposed by all wells
Promising complexes for hydrocarbon accumulation:
- the first, according to the rating, the Lower Dashava Miocene
- the second, by rating, is the Mesozoic complex, the Upper and Middle Jurassic deposits
- the third, the least studied, and therefore the least perspective, is the Sambir zone Lower Baden complex
The results of reinterpretation of seismic and well data have been specified:
- stratigraphic division of wells within the area with wells outside (Grushiv, Letnja, East Dovge, Gaivske)
- tectonic structure
- structural maps by LD-3, LD-5, LD-7, LD-8, LD-9, LD-12, LD-13, LD-14, LD-15, LD-16, LD-17
- sequence conditions of Lower Dashava sediments. Sequence analysis shows that transgressive sandstones in the top of each LD horizon are potential traps of hydrocarbons (LD-3 and 5 in South Opary 1, LD-7 in Grushiv 13, LD-8 in East Dovge 4, LD-9 in South Opary 1)
- carbonate formations of the Upper Jurassic age are a lateral screen for from LD-13 lower to LD-17 on South Opary, Voroblevycka and Nyzhniogaivska structures. Gas flow from LD-12 and LD-13 10-30 th.m3/day in wells of South Opary and Voroblevycka structures
- found perspective traps of hydrocarbons on Roliv, South Roliv, Nyzhniogaivska, Nezhukhivska, South Nezhukhiv and South Gaivske structures at depth interval 2000-3500 m
- Found in the northwestern part of the area South Ortynytsia structure at depths interval 4500-5500 m
- the perspective of the Lower Baden sediments of the Sambir zone near the well Dorozhiv 1
SUSOLIV GAS FIELD
Susoliv gas field is analogue of South Opary, Voroblevycka, Nyzhniogaiska and South Nezhukhiv structures
Two reservoirs are laterally screened Upper jurassic carbonate deposits. Gas flow from LD-15А 37,6 th.m3/day (int. 2425-2475 m) and from LD-15B 44 th.m3/day (int. 2495-2530 m).
Initial gas reserves 1100 mln.m3.
Well Grushiv-2a was in operation, which opened the Susoliv field. It produced 3.5 million m3 of gas from LD-15.
1. Grushiv 28 located at Susoliv gas field
Reservoirs LD-16-17 don’t testing. Gas flow from Middle Jurassic deposits 10 th. m3 per day.
2. Grushiv 8 located at Grushiv gas and condensate field
From LD-16-17 received from 100 to 200 thousand m3 of gas per day, produced 59 million m3 of gas. From the Middle Jurassic deposits from 137 to 215 thousand m3 of gas per day.
The lateral screen is carbonate deposits of Jurassic age and shale of Badenian age
Mainych gas field
Mainych gas field in Northwestern direction is analogue of Roliv structure
Reservoir is laterally screened Sarmat shale deposits. Gas flow from LD-13 10,9 th.m3/day (int. 3120-3215 m). Initial gas reserves 1000 mln.m3.
Today, a new well with a flow gas rate of 50 th.m3/day has been drilled on the South Zaluzhany area using modern drilling technology.
STRATIGRAPHIC DIVISION
Stratigraphic division of wells within Drohobych area and beyond
Geological conclusions
- The processing and re-interpretation of logging and seismic data was carried out
- The geologic section of lithology and porosity are predicted by means of calculations of these data in deep drilling wells
- New structures are highlighted: South Opary, Voroblevycka, Nyzhniogaivska, South Gaivska, South Nezhukhiv, Roliv, South Roliv, South Ortynychi. Confirmed previously identified structure Nezhukhiv
- The resource base of each structure and its blocks was calculated taking into account the determined gas and oil saturation data in deep drilling wells within the Drohobych area
- Resources of gas 74 mln.m3 – С2 and initial reserves gas – 2096 mln.m3 and 22 th.t of condensate
- Initial reserves gas 3751 mln.m3 – in South Ortynychi hemiantycline
- The revised geological and geophysical information opens perspectives for hydrocarbons production in the Lower Dashava sediments, the Middle Jurassic of the Bilche-Volytsya zone and the Lower Baden Sambir zone
