a 2022

Understanding of Eocene turbidite system of Nesvačilka paleovalley as a succesfull Oil and Gas exploration target in south eastern part of the Czech Republic

OPLETAL, Vladimír, Slavomír NEHYBA and Tomáš BALDRIÁN

Basic information

Original name

Understanding of Eocene turbidite system of Nesvačilka paleovalley as a succesfull Oil and Gas exploration target in south eastern part of the Czech Republic

Name in Czech

Understanding of Eocene turbidite system of Nesvačilka paleovalley as a succesfull Oil and Gas exploration target in south eastern part of the Czech Republic

Authors

OPLETAL, Vladimír, Slavomír NEHYBA and Tomáš BALDRIÁN

Edition

AAPG Europe Regional Conference 2022, 2022

Other information

Language

English

Type of outcome

Konferenční abstrakt

Field of Study

10505 Geology

Country of publisher

Hungary

Confidentiality degree

není předmětem státního či obchodního tajemství

Organization unit

Faculty of Science
Změněno: 7/12/2022 14:12, prof. RNDr. Slavomír Nehyba, Dr.

Abstract

ORIG CZ

V originále

Two main oil and gas provinces exist in the south-eastern part of Czech Republic. The Vienna Basin where the main hydrocarbon exploration effort was concentrated during major part of 20th century and the Slopes of Bohemian Massif (SBM) area where the successful exploration story required deeper understanding of geology based mainly on the large seismic dataset supported by the intensive well drilling. The complex geological setting of the area consists of oldest crystalline basement of Bohemian Massif and its Palaeozoic, Mesozoic and Cenozoic Sedimentary cover, which are deeply buried here under the thrust units of Outer Western Carpathians. Untill the 1990s the major oil and gas fields were discovered mainly in Jurassic sediments or Precambrian weathered crystalline in the SBM area. In 1993 finally the first oil and gas discovery Karlín proved also hydrocarbon potential of Paleogene sedimentary infill of Nesvačilka paleovalley. In the beginning the exploration focused mainly on basal turbidite system of Nesvačilka paleovalley, known well from older wells results, but after covering of major part of this area by 3D seismic, the younger depositional system formed by gravity flows deposits was recognized also along eastern slope of Nesvačilka paleovalley incised in the older Paleogene depositional system. First hydrocarbon discovery in this depositional system was small oil field Bošovice in 2011. As Nesvačilka paleovalley basin was opened mainly during the end of Cretaceous to Upper Eocene as a major half graben structure with western master fault accompanied by significant amount of related faults perpendicular to its axis it divided the Paleogene sedimentary infill to a number of discrete structural blocks serving here as a sealing barriers for oil and gas migration. One of the largest blocks formed by these Eocene deposits was drilled in 2012 by Borkovany 101 well which discovered the set of Borkovany oil and gas fields. From that time these Eocene sediments were studied in detail and whole Eocene gravity flow depositional system was described in all depth levels within Nesvačilka paleovalley. This gravity flow system formed at the base by debris flows and mud slumps, followed by classical turbidite channel deposits accompanied by turbidite deposits of overbank and crevasse splays was described using the well cores as well as the finer grained distal parts of gravity flow system in the deepest part of Nesvačilka paleovalley.

In Czech

Two main oil and gas provinces exist in the south-eastern part of Czech Republic. The Vienna Basin where the main hydrocarbon exploration effort was concentrated during major part of 20th century and the Slopes of Bohemian Massif (SBM) area where the successful exploration story required deeper understanding of geology based mainly on the large seismic dataset supported by the intensive well drilling. The complex geological setting of the area consists of oldest crystalline basement of Bohemian Massif and its Palaeozoic, Mesozoic and Cenozoic Sedimentary cover, which are deeply buried here under the thrust units of Outer Western Carpathians. Untill the 1990s the major oil and gas fields were discovered mainly in Jurassic sediments or Precambrian weathered crystalline in the SBM area. In 1993 finally the first oil and gas discovery Karlín proved also hydrocarbon potential of Paleogene sedimentary infill of Nesvačilka paleovalley. In the beginning the exploration focused mainly on basal turbidite system of Nesvačilka paleovalley, known well from older wells results, but after covering of major part of this area by 3D seismic, the younger depositional system formed by gravity flows deposits was recognized also along eastern slope of Nesvačilka paleovalley incised in the older Paleogene depositional system. First hydrocarbon discovery in this depositional system was small oil field Bošovice in 2011. As Nesvačilka paleovalley basin was opened mainly during the end of Cretaceous to Upper Eocene as a major half graben structure with western master fault accompanied by significant amount of related faults perpendicular to its axis it divided the Paleogene sedimentary infill to a number of discrete structural blocks serving here as a sealing barriers for oil and gas migration. One of the largest blocks formed by these Eocene deposits was drilled in 2012 by Borkovany 101 well which discovered the set of Borkovany oil and gas fields. From that time these Eocene sediments were studied in detail and whole Eocene gravity flow depositional system was described in all depth levels within Nesvačilka paleovalley. This gravity flow system formed at the base by debris flows and mud slumps, followed by classical turbidite channel deposits accompanied by turbidite deposits of overbank and crevasse splays was described using the well cores as well as the finer grained distal parts of gravity flow system in the deepest part of Nesvačilka paleovalley.