Geološka karakterizacija 3D seizmičkog zapisa u gornjomiocenskim naslagama sjevernog dijela Bjelovarske subdepresije

doctoral thesis

• Title (english): Geological characterization of the 3Dd seismic record in the upper miocene deposits of the northern part of Bjelovar subdepression
• Author: Tihana Ružić
• Mentor: Marijan Kovačić (mentor)
• Mentor: Marko Cvetković (mentor)
• Committee member: Davor Pavelić (predsjednik povjerenstva)
• Committee member: Katarina Gobo (član povjerenstva)
• Committee member: Alan Vranjković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geology); Zagreb
• Defense date and country: 2021-12-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology; Mineralogy and Petrology
• Universal decimal classification (UDC): 55 - Geology. Meteorology. Hydrology

Abstract

Područje istraživanja nalazi se u sjevernom dijelu Bjelovarske subdepresije. Na ovom su području
izbušene tri bušotine: B-1, B-2 i B-3. Bušotinom B-1 nađena su dva plinska ležišta unutar pješčenjaka Pepelana,
člana formacije Kloštar Ivanić. U bušotinama B-2 i B-3 nisu dokazane značajnije pojave ugljikovodika, već
količine plinova u vrlo malim postocima. Na temelju analize jednostavnih i kombiniranih seizmičkih atributa, te
primarnih i sekundarnih AVO (Amplitude versus offset) atributa krovine dvaju ležišta i pripadajućih
litostratigrafskih ekvivalenata zaključeno je da se bušotina B-1 nalazi u području povećanih amplituda na gotovo
svim atributima. Izrazito razgraničenje između pozitivne i negativnih bušotina pokazuju sekundarni AVO atributi
Sign(Intercept)*gradient i Intercept*Gradient, te njihova primjena ukazuje na pozitivne indikacije u budućim
istraživanjima ležišta plina. Rezultati analiza vrijednosti odabranih svojstava (spontani potencijal, gustoća,
otpornost, brzina) pomoću neuronskih mreža pokazuju slične rezultate na području pozitivne bušotine B-1.
Usporedno tumačenje geometrijskog atributa koherencije i kombiniranog seizmičkog atributa spektralne
dekompozicije zajedno sa atributom dobivenog AVO RGB Blending metodom jasnije opisuje razlomljene zone,
obrise kanala, kanale i turbiditne lepeze na jugu i jugoistoku analiziranog područja, te bi ta vrsta primjene bila od
koristi za točniju interpretaciju u budućim istraživanjima.

Abstract (english)

The research area is in the northern part of the Bjelovar subdepression. Three wells were drilled in this
area: B-1, B-2, and B-3. Two gas accumulations were discovered in well B-1, within the Pepelan sandstone, which
is a member of the Kloštar Ivanić formation. No significant occurrences of hydrocarbons were proven in wells B-
2 and B-3, except for gas in very small percentages. Based on the analysis of simple and combined seismic
attributes, and primary and secondary AVO (Amplitude versus offset) attributes of two resevoirs and associated
lithostratigraphic equivalents, it was concluded that well B-1 is in the range of increased amplitudes on almost all
attributes. A distinction between positive and negative wells is shown by the secondary AVO attributes Sign
(Intercept) * gradient and Intercept * Gradient, and their application may be useful for future gas reservoir
exploration. The results of the analysis of the values of selected properties (spontaneous potential, density,
resistivity, velocity) using neural networks show similar results in the positive B-1 well.
Comparative interpretation of the geometric attribute of coherence and the combined seismic attribute of spectral
decomposition together with the attribute obtained by the AVO RGB Blending method more clearly describes the
faults, channel contours, channels and turbidite fans in the south and southeast of the analyzed area. and this type
of application would be useful for as accurate an interpretation as possible in future research.

• Keywords: Bjelovarska subdepresija; seizmički atributi; AVO analiza; seizmičke inverzije; istraživanje ugljikovodika
• Keywords (english): Bjelovar subdepression; seismic attributes; AVO analysis; seismic inversions; hydrocarbon exploration
• Language: croatian
• URN:NBN: urn:nbn:hr:217:081396
• Study programme: Title: Doctoral study of Geology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje geologija (doktor/doktorica znanosti, područje prirodnih znanosti, polje geologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-02-17 11:27:49