This paper presents core data on the composition and reservoir properties of the Tourneisian carbonate rocks in typical well section on the southern slope of South-Tatarian Arc. The core data include structures, minerals, reservoir properties measurements from previous studies and geochemical signs, just received by method of electron spin resonance (ESR).
Investigated interval of 12 m thickness belongs to an upper part of the Tourneisian stage. It is composed of two layers: upper grainstone layer (5 m) and lower packstone layer (7 m). The granulated fossils predominate in the studied limestones. A porous space is controlled by primary structures and also by leaching processes, a secondary calcite mineralization and stylolites.
ESR data have been obtained on 21 samples collected with a step 0.4-0.6 m along the section. ESR spectra are characterized by narrow lines, pointing on a marine genesis of the carbonates. Paramagnetic centers of Mn2+ and SO2- have been observed as typical features of the rocks due by primary processes of carbonate sedimentation.A spatial distribution of limestones types, its geochemical and reservoir signatures is explained by the sedimentary succession of progradation type. The calcite mineralization and a distribution of Mn2+ and SO2- paramagnetic ions have been determined along the section profile simultaneously with reservoir zoning due by facies and a history of hydrocarbons.
1. Nurgalieva N.G., Microfacies, petrophysics and sequence-stratigraphic
frame of carbonate reservoir rocks of Kizelovskian formation (In Russ.),
Neftyanoe khozyaystvo = Oil Industry, 2012, no. 3, pp. 38–40.
2. Nurgalieva N.G., Smelkov V.M., Kal’cheva A.V., Lithological and petrophysical
features of Famenian and Tournesian carbonate reservoir rocks (In
Russ.), Neft’. Gaz. Novatsii, 2013, no. 4, pp. 38–44.
3. Nurgalieva N.D., Nurgalieva N.G., Cluster Image Processing technique
for porosity estimation of carbonate rocks, ARPN JEAS, 2015, V. 10, no. 4,
4. Nurgalieva N.D., Nurgalieva N.G., Porosity estimation of carbonate rocks
with Multispec processing technique, ARPN JEAS, 2014, no. 1, pp. 20–24.
5. Evdokimov S.A., Nurgalieva N.G., Kadyrov R.I., Evdokimova E.A., Some
modern methods of the pore space studying in the carboniferous carbonate
rocks, 75th EAGE Conference & Exhibition incorporating SPE EUROPEC
2013 Session: Carbonate Depositional Environments & diagenesis. 10 June
2013 – DOI: 10.3997/2214 – 4609.20130687.
6. Geologicheskoe stroenie i neftegazonosnost’ Orenburgskoy oblasti (Geology
and oil and gas potential of Orenburg region), Orenburg: Orenburg
Publishing House, 1997, 272 p.
7. Dunham R.J., Classification of carbonate rocks according to depositional
texture, In: Classification of carbonate rocks according to depositional
texture. In: Classification of carbonate rocks – a symposium, AAPG
Mem., 1962, no. 1, pp. 108–121.
8. Lucia F.J., Rock fabric/petrophysical classification of carbonate pore
space for reservoir characterization, AAPG Bulletin, 1995, V. 79, no. 9,
9. Bulka G.R., Nizamutdinov N.M., Mukhutdinova N.G. et al., ESR probes in
sedimentary rocks: the features of Mn2+ and free radicals distribution in the
Permian formation in Tatarstan, Applied Magnetic Resonance, 1991, V. 2,
no. 1, pp. 107–115.
10. Nurgalieva N.G., Galeev A.A., Issledovanie porod metodom ESR (Research
of rocks by ESR method), Collected papers “Stratotipicheskiy razrez
tatarskogo yarusa na reke Vyatke” (Stratigraphic section of Tatarian stage
on the Vyatka River), Moscow: GEOS Publ., 2001, pp. 56–68.
11. Nurgalieva N.G., Khasanova N.M., Gabdrakhmanov R.R., Conditions of
formation of Urzhum stage deposits on ESR data (In Russ.), Uchenye zapiski
Kazanskogo universiteta. Ser. Estestvennye nauki, 2010, V. 152, no. 1,
12. Fakhrutdinov E.I., Nurgalieva N.G., Khasanova N.M., Silant’ev V.V., The
Lower Kazanian substage in the key section: lithologies and paleoenvironments
based on the ESR data (In Russ.), Uchenye zapiski Kazanskogo universiteta,
2015, V. 157, no. 3, pp. 87–101.