Lithological and paleogeographic conditions for the formation of oil fields with complex clay reservoirs by example of Khadum-Batalpashinsk deposits

UDK: 553.98
DOI: 10.24887/0028-2448-2020-5-26-30
Key words: oil fields, clay reservoirs, oil-and-gas content, reservoir properties, suite, rock carbonate content, density, rock porosity, rock fracturing
Authors: R.A. Gasumov (SevKavNIPIgaz JSC, RF, Stavropol), E.R. Gasumov (Azerbaijan State University of Oil and Industry, Azerbaijan, Baku)

Most of small oil fields in the South of Russia have complex unconventional fractured clay reservoirs in geological section. To justify the effectiveness of prospecting and exploration, it is necessary to characterize the petrophysical model of the reservoir properties in the productive Khadum-Batalpashinsk deposits. During certain processes, clay Oligocene rocks acquire effective porosity, become reservoirs with necessary filtration-capacitive properties, and are one of the reserves for expanding the mineral resource base. The study found that the thin pores of the matrix and the thin inter-plate and inter-sheet voids are filled with film, capillary and free water disconnected and immobile. Oil content in clays is in the form of films and lenses along lithogenetic cracks that develop along the planes of bedding of clays of various compositions. Oil mobility is provided by cracks with increased openness. The results of study of the paleogeographic conditions of sedimentation show that the productive stratum consists of two clay reservoir rocks different in reservoir properties. There is a tendency to form first, primarily, clay strata in the Khadum and then the Batalpashinsk strata with improved reservoir properties. A study of the lithological characteristics of Lower Maikop sediments allowed to conclude that there is a wide siderite formation of rocks, including clay, previously rated as ‘non-carbonate’. It was revealed that if the contrast of petrophysical parameters can serve as a criterion for the oil content of a section in a particular well, then the uniformity of the rocks composing it can serve as a criterion for determining the productivity of a particular interval. This feature confirms the fact of the influence of secondary physical and chemical processes, under the influence of which the leveling of the petrophysical parameters of the rocks occurs in accordance with the new thermodynamic conditions. The considered complex of geological, geophysical, and laboratory methods of searching for oil in clay deposits enables to increase the efficiency of exploration.

References

1. Gasumov R.A., Causes of fluid entry absence when developing wells of small deposits (on the example of Khadum-Batalpashinsky horizon) (In Russ.), Zapiski Gornogo instituta = Journal of Mining Institute, 2018, V. 234, pp. 630–636.

2. Aksakalova Yu.S., The main directions of the search for non-structural type traps in the Central and Eastern Ciscaucasia (In Russ.), Vestnik SevKavGTU, 2009, no. 3, pp. 6–11.

3. Gasumov R.A., The specifics of operating minor deposits (as given by the examples of gas condensate deposits of the Northern Caucasus) (In Russ.), Zapiski Gornogo instituta = Journal of Mining Institute, 2016, V. 220, pp. 556–563.

4. Gasumov R.A., Gridin V.A. Kopchenkov V.G. et al., Research of mining and geological conditions for geological exploration in Pre-Caucasian Region (In Russ.), Zapiski Gornogo instituta = Journal of Mining Institute, 2017, V. 228, pp. 654–661.

5. Gasumov R.A., Kerimov I.A., Kharchenko V.M., The influence of geological factors on the collecting properties of productive formations composed of fractured clay reservoirs while their drilling-in (In Russ.), Stroitel'stvo neftyanykh i gazovykh skvazhin na sushe i na more, 2018, no. 7, pp. 28–32.

6. Gasumov R.A., Kerimov I.A., Kharchenko V.M., Permeability of clay reservoirs of small deposits (In Russ.), Neftepromyslovoe delo, 2018, no. 8, pp. 46–52.

7. Gasumov R.A., Substantiation of lower Maikop petroleum saturated claystone sections and their permeability (for example - some North Caucasus filds) (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2018, no. 3, V. 13, https://doi.org/10.17353/2070-5379/31_ 2018.

8. Gasumov R.A., Selection and assessment of filtration-capacitive parameters for clay reservoirs (In Russ.), Nauka. Innovatsii. Tekhnologii, 2018, no. 2, pp. 115–126.

9. Gasumov R.A., Nelepov S.V., Nelepov M.V. et al., The influence of a formation geo-mechanical properties on the success of geological-technical measures when developing the fields of the Eastern Pre-Caucasus (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2017, no. 11, pp. 59–65.

10. Gasumov R.A., Gasumov E.R., Geological factors influence on oilwells flooding at small fields (In Russ.), Nauka. Innovatsii. Tekhnologii, 2019, no. 4, pp. 8–18.

Most of small oil fields in the South of Russia have complex unconventional fractured clay reservoirs in geological section. To justify the effectiveness of prospecting and exploration, it is necessary to characterize the petrophysical model of the reservoir properties in the productive Khadum-Batalpashinsk deposits. During certain processes, clay Oligocene rocks acquire effective porosity, become reservoirs with necessary filtration-capacitive properties, and are one of the reserves for expanding the mineral resource base. The study found that the thin pores of the matrix and the thin inter-plate and inter-sheet voids are filled with film, capillary and free water disconnected and immobile. Oil content in clays is in the form of films and lenses along lithogenetic cracks that develop along the planes of bedding of clays of various compositions. Oil mobility is provided by cracks with increased openness. The results of study of the paleogeographic conditions of sedimentation show that the productive stratum consists of two clay reservoir rocks different in reservoir properties. There is a tendency to form first, primarily, clay strata in the Khadum and then the Batalpashinsk strata with improved reservoir properties. A study of the lithological characteristics of Lower Maikop sediments allowed to conclude that there is a wide siderite formation of rocks, including clay, previously rated as ‘non-carbonate’. It was revealed that if the contrast of petrophysical parameters can serve as a criterion for the oil content of a section in a particular well, then the uniformity of the rocks composing it can serve as a criterion for determining the productivity of a particular interval. This feature confirms the fact of the influence of secondary physical and chemical processes, under the influence of which the leveling of the petrophysical parameters of the rocks occurs in accordance with the new thermodynamic conditions. The considered complex of geological, geophysical, and laboratory methods of searching for oil in clay deposits enables to increase the efficiency of exploration.

References

1. Gasumov R.A., Causes of fluid entry absence when developing wells of small deposits (on the example of Khadum-Batalpashinsky horizon) (In Russ.), Zapiski Gornogo instituta = Journal of Mining Institute, 2018, V. 234, pp. 630–636.

2. Aksakalova Yu.S., The main directions of the search for non-structural type traps in the Central and Eastern Ciscaucasia (In Russ.), Vestnik SevKavGTU, 2009, no. 3, pp. 6–11.

3. Gasumov R.A., The specifics of operating minor deposits (as given by the examples of gas condensate deposits of the Northern Caucasus) (In Russ.), Zapiski Gornogo instituta = Journal of Mining Institute, 2016, V. 220, pp. 556–563.

4. Gasumov R.A., Gridin V.A. Kopchenkov V.G. et al., Research of mining and geological conditions for geological exploration in Pre-Caucasian Region (In Russ.), Zapiski Gornogo instituta = Journal of Mining Institute, 2017, V. 228, pp. 654–661.

5. Gasumov R.A., Kerimov I.A., Kharchenko V.M., The influence of geological factors on the collecting properties of productive formations composed of fractured clay reservoirs while their drilling-in (In Russ.), Stroitel'stvo neftyanykh i gazovykh skvazhin na sushe i na more, 2018, no. 7, pp. 28–32.

6. Gasumov R.A., Kerimov I.A., Kharchenko V.M., Permeability of clay reservoirs of small deposits (In Russ.), Neftepromyslovoe delo, 2018, no. 8, pp. 46–52.

7. Gasumov R.A., Substantiation of lower Maikop petroleum saturated claystone sections and their permeability (for example - some North Caucasus filds) (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2018, no. 3, V. 13, https://doi.org/10.17353/2070-5379/31_ 2018.

8. Gasumov R.A., Selection and assessment of filtration-capacitive parameters for clay reservoirs (In Russ.), Nauka. Innovatsii. Tekhnologii, 2018, no. 2, pp. 115–126.

9. Gasumov R.A., Nelepov S.V., Nelepov M.V. et al., The influence of a formation geo-mechanical properties on the success of geological-technical measures when developing the fields of the Eastern Pre-Caucasus (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2017, no. 11, pp. 59–65.

10. Gasumov R.A., Gasumov E.R., Geological factors influence on oilwells flooding at small fields (In Russ.), Nauka. Innovatsii. Tekhnologii, 2019, no. 4, pp. 8–18.



Attention!
To buy the complete text of article (a format - PDF) or to read the material which is in open access only the authorized visitors of the website can. .

Mobile applications

Read our magazine on mobile devices

Загрузить в Google play

Press Releases

11.10.2021
07.10.2021
29.09.2021
Конкурс на соискание молодежной премии имени академика И.М. Губкина