Reservoir simulation modeling of Bobric formations considering rheological properties of oil

UDK: 665.61.035.6+622.276.1/.4.001.57
Key words: structural and mechanical properties, yield limit, non-Newtonian fluid, development system, oil recovery factor
Authors: R.Kh. Nizaev, R.Sh. Nazmutdinov, R.I. Khafizov (TatNIPIneft, RF, Bugulma)

Over the past decades, high-viscosity and heavy oil fields have been explored and put on stream. Generally, these oils have viscoplastic properties due to high-molecular-weight components, such as resins and asphaltenes. This paper presents some aspects of producing oils that behave like non-Newtonian fluids. Based on the analysis of crude oil rheology in Tatarstan fields, interpretation technique has been developed for the available data to be used in reservoir simulators. This paper reviews various fluid types and analyzes viscosity versus shear rate. It is concluded that in reality, fluids often demonstrate pseudo-plastic characteristics with yield limits, and require more complicated equations to characterize their flow behavior, compared to Newtonian fluids.

By the example of Bobrik horizon, the Melninsky field, pressure differential –viscosity relationship has been identified wherein simulated cutoff values of these parameters yield a 5% error, compared to the case without regard to oil viscoplastic properties. Numerical studies prove the necessity of considering the structural and mechanical oil properties. When modeling oil fields where these properties are well-pronounced, pressure gradient distribution maps should be used based on isobar maps to identify the most promising areas for reservoir stimulation operations, including infill drilling, reservoir pressure maintenance, and formation heating. Optimization of reservoir pressure maintenance system and denser well spacing pattern increase sweep efficiency and maintain pressure differential required for heavy oil flowing while providing a larger radial extent of the reservoir.  Formation heating reduces the effect of viscoplastic properties in the zones with low oil mobility.
References
1. Devlikamov V.V., Khabibullin Z.A., Kabirov M.M., Anomalnye nefti (Anomalous
oil), Moscow: Nedra Publ., 1975, 168 p.
2. Khafizov R.I. Nizaev R.Kh. Burkhanov R.N., High viscosity energy sources development
features: a case study of the Urmyshlinskoye oil field (In Russ.), Vestnik
TsKR Rosnedra, 2015, no. 5–6, pp. 40–45.
3. Khamidullin F.F. Amerkhanov, I.I., Gibadullin A.A., Reologicheskie svoystva
neftey i vodoneftyanykh emul'siy na mestorozhdeniyakh Respubliki Tatarstan:
spravochnik (The rheological properties of oil and oil-water emulsions in the
fields of the Republic of Tatarstan: Handbook), Bugul'ma, 2001, 557 p.
4. Sultanov B.N., About viscoplastic fluid filtration in porous media (In Russ.),
Izvestiya AN Azerbaydzhanskoy SSR, 1960, no. 5.
5. Nazmutdinov R.Sh., The influence of viscoplastic properties of oil on petroleum
development (In Russ.), Uchenye zapiski Al'met'evskogo gosudarstvennogo
neftyanogo instituta, 2015, V. 13, no. 1, pp. 60-63.
6. Nizaev R.Kh., Gus'kova I.A., Nazmutdinov R.Sh., Development of oil reservoirs
with non-Newtonian fluids (In Russ.), Neftyanaya provintsiya, 2015,
no. 2, pp. 92-101, URL:
http://media.wix.com/ugd/2e67f9_f99d238efdec4dab98cc9e25bcb933
5b.pdf.

Over the past decades, high-viscosity and heavy oil fields have been explored and put on stream. Generally, these oils have viscoplastic properties due to high-molecular-weight components, such as resins and asphaltenes. This paper presents some aspects of producing oils that behave like non-Newtonian fluids. Based on the analysis of crude oil rheology in Tatarstan fields, interpretation technique has been developed for the available data to be used in reservoir simulators. This paper reviews various fluid types and analyzes viscosity versus shear rate. It is concluded that in reality, fluids often demonstrate pseudo-plastic characteristics with yield limits, and require more complicated equations to characterize their flow behavior, compared to Newtonian fluids.

By the example of Bobrik horizon, the Melninsky field, pressure differential –viscosity relationship has been identified wherein simulated cutoff values of these parameters yield a 5% error, compared to the case without regard to oil viscoplastic properties. Numerical studies prove the necessity of considering the structural and mechanical oil properties. When modeling oil fields where these properties are well-pronounced, pressure gradient distribution maps should be used based on isobar maps to identify the most promising areas for reservoir stimulation operations, including infill drilling, reservoir pressure maintenance, and formation heating. Optimization of reservoir pressure maintenance system and denser well spacing pattern increase sweep efficiency and maintain pressure differential required for heavy oil flowing while providing a larger radial extent of the reservoir.  Formation heating reduces the effect of viscoplastic properties in the zones with low oil mobility.
References
1. Devlikamov V.V., Khabibullin Z.A., Kabirov M.M., Anomalnye nefti (Anomalous
oil), Moscow: Nedra Publ., 1975, 168 p.
2. Khafizov R.I. Nizaev R.Kh. Burkhanov R.N., High viscosity energy sources development
features: a case study of the Urmyshlinskoye oil field (In Russ.), Vestnik
TsKR Rosnedra, 2015, no. 5–6, pp. 40–45.
3. Khamidullin F.F. Amerkhanov, I.I., Gibadullin A.A., Reologicheskie svoystva
neftey i vodoneftyanykh emul'siy na mestorozhdeniyakh Respubliki Tatarstan:
spravochnik (The rheological properties of oil and oil-water emulsions in the
fields of the Republic of Tatarstan: Handbook), Bugul'ma, 2001, 557 p.
4. Sultanov B.N., About viscoplastic fluid filtration in porous media (In Russ.),
Izvestiya AN Azerbaydzhanskoy SSR, 1960, no. 5.
5. Nazmutdinov R.Sh., The influence of viscoplastic properties of oil on petroleum
development (In Russ.), Uchenye zapiski Al'met'evskogo gosudarstvennogo
neftyanogo instituta, 2015, V. 13, no. 1, pp. 60-63.
6. Nizaev R.Kh., Gus'kova I.A., Nazmutdinov R.Sh., Development of oil reservoirs
with non-Newtonian fluids (In Russ.), Neftyanaya provintsiya, 2015,
no. 2, pp. 92-101, URL:
http://media.wix.com/ugd/2e67f9_f99d238efdec4dab98cc9e25bcb933
5b.pdf.


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