Peculiarities in formation wettability evaluation techniques

UDK: 622.276.031:53
Authors: B.C. Gabsia (VNIIneft AO, RF, Moscow)

Effective evaluation of formation wettability plays a key role in determining reservoir fluid distribution and flow properties. Knowledge of formation wettability is very crucial for carrying out a better control of reservoir performance and enhancing field production prediction, especially in complex reservoirs.

The methods generally employed for determining rock wettability, both qualitative and quantitative, were revised. Detailed analyses of relative permeability curves from steady state core tests, generally used in the qualitative analyses, show that their resultant shapes, not only depend on rock wettability, but also on pore space geometry.  Studies have shown that, for better results, alongside relative permeability curves, capillary curves and core samples pore geometry are needed to determine wettability.

Unlike qualitative evaluation, quantitative wettability techniques require direct laboratory measurements and provide adequate results with response to the solid surfaces and liquids used. In conventional laboratory tests on reservoir rocks the contacting liquids used are usually well defined, but the interacting solid surface (pore surface) remains partially unknown. It isn’t quite clear what core (pore) surface is suitable for the right results to be obtained – pure (clean) mineral surface or ‘stained’ (with oil of some thickness). Core ageing can only restore a certain (unknown) wettability, as the real in situ formation wettability before drilling and coring has always been undefined and, ageing periods can never meet up with the formation geological time. Hence alternative core preparation methods are needed.

This article focuses not only on the development of new drilling, coring and core handling methods, but also on more effective wettability measurement and calculation techniques, necessary to meet the present day challenges of complex reservoirs and hence optimize production.

References

1. Gimmatudinov Sh.K., Fizika neftyanogo i gazovogo plasta (Physics of oil

and gas reservoir), Moscow: Nedra Publ., 1971, 312 p.

2. Tul'bovich B.I., Metody izucheniya porod-kollektorov nefti i gaza (Methods

of study of oil and gas reservoir rocks), Moscow: Nedra Publ., 1979, 199 p.

3. Amott E., Observations relating to the wettability of porous rock, Petroleum

Trans., AIME 216, 1959, pp. 156-162.

4. Anderson W.G., Wettability literature survey, Part 2: Wettability measurement,

Journal of Petroleum Technology, 1986, V. 38, no. 11, pp. 1246–1262.

5. Cuiec L.E., Restoration of the natural state of core samples, SPE 5634-MS,

1975.

6. Morrow N.R., Wettability and its effect on oil recovery, JPT, 1990, V. 42,

pp. 1476-1484.

7. Mikhaylov N.N., Gurbatova I.P., Motorova K.A., Sechina L.S., New representations

of wettability of oil and gas reservoirs (In Russ.), Neftyanoe khozyaystvo

= Oil Industry, 2016, no. 7, pp. 80–85.

8. Hirasaki G.J., Dubey , Niko H., Wettability evaluation during restored-state

core analysis, SPE 20506-MS, 1990.

9. Barro J., Blanc Ph., Efficiency of cleaning techniques for oil and ester based

muds on unconsolidated and tight sands, International Symposium of the Society

of Core Analysts, SCA2003-04, Pau, France, 21-24 September 2003, URL:

http://jgmaas.com/SCA/2003/SCA2003-04.pdf

10. Cuiec L.E., Study of problems related to the restoration of the natural state

of core samples, J. Can. Petrol. Tech, 1977, V. 16, no. 4, pp. 68-80.

11. Kelleher H.A., Braun E.M., Milligan B.E., Glotzbach R.C., Haugen E., Wettability

restoration in cores contaminated by fatty acid emulsifiers, International

Symposium of the Society of Core Analysts, Calgary, Canada, 10-12 September,

2007, URL: http://www.jgmaas.com/SCA/2007/03.pdf

12. Graue A., Viksund B. G., Eilertsen T., Moe R.W., Systematic wettability alteration

by aging sandstone and carbonate rock in crude oil, J. of Petrol. Science

& Eng., 1999 (December), V. 24(2), pp.85-97.

13. Al-Mahrooqi S.H., Grattoni C.A., Muggeridge A. H., Jing X.D., Wettability alteration

during aging: the application of NMR to monitor fluid redistribution,

Int. Symposium, Society of Core Analysts, Toronto, Canada, 21-25 August,

2005, URL: http://www.ibrarian.net/navon/paper/WETTABILITY_ALTERATION_

DURING_AGING__THE_APPLICAT.pdf?paperid=16470214

14. Kowalewski E., Boassen T., Torsaeter O., Wettability alterations due to aging

in crude oil; wettability and Cryo-ESEM analyses, J Pet. Science & Engineering,

2003, V. 39, no. 3-4, pp. 377-388.

15. Shaddel S., Hemmati M., Zamanian E., Moharrami N.N., Core flood studies

to evaluate efficiency of oil recovery by low salinity water flooding as a secondary

recovery process, J. Petr. Science & Technol., 2014, no. 4 (1),

pp. 47-56.

Effective evaluation of formation wettability plays a key role in determining reservoir fluid distribution and flow properties. Knowledge of formation wettability is very crucial for carrying out a better control of reservoir performance and enhancing field production prediction, especially in complex reservoirs.

The methods generally employed for determining rock wettability, both qualitative and quantitative, were revised. Detailed analyses of relative permeability curves from steady state core tests, generally used in the qualitative analyses, show that their resultant shapes, not only depend on rock wettability, but also on pore space geometry.  Studies have shown that, for better results, alongside relative permeability curves, capillary curves and core samples pore geometry are needed to determine wettability.

Unlike qualitative evaluation, quantitative wettability techniques require direct laboratory measurements and provide adequate results with response to the solid surfaces and liquids used. In conventional laboratory tests on reservoir rocks the contacting liquids used are usually well defined, but the interacting solid surface (pore surface) remains partially unknown. It isn’t quite clear what core (pore) surface is suitable for the right results to be obtained – pure (clean) mineral surface or ‘stained’ (with oil of some thickness). Core ageing can only restore a certain (unknown) wettability, as the real in situ formation wettability before drilling and coring has always been undefined and, ageing periods can never meet up with the formation geological time. Hence alternative core preparation methods are needed.

This article focuses not only on the development of new drilling, coring and core handling methods, but also on more effective wettability measurement and calculation techniques, necessary to meet the present day challenges of complex reservoirs and hence optimize production.

References

1. Gimmatudinov Sh.K., Fizika neftyanogo i gazovogo plasta (Physics of oil

and gas reservoir), Moscow: Nedra Publ., 1971, 312 p.

2. Tul'bovich B.I., Metody izucheniya porod-kollektorov nefti i gaza (Methods

of study of oil and gas reservoir rocks), Moscow: Nedra Publ., 1979, 199 p.

3. Amott E., Observations relating to the wettability of porous rock, Petroleum

Trans., AIME 216, 1959, pp. 156-162.

4. Anderson W.G., Wettability literature survey, Part 2: Wettability measurement,

Journal of Petroleum Technology, 1986, V. 38, no. 11, pp. 1246–1262.

5. Cuiec L.E., Restoration of the natural state of core samples, SPE 5634-MS,

1975.

6. Morrow N.R., Wettability and its effect on oil recovery, JPT, 1990, V. 42,

pp. 1476-1484.

7. Mikhaylov N.N., Gurbatova I.P., Motorova K.A., Sechina L.S., New representations

of wettability of oil and gas reservoirs (In Russ.), Neftyanoe khozyaystvo

= Oil Industry, 2016, no. 7, pp. 80–85.

8. Hirasaki G.J., Dubey , Niko H., Wettability evaluation during restored-state

core analysis, SPE 20506-MS, 1990.

9. Barro J., Blanc Ph., Efficiency of cleaning techniques for oil and ester based

muds on unconsolidated and tight sands, International Symposium of the Society

of Core Analysts, SCA2003-04, Pau, France, 21-24 September 2003, URL:

http://jgmaas.com/SCA/2003/SCA2003-04.pdf

10. Cuiec L.E., Study of problems related to the restoration of the natural state

of core samples, J. Can. Petrol. Tech, 1977, V. 16, no. 4, pp. 68-80.

11. Kelleher H.A., Braun E.M., Milligan B.E., Glotzbach R.C., Haugen E., Wettability

restoration in cores contaminated by fatty acid emulsifiers, International

Symposium of the Society of Core Analysts, Calgary, Canada, 10-12 September,

2007, URL: http://www.jgmaas.com/SCA/2007/03.pdf

12. Graue A., Viksund B. G., Eilertsen T., Moe R.W., Systematic wettability alteration

by aging sandstone and carbonate rock in crude oil, J. of Petrol. Science

& Eng., 1999 (December), V. 24(2), pp.85-97.

13. Al-Mahrooqi S.H., Grattoni C.A., Muggeridge A. H., Jing X.D., Wettability alteration

during aging: the application of NMR to monitor fluid redistribution,

Int. Symposium, Society of Core Analysts, Toronto, Canada, 21-25 August,

2005, URL: http://www.ibrarian.net/navon/paper/WETTABILITY_ALTERATION_

DURING_AGING__THE_APPLICAT.pdf?paperid=16470214

14. Kowalewski E., Boassen T., Torsaeter O., Wettability alterations due to aging

in crude oil; wettability and Cryo-ESEM analyses, J Pet. Science & Engineering,

2003, V. 39, no. 3-4, pp. 377-388.

15. Shaddel S., Hemmati M., Zamanian E., Moharrami N.N., Core flood studies

to evaluate efficiency of oil recovery by low salinity water flooding as a secondary

recovery process, J. Petr. Science & Technol., 2014, no. 4 (1),

pp. 47-56.



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