Abstract
There are two ways of increasing viscosity, dilute and concentrated, in the diverting acid system, which is suitable for carbonate rock stimulation. However, the micro understanding of its viscosity increasing law is not clear.
This paper analyze and compare the microstructure of diverting agent solutions using scanning electron microscopy and elemental distribution.
The results show that the peak viscosity of dilute and concentrated diverting acids appear at 0%–2% and 8%–10% acid concentration, respectively, with a higher viscosity in the former. Surfactant molecules are difficult to separate when concentrated diverting agent is dispersed in water owing to low hydrophilicity, whereas only high temperatures can enhance the solubility of dilute diverting agent. Worm-like micelles that form in concentrated diverting acid are more compact, whereas the spatial network structure that forms in dilute diverting acid is arranged in an orderly manner but relatively sparse.
In this paper, the viscosity increasing law of different diverting acids is clarified through microstructure study, which provides a new understanding for further research and development of diverting acids.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Al-Ghamdi, A.H., Wang, G., Hill, A.D., et al.: Acid diversion by use of viscoelastic surfactants: the effects of flow rate and initial permeability contrast. SPE142564 (2014)
Gomaa, A.M., Cutler, J., Qu, Q., et al.: Acid placement: an effective VES system to stimulate high-temperature carbonate formations. SPE157316 (2012)
Wang, G., Gomaa, A.M., Nasr-El-Din, H.A.: Effect of initial HCl concentration on the performance of new VES acid system. SPE143449 (2011)
Wang, G., Nasr-El-Din, H.A., Zhou, J., et al.: A new viscoelastic surfactant for high temperature carbonate acidizing. SPE160884 (2012)
Cetin, S., Nasr-El-Din, H.A.: Rheological study of a novel sulfobetaine surfactant-based acid system. SPE183652 (2017)
Zebarjad, F.S., Nasr-El-Din, H.A., Badraoui, D.A.: Effect of Fe III and chelating agents on performance of new VES-based acid solution in high-temperature wells. SPE184588 (2017)
Toseef, A., Beaman, D.J.: Viscoelastic surfactant diversion: an effective way to acidize low-temperature wells. SPE136574 (2010)
Taylor, D., Kumar, P.S., Fu, D., et al.: Viscoelastic surfactant based self-diverting acid for enhanced stimulation in carbonate reservoirs. SPE82263 (2003)
Kayumov, R., Konchenko, A., Bairamov, A., et al.: Experience of carbonate acidizing in the challenging environment of the Volga-Urals region of Russia. SPE168167 (2014)
Al-Ghamdi, A.H., Nasr-El-Din, H.A., Hill, A.D.: Propagation of viscoelastic surfactant based acid in carbonate cores. In: Presented at the SPE International Symposium on Oilfield Chemistry, The Woodlands, Texas, 20–22 April. SPE-121713 (2009)
Bulgakova, G.T., Kharisov, R.Y., Pestrikov, A.V., et al.: Experimental study of a viscoelastic surfactant-based in situ self-diverting acid system: results and interpretation. In: Presented at the 14th International Conference on Petroleum Phase Behavior and Fouling, Malmaison, France, 10–13 June (2013)
Hoefner, M.L., Fogler, H.S.: Fluid-velocity and reaction-rate effects during carbonate acidizing: application of network model. SPE Prod. Eng. 4(1), 56–62 (1989). SPE-15573
Liu, P., Xue, H., Zhao, L.Q., et al.: Analysis and simulation of rheological behavior and diverting mechanism of in situ self-diverting acid. J. Pet. Sci. Technol. 132(2015), 39–52 (2015)
Mou, J., Liu, M., Zheng, K., et al.: Diversion conditions for viscoelastic-surfactant-based self-diversion acid in carbonate acidizing. SPE Prod. Oper. 30(2), 121–129 (2015). SPE-173898
Nasr-El-Din, H.A., Chesson, J.B., Cawiezel, K.E., et al.: Lessons learned and guidelines for matrix acidizing with viscoelastic surfactant diversion in carbonate formations. In: Presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 24–27 September. SPE-102468 (2006)
Nasr-El-Din, H.A., Samuel, M.: Lesson learned from using viscoelastic surfactants in well stimulation. SPE Prod. Oper. 22(1), 112–120 (2007). SPE-90383
Skauge, A., Vik, B., Pourmohammadi, S., et al.: Dispersion measurements used in special core analysis of carbonates. In: Presented at the International Symposium of the Society of Core Analysts, Trondheim, Norway, 12–16 September (2006)
Yu, M., Mahmoud, M.A., Nasr-El-Din, H.A.: Propagation and retention of viscoelastic surfactants following matrix-acidizing treatments in carbonate cores. SPE J. 16(4), 993–1001 (2011). SPE-128047
Hanafy, A., Nasr-El-Din, H.A., Rabie, A., et al.: New viscoelastic surfactant with improved diversion characteristics for carbonate matrix acidizing treatments. In: Presented at the SPE Western Regional Meeting, Anchorage, Alaska, USA, 23–26 May. SPE-180435 (2016)
Li, L., Nasr-El-Din, H.A., Cawiezel, K.E.: Rheological properties of a new class of viscoelastic surfactant. SPE Prod. Oper. 25(03), 355–366 (2010)
Rabie, A.I., Nasr-El-Din, H.A.: Effect of acid additives on the reaction of stimulating fluids during acidizing treatments. In: Presented at the SPE North Africa Technical Conference and Exhibition, Cairo, Egypt, 14–16 September. SPE-175827 (2015)
Acknowledgments
This project is supported by Major National Science and Technology Project (No. 2016ZX05052), Southwest Oil & Gasfield Company Project (No. 20180302-06).
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2021 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Sun, C., Huang, Cz., Wang, C., Liu, S., Li, Q. (2021). Microstructure of Diverting Acids of Variable Viscosity. In: Lin, J. (eds) Proceedings of the International Field Exploration and Development Conference 2020. IFEDC 2020. Springer Series in Geomechanics and Geoengineering. Springer, Singapore. https://doi.org/10.1007/978-981-16-0761-5_248
Download citation
DOI: https://doi.org/10.1007/978-981-16-0761-5_248
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-16-0762-2
Online ISBN: 978-981-16-0761-5
eBook Packages: EngineeringEngineering (R0)