Release:

2016, Vol. 2. №3Title:

Cleaning the Bottom-Hole Zone of Wells
Authors:
Alexey V. Tatosov, Artem I. Varavva

About the authors:

Alexey V. Tatosov, Dr. Sci. (Phys.-Math.), Professor, Department of Fundamental Mathematics and Mechanics, University of Tyumen; atatosov@utmn.ruArtem I. Varavva, Chief Specialist, Gazprom Neft (Tyumen); artevar@yandex.ru

Abstract:

In recent years, interest in the use of oil production intensification of thermochemical treatments increased. One of perspective and scientific interest is a method of feeding into the reservoir responsive energy emmitting binary mixture, the main component of which is an aqueous solution of ammonium nitrate. During the exothermic reaction initiated in the reservoir, the area near wellbore is warming up, and a large amount of gas under pressure enters the formation. As a result of the processing of binary mixtures of oil the viscosity decreases, clogging of the bottom zone is removed, dirt and paraffins washed out. Upon melting paraffin wax the pore volume available for filtering increases, thereby increasing the productivity of the well. In this paper we propose a mathematical model describing the processes that occur when downloading a binary mixture into a layer: a chemical reaction decomposition of ammonium nitrite, melting and washing away deposits of paraffin and dirt, pressure and temperature that occur near the well. The model takes into account the changes in porosity associated with the dissolution of a paraffin wax and a compressibilities fluid and the rock matrix. A numerical algorithm for solving the system of equations is presented. An example of calculation in a binary mixture feed vertical well bore at a predetermined pick-up over a period of time is observed. The effect of determining the parameters of the problem on the nature of multiphase flow is studied. It is found that the reaction temperature in the well bottom zone increases, which results in the dissolution of solid paraffin and its subsequent leaching. Near the well there is a significant short-term pressure.

Keywords:

References:

- Barenblatt G. I., Entov V. M., Ryzhik V. M. 1984. Dvizhenie zhidkosti i gazov v prirodnykh plastakh [Movement of Liquids and Gases in natural Reservoirs]. Moscow: Nedra.
- Basniev K. S., Kochina I. N., Maksimov V. M. 1993. Podzemnaya gidromekhanika [Underground Hydromechanics]. Moscow: Nedra.
- Entov V. M., Zazovskiy A. F. 1989. Gidrodinamika protsessov povysheniya nefteotdachi [Hydrodynamics of Enhanced Oil Recovery Processes]. Moscow: Nedra.
- Huang Z., Lee H. S., Senra M., Fogler H. S. 2011. “A Fundamental Model Wax Deposition in Subsea Oil Pipelines”. AIChE Journal, vol. 57, no 11, pp. 2955-2964. DOI: 10.1002/aic.12517
- Kanevskaya R. D. 2002. Matematicheskoe modelirovanie gidrodinamicheskikh protsessov razrabotki mestorozhdeniy uglevodorodov [Mathematical Modeling of Hydrodynamic Processes of Hydrocarbon Field Development]. Moscow-Izhevsk: Institut komp'yuternykh issledovaniy.
- Kline W. E., Fogler H. S. 1981. “Dissolution of Silicate Minerals by Hydrofluoric Acid.” Industrial & Engineering Chemistry Fundamentals, vol. 20(2), pp. 151-161. DOI: 10.1021/i100002a008
- Tatosov A. V., Kozlov V. D. 2015. “Ochistka prizaboynoy zony skvazhiny reagiruyushchey binarnoy smes'yu” [Cleaning Bottom Hole Zone Reacting Binary Mixtures]. Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy, vol. 1, no 4(4), pp. 112-116.
- Vershinin V., Fedorov K., Lishchuk A. 2016. “Mechanisms of Thermal-Pressure Induced Impact of Binary Mixture Reaction Near Wellbore”. Paper Presented at SPE Russian Petroleum Technology Conference and Exhibition (Moscow). SPE-182048-RU.
- Williams B. B. 1975. Hydrofluoric Acid Reaction with Sandstone Formations.
- Zvyagin G. A., Yuzhaninov P. M., Dzyubenko A. I. 1982. “Issledovanie istochnikov zagryazneniya i tekhnologiy obrabotok nagnetatel'nykh skvazhin” [The Study of Pollution Sources and Technologies Treatments Injectors]. Neftepromyslovoe delo, no 11, pp. 114-115.