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Changes in the properties of fluids and chemical reactions products caused by acid treatment of carbonate reservoirs
- Source :
- Perm Journal of Petroleum and Mining Engineering, Vol 19, Iss 3, Pp 275-289 (2019)
- Publication Year :
- 2019
- Publisher :
- Perm National Research Polytechnic University, 2019.
-
Abstract
- Acid treatment is one of the main methods of stimulating the near wellbore area of the wells opening the carbonate reservoirs. Despite the extensive experience of using this technology both in Russia and abroad, as well as a significant number of studies, the success rate is hardly ever estimated at over 30%. One of the reasons for the low success rate is neglect to the changes in the physical properties of fluids during injection, interaction with the rock and the properties of the reaction products in the wellbore and the near wellbore area during the acid treatment planning. This paper discusses the main chemical reactions occurring during the interaction of hydrochloric acid with limestones and dolomites. The quantities of the substances resulting from a chemical reaction between 15% aqueous solution of acid and the carbonates have been determined. The properties (phase state, solubility, dependences of viscosity and density on pressure and temperature) of water, carbon dioxide, nitrogen, 15% aqueous solution of acid, solutions of calcium and magnesium chloride salts in the range of possible pressures and temperatures during the acid treatment were evaluated. Due to the diversity of additives used in acid solutions, the paper proves the necessity of conducting laboratory experiments to evaluate their properties under the conditions expected during the acid stimulation. Based on laboratory studies, the reaction time of 15% solution of hydrochloric acid with calcium carbonate was estimated. The impact of the chemical diverter used for primary treatments at the Badra oilfield (Iraq) on the properties of the acid solution and the reaction time was determined. The changes in the solution viscosity depending on the acid temperature and concentration were determined. The results provided in the work were used for the purposes of forecasting and evaluating the efficiency of acid treatment performed on the wells of the Badra oilfield.
- Subjects :
- carbonates
limestone
dolomite
acid treatment
diverter
viscosity
density
volume ratio
chemical reaction
reaction products
hydrochloric acid
phase state
calcium chloride
magnesium chloride
carbon dioxide
nitrogen
solubility
supercritical fluid
pressure
temperature
reaction time
reaction rate
core
neutralization
dissolving ability
badra
iraq
Environmental sciences
GE1-350
Subjects
Details
- Language :
- English, Russian
- ISSN :
- 22249923 and 23051140
- Volume :
- 19
- Issue :
- 3
- Database :
- Directory of Open Access Journals
- Journal :
- Perm Journal of Petroleum and Mining Engineering
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.15f2db01584dd7856ee9d6ce1b3b26
- Document Type :
- article
- Full Text :
- https://doi.org/10.15593/2224-9923/2019.3.7