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ICAGE 2016

Calcite and barite precipitation in CaCO3-BaSO4-NaCl and BaSO4-NaCl-CaCl2 aqueous systems: kinetic and microstructural study Hanen Azaza 1 & Lassaad Mechi 1 & Amira Doggaz 1 & Virgil Optasanu 2 & Mohamed Tlili 1,3 & Mohamed Ben Amor 2,3

Received: 28 October 2016 / Accepted: 25 April 2017 # Saudi Society for Geosciences 2017

Abstract During the production of hydrocarbons from subterranean reservoirs, scaling with calcium carbonate and barium sulfate causes flux decline and dangerous problems in production facilities. This work is intended to study the effect of calcium ions on the precipitation of barium sulfate (barite); then, the effect of the formed barite on calcium carbonate crystallization. The conductometric and pH methods were used to follow the progress of the precipitation reaction in aqueous medium. The obtained precipitates were characterized by FTIR, RAMAN, SEM, and XRD. It was shown that Ca2+ in the reaction media does not affect the microstructure of barite even for higher calcium–barium molar ratio. It influences the precipitation kinetics and the solubility of barite by the formation of CaSO4° ion pairing as a predominant role of complex formation (CaSO4) and the increase of the ionic strength. In Ca(HCO3)2-BaSO4-NaCl aqueous system, experiments have showed that added or formed barite in the reaction media accelerates calcite precipitation. No effect on the microstructure of heterogeneous formed calcite which remain

calcite shape. However the presence of carbonate ions affects slightly the microstructure of barite. Keywords Calcium carbonate . Barite . FTIR

Introduction Inorganic salts such as barium sulfate, calcium carbonate, and calcium sulfate are generated in water treatment systems, particularly in off-shore oil production, forming hard scales in production facilities. These unwanted minerals are a persistent and common problem encountered during the production of hydrocarbons from subterranean reservoirs, result of variation in chemical and thermodynamic parameters (Melo et al. 1988; Breen et al. 1991; Hamed et al. 2000). The mixture of incompatible fluids containing various ions is the main reason for the precipitation of more salts, may be combined to form scale on the wall of pipes, pumps, etc. This

This article is part of the Topical Collection on Georesources and Environmental Management * Lassaad Mechi [email protected] Hanen Azaza [email protected]

Mohamed Ben Amor [email protected] 1

Lab of Natural Water Treatment, Water Research and Technologies Center, Borj-Cedria Technopark University of Cartage, PO-box N°273, 8020 Soliman, Tunisia

2

ICB UMR 6303 CNRS, Université de Bourgogne Franche Comté, 9 av Alain Savary, 21078 Dijon Cedex, France

3

Department of Chemistry, Faculty of Science—King Khalid University, Abha 9033, Saudi Arabia

Amira Doggaz [email protected] Virgil Optasanu [email protected] Mohamed Tlili [email protected]

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Arab J Geosci (2017) 10:220

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insoluble and very compact deposit can c