Application of nonionic surfactant nonylphenol to control acid stimulation in carbonate matrix

• Published in: Journal of petroleum science & engineering 2021-08, Vol.203, p.108654, Article 108654
• Main Authors: Rodrigues, Marcos Allyson Felipe, Arruda, Guilherme Mentges, da Silva, Dennys Correia, da Costa, Francisco Moisés Freitas, de Brito, Marcio Fernando Paixão, Antonino, Antonio Celso Dantas, Wanderley Neto, Alcides de Oliveira
• Format: Article
• Language: English
• Subjects: Acid stimulation; Carbonate matrix; Nonionic surfactant; Wormhole
• ISSN: 0920-4105; 1873-4715
• DOI: 10.1016/j.petrol.2021.108654

One of the main challenges of the acid stimulation process in carbonate matrix is the formation of a dominant pattern wormhole, which is generally not obtained with the application of concentrated hydrochloric acid. Due to its high reactivity, the calcite will be consumed around the oil well, thus not forming the appropriate extension channels to reach the desired breakthrough. From this context, this work aimed to evaluate the behavior of the surfactant Nonylphenol 100 EO in delaying the reaction between HCl 15% and the carbonate in order to form the desired wormhole, where little acid is consumed to reach breakthrough. For this, flow tests were performed in porous medium at different injection rates (0.5, 2 and 5 mL/min), in which it was possible to determine the PVBt curves of HCl and HCl with 10% of the surfactant. The wormhole patterns obtained were identified through computed tomography images. It was noticed that the presence of the surfactant in the acid solution provided the reaction delay, which consequently reduced the values of PVBt in all flow rates. Computed tomography images showed a dominant pattern in all injection rates with the presence of surfactant, which was not seen with pure HCl. [Display omitted] •Nonylphenol 100 EO was used to delay the matrix acidizing.•The PVBt value decreased for all flow rates used.•Dominant wormhole patterns were obtained in the presence of surfactant.