Heavy Oil and High-Temperature Polymer EOR Applications

• Published in: C T & F : ciencia, tecnología y futuro Vol. 10; no. 2; pp. 73 - 83
• Main Authors: Castro García, Rubén Hernán, Llanos Gallo, Sebastián, Rodriguez Ardila, Jenny Liseth, Quintero Pérez, Henderson Iván, Manrique Ventura, Eduardo José, Zapata Arango, Jose Francisco
• Format: Journal Article
• Language: English
• Published: Instituto Colombiano del Petróleo (ICP) - ECOPETROL S.A 17-12-2020
• Subjects: ATBS; biopolymer; ENGINEERING, MULTIDISCIPLINARY; enhanced oil recovery (EOR); filter ratio; scleroglucan; shear degradation; sulfonated polyacrylamide; Enhanced oil recovery (EOR)| Biopolymer; Relación de filtrabilidad; Escleroglucano; Filter ratio; ATBS; Degradación mecánica; Sulfonated polyacrylamide; Scleroglucan; Recuperación mejorada de petróleo (EOR); Shear degradation; Biopolímero; Poliacrilamida sulfonada
• ISSN: 0122-5383; 2382-4581; 2382-4581
• DOI: 10.29047/01225383.258

Polymer flooding represents the most common chemical enhanced oil recovery (CEOR) method used at commercial scale. In this process, the polymeric solutions (generally hydrolyzed polyacrylamide - HPAM) are injected to improve the oil/water mobility ratio (M). However, due to mechanical, chemical, bio, and thermal degradation, polymer viscosity losses can occur, causing a negative impact on oil sweep efficiency. In this case, biopolymers seem to be promising candidates in EOR applications with special structural characteristics, which result in excellent stability in harsh environments with high temperatures, ionic forces, and shear stresses. This paper presents the laboratory evaluation of Scleroglucan (SG) and a commercial sulfonated polyacrylamide (ATBS) in synthetic brine, representative of a Colombian heavy-oil field. The effects of ionic strength, pH, temperature, and shear degradation effects on polymer viscosity were also evaluated. For SG, the results reflect its tolerance to high salinities (0-5%wt), ionic strengths (Na+, K+, Ca2+, and Mg2+), shear rates (0-300,000 s-1), temperatures (30, 50, 80 and 100 °C), and pH variations (3-10). The biopolymer was capable of preserving its viscous properties and stability after of the effect of these variables. Finally, the target viscosity (set as 17 cp) was achieved with a lower concentration (2.7 times) than the ATBS polymer tested.