**1. Introduction**

Over the past 50 years, several research groups have attempted to increase the viscosity of gas-solvents for two purposes. The first purpose is to reduce the gas mobility and improve conformance control for miscible gas injection (MGI). By simply increasing the injected gas viscosity, gas mobility will be reduced, and as a result the sweep efficiency and oil recovery would be improved. The second purpose is to thicken supercritical fracturing fluids to enhance well productivity in tight reservoirs [1–3]. This former application is particularly useful for reservoirs

**64**

*Enhanced Oil Recovery Processes - New Technologies*

the Petroleum Industry. Cambrigde: University of Cambrige; 2000

[9] Patricia RJ. Relationship between the structure of Fe-lignosulfonate complexes determined by FTIR

California; 2009. p. 1

[11] Setiati R, Siregar S,

www.theijst.com

Technology; 2017

[12] Setiati R. Synthesis and characterization of sodium lignosulfonate from bagasse: The effects of concentration and salinity toward the performance of oil injection

in core [Doctoral dissertation]. Indonesia: Bandung Institute of

considering carbon number. In: Simposium IATMI; 1-3 October 2018;

[14] Akzo N. HLB and Emulsification. Surface Chemistry LLC. 2011. Available from: http://surface.akzonobel.com

Marhaendrajana T, Wahyuningrum D, et al. IOP Conf. Series: Materials Science and Engineering. 2018;**434**:012083. DOI: 10.1088/1757-899X/434/1/012083

Padang, Indonesia; 2018

[15] Setiati R, Siregar S,

[13] Setiati R, Siregar S, Marhaendrajana T, Wahyuningrum D. Application of sodium lignosulfonate surfactant synthesized bagasse as an alternative surfactant flooding for light oil reservoir

spectroscopy and their reduction by the leaf Fe reductase. In: The Proceedings of the International Plant Nutrition Colloquium XVI. Davis: University of

[10] Green DW, Willhite G. Enhanced Oil Recovery. Texas: SPE; 1998

Marhaendrajana T, Wahyuningrum D. Infra red evaluation of sulfonation surfactant sodium lignosulfonate on bagasse. The Interrnational Journal of Science and Technoledge. 2017;**5**(3):137- 142. ISSN: 2321-919X. Available from:

[1] Sheng JL. Chemical flooding. In: Modern Chemical Enhanced Oil Recovery. Oxford: Elsevier; 2011.

Marhaendrajana T, Fajriah S. Sulfonation of Lignin's bagasse into lignosulfonate surfactants as alternative raw materials for injection of surfactants in the petroleum industry. In: Proceedings of the Lignocellulose Seminar; Center for Biomaterial Research LIPI; 2016. Available from: www.biomaterial.lipi. go.id/epub/index.php/1/prosligno

[3] Sandersen SB. Enhanced Oil Recovery with Surfactant Flooding. Denmark: Center for Energy Resources

[4] Myers D. Surfactant Science and Technology. New Jersey: Wiley

Wahyuningrum D, Synergetic Effect of SLS Surfactant of Bagasse to Enhanced Oil Recovery. In: Proceedings of the 1st Conference of the Arabian Journal of Geosciences (CAJG-1); March 2019. Springer International Publishing; 2019. DOI: 10.1007/978-3-030-01578-7\_17

[6] Hermiati E. Utilization of lignocellulosic biomass from sugarcane bagasse for bioethanol. Journal of Agricultural Research and Development. 2010;**29**(4):121-130. DOI:

10.21082/jp3.v29n4.2010

[8] Schramm L. Surfactant: Fundamentals and Application in

Oklahoma; 2004

[7] Acosta E. Modeling and Formulation of Microemulsions: The Net-Average Curvatre Model and the Combine Linker Effect. Norman: University of

[5] Setiati R, Siregar S, Marhaendrajana T,

Engineering—CERE; 2012

Interscience; 2006

pp. 239-335

**References**

[2] Setiati R, Putri EAM, Wahyuningrum D, Siregar S, that are sensitive to the typical water-based fluids used for fracturing. Increasing the fluid viscosity results in a more effective fracturing fluid [1]. In addition, at high pressures, viscous fluids would be able to propagate wider fractures by improving the transport of proppant particles and reducing the leak-off of gas into the faces of the fracture [1, 3, 4].

In previous studies, efforts were centred on identifying thickeners for CO2 and natural gas liquid (NGL) (i.e. ethane, propane, and butane) thickeners. These attempts are based on polymeric and small-molecule candidates as will be reviewed and highlighted in this chapter. The mechanisms behind the thickening of any solvent depend on polymer coil expansion, intermolecular interactions, entanglement, aggregation (affected by the polymer molecular weight distributions), and self-assembly and indirectly through the effect of polymer molecules on nearby solvent molecules [5].
