Experimental Study of Sulfonate Gemini Surfactants as Thickeners for Clean Fracturing Fluids

Abstract

Hydraulic fracturing is one of the important methods to improve oil and gas production. The performance of the fracturing fluid directly affects the success of hydraulic fracturing. The traditional cross-linked polymer fracturing fluid can cause secondary damage to oil and gas reservoirs due to the poor flow-back of the fracturing fluid, and existing conventional cleaning fracturing fluids have poor performance in high temperature. Therefore, this paper has carried out research on novel sulfonate Gemini surfactant cleaning fracturing fluids. The rheological properties of a series of sulfonate Gemini surfactant (DSm-s-m) solutions at different temperatures and constant shear rate (170 s−1) were tested for optimizing the temperature-resistance and thickening properties of anionic Gemini surfactants in clean fracturing fluid. At the same time, the microstructures of solutions were investigated by scanning electron microscope (SEM). The experimental results showed that the viscosity of the sulfonate Gemini surfactant solution varied with the spacer group and the hydrophobic chain at 65 °C and 170 s−1, wherein DS18-3-18 had excellent viscosity-increasing properties. Furthermore, the microstructure of 4 wt.% DS18-3-18 solution demonstrated that DS18-3-18 self-assembled into dense layered micelles, and the micelles intertwined with each other to form the network structure, promoting the increase in solution viscosity. Adding nano-MgO can increase the temperature-resistance of 4 wt.% DS18-3-18 solution, which indicated that the rod-like and close-packed layered micelles were beneficial to the improvement of the temperature-resistance and thickening performances of the DS18-3-18 solution. DS18-3-18 was not only easy to formulate, but also stable in all aspects. Due to its low molecular weight, the damage to the formation was close to zero and the insoluble residue was almost zero because of the absence of breaker, so it could be used as a thickener for clean fracturing fluids in tight reservoirs.

Research progress of viscoelastic surfactants for enhanced oil recovery

“…Compared with cationic Gemini surfactants, anionic Gemini surfactants have obvious advantages in tertiary oil recovery. Due to the negative charge characteristics of the rock formation surface, the cationic wormlike micelle system is not suitable for such occasions, while the anionic Gemini surfactant has lower formation rock adsorption loss, low reservoir damage rate, and better environment (high-salinity, high-temperature) adaptability (Tang et al, 2018;Yixiu et al, 2015;Zheng et al, 2018). Therefore, the use of high-performance anionic Gemini surfactants to construct low interfacial tension viscoelastic fluids for chemical flooding to improve oil recovery has broad application prospects (Hu et al, 2020;Ruizhi et al, 2020).…”

A Novel Approach to Stabilize Foam Using Fluorinated Surfactants

“…Selection of surfactants for foaming application in EOR, CO 2 sequestration, hydraulic fracturing, and other upstream applications is a challenging task [17][18][19][20][21][22][23][24][25]. A surfactant for foaming applications should be generally thermally stable, compatible with reservoir brine and other chemicals, have lower adsorption on reservoir rock, have high foamability and foam stability, and should be economically viable [26][27][28][29][30].…”

Recent Advances in Flow and Transport Properties of Unconventional Reservoirs

“…By measuring the solution viscosity, Tang et al [17] investigated the effects of hydrophobic chain, spacer group, concentration, temperature, and addition of nano-MgO on the viscosity of sulfonate Gemini surfactant solution. Moreover, their micellar microstructures were observed by Cryo-SEM.…”