# Design and Evaluation of a Thermally Stable and Salt-Resistant Amphoteric Surfactant-Based Fracturing Fluid for High-Performance Hydraulic Stimulation

## TL;DR

A new amphoteric surfactant-based fracturing fluid was developed to improve oil and gas extraction in harsh reservoir conditions.

## Contribution

The novel silane-grafted amphoteric surfactant design enables superior thermal and salt resistance compared to conventional surfactants.

## Key findings

- The fracturing fluid retained over 96.7% viscosity after 72 hours at 150 °C and 20 wt% NaCl.
- Field tests showed 81% and 133% increases in oil and gas production, respectively.
- The fluid improved wettability and oil flow by reducing contact angles on sandstone surfaces.

## Abstract

As oil and gas exploration advances, the development of deep, low-permeability, high-temperature, and high-salinity reservoirs poses increasing challenges. To address this, a novel amphoteric surfactant (TASS) was synthesized via free radical polymerization, and a high-performance water-based fracturing fluid system was developed. The system exhibited excellent thermal and salt resistance, with viscosity decreasing by less than 3.3% after 72 h at 150 °C and 20 wt% NaCl. It demonstrated clear shear-thinning behavior and strong elasticity. Interfacial activity tests showed that increasing NaCl concentrations reduced interfacial tension from 28.5 to 24.3 mN/m, while the contact angle on sandstone surfaces decreased significantly, indicating enhanced wettability and oil flow. Field applications further confirmed its effectiveness, with oil and gas production increasing by 81% and 133%, respectively, and a payback period of around 10 days. These results highlight the TASS fracturing fluid as a promising solution for stimulation in complex reservoirs. Unlike conventional betaine-type VES, the silane-grafted amphoteric design of TASS ensures viscosity retention at 220 °C and 25 wt% salinity.