Development and Performance Evaluation of a High-Temperature-Resistant Salt-Responsive Micro-Crosslinked Polymer Gel
Fengfeng Xiao1, Yuhao Xia1, Wushuo Liu2
1Drilling Fluid Technology Service Company, CNPC Chuanqing Drilling Engineering Co., Ltd., Chengdu 610051, China.
Gels (Basel, Switzerland)
|July 27, 2026
Summary
A novel salt-responsive polymer gel, LZX, effectively controls fluid loss in high-temperature, high-salinity drilling fluids. This advanced material maintains filtration performance under extreme conditions, crucial for deep-earth drilling operations.
Area of Science:
- Materials Science
- Chemical Engineering
- Petroleum Engineering
Background:
- Drilling fluids face challenges in high-temperature and high-salinity environments common in deep and ultra-deep wells.
- Controlling filtration performance under these extreme conditions is critical for wellbore stability and drilling efficiency.
Purpose of the Study:
- Develop a novel salt-responsive micro-crosslinked polymer gel filtration loss reducer (LZX) for challenging drilling conditions.
- Evaluate the thermal stability, filtration control performance, and salt responsiveness of the developed LZX material.
Main Methods:
- Synthesized LZX using monomers like 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and a betaine monomer, with polyethylene glycol diacrylate (PEGDA) as a crosslinker.
- Tested LZX's thermal stability via decomposition temperature analysis.
- Assessed filtration loss (API and HPHT) at 220 °C under saturated salt conditions.
- Conducted comparative performance tests against commercial fluid loss reducers.
- Analyzed rheological properties and molecular weight to understand salt responsiveness.
Main Results:
- LZX demonstrated excellent thermal stability with a decomposition temperature over 290 °C.
- A dosage of 2.5 wt% LZX achieved API filtration loss of 5.8 mL and HPHT filtration loss of 28.6 mL at 220 °C under saturated salt.
- LZX outperformed commercial fluid loss reducers (Driscal Temp, Driscal D) in filtration control.
- LZX exhibited antipolyelectrolyte behavior in high salinity, extending molecular chains and maintaining filtration reduction capability.
- The micro-crosslinked structure enhanced LZX's thermal resistance.
Conclusions:
- LZX is a highly effective filtration loss reducer for high-temperature, high-salinity water-based drilling fluids.
- The material shows a transition from passive salt tolerance to active salt responsiveness, enhancing its applicability.
- LZX is a promising candidate for developing advanced drilling fluids for future deep-earth exploration.
