Synthesis, Characteristics, and Field Applications of High-Temperature and Salt-Resistant Polymer Gel Tackifier

Area of Science:

• Materials Science
• Polymer Chemistry
• Petroleum Engineering

Background:

• High polymer gel viscosity reducers often fail at elevated temperatures, complicating fluid loss control.
• Developing robust tackifiers is crucial for efficient drilling operations in challenging geological conditions.

Purpose of the Study:

• To synthesize and evaluate a novel polymer-based nano calcium carbonate composite tackifier (GW-VIS) for high-temperature applications.
• To assess the rheological properties, thermal stability, and salt tolerance of the developed material for drilling fluid formulations.

Main Methods:

• Water suspension polymerization of acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N-vinylpyrrolidone (NVP), and nano calcium carbonate.
• Characterization using infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy.
• Rheological testing, thermal resistance experiments, and salt tolerance tests at elevated temperatures.

Main Results:

• The GW-VIS composite exhibited a high consistency coefficient (k = 761), exceeding requirements for clay-free drilling fluids.
• Stable viscosity was maintained at 180 °C (0% reduction) and showed only a 14.8% decrease at 200 °C.
• The material demonstrated excellent salt tolerance, with only a 17.31% viscosity reduction at saturated NaCl concentration after hot rolling at 200 °C.

Conclusions:

• The polymer gel forms a network structure, providing excellent rheological stability up to 200 °C, suitable for deep oil and gas well development.
• Nano calcium carbonate incorporation enhances temperature resistance and NaCl tolerance in polymer materials.
• Field trials confirmed the efficacy of GW-VIS in clay-free drilling fluids, supporting successful formation operations.