Development status of crosslinking agent in high-temperature and pressure fracturing fluid: A review

With the continuous development of unconventional oil and gas in recent years, researchers have set higher requirements on crosslinker performance. Therefore, research on the crosslinking agent that is suitable for the high-temperature/high-pressure (HT/HP) fracturing fluid system is particularly important. This work reviews the development status of a crosslinker for the HT/HP fracturing fluid system. Our results show that the cost of a boron crosslinking agent is low; however, it is not suitable under very high temperatures. Metal crosslinking agents are suitable for a wide range of pH but have poor shear resistance. Meanwhile, the nano crosslinking agent has a high applicable temperature and a strong comprehensive performance but is relatively expensive. How to further improve the adaptability of crosslinking agents to high temperature and pressure and reduce the additive dosage are the focus of future research.