Preparation and application of melamine cross-linked poly ammonium as shale inhibitor

摘要

In this paper, a series of poly ammonium shale inhibitors were prepared from diethylamine, epichlorohydrin, andmelamine (DEM) and their inhibition to shale were evaluated by bentonite linear expansion test, anti-swelling experiments, and mud ball experiments. Additionally, other properties of drilling fuid treated by poly ammonium wereevaluated. Anti-swelling results showed that anti-swelling rate of DEM-8 reaches up to 97.8% when its concentrationreaches to 0.8%. Mud ball experiment and drilling fuid evaluation showed DEM-8 has strong inhibitive capability tobentonite hydration swelling and controlling the particle size of bentonite in a large scale. The inhibition mechanismof DEM-8 was studied by thermogravimetric analysis and scanning electron microscope. The results demonstrate thatDEM-8 can be adsorbed on clay surface through electrostatic interaction and hydrogen bonds by an anchoring efectand a hydrophobic efect.