Stabilization of Montmorillonite by Ammoniated Lignosulfonates and Its Use in Water-Based Drilling Fluid

摘要

During the oil/gas field exploration, the stabilization of the shale is one of the most challenging work, due to the water sensitive montmorillonite contained in the shale. In this work, sodium ammoniated lignosulfonate (NaALS) was prepared from sodium lignosulfonate (NaLS), formaldehyde and amine to enhance the performance in the treatment of montmotrillonite. The NaALS can inhibit the swelling of montmorillonite in water, and NaALS(5) exhibits the best performance by controlling the swelling ratio below 40% within 480 min. The ammoniation lignosulfonates can enhance the viscosity of water based drilling fluid at low-temperature and reduce the viscosity at relative high temperature. Furthermore, after adding NaALS, the filtration loss of mud is decreased, which can benefit the stabilization of shale. The NaALS is compatible with polysaccharide and PAM in water based drilling fluid. In CNFK drilling fluids, NaALS(2) can reduce the viscosity effectively, and NaALS(4) can reduce viscosity and filtration at room temperature effectively, which makes NaALS to be an effective eco-friendly drilling fluid additives potentially.