A Novel Aluminum-based Shale Stabilizer

摘要

A novel aluminum-based shale stabilizer used in drilling fluid composed of humic acid and aluminum (HA-Al) was synthesized. The expansion rate of shale sample in HA-Al solution was 12.87% (23.21% in pure water) in linear expansion test. Shale stability index values of high water content and low water content samples were 73.00 and 55.94, respectively, indicating HA-Al had good inhibition performance by absorbing between clay particles. The pore pressure transmission test indicated that after 20 h, the result was 0.4 MPa in glycols solution, 0.15 MPa in sodium silicate solution, and 0.07 MPa in HA-Al solution. Obviously, the last one was the best. So HA-Al had excellent performance to reduce pore pressure transmission. By scanning electron microscopy and energy-dispersive spectrometer analysis, it was confirmed that HA-Al could precipitate in the shale pores. As a result, the pore pressure transmission reduced and the shale stability increased.