Polyoxyalkyleneamine as shale inhibitor in water-based drilling fluids

According to the conventional evaluation methods of drilling fluids, the inhibitive property of polyoxyalkyleneamine (POAM), which was prepared in the laboratory, to sodium montmorillonite (Na-MMT) was investigated, and the shale cuttings recovery ratio and the rheological properties of drilling fluids were measured before and after adding POAM in several water-based drilling fluids. The results showed that POAM was completely water-soluble, exhibited the superior performance to inhibit the hydration of Na-MMT and reduced the swelling or hydration of shale cuttings effectively. In addition, the determination of the biological toxicity and compatibility of POAM indicated that POAM was low toxic and compatible with other common drilling fluid additives.