一种新型双季铵盐页岩抑制剂的制备及其作用机理

In order to improve the inhibition effect of polyether amine (PEA) inhibitor, a new type of double quaternary ammonium salt shale inhibitor SJAY was prepared by quaternization reaction. Its molecular structure was characterized by infrared spectroscopy, its hydration inhibition was evaluated by linear expansion test and rolling dispersion test, and its hydration inhibition mechanism was analyzed by Zeta potential, clay particle size distribution, surface tension, clay wettability, clay layer spacing and other tests. The results show that the hydration inhibition performance of SJAY is better than that of potassium chloride (KCl), polymeric alcohol (PMA) and PEA inhibitors. 1% SJAY can reduce the expansion of bentonite from 9.35 mm to 4.67 mm, and increase the recovery of shale from 9.37% to 75.29%. SJAY can neutralize the negative charge on the clay surface, insert it between layers of clay, adsorb it on the clay surface to make it more hydrophobic, greatly reduce the surface tension of water-based fluid, thus effectively inhibiting the hydration expansion and dispersion of shale. Field application results show that L-2 well was successfully drilled during the second opening interval, without wellbore instability problems such as wellbore falling, and the borehole enlargement rate was significantly reduced. SJAY can meet the requirements for hydration inhibition when drilling shale formation.