Reaction between gelled HCl and calcite or dolomite at high mineralization

Abstract

The paper is devoted to reactions of the interaction of gelled aqueous salt solutions (CNaCl = =15 wt %) of HCl (12 wt %) with CaCO3, Ca1.16Mg0.84(CO3)2 carbonate core minerals on the quasi-static conditions at a temperature of 10, 17, 25℃. Increase of HCl viscosity by xanthan gum, scleroglucan biopolymers and amidoalkylbetaine, reactions of acid-carbonate interaction take place in the diffusion region. The values of apparent activation energy Ea reactions between HCl with dolomite and calcite are determined by the structural and mechanical properties of the liquid phase. Viscosity of HCl is stable for more than 4 hours at t = 12℃, P = 10 MPa, CNaCl = 15 wt %. Viscosity of micellar solution HCl (12 wt %) + Amidoalkylbetaine (6,5 wt %) is equal to 109 mPa·s, at neutralization increases to more than 600 mPa·s. Initial micellar solution has 60 wt % of the micelles with a size in the range from 1 to 10 nm, 40 wt % of micelles have sizes 200–1000 nm. The sizes of micelles are increased to 2000–7000 nm, structural and mechanical properties of the solution are change. Homogeneous profile of dissolution of carbonate CaCO3, Ca1.16Mg0.84(CO3)2 after interaction with gelled HCl was imaged by electron microscope. Refs 20. Figs 5. Tables 2.