Theory and Practice of Acidizing High Temperature Carbonate Reservoirs of R. Trebs Oil Field, Timan-Pechora Basin

摘要

The oil reservoirs of R. Trebs field are predominately heterogeneous carbonates with a well developed network of natural fractures, high formation temperature and high concentration of resins and asphaltenes in the produced crude. Such complicated reservoir conditions entail integrated acid treatment engineering and design to include physical and chemical analysis of acid compositions, formation fluids and reservoir rock; physical simulation of acidizing on core from target intervals and numerical modeling of the optimum acid job design. The conducted research supported the selection of the optimum acids for the geological and engineering conditions of R.Trebs oil field to secure better compatibility with the formation fluids from the target intervals, lower corrosion activity and retarded reaction rate. The findings also identified the range of critical values for permeability and mineralogy of the rock whereby acid flows through a reservoir rock in a growing dominant wormhole.