Dissolution Response Mechanism of the Carbonate Mineral with the Increase of Depth and Its Reservoir Significance

Based on the chemical thermodynamics,the dissolution response mechanism of the calcite and dolomite with the increase of depth in the CO2-beared fluid and H2 S-beared fluid was studied by the method of numerical simulation.The result indicates that the dissolution of calcite is always more evident than dolomite in same conditions.The amount of gas confined in the dissolution system is another important factor which influences the dissolution of carbonate mineral except the temperature,pressure,partial pressure of the acid gas and the component of fluid.When the amount of confined gas is relative large,with the depth increases,the dissolution amount curve shows an increase followed by a decline.And the dissolution pore in the dolomite is more developed than that in the calcite.When the amount of confined gas is relative short,both minerals' dissolution amount curves declines tonelessly.