Effects of acid dissolution capacity on the propagation of an acid-dissolution front in carbonate rocks

• Published in: Computers & geosciences Vol. 102; pp. 109 - 115
• Main Authors: Zhao, Chongbin, Hobbs, B.E., Ord, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2017
• Subjects: Acid dissolution capacity; Acidization; Carbonate rocks; Front propagation; Numerical solutions; Acid dissolution capacity; Carbonate rocks; Numerical solutions; Acidization; Front propagation
• ISSN: 0098-3004; 1873-7803
• DOI: 10.1016/j.cageo.2017.02.013

Acid dissolution capability plays a considerable role in controlling the propagation of an acid-dissolution front in the carbonate rocks that are saturated by pore fluids. This capability can be represented by a dimensionless number, known as the acid dissolution capability number, by which we mean the quotient of the volume of an acid-dissolved carbonate rock divided by that of the acid itself. This paper aims primarily to investigate why and how the acid dissolution capacity can affect the behaviors of the acid-dissolution front propagation in the carbonate rocks that are saturated by pore fluids. If the acid dissolution capacity number is a nonzero finite number, as in a general case, then the computational simulation method needs to be employed to get numerical solutions for the acid-dissolution system. The relevant computational simulation results have demonstrated that: (1) with an increase in the value of the Zhao number (namely another dimensionless number), which is used to denote the dynamic characteristics of an acid-dissolution system, the acid-dissolution front becomes more unstable in the corresponding supercritical acid-dissolution system. (2) When the acid dissolution capacity number is small enough, the propagating speed of a planar acid-dissolution front in the corresponding subcritical acid-dissolution system is linearly dependent on the acid dissolution capacity number, indicating that the smaller the acid dissolution capacity, the slower the propagating speed of a planar acid-dissolution front in the corresponding subcritical acid-dissolution system. (3) With a decrease in the acid dissolution capacity number, the acid-dissolution front can exhibit more unstable behavior in the corresponding supercritical acid-dissolution system. •To investigate effects of acid dissolution capacity on the propagation behaviors of acid-dissolution fronts.•An increase in the value of the Zhao number can destabilize acid-dissolution fronts in the supercritical system.•The smaller the acid dissolution capacity, the slower the propagating speed of an ADF in the subcritical system.•A decrease in the acid dissolution capacity can lead to the more unstable ADF in the supercritical system.