Method for estimating dissolution of salt

1 . A method of estimating dissolution progress of a salt in construction of a salt cavern, comprising:

defining, for each of a plurality of parameters, an operable range of respective parameter and an average value of the operable range of respective parameter;

performing a plurality of flooding tests, by varying one particular parameter among the plurality of parameters from a lowest value to a highest value in the operable range of the one particular parameter and keeping all other parameters at the average value of respective parameter;

wherein each of the flooding tests is performed by:

injecting a dissolving fluid into the salt disposed in a core flooding apparatus, producing a brine containing dissolved salt; and

calculating the mass of the dissolved salt in the brine,

obtaining an analytical relationship of a mass of dissolved salt versus the one particular parameter;

varying each of the parameters while keeping all other parameters at their average values to obtain a plurality of the analytical relationships for each of the parameters; and

combining the plurality of the analytical relationships to obtain a total relationship between the mass of dissolved salt and all of the parameters, the parameters include flow rate, injection frequency, and salt concentration of the dissolving fluid.

2 . The method according to claim 1 , wherein the analytical relationship is obtained by fitting a curve of the flooding tests in the operable range of the one particular parameter.

3 . The method according to claim 1 , further comprises using the analytical relationship to estimate the dissolution progress of the salt.

4 . The method according to claim 1 , further comprising controlling a shape and/or a size of the salt cavern during the construction of the salt cavern by controlling at least one of an injection location, injection frequency, flow rate, and salt concentration of the dissolving fluid.

5 . The method according to claim 1 , wherein the plurality of parameters is selected from a group consisting of flow rate, temperature, pressure, injection frequency, and composition of a dissolving fluid.

6 . A method for constructing a salt cavern, comprising:

injecting a dissolving fluid into a salt formation, producing a brine containing dissolved salt; and

controlling a plurality of parameters during the injecting to control a shape and/or size of the salt cavern by controlling at least one of an injection location, injection frequency, flow rate, and salt concentration of the dissolving fluid,

wherein each of the analytical relationships for respective parameter is obtained by:

defining, for each of the plurality of parameters, an operable range of respective parameter and an average value of the operable range of respective parameter;

performing a plurality of flooding tests, by varying one particular parameter among the plurality of parameters from a lowest value to a highest value in the operable range of the one particular parameter and keeping all other parameters at the average value of respective parameter;

wherein each of the flooding tests is performed by:

injecting a dissolving fluid into the salt disposed in a core flooding apparatus, producing a brine containing dissolved salt; and

calculating the mass of the dissolved salt in the brine,

obtaining an analytical relationship of a mass of dissolved salt versus the one particular parameter;

varying each of the parameters while keeping all other parameters at their average values to obtain a plurality of the analytical relationships for each of the parameters; and

combining the plurality of the analytical relationships to obtain a total relationship between the mass of dissolved salt and all of the parameters, the parameters include flow rate, injection frequency, and salt concentration of the dissolving fluid.

7 . The method according to claim 6 , wherein the analytical relationship is obtained by fitting a curve of the flooding tests in the operable range of the one particular parameter.

8 . The method according to claim 6 , further comprises using the analytical relationships to estimate a dissolution progress of the salt.