Systems and methods for discovering and recovering subsurface fluids and verification of subsurface storage fluids

1 . A method for drilling a borehole to a depth associated with a fluid type in a rock formation, the method comprising:

determining a rock matrix type of the rock formation at a geological area of interest;

determining a porosity of the rock formation;

determining a fluid density of a fluid within a pore space of the rock formation;

determining an acoustic slowness of the fluid within the pore space;

determining, based on the fluid density and the acoustic slowness, the fluid type of the fluid within the pore space, wherein determining the fluid type within the pore space includes correlating the fluid density and the acoustic slowness of the fluid within the pore space to a known combination of fluid density and acoustic slowness of one or more of hydrogen, methane, nitrogen, helium, water, or carbon dioxide;

flagging the fluid type within the rock formation, wherein the flagging includes providing the depth within the rock formation having geophysical properties indicative of a presence or an amount of the fluid type; and

in response to determining the fluid type, drilling the borehole in the rock formation to the depth of the fluid type.

2 . The method of claim 1 , wherein determining a rock matrix type at a geological area of interest includes examining one or more well logs for the rock matrix type based on geophysical properties thereof.

3 . The method of claim 1 , wherein determining a rock matrix type at a geological area of interest includes examining one or more of gamma ray logs, geophysical logs, mud logs, or cuttings or cores from a well into the rock matrix at the geological area of interest.

4 . The method of claim 1 , wherein determining porosity of the rock formation includes obtaining porosity data from one or more well logs, including at least one of a resistivity log, neutron porosity log, an image log.

5 . The method of claim 1 , wherein determining a fluid density of a fluid within the pore space includes calculating the fluid density of the fluid within the pore space by solving for ρ fluid using a density equation, ρ log =(Φ)*ρ fluid +(1−Φ)*ρ matrix , where:

ρ log =bulk density measured by a density log tool (g/cm 3 );

Φ=porosity of the rock formation expressed as a fraction;

ρ fluid =fluid density of the fluid contained in the pore space of the rock formation (g/cm 3 )

1−Φ=volume fraction of rock in the rock formation expressed as a fraction; and

ρ matrix =density of the rock matrix (g/cm 3 ).

6 . The method of claim 5 , wherein one or more of ρ log , Φ, or ρ matrix are obtained or derived from one or more well logs.

7 . The method of claim 1 , wherein determining an acoustic slowness of the fluid within the pore space includes calculating the acoustic slowness of the fluid within the pore space by solving for Δt fluid using an acoustic slowness equation, Δt log =(Φ)*Δt fluid +(1−Φ)*Δt matrix , where:

Δt log =acoustic slowness within the rock formation (μs/ft);

Φ=porosity of the rock formation expressed as a fraction;

Δt fluid =acoustic slowness the fluid contained in the pore space of the rock formation (μs/ft);

1−Φ=volume fraction of rock in the rock formation expressed as a fraction; and

Δt matrix =acoustic slowness of the rock matrix.

8 . The method of claim 7 , wherein one or more of Δt log , Φ, or Δt matrix are obtained or derived from one or more well logs.

9 . The method of claim 1 , further comprising identifying a geological area of interest.

10 . The method of claim 1 , further comprising determining a relative amount of the fluid within the rock formation.

11 . The method of claim 1 , wherein the fluid type includes one or more of hydrogen, helium, or carbon dioxide.

12 . The method of claim 1 , further comprising one or more of planning or drilling one or more additional wells at locations determined to exhibit a presence of one or more selected fluid types.

13 . A system for drilling a borehole to a depth associated with a fluid type in a rock formation, the system comprising:

a computing device having a processor and memory storage operably coupled to the processor, the memory storage having one or more operational programs including machine readable and executable instructions for determining the fluid type within the rock formation based on data from one or more well logs and flagging the fluid type within the rock formation, wherein the flagging comprises providing the depth having geophysical properties indicative of a presence or a relative amount of the fluid type, and the processor being configured to read and execute the one or more operational programs;

wherein the data from the one or more well logs indicate one or more of a rock matrix type, a porosity of the rock formation, a fluid density of the fluid within a pore space of the rock formation, or an acoustic slowness of the fluid within the pore space of the rock formation, and wherein the one or more operational programs including machine readable and executable instructions to:

determine the rock matrix type of the rock formation at a geological area of interest,

determine the porosity of the rock formation,

determine the fluid density of the fluid within the pore space of the rock formation,

determine the acoustic slowness of the fluid within the pore space, and

determine a fluid type of the fluid within the pore space; and

wherein the instructions to determine the fluid type within the pore space include instructions to correlate the fluid density and the acoustic slowness of the fluid within the pore space to a known combination of fluid density and acoustic slowness of one or more of hydrogen, methane, nitrogen, helium, water, or carbon dioxide; and

a drill rig configured to drill the borehole in the rock formation to the depth of the fluid type in response to the computing device determining the fluid type.

14 . The system of claim 13 , wherein the instructions to determine a rock matrix type of a rock formation at a geological area of interest include instructions to examine the one or more well logs for geophysical properties indicating a rock matrix type.

15 . The system of claim 13 , wherein the instructions to determine porosity of the rock formation include instructions for obtaining porosity data from the one or more well logs.

16 . The system of claim 13 , wherein the computing device is configured to identify the fluid type within the rock formation based on the fluid density and the acoustic slowness derived from the data from the one or more well logs.