Deep transient testing (DTT) downhole and surface gas rate integration workflow

1 . A method, comprising:

flowing one or more fluids from a subterranean formation to flow through a downhole well tool disposed in a wellbore of a well during a deep transient testing (DTT) operation performed by the downhole well tool;

measuring data related to one or more properties of the one or more fluids using one or more downhole fluid analysis sensors disposed within the downhole well tool;

predicting, via a control system, a first predicted DTT surface gas rate based on the data measured related to the one or more properties of the one or more fluids;

determining, via the control system, a total number of moles of gas released at a surface of the well for each component of each fluid of the one or more fluids by dividing a mass of each component of each fluid of the one or more fluids by molecular weight of the one or more fluids; and

determining, via the control system, a total volume of gas released at the surface of the well for each component of each fluid of the one or more fluids by multiplying the total number of moles for each component of each fluid of the one or more fluids by a molecular volume for each component of each fluid of the one or more fluids.

2 . The method of claim 1 , wherein the first predicted DTT surface gas rate comprises hydrocarbon content of the one or more fluids and gas emissions relating to the one or more fluids.

3 . The method of claim 1 , comprising:

detecting, via a gas meter of a mud-gas separator, surface measurement data relating to the one or more properties of the one or more fluids; and

predicting, via the control system, a second predicted DTT surface gas rate based on the surface measurement data relating to the one or more properties of the one or more fluids.

4 . The method of claim 1 , wherein the one or more fluids comprise an oil-based mud.

5 . The method of claim 1 , wherein the one or more fluids comprise a water-based mud.

6 . The method of claim 1 , wherein the downhole well tool comprises the control system, and wherein predicting the first predicted DTT surface gas rate comprises:

determining, via the downhole well tool, each fluid of the one or more fluids flowing through the downhole well tool;

mapping, via the downhole well tool, a flowrate to a fluid density estimation or fluid density measurement for each fluid of the one or more fluids;

summing, via the downhole well tool, flowrates of similar fluids of the one or more fluids; and

converting, via the downhole well tool, the summed flowrates from volume rates to mass rates by multiplying the volume rates to the fluid density estimation or fluid density measurement.

7 . The method of claim 6 , wherein the fluid density estimation or fluid density measurement comprises a direct measurement of fluid density via a fluid density sensor of the one or more downhole fluid analysis sensors.

8 . The method of claim 6 , wherein the fluid density estimation or fluid density measurement comprises an estimate of fluid density performed by the downhole well tool using one or more compositional measurements of the one or more fluids and a fluid model.

9 . The method of claim 1 , comprising determining, via the control system, a total volume of gas released at the surface of the well by summing the total volume of gas released at the surface of the well for each component of each fluid of the one or more fluids.

10 . The method of claim 1 , wherein the control system is a surface control system located at a surface of the well.

11 . The method of claim 1 , wherein the downhole well tool comprises the control system.

12 . The method of claim 1 , wherein the control system comprises a surface control system located at the surface of the well and a downhole control system disposed within the downhole well tool, and wherein the surface control system and the downhole control system are communicatively coupled.

13 . The method of claim 1 , further comprising:

flowing the one or more fluids to a surface of the well, wherein the one or more fluids comprise gas and mud; and

separating the gas and the mud of the one or more fluids at the surface using a separator.

14 . A method, comprising:

flowing one or more fluids from a subterranean formation to flow through a downhole well tool disposed in a wellbore of a well during a deep transient testing (DTT) operation performed by the downhole well tool;

measuring data related to one or more properties of the one or more fluids using one or more downhole fluid analysis sensors disposed within the downhole well tool;

predicting, via a control system, a first predicted DTT surface gas rate based on the data measured related to the one or more properties of the one or more fluids;

predicting, via the control system, a second predicted DTT surface gas rate based on measurement data detected by surface equipment of the well; and

calculating, via the control system, a vapor fraction for each gaseous component of the one or more fluids, by comparing the first predicted DTT surface gas rate and the second predicted DTT surface gas rate.

15 . The method of claim 14 , wherein the control system is a surface control system located at a surface of the well.

16 . The method of claim 14 , wherein the downhole well tool comprises the control system.

17 . A method, comprising:

flowing one or more fluids from a subterranean formation to flow through a downhole well tool disposed in a wellbore of a well during a deep transient testing (DTT) operation performed by the downhole well tool;

measuring data related to one or more properties of the one or more fluids using one or more downhole fluid analysis sensors disposed within the downhole well tool; and

predicting, via a control system, a first predicted DTT surface gas rate based on the data measured related to the one or more properties of the one or more fluids, wherein the downhole well tool comprises the control system, and wherein predicting the first predicted DTT surface gas rate comprises:

determining, via the downhole well tool, a weight fraction for each fluid of the one or more fluids at a plurality of time steps; and

determining, via the downhole well tool, a mass rate of each component of each fluid of the one or more fluids by multiplying the weight fraction for each component of each fluid of the one or more fluids by a total mass flowrate of the one or more fluids.

18 . The method of claim 17 , comprising:

determining, via the control system, a mass rate of gas released at a surface of the well by multiplying the mass rate of each component of each fluid of the one or more fluids with a vapor fraction of each component of each fluid of the one or more fluids; and

determining, via the control system, a total mass of gas released at the surface of the well for each component of each fluid of the one or more fluids by summing the mass rate of gas released at the surface of the well over total time of the plurality of time steps.

19 . The method of claim 17 , comprising determining, via the control system, a total mass pumped into the wellbore of the well for each component of each fluid of the one or more fluids by summing the mass rate of each component of each fluid of the one or more fluids over total time of the plurality of time steps.

20 . The method of claim 17 , wherein the control system is a surface control system located at a surface of the well.