Validation of the effectiveness of facies prediction methods used for geological models

1 . A method comprising:

measuring a first set of formation properties across a first depth interval in a first wellbore penetrating a subsurface region, the measuring comprising:

obtaining a first plurality of well logs using at least one logging tool,

wherein the first plurality of well logs comprises a first non-nuclear magnetic resonance (NMR) well log; and

physically extracting a core sample from the first wellbore and deriving an interpreted facies, a capillary pressure curve, and a saturation height function (SHF) from the core sample,

wherein the first set of formation properties comprises the first plurality of well logs, the interpreted facies, the capillary pressure curve, and the SHF;

generating a hydrocarbon pore volume (HcPV) prediction method based, at least in part, on the first set of formation properties, wherein the HcPV prediction method predicts a predicted HcPV, a predicted facies, and a developed SHF;

measuring, across a second depth interval using the at least one logging tool, a second set of formation properties in a second wellbore penetrating the subsurface region by:

obtaining a second plurality of well logs, wherein the second plurality of well logs comprises an NMR well log and a second non-NMR well log,

wherein the NMR well log comprises a set of NMR measurements comprising T2 distributions, free fluid index (FFI), and bulk volume irreducible (BVI),

wherein the second set of formation properties comprises the second plurality of well logs;

deriving a measured HcPV across the second depth interval based, at least in part, on the set of NMR measurements in the NMR well log;

calculating the predicted HcPV using the second non-NMR well log and the HcPV prediction method;

defining a stopping criterion based, at least in part, on a dissimilarity of the measured HcPV and the predicted HcPV;

calculating a difference between the measured HcPV and the predicted HcPV;

iteratively, or recursively, while the difference exceeds the stopping criterion;

adjusting at least one of: the SHF, the capillary pressure curve, or the interpreted facies;

generating an updated HcPV prediction method using the adjusted first set of formation properties;

re-calculating the predicted HcPV using the second non-NMR well log and the updated HcPV prediction method; and

re-calculating the difference between the measured HcPV and the predicted HcPV;

generating a calibrated HcPV prediction method based, at least in part, on the predicted HcPV that satisfies the stopping criterion, wherein the calibrated HcPV prediction method comprises a calibrated facies prediction method and a calibrated SHF prediction method;

measuring, across a targeted depth interval using the at least one logging tool, a third set of formation properties in a third wellbore penetrating the subsurface region by:

obtaining a third plurality of well logs, wherein the third plurality of well logs comprises a third non-NMR well log;

predicting a calibrated facies of the third wellbore at the targeted depth interval using the third plurality of well logs and the calibrated facies prediction method;

updating a geological model based, at least in part, on the calibrated facies;

identifying, using the calibrated facies, an identified drilling target within the subsurface region,

wherein the identified drilling target corresponds to an advantageous location to penetrate the subsurface region due to an expected preferred fluid flow amount indicated by the calibrated facies; and

drilling, using a wellbore drilling system, a wellbore to intersect the identified drilling target.

2 . The method of claim 1 , further comprising:

predicting a calibrated SHF using the third plurality of well logs and the calibrated SHF prediction method; and

updating the geological model based, at least in part, on the calibrated SHF.

3 . The method of claim 1 , wherein generating the HcPV prediction method comprises:

determining a facies prediction method based, at least in part, on the interpreted facies and the first non-NMR well log, wherein the facies prediction method generates the predicted facies from non-NMR type well logs;

determining an SHF prediction method based, at least in part, on the predicted facies and the capillary pressure curve; and

determining the predicted HcPV based, at least in part, on the developed SHF.

4 . The method of claim 1 , wherein the stopping criterion comprises a value of an objective function.

5 . The method of claim 1 , wherein the HcPV prediction method comprises a machine learning method.

6 . The method of claim 1 , wherein the measured HcPV and the predicted HcPV span a common depth range of the second wellbore.

7 . The method of claim 1 , further comprising:

performing a reservoir simulation based, at least in part, on the geological model; and

determining the identified drilling target within the subsurface region based, at least in part, on the reservoir simulation.

8 . The method of claim 7 , comprising:

planning, using a wellbore planning system, a wellbore path to intersect the identified drilling target; and

drilling, using the wellbore drilling system, the wellbore guided by the planned wellbore path.

9 . A non-transitory computer readable medium storing a set of instructions, executable by a computer processor, the set of instructions comprising functionality for:

receiving a first set of formation properties across a first depth interval in a first wellbore penetrating a subsurface region, the first set of formation properties comprising:

a first plurality of well logs measured by at least one logging tool, wherein the first plurality of well logs comprises a first non-nuclear magnetic resonance (NMR) well log; and

an interpreted facies, a capillary pressure curve, and a saturation height function (SHF derived from a core sample dataset obtained by physically extracting a core sample from the first wellbore;

generating a hydrocarbon pore volume (HcPV) prediction method based, at least in part, on the first set of formation properties, wherein the HcPV prediction method predicts a predicted HcPV, a predicted facies, and a developed SHF;

receiving a second set of formation properties across a second depth interval in a second wellbore penetrating the subsurface region, the second set of formation properties comprising:

a second plurality of well logs measured by the at least one logging tool, wherein the second plurality of well logs comprises an NMR well log and a second non-NMR well log,

wherein the NMR well log comprises a set of NMR measurements comprising T2 distributions, free fluid index (FFI), and bulk volume irreducible (BVI);

deriving a measured HcPV across the second depth interval based, at least in part, on the set of NMR measurements in the NMR well log;

calculating the predicted HcPV using the second non-NMR well log and the HcPV prediction method;

defining a stopping criterion based, at least in part, on a dissimilarity of the measured HcPV and the predicted HcPV;

calculating a difference between the measured HcPV and the predicted HcPV;

iteratively, or recursively, while the difference exceeds the stopping criterion:

adjusting at least one of: the SHF, the capillary pressure curve, or the interpreted facies;

generating an updated HcPV prediction method using the adjusted first set of formation properties;

re-calculating the predicted HcPV using the second non-NMR well log and the updated HcPV prediction method; and

re-calculating the difference between the measured HcPV and the predicted HcPV;

generating a calibrated HcPV prediction method based, at least in part, on the predicted HcPV that satisfies the stopping criterion, wherein the calibrated HcPV prediction method comprises a calibrated facies prediction method and a calibrated SHF prediction method;

receiving a third set of formation properties across a targeted depth interval in a third wellbore penetrating the subsurface region, the third set of formation properties comprising:

a third plurality of well logs measured by the at least one logging tool, wherein the third plurality of well logs comprises a third non-NMR well log;

predicting a calibrated facies of the third wellbore at the targeted depth interval using the third plurality of well logs and the calibrated facies prediction method;

updating a geological model based, at least in part, on the calibrated facies;

identifying, using the calibrated facies, an identified drilling target within the subsurface region,

wherein the identified drilling target corresponds to an advantageous location to penetrate the subsurface region due to an expected preferred fluid flow amount indicated by the calibrated facies; and

outputting control instructions to a wellbore drilling system to control the wellbore drilling system to drill a wellbore that intersects the identified drilling target.

10 . The non-transitory computer readable medium of claim 9 , further comprising:

predicting a SHF using the third plurality of well logs and the calibrated SHF prediction method; and

updating the geological model based, at least in part, on the calibrated SHF.

11 . The non-transitory computer readable medium of claim 9 , wherein generating the HcPV prediction method comprises:

determining a facies prediction method based, at least in part, on the interpreted facies and the first non-NMR well log, wherein the facies prediction method generates the predicted facies from non-NMR type well logs;

determining an SHF prediction method based, at least in part, on the predicted facies and the capillary pressure curve; and

determining the predicted HcPV based, at least in part, on the developed SHF.

12 . The non-transitory computer readable medium of claim 9 , wherein the stopping criterion comprises a value of an objective function.

13 . The non-transitory computer readable medium of claim 9 , further comprising:

performing a reservoir simulation based, at least in part, on the geological model; and

determining the identified drilling target within the subsurface region based, at least in part, on the reservoir simulation.

14 . The non-transitory computer readable medium of claim 13 , comprising planning, using a wellbore planning system, a wellbore path to intersect the identified drilling target within the subsurface region.

15 . A system comprising:

a well logging system configured to use at least one logging tool to record:

a first plurality of well logs from a first wellbore penetrating a subsurface region, wherein the first plurality of well logs comprises a first non-nuclear magnetic resonance (NMR) well log,

wherein the first plurality of well logs are measured across a first depth interval;

a second plurality of well logs from a second wellbore penetrating the subsurface region, wherein the second plurality of well logs comprises an NMR well log and a second non-NMR well log,

wherein the second plurality of well logs are measured across a second depth interval,

wherein the NMR well log comprises a set of NMR measurements comprising T2 distributions, free fluid index (FFI), and bulk volume irreducible (BVI), and

a third plurality of well logs for a third wellbore penetrating the subsurface region,

wherein the third plurality of well logs comprises a third non-NMR well log,

wherein the third plurality of well logs are measured across a targeted depth interval;

a well coring system equipped to physically extract a core sample from the first wellbore; and

a computer processor configured to:

derive an interpreted facies, a capillary pressure curve, and a saturation height function (SHF) from the core sample,

generate a hydrocarbon pore volume (HcPV) prediction method based, at least in part, on the first plurality of well logs, the interpreted facies, the capillary pressure curve, and the SHF, wherein the HcPV prediction method predicts a predicted HcPV, a predicted facies, and a developed SHF,

derive a measured HcPV across the second depth interval based, at least in part, on the set of NMR measurements in the NMR well log,

calculate the predicted HcPV using the second non-NMR well log and the HcPV prediction method,

define a stopping criterion based, at least in part, on a dissimilarity of the measured HcPV and the predicted HcPV,

calculate a difference between the measured HcPV and the predicted HcPV,

iteratively, or recursively, while the difference exceeds the stopping criterion:

adjust at least one of: the SHF, the capillary pressure curve, or the interpreted facies;

generate an updated HcPV prediction method using the first plurality of well logs, the adjusted interpreted facies, the adjusted capillary pressure curve, and the adjusted SHF;

re-calculate the predicted HcPV using the second non-NMR well log and the updated HcPV prediction method; and

re-calculate the difference between the measured HcPV and the predicted HcPV;

generate a calibrated HcPV prediction method based, at least in part, on the predicted HcPV that satisfies the stopping criterion, wherein the calibrated HcPV prediction method comprises a calibrated facies prediction method and a calibrated SHF prediction method,

predict a calibrated facies at the targeted depth interval using the third plurality of well logs and the calibrated facies prediction method,

update a geological model based, at least in part, on the calibrated facies, and

identify, using the calibrated facies, an identified drilling target within the subsurface region,

wherein the identified drilling target corresponds to an advantageous location to penetrate the subsurface region due to an expected preferred a fluid flow amount indicated by the calibrated facies; and

control a wellbore drilling system to drill a wellbore that intersects the identified drilling target.

16 . The system of claim 15 , wherein the computer processor is further configured to:

predict a calibrated SHF using the third plurality of well logs and the calibrated SHF prediction method; and

update the geological model based, at least in part, on the calibrated SHF.

17 . The system of claim 15 , wherein generating the HcPV prediction method comprises:

determining a facies prediction method based, at least in part, on the interpreted facies and the first non-NMR well log, wherein the facies prediction method generates the predicted facies from non-NMR type well logs;

determining an SHF prediction method based, at least in part, on the predicted facies and the capillary pressure curve; and

determining the predicted HcPV based, at least in part, on the developed SHF.

18 . The system of claim 15 , wherein the stopping criterion comprises a value of an objective function.

19 . The system of claim 15 , further comprising a reservoir simulator configured to:

perform a reservoir simulation based, at least in part, on the geological model; and

determine the identified drilling target within the subsurface region based, at least in part, on the reservoir simulation.

20 . The system of claim 19 , comprising:

a wellbore planning system, to plan a wellbore path to intersect the identified drilling target; and

the wellbore drilling system, to drill the wellbore guided by the planned wellbore path.