Systems and methods for optimizing rate of penetration in drilling operations
Systems and methods for predicting an efficient hole cleaning in vertical, deviated, and horizontal holes by developing a hole cleaning model that combines hole cleaning and drilling rate to optimize performance. Specifically by ensuring optimum mud rheology values that have an influence on drilling mud from the aspects of ECD, cuttings transport, shear thinning, and thixotropic, and developing an effective hole cleaning model by utilizing carrying capacity index (CCI) and cutting concentration in annulus (CCA).
1. A method of drilling a borehole with a drill tool of a drilling system that uses drilling mud to transport cuttings of a formation to surface, the method comprising:
receiving a plurality of input parameters of a drilling operation conducted with the drilling system, the input parameters at least including a cuttings parameter related to the cuttings produced in the drilling operation;
determining a current concentration of the cuttings in annulus (CCA) near the drill tool based on the input parameters;
determining a desired rate of penetration for the drilling operation based on the determined cuttings concentration in annulus (CCA); and
altering a current rate of penetration based on the determined desired rate, wherein CCA is determined used a formula:
C
C
A
=
R
O
P
OH
2
1472
G
P
M
T
R
wherein ROP is the current rate of penetration, OH is the hole size, GPM is the flow rate of mud pump, and TR is the transport ratio.
2. The method of claim 1 , further comprising:
determining a carrying capacity index (CCI) based on the plurality of input parameters;
determining a second desired rate of penetration for the drilling operation based on the determined cutting concentration in annulus (CCA) and the carrying capacity index (CCI); and
altering the current rate of penetration based on the determined second desired rate.
3. The method of claim 2 , wherein CCI in a vertical well is determined using a formula:
CCI
=
MW
K
Av
400
,
000
where MW is the mud weight, K is the consistency index, and A v , if the mud annular velocity.
4. The method of claim 2 , wherein CCI in a deviated or horizontal well is determined using a formula:
CCI
=
(
K
SG
Af
3585
Aa
)
where K is the consistency index, SG is the specific gravity, A f is the angle factor of the deviated or horizontal well, and A a is the annular area.
5. The method of claim 1 , wherein receiving the input parameters comprises obtaining one or more of: a weight of the drilling mud (MW), flow rate of the drilling mud (GPM), the current rate of penetration (ROP) of the drilling system, a depth of the borehole, a depth of the drill tool of the drilling system, a density of the cuttings, a diameter of the cuttings, an eccentricity factor of the borehole, and a porosity of the formation.
6. The method claim 1 , wherein determining the current concentration of the cuttings in the annulus (CCA) near the drill tool based on the input parameters comprises using a volumetric flow rate of the drilling mud, a volumetric flow rate of the cuttings, and a relationship between slip velocity and axial velocity in the determination.
7. The method of claim 6 , wherein determining the current concentration of the cuttings in the annulus (CCA) near the drill tool based on the input parameters further comprises using in the determination one or more of:
an area of an annulus near the drill tool, an eccentricity of the borehole, a surface area of the drill tool of the drilling system, and a porosity of the formation.
8. The method of claim 1 , wherein the input parameters further comprise hole size (OH), measured rate of penetration (ROP), transport ratio (TR), mud type, footage, hours spent for drilling the footage, mud density in pounds per cubic feet (pcf) and pounds per gallon (ppg), funnel viscosity, plastic viscosity (PV) in centipoise (cp), yield point (YP) in lb/100 sqft, weight of blend (WOB) in Klb, revolutions per minute (RPM), stand pipe pressure in psi, torque in lbf.ft, total flow area of the bit in square inches, initial gel and final gel types, and flow rate of the mud pump (GPM).
9. The method of claim 8 , further comprising:
determining the transport ratio (TR) is less than a predetermined threshold value;
altering the flow rate of mud pump (GPM) in order to increase the current concentration of the cuttings in the annulus (CCA) to above 5%.
10. The method of claim 8 , further comprising:
determining that a ratio of yield point versus plastic velocity (YP/PV) is less than a predetermined threshold value;
altering the YP/PV in order to reach a YP/PV value of at least 3.
11. The method of claim 10 , further comprising:
determining the flow rate of mud pump (GPM) is less than a predetermined threshold value;
altering the GPM in order to reach a GPM value of at least 1200.
12. The method of claim 1 , further comprising:
determining drilling specific energy (DSE) using a formula:
DSE
=
4
WOB
nD
B
2
+
480
RPM
TRQ
D
B
2
ROP
-
3
,
189
,
335
HHP
B
D
B
*
ROP
where WOB is the weight of blend, RPM is the revolutions per minute, TRQ is the torque, HHP B is the hydraulic horsepower of the bit, D B is the diameter of the bit, and ROP is the measured rate of penetration.
13. A program storage device having program instructions stored thereon for causing a programmable control device to perform the method of drilling the borehole according to claim 1 .
14. A drilling system for drilling a borehole with a drill tool using drilling mud to transport cuttings of a formation to surface, the system comprising:
storage configured to store historical information;
an interface obtaining a plurality of parameters of a drilling operation conducted with the drilling system, the input parameters at least including a cuttings parameter related to the cuttings produced in the drilling operation; and
a processing unit in communication with the storage and the interface and configured to:
receive the plurality of input parameters;
determine a current concentration of the cuttings in annulus (CCA) near the drill tool based on the input parameters;
determine a desired rate of penetration for the drilling operation based on the determined cuttings concentration in annulus (CCA); and
alter a current rate of penetration based on the determined desired rate, wherein CCA is determined used a formula:
C
C
A
=
R
O
P
OH
2
1472
G
P
M
T
R
wherein ROP is the current rate of penetration, OH is the hole size, GPM is the flow rate of mud pump, and TR is the transport ratio.
15. The system of claim 14 , wherein the processing unit is further configured to:
determine a carrying capacity index (CCI) based on the plurality of input parameters;
determine a second desired rate of penetration for the drilling operation based on the determined cutting concentration in annulus (CCA) and the carrying capacity index (CCI); and
alter a current rate of penetration based on the determined second desired rate.
16. The system of claim 14 , wherein obtaining the input parameters comprises obtaining one or more of: a weight of the drilling mud (MW), flow rate of the drilling mud (GPM), the current rate of penetration (ROP) of the drilling system, a depth of the borehole, a depth of the drill tool of the drilling system, a density of the cuttings, a diameter of the cuttings, an eccentricity factor of the borehole, and a porosity of the formation.
17. The system of claim 14 , wherein determining the current concentration of the cuttings in the annulus (CCA) near the drill tool based on the input parameters comprises using a volumetric flow rate of the drilling mud, a volumetric flow rate of the cuttings, and a relationship between slip velocity and axial velocity in the determination.
18. The system of claim 17 , wherein determining the current concentration of the cuttings in the annulus (CCA) near the drill tool based on the input parameters further comprises using in the determination one or more of:
an area of an annulus at least near the drill tool, an eccentricity of the borehole, a surface area of the drill tool of the drilling system, and a porosity of the formation.
19. The system of claim 14 , wherein the input parameters further comprise hole size (OH), measured rate of penetration (ROP), transport ratio (TR), mud type, footage, hours spent for drilling the footage, mud density in pounds per cubic feet (pcf) and pounds per gallon (ppg), funnel viscosity, plastic viscosity (PV) in centipoise (cp), yield point (YP) in lb/100 sqft, weight of blend (WOB) in Klb, revolutions per minute (RPM), stand pipe pressure in psi, torque in lbf.ft, total flow area of the bit in square inches, initial gel and final gel types, and flow rate of the mud pump (GPM).
20. The system of claim 19 , wherein the processing unit is further configured to:
determine the transport ratio (TR) is less than a predetermined threshold value;
alter the flow rate of mud pump (GPM) in order to increase the current concentration of the cuttings in annulus (CCA) to above 5%.
21. The system of claim 19 , wherein the processing unit is further configured to:
determine that a ratio of yield point versus plastic velocity (YP/PV) is less than a predetermined threshold value;
alter the YP/PV in order to reach a YP/PV value of at least 3.
22. The system of claim 14 , wherein CCI in a vertical well is determined using a formula:
CCI
=
MW
K
Av
400
,
000
where MW is the mud weight, K is the consistency index, and A v , if the mud annular velocity.
23. The system of claim 14 , wherein CCI in a deviated or horizontal well is determined using a formula:
CCI
=
(
K
SG
Af
3585
Aa
)
where K is the consistency index, SG is the specific gravity, A f is the angle factor of the deviated or horizontal well, and A a is the annular area.
24. The system of claim 14 , wherein the processing unit is further configured to:
determine drilling specific energy (DSE) using a formula:
DSE
=
4
WOB
nD
B
2
+
480
RPM
TRQ
D
B
2
ROP
-
3
,
189
,
335
HHP
B
D
B
*
ROP
where WOB is the weight of blend, RPM is the revolutions per minute, TRQ is the torque, HHP B is the hydraulic horsepower of the bit, D B is the diameter of the bit, and ROP is the measured rate of penetration.