Methods and systems for determining well shut-in pressures of oil and gas well drilling
Methods and systems for determining a well shut-in pressure of oil and gas well drilling are provided. The method comprises: obtaining, by a first processor, a basic parameter of a target oil and gas well, the basic parameter including at least one of a wellbore structure parameter, a well drilling fluid performance parameter, or a casing string parameter; obtaining, by the first processor, a pressure calculation model; and determining, by the first processor, a maximum well shut-in pressure during well drilling of the target oil and gas well based on the pressure calculation model and the basic parameter.
1 . A method for determining a well shut-in pressure of oil and gas well drilling, comprising:
obtaining, by a first processor, a basic parameter of a target oil and gas well, the basic parameter including at least one of a wellbore structure parameter, a well drilling fluid performance parameter, or a casing string parameter; wherein the pressure calculation model is:
P
Cmax
=
min
{
P
1
=
0.8
(
min
{
P
T
,
P
R
}
)
;
P
2
=
P
ba
-
P
be
;
P
3
=
0.8
(
0.0098
ρ
f
H
f
)
;
}
(
1
)
where P cmax denotes the maximum well shut-in pressure in MPa; P 1 denotes a minimum value of pressure limitation of a wellhead device in MPa; P T denotes a maximum test pressure of a support casing of the wellhead device in MPa; P R denotes a rated working pressure of the support casing of the wellhead device in MPa; P 2 denotes a minimum value of pressure limitation of the casing string in MPa; p ba denotes a maximum internal pressure strength of the casing string in MPa; P be denotes an effective internal pressure of the casing string in MPa: P 3 denotes a minimum value of a formation rupture pressure limitation in MPa; ρ f denotes a well drilling fluid density in g/cm 3 ; H f denotes a formation depth (vertical depth) corresponding to a position of a casing shoe in m; P cmax , P 1 , P 2 , p ba , P be , and P 3 are calculated by the first processor; and P R , P R , ρ f , and H f are obtained by the first processor from the monitoring device;
obtaining, by the first processor, a pressure calculation model;
determining, by the first processor, a maximum well shut-in pressure during well drilling of the target oil and gas well based on the pressure calculation model and the basic parameter;
determining, by the first processor, a recommended monitoring parameter and a recommended well drilling parameter based on the maximum well shut-in pressure and a wellhead pressure sequence and a bottomhole pressure sequence in a preset time period collected by a monitoring device;
generating, by the first processor, a monitoring adjustment instruction based on the recommended monitoring parameter and sending the monitoring adjustment instruction to the monitoring device to adjust a monitoring parameter of the monitoring device to the recommended monitoring parameter, wherein the monitoring device includes a pressure monitoring device, a density detection device, a depth detection device and a length measurement device, the monitoring parameter includes a monitoring accuracy degree and a monitoring frequency of the monitoring device; and
generating, by the first processor, a well drilling operation instruction based on the recommended well drilling parameter and sending the well drilling operation instruction to a second processor, the second processor being located at a terminal device, wherein the well drilling operation instruction is used to control the well drilling operation device to perform the well drilling operation with the recommended well drilling parameter, the well drilling operation device includes a drilling rig, a well drilling fluid pump and a well drilling mud mixer, the recommended well drilling parameter includes a recommended well shut-in time and a well drilling device parameter, the well drilling device parameter includes a density and a circulation speed of the well drilling fluid when the well drilling operation device works.
2 . The method according to claim 1 , wherein the determining, by the first processor, a recommended well drilling parameter based on the maximum well shut-in pressure and based on a wellhead pressure sequence and a bottomhole pressure sequence in a preset time period collected by a monitoring device includes:
obtaining, by the first processor, a parameter recommendation model based on preliminary training; and
predicting, by the first processor, the recommended well shut-in time by processing the maximum well shut-in pressure, the wellhead pressure sequence, and the bottomhole pressure sequence based on the parameter recommendation model, the parameter recommendation model being a machine learning model.
3 . The method according to claim 2 , further comprising:
in response to receiving a feedback signal from the monitoring device and/or a well drilling operation device, sending, by the first processor, an update instruction to the second processor; and
in response to receiving the update instruction, obtaining, by the second processor, an updated wellhead pressure sequence and an updated bottomhole pressure sequence from the monitoring device, processing the updated wellhead pressure sequence and the updated bottomhole pressure sequence, and determining an updated recommended well shut-in time based on the parameter recommendation model obtained from the first processor.
4 . The method according to claim 2 , wherein the parameter recommendation model includes:
a sequence feature extraction layer, an input of the sequence feature extraction layer including the wellhead pressure sequence and the bottomhole pressure sequence and an output of the sequence feature extraction layer including a fused sequence feature; and
a prediction layer, an input of the prediction layer including the fused sequence feature and the maximum well shut-in pressure and an output of the prediction layer including the recommended well shut-in time,
wherein the sequence feature extraction layer and the prediction layer are obtained through joint training.
5 . The method according to claim 4 , wherein different oil and gas wells correspond to different terminal devices, and different second processors and different monitoring devices corresponding to the different oil and gas wells are disposed in the different terminal devices; and
the second processors of the different terminal devices perform enhanced training on the parameter recommendation model based on well drilling feature information of the oil and gas wells corresponding to the different terminal devices, including:
for each of the different second processors and each of the different oil and gas wells corresponding to the each of the different second processors,
obtaining, by the second processor, actual well drilling data of the oil and gas well from a storage device as a training sample of the enhanced training;
obtaining, by the second processor, a predicted value by inputting the training sample into the parameter recommendation model obtained by the first processor; and
determining, by the second processor, a difference value based on the predicted value and a labeled value of the training sample and sending the difference value to the first processor:
constructing, by the second processor, a first loss function based on the difference values and updating the parameter recommendation model of the second processor based on the first loss function;
generating, by the first processor, a fused difference value by fusing different difference values obtained from the different second processors; and
constructing, by the first processor, a second loss function based on the fused difference value and updating the parameter recommendation model of the first processor based on the second loss function.
6 . The method according to claim 1 , wherein the maximum internal pressure strength of the casing string is calculated by:
P
ba
=
P
ba
1
+
Δ
p
ba
(
2
)
p
b
a
1
=
0
.
8
×
2
δ
y
m
n
(
k
wall
t
wall
)
/
D
o
u
t
(
3
)
Δ
p
ba
=
0.2
×
2
k
d
r
δ
tmn
(
k
wall
t
wall
-
k
a
f
N
)
D
out
-
(
k
wall
t
wall
-
k
a
f
N
)
(
4
)
where p ba1 denotes an internal pressure of the casing string when the casing string satisfies a yield strength in MPa; Δp ba denotes a safety margin of an internal pressure strength of the casing string in MPa; δ ymn denotes a minimum yield strength in MPa; k wall denotes a tolerance factor of a casing string wall without a dimension; t wall denotes a wall thickness of the casing string in mm; D out denotes an outer diameter of the casing string in mm; k dr denotes a correction factor of hardening based on material stress-strain characteristics without a dimension; δ tmn denotes a minimum tensile strength in MPa; k a denotes an internal pressure strength factor without a dimension; and f N denotes a defect depth in mm.
7 . The method according to claim 6 , wherein
the wall thickness of the casing string is calculated and determined by the first processor based on measured values of wall thicknesses of the casing string at a plurality of positions;
the outer diameter of the casing string is calculated and determined by the first processor based on measured values of outer diameters of the casing string at the plurality of positions; and
the measured values of wall thicknesses of the casing string and the measured values of outer diameters of the casing string are obtained by a logging device and transmitted to the first processor.
8 . The method according to claim 7 , wherein the plurality of positions are determined by the first processor based on appearance features of the casing string and an order in which the casing string is lowered to the well, and the appearance features of the casing string are determined based on scanning data of the casing string; and obtaining the measured values of wall thicknesses of the casing string and the measured values of outer diameters of the casing string based on a logging device includes:
completing monitoring, through the logging device, based on the plurality of positions to obtain the measured values of wall thicknesses of the casing string and the measured values of outer diameters of the casing string, the logging device including an electronic logging instrument.
9 . The method according to claim 6 , wherein the correction factor of hardening based on material stress-strain characteristics is calculated by:
k
d
r
=
(
1
/
2
)
n
+
1
+
(
1
/
3
)
n
+
1
(
5
)
where n denotes a hardening index without a dimension.
10 . The method according to claim 1 , wherein the effective internal pressure of the casing string is calculated by:
P
b
e
=
P
b
h
-
0
.
0
0
9
8
1
ρ
c
H
(
6
)
P
b
h
=
0
.
0
0
9
8
1
(
a
ρ
w
+
b
ρ
g
)
H
(
7
)
where P bh denotes an internal pressure of the casing string of a certain well section and a certain well depth in MPa; ρ c denotes a formation fluid density in g/cm 3 ; H denotes the well depth in m; a denotes a proportion of a volume of well drilling fluid in a wellbore to a wellbore volume in %; ρ w denotes the well drilling fluid density in g/cm 3 ; b denotes a proportion of a volume of gas in the wellbore to the wellbore volume in %; and ρ g denotes a density of gas intruding into the wellbore in g/cm 3.
11 . A system for determining a well shut-in pressure of oil and gas well drilling, comprising a first processor, wherein the first processor is configured to:
obtain a basic parameter of a target oil and gas well, the basic parameter including at least one of a wellbore structure parameter, a well drilling fluid performance parameter, or a casing string parameter r; wherein the pressure calculation model is:
P
Cmax
=
min
{
P
1
=
0.8
(
min
{
P
T
,
P
R
}
)
;
P
2
=
P
ba
-
P
be
;
P
3
=
0.8
(
0.0098
ρ
f
H
f
)
;
}
(
1
)
where P cmax denotes the maximum well shut-in pressure in MPa; P 1 denotes a minimum value of pressure limitation of a wellhead device in MPa; P T denotes a maximum test pressure of a support casing of the wellhead device in MPa; P R denotes a rated working pressure of the support casing of the wellhead device in MPa; P 2 denotes a minimum value of pressure limitation of the casing string in MPa; p ba denotes a maximum internal pressure strength of the casing string in MPa; P be denotes an effective internal pressure of the casing string in MPa; P 3 denotes a minimum value of a formation rupture pressure limitation in MPa; ρ f denotes a well drilling fluid density in g/cm 3 ; H f denotes a formation depth (vertical depth) corresponding to a position of a casing shoe in m; P cmax , P 1 , P 2 , P ba , P be , and P 3 are calculated by the first processor; and P T , P R , ρ f , and H f are obtained by the first processor from the monitoring device; and
obtain a pressure calculation model;
determine a maximum well shut-in pressure during well drilling of the target oil and gas well based on the pressure calculation model and the basic parameter;
determine a recommended monitoring parameter and a recommended well drilling parameter based on the maximum well shut-in pressure and a wellhead pressure sequence and a bottomhole pressure sequence in a preset time period collected by a monitoring device;
generate a monitoring adjustment instruction based on the recommended monitoring parameter and sending the monitoring adjustment instruction to the monitoring device to adjust a monitoring parameter of the monitoring device to the recommended monitoring parameter, wherein the monitoring device includes a pressure monitoring device, a density detection device, a depth detection device and a length measurement device, the monitoring parameter includes a monitoring accuracy degree and a monitoring frequency of the monitoring device; and
generate a well drilling operation instruction based on the recommended well drilling parameter and sending the well drilling operation instruction to a second processor, the second processor being located at a terminal device, wherein the well drilling operation instruction is used to control the well drilling operation device to perform the well drilling operation with the recommended well drilling parameter, the well drilling operation device includes a drilling rig, a well drilling fluid pump and a well drilling mud mixer, the recommended well drilling parameter includes a recommended well shut-in time and a well drilling device parameter, the well drilling device parameter includes a density and a circulation speed of the well drilling fluid when the well drilling operation device works.
12 . The system according to claim 11 , wherein the first processor is further configured to:
obtain a parameter recommendation model based on preliminary training; and
predicting the recommended well shut-in time by processing the maximum well shut-in pressure, the wellhead pressure sequence, and the bottomhole pressure sequence based on the parameter recommendation model, the parameter recommendation model being a machine learning model.
13 . The system according to claim 11 , wherein the maximum internal pressure strength of the casing string is calculated by:
P
ba
=
P
ba
1
+
Δ
p
ba
(
2
)
p
b
a
1
=
0
.
8
×
2
δ
y
m
n
(
k
wall
t
wall
)
/
D
o
u
t
(
3
)
Δ
p
ba
=
0.2
×
2
k
d
r
δ
tmn
(
k
wall
t
wall
-
k
a
f
N
)
D
out
-
(
k
wall
t
wall
-
k
a
f
N
)
(
4
)
where p ba1 denotes an internal pressure of the casing string when the casing string satisfies a yield strength in MPa; Δp ba denotes a safety margin of an internal pressure strength of the casing string in MPa; δy ymn denotes a minimum yield strength in MPa; k wall denotes a tolerance factor of a casing string wall without a dimension; t wall denotes a wall thickness of the casing string in mm; D out denotes an outer diameter of the casing string in mm; kdenotes a correction factor of hardening based on material stress-strain characteristics without a dimension; δ tmn denotes a minimum tensile strength in MPa; k a denotes an internal pressure strength factor without a dimension; and f N denotes a defect depth in mm.
14 . The system according to claim 13 , wherein the correction factor of hardening based on material stress-strain characteristics is calculated by:
k
d
r
=
(
1
/
2
)
n
+
1
+
(
1
/
3
)
n
+
1
(
5
)
where n denotes a hardening index without a dimension.
15 . The system according to claim 11 , wherein the effective internal pressure of the casing string is calculated by:
P
b
e
=
P
b
h
-
0
.
0
0
9
8
1
ρ
c
H
(
6
)
P
b
h
=
0
.
0
0
9
8
1
(
a
ρ
w
+
b
ρ
g
)
H
(
7
)
where P bh denotes an internal pressure of the casing string of a certain well section and a certain well depth in MPa; ρ c denotes a formation fluid density in g/cm 3 ; H denotes the well depth in m; a denotes a proportion of a volume of well drilling fluid in a wellbore to a wellbore volume in %; p w denotes the well drilling fluid density in g/cm 3 ; b denotes a proportion of a volume of gas in the wellbore to the wellbore volume in %; and ρ g denotes a density of gas intruding into the wellbore in g/cm 3.