06 Pressure Losses
-
Upload
brahim-letaief -
Category
Documents
-
view
220 -
download
0
Transcript of 06 Pressure Losses
-
8/11/2019 06 Pressure Losses
1/45
2005 PetroSkills LLC, All Rights Reserved
PRESSURE LOSSES
The pressure losses within a well
are reflected in the standpipe
pressure
-
8/11/2019 06 Pressure Losses
2/45
2005 PetroSkills LLC, All Rights Reserved2
Pressure Losses
Pressure lossesare the sum of all
pressure losses in
the system
dcadpabitdcdpsurfs PPPPPPP
-
8/11/2019 06 Pressure Losses
3/45
2005 PetroSkills LLC, All Rights Reserved3
Pressure Losses
The majority of the pressurelosses in the circulating system
are in turbulent flow
Surface connections, drill pipe,
drill collars and bit
-
8/11/2019 06 Pressure Losses
4/45
2005 PetroSkills LLC, All Rights Reserved4
Pressure Losses
The velocityvectors are not
ordered and the
velocity profile isvery flat with the
average velocity
approximatelyequal to the
maximum velocity
-
8/11/2019 06 Pressure Losses
5/45
2005 PetroSkills LLC, All Rights Reserved5
Pressure Losses
This is the classicFanning Friction
Factor Diagram
The friction factoris a function of the
roughness of the
pipe and theReynolds number
-
8/11/2019 06 Pressure Losses
6/45
2005 PetroSkills LLC, All Rights Reserved6
Pressure Losses
The Reynolds number can bedetermined from the following
equation
In turbulent flow the viscosity is
me
vDR 47.15
2.3
PV
-
8/11/2019 06 Pressure Losses
7/45 2005 PetroSkills LLC, All Rights Reserved7
Pressure Losses
e/D comes from the
Moody Diagram1. Cast Iron
2. Galvanized Iron
3. Asphalted CastIron
4. Commercial
Steel or Wrought Iron5. Drawn Tubing
0.000010
0.000100
0.001000
0.010000
0.100000
1 10 100
Pipe diameter, inches
e/D
Riveted Steel
Concrete
e=0.03
e=0.01
e=0.003
e=0.001e=0.00085
e=0.0005
e=0.0004
e=0.00015
e=0.000005
1
2
3
4
5
-
8/11/2019 06 Pressure Losses
8/45 2005 PetroSkills LLC, All Rights Reserved8
Pressure Losses
The frictional pressure loss isrelated to the friction factor by
the following equation
e/D is 0.0006 if you assume 4 IDsteel and the friction factor
would be
D
lfvP m
)10(298.9 4
2
-
8/11/2019 06 Pressure Losses
9/45 2005 PetroSkills LLC, All Rights Reserved9
Pressure Losses
By substituting into the equationfor pressure losses, one can
determine the pressure losses
inside pipefor turbulent flow
19.00458.0
eR
f
-
8/11/2019 06 Pressure Losses
10/45 2005 PetroSkills LLC, All Rights Reserved10
Pressure Losses
In this class we will use Equation6-6for turbulent flow in pipe
It includes pressure losses in the
surface connections, drill pipeand drill collars
83.4
19.081.181.05 )10(68.7
D
lPVQP m
-
8/11/2019 06 Pressure Losses
11/45 2005 PetroSkills LLC, All Rights Reserved11
Pressure Losses
Classes of surface equipment
COMPONENTS - LENGTH AND ID
CLASS # STANDPIPE HOSE SWIVEL KELLY
1 40' - 3" 45' - 2" 20' - 2" 40' - 2 1/4"
2 40' - 3 1/2" 55' - 2 1/2" 25' - 2 1/2" 40' - 3 1/4"
3 45' - 4" 55' - 3" 25' - 2 1/4" 40' - 3 1/4"
4 45' - 4" 55' - 3" 30' - 3" 40' - 4"
-
8/11/2019 06 Pressure Losses
12/45 2005 PetroSkills LLC, All Rights Reserved12
Pressure Losses
Example 6-1
Total Depth 17,193 feet (5240m)Hole Size 6 1/2 inches (165mm)
Rheology in Figure 4-16 and Table 4-5 of theDrilling Fluids Chapter
BHA 818 ft (249m). 4.8" OD (122mm) by 1 1/2" ID(38mm) DCs
Drill pipe 3 1/2" 15.5 #/ft, ID = 2.602 (89 by66mm)
Drill pipe length is 16, 375 feet (4991m)Surface Equipment is Class 2
Nozzles 2-11 and 1-12 (2-8.7mm and 1-9.5mm)
Drilling with 147 gpm at 3100 psi (0.556m3at
21,370 kPa)
-
8/11/2019 06 Pressure Losses
13/45 2005 PetroSkills LLC, All Rights Reserved13
Pressure Losses
Calculate pressure losses in thesurface connections using
Equation 6-6
Standpipe
Hose
psi1)5.3(
)40()29()147()15)(10(68.783.4
19.081.181.05
P
psi7)5.2(
)55()29()147()15)(10(68.783.4
19.081.181.05
P
(7 kPa)
(48 kPa)
-
8/11/2019 06 Pressure Losses
14/45 2005 PetroSkills LLC, All Rights Reserved14
Pressure Losses
Swivel
Kelly
Total
psi3)5.2(
)25()29()147()15)(10(68.783.4
19.081.181.05
P
psi1)25.3(
)40()29()147()15)(10(68.783.4
19.081.181.05
P
psi121371 surfP
(21 kPa)
(7 kPa)
(83 kPa)
-
8/11/2019 06 Pressure Losses
15/45 2005 PetroSkills LLC, All Rights Reserved15
Pressure Losses
Pressure losses in surfaceconnections are small and not
worth calculating unless done on
a computer
-
8/11/2019 06 Pressure Losses
16/45 2005 PetroSkills LLC, All Rights Reserved16
Pressure Losses
Calculate the pressure losses inthe drill pipe using Equation 6-6
psi1766)602.2(
)16375()29()147()15)(10(68.7
83.4
19.081.181.05
dpP
(12,180 kPa)
83.4
19.081.181.0
5 )10(68.7D
lPVQP m
-
8/11/2019 06 Pressure Losses
17/45 2005 PetroSkills LLC, All Rights Reserved17
Pressure Losses
Calculate pressure losses in thedrill collars using Equation 6-6
Pdc 7 68 10 15 147 29 818
1 51262
5 0 81 1 81 0 19
4 83
. ( )( ) ( ) ( ) ( )
( . )
. . .
.psi
(8700 kPa)
83.4
19.081.181.05 )10(68.7
D
lPVQ
P m
-
8/11/2019 06 Pressure Losses
18/45 2005 PetroSkills LLC, All Rights Reserved18
Pressure Losses
In this class, we will assume thatpressure losses in the drill string
are always turbulent which they
will be under almost anycircumstance
-
8/11/2019 06 Pressure Losses
19/45 2005 PetroSkills LLC, All Rights Reserved19
Pressure Losses
Equation 6-11is for pressurelosses through the jet nozzles
The pressure loss is based onthe change in kinetic energy
2
25
)10(14.9n
mbitA
QP
-
8/11/2019 06 Pressure Losses
20/45 2005 PetroSkills LLC, All Rights Reserved20
Pressure Losses
Example 6-2calculate thepressure loss through the jet
nozzles for the given well
23
22
214/ SSSAn
2222
in2961.032
12
32
11
32
11
4/
nA (7.52 mm2)
-
8/11/2019 06 Pressure Losses
21/45 2005 PetroSkills LLC, All Rights Reserved21
Pressure Losses
psi338
)2961.0(
)147)(15)(10(14.92
25
bitP (2330 kPa)
2
25 )10(14.9
n
mbit
A
QP
-
8/11/2019 06 Pressure Losses
22/45 2005 PetroSkills LLC, All Rights Reserved22
Pressure Losses
Laminar flow is a smoothordered flow
Distinguishing between turbulent
and laminar flow has always
been a problem
With classic fluids such aswater, turbulence occurs at a
Reynolds Number of 2000
-
8/11/2019 06 Pressure Losses
23/45 2005 PetroSkills LLC, All Rights Reserved23
Pressure Losses
With non-Newtonian fluids, thetransition can occur anywhere
between Reynolds Number of
2000 to 4000
-
8/11/2019 06 Pressure Losses
24/45
2005 PetroSkills LLC, All Rights Reserved24
Pressure Losses
Equation 6-14 is assumed to bethe break over between laminar
and turbulent flow at a Reynolds
Number of 2000
n
n
ph
n
m n
n
DD
kV
22
14
2000
3
124.2)10(59.2
-
8/11/2019 06 Pressure Losses
25/45
2005 PetroSkills LLC, All Rights Reserved25
Pressure Losses
Example 6-3Determine thecritical velocity in the drill pipe
annulus
fpm212)43.0)(3(1)43.0)(2(
5.35.64.2
15)45.2)(10(59.2 43.02
43.0
43.02
14
2000
V
(64.6 m/min)
nn
ph
n
m n
n
DD
kV
22
14
20003
124.2)10(59.2
-
8/11/2019 06 Pressure Losses
26/45
2005 PetroSkills LLC, All Rights Reserved26
Pressure Losses
The annular velocity is
)(
5.2422
ph DD
Qv
fpm120)5.35.6(
)147)(5.24(22
v (36.6 m/min)
-
8/11/2019 06 Pressure Losses
27/45
2005 PetroSkills LLC, All Rights Reserved27
Pressure Losses
Can calculatefriction in both
laminar and
turbulent flowWhichever is
greater is
correct
P
-
8/11/2019 06 Pressure Losses
28/45
2005 PetroSkills LLC, All Rights Reserved28
Pressure Losses
For this class, we will assumethat the flow in the annulusis
always laminarand we will use
the power-law modelforcalculations
P L
-
8/11/2019 06 Pressure Losses
29/45
2005 PetroSkills LLC, All Rights Reserved29
Pressure Losses
Equation 6-22is used for power-law and laminar flow in the
annulus
)(3003
124.2
ph
n
ph DD
kl
n
n
DD
vP
P L
-
8/11/2019 06 Pressure Losses
30/45
2005 PetroSkills LLC, All Rights Reserved30
Pressure Losses
Example 6-4calculate frictionlosses in the annulus
Drill pipe
psi371)5.35.6(300)16375)(45.2(
)43.0)(3(1)43.0)(2(
5.35.6)120)(4.2(
43.0
dpaP
(2560 kPa)
)(3003
124.2
ph
n
ph DD
kl
n
n
DD
vP
P L
-
8/11/2019 06 Pressure Losses
31/45
2005 PetroSkills LLC, All Rights Reserved31
Pressure Losses
Drill collars
psi51)8.45.6(300
)818)(45.2(
)43.0)(3(
1)43.0)(2(
8.45.6
)187)(4.2(43.0
dcaP
(350 kPa)
)(3003
124.2
ph
n
ph DD
kl
n
n
DD
vP
P L
-
8/11/2019 06 Pressure Losses
32/45
2005 PetroSkills LLC, All Rights Reserved32
Pressure Losses
All the friction losses are addedtogether to determine the
standpipe pressure
P L
-
8/11/2019 06 Pressure Losses
33/45
2005 PetroSkills LLC, All Rights Reserved33
Pressure Losses
In Example 6-4, it is assumedthat the pipe is hydraulically
smooth and the standpipe
pressure is equal to
psi3594513713381157166512 sP
(24,780 kPa)
dcadpabitdcdpsurfs PPPPPPP
P L
-
8/11/2019 06 Pressure Losses
34/45
2005 PetroSkills LLC, All Rights Reserved34
Pressure Losses
The actual standpipe pressurewas 3100 psi
The calculated pressure does
not agree with the actual
pressure due to accuracy of the
equations, accuracy of the
standpipe gauge and estimated
pump efficiency
P L
-
8/11/2019 06 Pressure Losses
35/45
2005 PetroSkills LLC, All Rights Reserved35
Pressure Losses
Usually assume 95% to 98%
volumetric efficiency for triplex
pumps and 85% to 90%
volumetric efficiency for duplexpumps
P L
-
8/11/2019 06 Pressure Losses
36/45
2005 PetroSkills LLC, All Rights Reserved36
Pressure Losses
If the difference between actualand calculated standpipe
pressure is assumed to be pump
accuracy, the actual pumpefficiency can be determined
Friction losses in the system
should be a straight line on a
piece of loglog graph paper
P L
-
8/11/2019 06 Pressure Losses
37/45
2005 PetroSkills LLC, All Rights Reserved37
Pressure Losses
By plotting pressure lossesversus flow rate, the flow ratecan be determined from theactual standpipe pressure
An arbitrary flow rate of 100 gpm(0.379 m3/min) was chosen forthe second point on the graph
and the calculated standpipepressure was 1942 psi (13,390kPa)
P L
-
8/11/2019 06 Pressure Losses
38/45
2005 PetroSkills LLC, All Rights Reserved38
Pressure Losses
At a standpipe
pressure of3100 psi(21,370 kPa),the calculated
flow ratewould be 134gpm (0.507
m
3
/min) or apumpefficiency of92%
3100
134
Pressure Losses
-
8/11/2019 06 Pressure Losses
39/45
2005 PetroSkills LLC, All Rights Reserved39
Pressure Losses
ECDEquivalent circulatingdensity
A way of expressing friction losses in
the annulus
Expressed in terms of additional mud
weight
Convert the friction losses to a mudweight and add to the mud weight
Pressure Losses
-
8/11/2019 06 Pressure Losses
40/45
2005 PetroSkills LLC, All Rights Reserved40
Pressure Losses
Equation 6-25is used tocalculate ECD
The ECD at any point can be
calculated based on the frictionlosses downstream of that point
TVD
PP
ECD
dcadpa
m 052.0
Pressure Losses
-
8/11/2019 06 Pressure Losses
41/45
2005 PetroSkills LLC, All Rights Reserved41
Pressure Losses
Example 6-5 calculates the ECDfor the well
TVD
PP
ECD
dcadpa
m 052.0
ppg47.15
17193052.0
5137115
ECD (1856 kg/m3)
Pressure Losses
-
8/11/2019 06 Pressure Losses
42/45
2005 PetroSkills LLC, All Rights Reserved42
Pressure Losses
Class ProblemThe casing seat in the example well
is at 15,500 feet (4724m)
Calculate the ECD at the casing seat
Pressure Losses
-
8/11/2019 06 Pressure Losses
43/45
2005 PetroSkills LLC, All Rights Reserved43
Pressure Losses
Answers
The friction loss in 16,375 feet(4991m) of drill pipe annulus is 371psi (2558 kPa)
Since friction losses are linear, thefriction loss per foot can be calculatedas follows:
371 psi / 16,375 feet = 0.0227 psi/ft(0.5125 kPa/m)
Friction at 15,500 feet (4724m) is:
0.0227 x 15,500 = 351 psi (2421 kPa)
Pressure Losses
-
8/11/2019 06 Pressure Losses
44/45
2005 PetroSkills LLC, All Rights Reserved44
Pressure Losses
Calculate friction losses in theannulus
Drill pipe
psi351)5.35.6(300
)15500)(45.2(
)43.0)(3(
1)43.0)(2(
5.35.6
)120)(4.2(43.0
dpaP
(2420 kPa)
Pressure Losses
-
8/11/2019 06 Pressure Losses
45/45
Pressure Losses
The ECD can be calculated
ppg44.15
15500052.0
35115 ECD (1853 kPa)