Download - 28 SMD Well Control
-
7/29/2019 28 SMD Well Control
1/28
1
Petroleum Engineering 411
Well Drilling
Lesson 28
SMD Well Control
-
7/29/2019 28 SMD Well Control
2/28
2
Subsea
Mudlift
Drilling( SMD )
Note
Pump
andReturnLine
-
7/29/2019 28 SMD Well Control
3/28
3
DESIGN PROJECTDESIGN PROJECT
Your PETE 411 Design Project
is Due in Dr. J-Ws Office by 5 p.m. on
Monday, Dec. 9, 2002
Monday, Dec. 2 is set aside for you to gettogether with your team mates to work on
the project during regular class hours.
-
7/29/2019 28 SMD Well Control
4/28
4
Contents -
g Review of Conventional Well Control
gKick Detection in SMD
g Kick containment in SMD
gBehavior of Real Gases in SMD Wells
g Well Control in SMD
-
7/29/2019 28 SMD Well Control
5/28
5
Kick Detection & Well Control- Review - Conventional -
g Kick Indication (what is a KICK?)
g Kick Detection (confirmation)
g Kick Containment (stop flow into well)
g Circulate Kick out of hole
g Increase Mud Weight in hole (if necessary)
-
7/29/2019 28 SMD Well Control
6/28
6
Circulate Kick out of hole
Keep the BHP constant throughout
Conventional Wait and Weight Method
BHP = Constant
Old
Mud
KillMud
Kick
-
7/29/2019 28 SMD Well Control
7/28
7
Gas Kick Behavior - Perfect Gas
Effect of Temperature Gradient
0
2,000
4,000
6,000
8,000
10,000
12,000
0 10 20 30 40 50 60 70
Kick Volume, bbls
Depth,
ft0.00 deg F/ft
0.02 deg F/ft
0.01 deg F/ft
Maximum Choke Pressure = 1,000 psia. BHP = 6,000 psia
-
7/29/2019 28 SMD Well Control
8/28
8
Z-Factor - In Shallow Wells
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000
Pressure, psig
GasCompressibilityFactor
(Z-Factor)
30 F
60 F
100 F
150 F
200 F
300 F
400 F
Gas Specific Gravity = 0.65 (S.G. of air = 1)
-
7/29/2019 28 SMD Well Control
9/28
9
Shallow Gas Kick - SummaryEffect of Temperature and Z-Factor
0
2,000
4,000
6,000
8,000
10,000
12,000
0 10 20 30 40 50 60 70
Kick Volume, bbls
Depth,
ft
Real Gas
Ideal Gas
PV = constant
0.02 deg F/ft
-
7/29/2019 28 SMD Well Control
10/28
10
Gas Kicks in Deep SMD Wells
Kick Volume vs. Depth
0
5,000
10,000
15,000
20,000
25,000
30,000
0 5 10 15 20 25 30
Kick Volume, bbl
Dep
th,
ft
As expected, most of
the expansion occurs
in the top 3,000 ft or so
MudLine
MudLift
Pump
-
7/29/2019 28 SMD Well Control
11/28
11
Kick Volume vs. Depth
0
5,000
10,000
15,000
20,000
25,000
30,000
0 5 10 15 20 25 30 35 40 45 50
Kick Volume, bbl
Depth,
ft
Gas Kicks in Deep SMD Wells
PV = constant
PV = ZnRT
-
7/29/2019 28 SMD Well Control
12/28
12
Gas Kick Behavior - Z-Factor
0.5
1.0
1.5
2.0
2.5
3.0
0 5,000 10,000 15,000 20,000 25,000
Pressure, psig
C
ompressibility
(Z-Factor)
30
60
100
150
200
300
400
Temperature,oF
Gas Specific Gravity = 0.65 (S.G. of air = 1)
pV=ZnRT
-
7/29/2019 28 SMD Well Control
13/28
13
MUDLIFTBOP
Subsea Mudlift Drilling System
SEAFLOOR
~SEAWATERHYDROSTATIC
PRESSURE
FLOATER
30,000
10,000
KICK
Surface Pump: Constant RateMudlift : Const. Inlet Press.
What next??
-
7/29/2019 28 SMD Well Control
14/28
14
Kick Detection and Control
640
650
660
670
680
690
700
-30 -20 -10 0 10 20 30
Time, minutes
Circulatio
nRate,gal/min
Kick begins
Kick Detected - - Slow down Seafloor Pump
SEAFLOOR PUMP
SURFACE PUMP
-
7/29/2019 28 SMD Well Control
15/28
15ATM
Influx has stopped and
pressures have stabilized
Kick Detection and Control
-
7/29/2019 28 SMD Well Control
16/28
16ATM
Kick Detection and Control
640
650
660
670
680
690
700
-30 -20 -10 0 10 20 30 40 50
Time, minutes
Circu
lationRate,
gal/min
Kick begins
Kick Detected - - Slow down Seafloor Pump
SEAFLOOR PUMP
SURFACE PUMP
-
7/29/2019 28 SMD Well Control
17/28
17
Standpipe Pressure vs. Time
0
1,000
2,000
3,000
4,000
5,000
0 200 400 600 800
Time, minutes
Pressure,p
si
SMD
ConventionalStart cir culating kick out of hole
Kill mud enters top of dril lpipe
Kill mud at bit
-
7/29/2019 28 SMD Well Control
18/28
18
Surface Choke Pressure vs. Time
0
200
400
600
800
1,000
1,200
1,400
0 100 200 300 400 500 600 700
Time, minutes
Pressure,psi
SIDPP
Start circulating
kick out
Top of kick at surface
Kick out of return line
Kill mud enters annulusSICP
CONVENTIONAL
-
7/29/2019 28 SMD Well Control
19/28
19
Pit Gain vs. Time
0
10
20
30
40
50
60
70
0 100 200 300 400 500 600 700
Time, minutes
PitVolu
meGain,
bbls
SMD
Conventional
-
7/29/2019 28 SMD Well Control
20/28
20
Pressure at the Sea Floor vs. Time
0
1,000
2,0003,000
4,000
5,000
6,000
7,000
8,000
0 200 400 600 800
Time, minutes
Pres
sure,ps
i
Conventional
SMDStart circulating kick out
Kick at seafloor
Kill mud enters annulus
Kill mudat seafloor
Pressure at inlet to Mudlift System
-
7/29/2019 28 SMD Well Control
21/28
21
Kick Detection Method Still Valid for SMD?
Pit Gain Still valid
Flow Rate Increase (Returns) Much Better
Well Flows With Rig Pump Off U-tubing ...
Fluid Fill-up on Trips More complicated
Increased Hook Load Still Valid
Drop in Standpipe Pressure Better
Drop in BHP - MWD Still Valid
Drilling Break Still valid
Decreased Mud Weight (Gas Cut) Still valid
-
7/29/2019 28 SMD Well Control
22/28
22
Well Control Summary
g Most Conventional kick detection methods
are still validg New differential flow rate method -
better - use with computer monitoring
g Lower standpipe pressure makes kick
detection easier and faster
g Conventional well control can be adapted
- with modifications
-
7/29/2019 28 SMD Well Control
23/28
23
Well Control Summary contd
g Not necessary to shut well in
g Seafloor pump controls the BHP
g Surface choke pressure generally
does not affect wellbore pressures
g Well control training will be essential !!
-
7/29/2019 28 SMD Well Control
24/28
24
General SummarySubsea Mudlift Drilling is a method that offers
potential for lowering drilling costs in very deepwaters.
( fewer casing strings, smaller rigs,
less time on location, larger hole )
The method utilizes one or more small-diameter
return lines from the seafloor to the surface. The
drillpipe is not inside a return line.
-
7/29/2019 28 SMD Well Control
25/28
25
Summary - contd
A mudlift system is used in the return line
thereby making a dual-density mud system
possible.
Wellhead pressure is maintained at seawater
hydrostatic, so well is dead at all times
Well control is quite similar to that in
conventional drilling with a riser- There are some real advantages:
higher margins, choke line P, etc.
-
7/29/2019 28 SMD Well Control
26/28
26
ATM
-
7/29/2019 28 SMD Well Control
27/28
27
ATM
MUDLIFT
U-Tubing in SMD
~SEAWATER
HYDROSTATICPRESSURE
BOP
STATIC
FLUID
LEVEL
FLOATER
-
7/29/2019 28 SMD Well Control
28/28
28
Static Pressures - SMD
SEAFLOOR
SEA WATER
HYDROSTATIC
PRESSURE
PRESSURE
DEPTH
ANNULUS AND RETURN LINE
DRILLSTRING PRESSURE