RISER STATIC ANALYSIS ODEBRECHT PROJECT 2000 m Water Depth Scenario
Prepared By: Dr. Jim Kaculi, P.E. Reviewed & Approved by: Dale Marietta Date: May 3, 2007 Ref: Report-0121-Rev.2
Dril-Quip Inc., Analysis Group
SUMMARY A static analysis of the drilling riser was completed for 21" OD x 75’ long, with (2) 6.5" OD choke and kill lines, (1) 4.50" OD boost line, and (2) 2.875" OD hydraulic lines. The initial static analysis results are presented in the following sections. The results indicate that the wall thicknesses selected are appropriate for the given riser system configuration and water depth applicable (2,000 m). The maximum stress in the main riser assuming no load sharing with auxiliary lines is less than 2/3 of the yield stress, which indicates that the riser is strong enough to support the maximum design load. This conclusion is based on static riser calculations with no consideration of environmental loads and dynamic effects. Therefore, for more accurate results and to fully account for all the loading conditions, a more detailed analysis that considers the environment and other loading factors will be completed. The calculations presented here are based on API RP 16Q recommendations and other relevant information.
Dril-Quip Inc., Analysis Group
PURPOSE The purpose of this analysis is to statically analyze a riser system and determine some important parameters of the design such as, minimum top tension, riser and auxiliary line wall stresses, etc., from an initial system design configuration. The initial configuration (Figure 1) provides information on the selection of joints, buoyancy elements, weight, drilling fluids, water depth, etc. Based on this information, several other variables are computed such as air/submerged/effective weights, buoyancy lift, internal and external pressures, fluid colum n weights, effective/true tension at each section, etc. Finally, based on this information, some important parameters such as minimum top tension, stresses, etc. and other parameters are calculated. Calculations are based on API RP 16Q “Recommended Practice for Design Selection, Operation and Maintenance of Marine Drilling Riser Systems”.
ASSUMPTIONS v Water Depth: 2,000 m v Drilling Mud Density 16 ppg v Seawater Density 8.555 ppg v Hydraulic Fluid Density 8.345 ppg v Bottom Tension below LMRP: 176 Kips (per customer request) v Elastic Modulus: 30 x106 Psi v Poisson’s Ratio: 0.3 v Yield Strength: 80,000 Psi v Steel Density: 0.28 lb./in3 v Buoyancy (see attached customer supplied information below)
Dril-Quip Inc., Analysis Group
v Riser Joints Data: •
Telescopic Joint (at mid-stroke): o Length: 99.75’ o Air Weight: 83,600 lb.
•
Bare Joints: o Length: 75’ o Air Weight: 27,600 lb. o Number of Joints: 11 (1 at the top & 10 at the bottom)
•
Buoyancy Joints: o Number of Joints: 75 o Length: 75’ o Air Weight: 27,600 lb. (excluding buoyancy weight)
•
Pup Joints: o Number of Joints: 2 o Length: 15’ (10’ & 5’combined) o Air Weight: ~10,000 lb.
•
LMRP: o Length: 29’ o Air Weight: 344,289 lb.
•
BOP Stack: o Length: 20’ o Air Weight: 408,246 lb.
•
Riser Lines: o Main Pipe: 21” OD/ 19.5” ID o Choke & Kill Line: 6.5” OD/ 4.5” ID o Boost Line: 4.5” OD/ 3.938” ID o Hydraulic Lines: 2.875” OD/ 2.441” ID Dril-Quip Inc., Analysis Group
Drill Floor
18’ Diverter & Housing 70’ Air Telescopic Joint Length at Mid Stroke: 99.75 ft Sea 1x75’x21”x0.75” bare joint plus 2 pup joints (10’ & 5’)
36x75’x21”x0.75” buoyant joints 3000’
6632’ 26x75’x21”x0.75” buoyant joints 2000m (6562’)
13x75’x21”x0.75” buoyant joints
10x75’x21”x0.75” bare joints Lower flex-joint LMRP 18-3/4” 49’ BOP Stack 18-3/4” Mudline +/- 3m
Figure 1: Schematic Representation of Riser Configuration Dril-Quip Inc., Analysis Group
MODELING The model created is based on API RP 16Q recommendations, and specifically appendix D “Sample Riser Calculations”. All the calculations are carried out using Excel software. Some snapshots of the spreadsheet are included in this report. Two different general cases are considered: 1. drilling mode 2. non-drilling mode For the drilling mode case with 16 ppg mud weight, the bottom tension required below LMRP is assumed to be 176 kips. For non-drilling operations with sea water in all the lines, two sub-cases are considered: a. Riser weight including LMRP weight, excluding BOP stack weight b. Riser weight including both LMRP & BOP stack weight For all the cases the buoyancy information used is based on the information supplied by the customer, which is included at the end of this report.
RESULTS The analysis results are presented in the table below. The results will vary depending on the selection of certain factors such as number of tensioners subject to sudden failure, buoyancy factor, bottom tension desired, drilling or non-drilling mode, tolerances, etc. However, the stresses in the wall are below 2/3 of the material yield strength, which is an indication that there is sufficient strength available to accommodate the above factors. The summary below can easily be generated for any combination of the above factors.
Dril-Quip Inc., Analysis Group
Table 1: Non-Drilling Mode, Including LMRP, Excluding BOP CALCULATION SUMMARY Mud Density -1 (ppg)
16.000
Mud Density -2 (ppg)
16.000
Sea Water Density (ppg)
8.555
Hydraulic Fluid Density (ppg)
8.345
Main Riser Top Pressure
0.000
Choke & Kill Line Top Pressure
0.000
Boost Line Top Pressure
0.000
Hydraulic Line Top Pressure Submerged Weight of TJ
0.000 48720.00
Submerged Weight of LMRP & Flex Joint
299531.43
Submerged Weight of BOP Stack
355174.02
Average Compensation (All Joints) %
102.169
Average Compensation (Buoyancy Joints) %
118.827
Total Internal Area, (s-in.)
351.996
Submerged Weight of Riser (lb)
2421983.430
Submerged Weight Tolerance Factor
1.050
Apparent Mud Weight (lb)
0.000
Buoyancy (lb)
-2172021.881
Buoyancy Loss & Tolerance Factor Minimum Slip Ring Tension (lb) Recommended Bottom Tension (lb) Top Tension Factor
0.960 457941.596 0.000 1.000
Slip Ring Tension Considering Bottom Tension, etc.
457941.596
N: Number of Tensioners Supporting Riser
8.000
N: Number of Tensioners Subject to Sudden Failure
2.000
Rf: Reduction Factor-Drilling
0.950
Rf: Reduction Factor- Non-drilling
0.900
Minimum Recommended Top Tension (lb)
678431.993
Yield Stress (psi)
80000.000
Allowable Stress (psi)
53333.333
Maximum Riser Stress (psi)
13689.593
Dril-Quip Inc., Analysis Group
Table 2: Non-Drilling Mode, Including LMRP & BOP CALCULATION SUMMARY Mud Density -1 (ppg)
16.000
Mud Density -2 (ppg)
16.000
Sea Water Density (ppg)
8.555
Hydraulic Fluid Density (ppg)
8.345
Main Riser Top Pressure
0.000
Choke & Kill Line Top Pressure
0.000
Boost Line Top Pressure
0.000
Hydraulic Line Top Pressure
0.000
Submerged Weight of TJ
48720.00
Submerged Weight of LMRP & Flex Joint
299531.43
Submerged Weight of BOP Stack
355174.02
Average Compensation (All Joints) %
102.169
Average Compensation (Buoyancy Joints) %
118.827
Total Internal Area, (s-in.)
351.996
Submerged Weight of Riser (lb) Submerged Weight Tolerance Factor Apparent Mud Weight (lb) Buoyancy (lb)
2777157.450 1.050 -660.104 -2172021.881
Buoyancy Loss & Tolerance Factor Minimum Slip Ring Tension (lb)
0.960 830214.212
Recommended Bottom Tension below BOP (lb)
0.000
Top Tension Factor
1.000
Slip Ring Tension Considering Bottom Tension, etc.
830214.212
N: Number of Tensioners Supporting Riser
8.000
N: Number of Tensioners Subject to Sudden Failure
2.000
Rf: Reduction Factor-Drilling
0.950
Rf: Reduction Factor- Non-drilling Minimum Recommended Top Tension (lb)
0.900 1229946.981
Yield Stress (psi)
80000.000
Allowable Stress (psi)
53333.333
Maximum Riser Stress (psi)
21511.281
Dril-Quip Inc., Analysis Group
Table 3: Drilling Mode, Including LMR, Excluding BOP CALCULATION SUMMARY Mud Density -1 (ppg)
16.000
Mud Density -2 (ppg)
16.000
Sea Water Density (ppg)
8.555
Hydraulic Fluid Density (ppg)
8.345
Main Riser Top Pressure
0.000
Choke & Kill Line Top Pressure
0.000
Boost Line Top Pressure
0.000
Hydraulic Line Top Pressure Submerged Weight of TJ
0.000 48720.00
Submerged Weight of LMRP & Flex Joint
299531.43
Submerged Weight of BOP Stack
355174.02
Average Compensation (All Joints) %
102.169
Average Compensation (Buoyancy Joints) %
118.827
Total Internal Area, (s-in.)
351.996
Submerged Weight of Riser (lb) Submerged Weight Tolerance Factor Apparent Mud Weight (lb) Buoyancy (lb)
2421983.430 1.050 864805.227 -2178875.815
Buoyancy Loss & Tolerance Factor Minimum Slip Ring Tension (lb) Recommended Bottom Tension below LMRP (lb) Top Tension Factor
0.960 1316167.046 176000.000 1.000
Slip Ring Tension Considering Bottom Tension, etc.
1492167.046
N: Number of Tensioners Supporting Riser
8.000
N: Number of Tensioners Subject to Sudden Failure
2.000
Rf: Reduction Factor-Drilling
0.950
Rf: Reduction Factor- Non-drilling
0.900
Minimum Recommended Top Tension (lb)
2094269.538
Yield Stress (psi)
80000.000
Allowable Stress (psi)
53333.333
Maximum Riser Stress (psi)
34056.793
Dril-Quip Inc., Analysis Group
Riser Static Calculations 2,000 m Scenario (with 3 x75' jt spare plus 3 pup jt 40'/30'/5' equivalent 75') Page 1
JOINT DATA Depth
Buoyancy
(ft)
Yes/No
# Joints
BUOYANCY DATA
Length
Tot. Length
EFWL
DFWL
(ft)
(ft)
(ft)
(ft)
NBEPJ
NBEPS
BEV
BEVPJ
BEVPS
BED
BLPJ
BLPS
TBLPS
LB
(c.ft.)
(c.ft.)
(c.ft.)
(lb./c.ft.)
(lb.)
(lb.)
(lb.)
(lb.)
TJ, etc.
No
1
99.75
99.75
51.75
-48.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
10388.46
Pup Joints
No
1
15.00
114.75
-48.00
-63.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Bare-Top
Yes
1
75.00
189.75
-63.00
-138.00
8.00
8.00
99.45
795.60
795.60
22.00
33415.20
33415.20
33415.20
0.00
2000
Yes
0
0.00
189.75
-138.00
-138.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
33415.20
0.00
3000
Yes
37
75.00
2964.75
-138.00
-2913.00
8.00
296.00
99.45
795.60
29437.20
25.80
30391.92
1124501.04
1157916.24
0.00
4000
Yes
0
0.00
2964.75
-2913.00
-2913.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1157916.24
0.00
5000
Yes
27
75.00
4989.75
-2913.00
-4938.00
8.00
216.00
99.45
795.60
21481.20
29.30
27607.32
745397.64
1903313.88
0.00
6000
Yes
0
0.00
4989.75
-4938.00
-4938.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1903313.88
0.00
7000
Yes
11
75.00
5814.75
-4938.00
-5763.00
8.00
88.00
99.45
795.60
8751.60
33.70
24106.68
265173.48
2168487.36
0.00
8000
Yes
0
0.00
5814.75
-5763.00
-5763.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2168487.36
0.00
9000
Yes
0
0.00
5814.75
-5763.00
-5763.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2168487.36
0.00
10000
Yes
0.00
5814.75
-5763.00
-5763.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2168487.36
0.00
Bare-Bottom
No
10
75.00
6564.75
-5763.00
-6513.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2168487.36
0.00
LMRP
No
1
29.00
6593.75
-6513.00
-6542.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
BOP Stack
No
1
20.00
6613.75
-6542.00
-6562.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Dril-Quip Inc., Analysis Group
Riser Static Calculations 2,000 m Scenario (with 3 x75' jt spare plus 3 pup jt 40'/30'/5' equivalent 75') Page 2
WEIGHT (DRY & WET) AWWOBPJ
BAWPJ
AWWBPJ
WWWOBPJ
MAIN RISER PIPE
WWWOBPS
WWWBPJ
WWWBPS
COMP.PJ
OD
ID
CRS. AREA
1
INT. AREA
EXT. AREA
IPBS
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
%
(in)
(in)
(s.in.)
(s.in.)
(s.in.)
(psi)
56000.00
0.00
56000.00
48720.00
48720.00
48720.00
48720.00
0.00%
26.00
24.50
59.49
471.44
530.93
82.91
10000.00
0.00
10000.00
8700.00
8700.00
8700.00
8700.00
0.00%
21.00
19.50
47.71
298.65
346.36
95.38
27600.00
17503.20
45103.20
24012.00
24012.00
-9403.20
-9403.20
139.16%
21.00
19.50
47.71
298.65
346.36
157.71
27600.00 27600.00
0.00 20526.48
27600.00 48126.48
24012.00 24012.00
0.00 888444.00
24012.00 -6379.92
0.00 -236057.04
0.00% 126.57%
21.00 21.00
19.50 19.50
0.00 47.71
298.65 298.65
346.36 346.36
0.00 2464.21
27600.00 27600.00
0.00 23311.08
27600.00 50911.08
24012.00 24012.00
0.00 648324.00
24012.00 -3595.32
0.00 -97073.64
0.00% 114.97%
21.00 21.00
19.50 19.50
0.00 47.71
298.65 298.65
346.36 346.36
0.00 4147.32
27600.00
0.00
27600.00
24012.00
0.00
24012.00
0.00
0.00%
21.00
19.50
0.00
298.65
346.36
0.00
27600.00 27600.00
26811.72 0.00
54411.72 27600.00
24012.00 24012.00
264132.00 0.00
-94.68 24012.00
-1041.48 0.00
100.39% 0.00%
21.00 21.00
19.50 19.50
47.71 0.00
298.65 298.65
346.36 346.36
4833.04 0.00
27600.00 27600.00
0.00 0.00
27600.00 27600.00
24012.00 24012.00
0.00 0.00
24012.00 24012.00
0.00 0.00
0.00% 0.00%
21.00 21.00
19.50 19.50
0.00 0.00
298.65 298.65
346.36 346.36
0.00 0.00
27600.00 344289.00
0.00 0.00
27600.00 344289.00
24012.00 299531.43
240120.00 299531.43
24012.00 299531.43
240120.00 299531.43
0.00% 0.00%
21.00 21.00
19.50 19.50
47.71 47.71
298.65 298.65
346.36 346.36
5456.42 5480.52
408246.00
0.00
408246.00
355174.02
355174.02
355174.02
355174.02
0.00%
21.00
19.50
47.71
298.65
346.36
5497.14
Dril-Quip Inc., Analysis Group
Riser Static Calculations 2,000 m Scenario (with 3 x75' jt spare plus 3 pup jt 40'/30'/5' equivalent 75') Page 3
1
1
OD
ID
CHOKE & KILL LINE CRS. AREA
INT. AREA
EXT. AREA
IPBS-CHK
IPBS-KILL
(in.)
(in.)
(s.in.)
(s.in.)
(s.in.)
psi
6.50
4.50
17.28
15.90
33.18
95.38
6.50
4.50
17.28
15.90
33.18
157.71
6.50
4.50
0.00
0.00
0.00
0.00
6.50
4.50
17.28
15.90
33.18
6.50
4.50
0.00
0.00
6.50
4.50
17.28
6.50
4.50
6.50
BOOST LINE
1
HYDRAULIC LINE
OD
ID
CRS. AREA
INT. AREA
EXT. AREA
IPBS
OD
ID
CRS. AREA
INT. AREA
(in.)
(in.)
(s.in.)
(s.in.)
(s.in.)
psi
(in.)
(in.)
(s.in.)
(s.in.)
95.38
4.50
3.94
3.72
12.18
15.90
95.38
2.88
2.44
1.81
4.68
157.71
4.50
3.94
3.72
12.18
15.90
157.71
2.88
2.44
1.81
4.68
0.00
4.50
3.94
0.00
0.00
0.00
0.00
2.88
2.44
0.00
0.00
2464.21
2464.21
4.50
3.94
3.72
12.18
15.90
2464.21
2.88
2.44
1.81
4.68
0.00
0.00
0.00
4.50
3.94
0.00
0.00
0.00
0.00
2.88
2.44
0.00
0.00
15.90
33.18
4147.32
4147.32
4.50
3.94
3.72
12.18
15.90
4147.32
2.88
2.44
1.81
4.68
0.00
0.00
0.00
0.00
0.00
4.50
3.94
0.00
0.00
0.00
0.00
2.88
2.44
0.00
0.00
4.50
17.28
15.90
33.18
4833.04
4833.04
4.50
3.94
3.72
12.18
15.90
4833.04
2.88
2.44
1.81
4.68
6.50
4.50
0.00
0.00
0.00
0.00
0.00
4.50
3.94
0.00
0.00
0.00
0.00
2.88
2.44
0.00
0.00
6.50
4.50
0.00
0.00
0.00
0.00
0.00
4.50
3.94
0.00
0.00
0.00
0.00
2.88
2.44
0.00
0.00
6.50
4.50
0.00
0.00
0.00
0.00
0.00
4.50
3.94
0.00
0.00
0.00
0.00
2.88
2.44
0.00
0.00
6.50
4.50
17.28
15.90
33.18
5456.42
5456.42
4.50
3.94
3.72
12.18
15.90
5456.42
2.88
2.44
1.81
4.68
Dril-Quip Inc., Analysis Group
Riser Static Calculations 2,000 m Scenario (with 3 x75' jt spare plus 3 pup jt 40'/30'/5' equivalent 75') Page 4
2
2
IPBS-HYD1
IPBS-HYD2
psi
psi
FLUID COLUMN ACTUAL WEIGHT (PER JOINT)
ACTUAL WEIGHT
MAIN
CHOKE
KILL
BOOST
HYDR. 1
HYDR. 2
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
8751.80
AWPJ
AMWPJ
AWPS
TAWBS
1 AMWPS
TAMWBS
EPBS
IPBS
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
(lb.)
(psi)
(psi)
48720.00
8751.80
48720.00
48720.00
8751.80
8751.80
21.33
82.91
51.00
51.00
1732.54
92.27
92.27
70.66
-0.77
-0.77
8700.00
1986.20
8700.00
57420.00
1986.20
10738.00
28.00
95.38
84.33
84.33
8662.72
461.33
461.33
353.29
-3.83
-3.83
-9403.20
9931.01
-9403.20
48016.80
9931.01
20669.01
61.33
157.71
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
24012.00
0.00
0.00
48016.80
0.00
20669.01
61.33
157.71
1317.58
1317.58
8662.72
461.33
461.33
353.29
-3.83
-3.83
-6379.92
9931.01
-236057.04
-188040.24
367447.53
388116.54
1294.58
2464.21
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
24012.00
0.00
0.00
-188040.24
0.00
388116.54
1294.58
2464.21
2217.52
2217.52
8662.72
461.33
461.33
353.29
-3.83
-3.83
-3595.32
9931.01
-97073.64
-285113.88
268137.39
656253.93
2194.52
4147.32
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
24012.00
0.00
0.00
-285113.88
0.00
656253.93
2194.52
4147.32
2584.17
2584.17
8662.72
461.33
461.33
353.29
-3.83
-3.83
-94.68
9931.01
-1041.48
-286155.36
109241.16
765495.08
2561.17
4833.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
24012.00
0.00
0.00
-286155.36
0.00
765495.08
2561.17
4833.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
24012.00
0.00
0.00
-286155.36
0.00
765495.08
2561.17
4833.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
24012.00
0.00
0.00
-286155.36
0.00
765495.08
2561.17
4833.04
2917.48
2917.48
8662.72
461.33
461.33
353.29
-3.83
-3.83
24012.00
9931.01
240120.00
-46035.36
99310.14
864805.23
2894.48
5456.42
3349.59
299531.43
3349.59
299531.43
253496.07
3349.59
868154.81
2907.37
5480.52
2310.06
355174.02
2310.06
355174.02
608670.09
2310.06
870464.87
2916.26
5497.14
Dril-Quip Inc., Analysis Group
This information is supplied by the customer
Buoyancy calculation sheet (based on following riser) 21" OD x 75 ft. lg. Dril-Quip riser, w/ (2) 6.5" OD choke and kill lines, (1) 4.50" OD boost line and (2) 2.875" OD SS hyd line, all on 31" pcd 8 "Ultra-MIS" buoyancy elements per joint ea. 210" lg x 54" (+ 1/2")OD Possible 2,000 meter scenario
1-top & 10-bot. Water depth # of joints
3000' 37.000
5000' 27.000
7000' 13.000
bare 11.000
# elements per joint
8.000
8.000
8.000
0.000
total # of elements
296.000
216.000
112.000
0.000
Estimated Element density (pcf)
25.800
29.300
33.700
0.000
Est. element vol. (ft3)
99.450
99.450
99.450
0.000
Avg. buoyancy(uplift)/element (lbs), + 4%
3798.990
3450.915
3013.335
0.000
Buoyancy(uplift) /joint (lbs)
30391.920
27607.320
24106.680
0.000
Total Buoyancy (uplift) (lbs),
1124501.040
745397.640
337493.520
0.000
27600.000
27600.000
27600.000
27600.000
.750"
.750"
.750"
.750"
Buoyancy air wt per jt (lbs)
20526.480
23311.080
26811.720
0.000
Joint air wt w/ buoyancy (lbs)
48126.480
50911.080
54411.720
27600.000
Joint wt. in water, bare (lbs)
24012.000
24012.000
24012.000
24012.000
Joint air wt., bare (lbs) - wall thickness
-6379.920
-3595.320
-94.680
24012.000
All joints wt. in water, bare (lbs)
888444.000
648324.000
336168.000
264132.000
All joints wt. w/ buoyancy in water (lbs)
-236057.040
-97073.640
-1325.520
264132.000
Compensation %
1.266
1.150
1.004
0.000
Total Buoyancy/uplift (lbs)+2%
2207392.20
Joint wt. with buoyancy in water (lbs)
Avg. compensation for buoyant jts.
1.18
Avg. compensation for all jts.
1.03
Dril-Quip Inc., Analysis Group
Total jts 88.0000
Purposely left blank
Dril-Quip Inc., Analysis Group
