In the oil and gas industry, "control lines" refer to small-diameter pipes or tubes that are used to convey fluids, such as hydraulic fluid or control chemicals, in downhole applications. These lines play a critical role in controlling various aspects of well operations, such as monitoring and regulating pressure, temperature, and flow rates within the wellbore.
Key criteria for control lines include:
Functionality: Control lines are primarily used to transmit signals and fluids between surface and downhole equipment, such as valves, sensors, and other control devices. They enable remote operation and monitoring of downhole equipment, allowing for precise control of well conditions.
Construction: Typically made from corrosion-resistant materials like stainless steel or corrosion-resistant alloys, control lines are engineered to withstand high-pressure and high-temperature environments found in oil and gas wells.
Installation: Control lines are installed along with other tubing strings during the completion phase of well construction. They are run downhole either inside the production tubing or through dedicated control line conduits within the well casing.
Applications: Essential for a range of downhole operations, control lines support functions such as production control, well testing, hydraulic fracturing (fracking), well intervention, and safety shutdown systems (SSSV - Surface Safety and Subsurface Safety Valves).
Maintenance and monitoring: Regular inspection and maintenance of control lines is crucial to ensure integrity and reliability. Corrosion issues such as corrosion, mechanical damage, and fluid contamination can affect the performance. Monitoring techniques, including pressure testing and the use of downhole cameras, are employed to assess their condition.
Safety considerations: Proper installation and maintenance of control lines is vital for the safety and integrity of oil and gas wells. Malfunctions or failures in control lines can lead to operational disruptions, well control incidents, and potential environmental hazards.
Alleima control lines
Alleima offers a wide range of control line tubes, available in both seamless and welded formats. We also provide a variety of services, including encapsulation, and offer standard as well as custom-sized reels to meet specific customer requirements.
Fully integrated manufacturing sets us apart
From advanced R&D to one controlled melt, to extrusion of hollows and final control line manufacturing, we ensure the very highest quality and full traceability.
High priority on sustainability
At Alleima, sustainability is a top priority. We adhere to the UN Sustainability Goals (SDGs) and have set ambitious targets aligned with the Science Based Targets initiative (SBTi) to achieve zero emissions by 2050. In our manufacturing, we use 84% recycled material and utilize more than 96% fossil-free electricity across our sites.
Ensuring your well integrity – let us support you with:
Material selection
Annealed condition, HRB maximum 95 on welds for welded tube, HRB maximum 85 for seamless tubes upon request.
Material grades tailored to withstand your specific corrosive environment.
Challenges addressed:
Control line crushing – utilize encapsulation with or without bumper.
Control line weld splice failures – opt for seamless solutions.
Control line junctions with valves:
Use control line with dimensionally tight tolerance
Ensure uniform material hardness
Solid solution annealed material hardness < 83
Control line calculator
Alleima offers a control line calculator tool for estimating of the highest permissible internal pressure for various sizes and grades of control lines. Choose from three formulas, multiple outer diameters and wall thicknesses, seamless or welded options, and input well temperature.
Alleima's service center in Houston (TX), US holds extensive seamless coiled tube and laser welded tube stocks for control lines and chemical injection lines to ensure just-in-time deliveries. It also operates a complete package of additional services:
Cut to length
Hydrotesting
Paint striping
Encapsulation
Flush and fill (acc. to Nas Class 6)
Level wound on reels
Customer specified packaging
Direct delivery to site
Packing standards
Coils wound on wooden spools
Coils wound on customer-specific metal reels
Full package marking service, customer specific
The tables show materials, sizes and approvals for control lines and chemical injection lines in seamless condition.
Materials* (including nominal chemical composition)
* All materials are supplied in the solution annealed condition. Other grades can be offered on request.
Mechanical properties1)
Grade
Yield strength, psi (MPa)
Tensile strength, psi (MPa)
Elongation %
TP 316L
32,000 (220)
75,000 (515)
35
Alloy 825
35,000 (240)
80,000 (550)
30
Sanicro® 28
32,000 (220)
100,000 (690)
40
Alleima SAF 2205™
70,000 (485)
99,000 (680)
25
Alleima SAF 2507®
80,000 (550)
116,000 (800)
25
1) All materials in the solution annealed condition
Corrosion properties
Grade
UNS
PRE1)
CPT2) o F (oC)
Max. H2S3psi
CO24)
TP 316L
S31600/S31603
24
95 (35)
No Limit
+
Alloy 825
N08825
29
140 (60)
No Limit
++
Sanicro® 28
N08028
39
150 (65)
No Limit
++
Alleima SAF 2205™
S31803/S32205
>35
150 (65)
1.5
+
Alleima SAF 2507®
S32750
>42.5
195 (90)
3
++
1) PRE = (%Cr) + 3.3 (%Mo) +16 (%N) 2) Critical Pitting Temperature in neutral solution with approximately 3% chlorides 3) Per NACE MR0175 / ISO 15156 for downhole control lines in the solution annealed condition 4) General resistance to CO2 corrosion. '++' indicates better resistance than '+'
Approvals
ISO 9001:2000
ISO 14001:2004
OHSAS 18001
PED 97/23/EC
ANSI NACE MR 0175 / ISO 15156
API Q1
The tables show materials, sizes and approvals for control lines and chemical injection lines in welded condition.
Materials* (including nominal chemical composition)
Grade
UNS
C
max.
Cr
Ni
Mo
Others
TP 316L
S31600/S31603
0.030
17.5
13
2.1
0.1
Alloy 825
N08825
0.030
20
38.5
2.6
Cu=1.7, Ti=0.7
Alloy 625
N6625
0.10
21.5
>=58
9
Nb=3.5
*All materials are supplied in the solution annealed condition. Other grades can be offered on request.
Mechanical properties1)
Grade
Yield strength,
psi (MPa)
Tensile strength,
psi (MPa)
Elongation
%
TP 316L
32,000 (220)
75,000 (515)
35
Alloy 825
35,000 (240)
80,000 (550)
30
Alloy 625
60,000 (415)
110,000 (760)
30
1) All materials in the solution annealed condition
Corrosion properties
Grade
UNS
PRE1)
CPT2)F (oC)
Max H2S3)psi
CO24)
TP 316L
S31600/S31603
24
95 (35)
No limit
+
Alloy 825
N08825
29
140 (60)
No limit
++
Alloy 625
N06625
52
195 (90)
No limit
++
1) PRE = (%Cr) + 3.3 (%Mo) +16 (%N) 2) Critical Pitting Temperature in neutral solution with approximately 3% chlorides 3) Per NACE MR0175 / ISO 15156 for downhole control lines in the solution annealed condition 4) General resistance to CO2 corrosion. '++' indicates better resistance than '+'
Size range (in.)
The table shows stock standard sizes. Other sizes can be offered on request.
OD
WT
OD
WT
OD
WT
OD
WT
OD
WT
1/4
0.035
3/8
0.035
1/2
0.035
5/8
0.035
3/4
0.035
1/4
0.049
3/8
0.049
1/2
0.049
5/8
0.049
3/4
0.049
1/4
0.065
3/8
0.065
1/2
0.065
5/8
0.065
3/4
0.065
-
-
3/8
0.083
1/2
0.083
5/8
0.083
3/4
0.083
OD = Outside diameter, WT = Wall thickness
Approvals
ISO 9001:2000
Intertek
MGMT. SYS. RvA 050
ANAB
Alleima offers a wide range of encapsulation materials. The most frequent ones can be found in the table below. Other encapsulation materials can be offered upon request.
Material rating on a scale of 1 to 5 (1=not good, 5=excellent)
Materials
Max temp. oF (Co)
Abrasion resistance
Resistance to inhibited brine well fluids
Resistance to oil/diesel well fluids
Polypropylene
150 (65)
2
5
3
Nylon 11
200 (93)
4
3
3
PVC
174 (79)
3
2
3
TPV
275 (135)
3
5
3
Halar
300 (149)
4
4
5
PVDF
310 (154)
4
3
5
MPH340G
340 /171)
4
4
5
Selection of the appropriate material for any given control or chemical injection line is subject to the prevailing operational and site conditions. In order to assist in the selection, the following tables provide internal pressure ratings and the adjustments factors for a range of common grades and sizes of seamless and laser welded stainless tubing.
Maximum pressure (P) for TP 316L at 100°F (38°C)1)
Please refer to grade and product form adjustment factors below.
Outside diameter, in.
Wall thickness, in.
Working pressure2) psi (MPa)
Burst pressure2) psi (MPa)
Collapse pressure4) psi (MPa)
1/4
0.035
6,600 (46)
22,470 (155)
6,600 (46)
1/4
0.049
9,260 (64)
27,400 (189)
8,710 (60)
1/4
0.065
12,280 (85)
34,640 (239)
10,750 (74)
3/8
0.035
4,410 (30)
19,160 (132)
4,610 (32)
3/8
0.049
6,170 (43)
21,750 (150)
6,220 (43)
3/8
0.065
8,190 (56)
25,260 (174)
7,900 (54)
3/8
0.083
10,450 (72)
30,050 (207)
9,570 (66)
1/2
0.049
4,630 (32)
19,460 (134)
4,820 (33)
1/2
0.065
6,140 (42)
21,700 (150)
6,200 (43)
1/2
0.083
7,840 (54)
24,600 (170)
7,620 (53)
5/8
0.049
3,700 (26)
18,230 (126)
3,930 (27)
5/8
0.065
4,900 (34)
19,860 (137)
5,090 (35)
5/8
0.083
6,270 (43)
26,910 (151)
6,310 (44)
3/4
0.049
3,080 (21)
17,470 (120)
3,320 (23)
3/4
0.065
4,090 (28)
18,740 (129)
4,310 (30)
3/4
0.083
5,220 (36)
20,310 (140)
5,380 (37)
1) Estimates only. Actual pressures should be calculated considering all stress factors in the system. 2) Based on calculations from API 5C3, using a wall tolerance of +/-10% 3) Based on ultimate strength burst calculations from API 5C3 4) Based on yield strength collapse calculations from API 5C3
Adjustment factors for working pressure limits1)
Pw = reference working pressure rating for TP 316L at 100°F (38°C). To determine working pressure for grade/temperature combination, multiply Pw by adjustment factor.
Grade
100°F (38°C)
200°F (93°C)
300°F (149°C)
400°F (204°C)
TP 316L, seamless
1.00
0.87
0.70
0.63
TP 316L, welded
0.85
0.74
0.60
0.54
Alleima SAF 2205™, seamless
2.17
2.00
1.77
1.60
Alleima SAF 2205™, welded
1.84
1.70
1.50
1.36
Alloy 825, seamless
1.33
1.17
1.10
1.03
Alloy 825, welded
1.13
0.99
0.94
0.88
Alleima SAF 2507® , seamless
2.67
2.33
2.17
1.70
Alleima SAF 2507® , welded
2.27
1.98
1.84
1.45
1) Adjustment factors based on allowable stress in ASME. Example: The maximum factors allowable working pressure for seamless 1/2 x 0.049 in. Alleima SAF 2507® tubing at 100°F (38°C) can be calculated as: 4,630 psi – Pressure rating for TP 316L at 100°F (38°C) x 2.67 – Adjustment factor for Alleima SAF 2507, seamless at 100°F (38°C) 12,362 psi – Working pressure rating for Alleima SAF 2507® tubing
Adjustment factors for burst pressure limits1)
Pb = reference burst pressure for TP 316L at 100°F. To determine burst pressure for grade/temperature combination, multiply Pb by adjustment factor.
Grade
100°F (38°C)
200°F (93°C)
300°F (149°C)
400°F (204°C)
TP 316L, seamless
1.00
0.93
0.87
0.80
TP 316L, welded
0.85
0.79
0.74
0.68
Alleima SAF 2205™, seamless
1.71
1.33
1.20
1.07
Alleima SAF 2205™, welded
1.45
1.13
1.02
0.91
Alloy 825, seamless
1.13
1.07
1.00
0.87
Alloy 825, welded
0.96
0.91
0.85
0.74
Alleima SAF 2507® , seamless
1.97
1.75
1.57
1.35
Alleima SAF 2507® , welded
1.64
1.47
1.31
1.13
1) Adjustment factors based on ultimate strength in ASME. Example: The maximum factors burst pressure for seamless 3/8 x 0.049 in. Alleima SAF 2507® tubing at 200°F (93°C) can be calculated as: 21,750 psi – burst pressure rating for TP 316L at 100°F (38°C) x 1.73 – Adjustment factor for Alleima SAF 2507, seamless at 200°F (93°C) 37,627 psi – burst pressure rating for Alleima SAF 2507® tubing
Adjustment factors for collapse pressure limits1)
Pc = reference collapse pressure rating for TP 316L at 100°F (38°C). To determine collapse pressure for grade/temperature combination, multiply Pc by adjustment factor.
Grade
100°F (38°C)
200°F (93°C)
300°F (149°C)
400°F (204°C)
TP 316L, seamless
1.00
0.87
0.70
0.63
TP 316L, welded
0.85
0.74
0.60
0.54
Alleima SAF 2205™, seamless
2.17
2.00
1.77
1.60
Alleima SAF 2205™, welded
1.84
1.70
1.50
1.36
Alloy 825, seamless
1.33
1.17
1.10
1.03
Alloy 825, welded
1.13
0.99
0.94
0.88
Alleima SAF 2507® , seamless
2.67
2.33
2.17
1.70
Alleima SAF 2507® , welded
2.27
1.98
1.84
1.45
1) Adjustment factors based on yield strength in ASME. Example: The maximum factors collapse pressure for seamless 1/4 x 0.035 in. Alloy 825 tubing at 200°F (93°C) can be calculated as: 6,600 psi – Collapse pressure rating for ASTM 316L at 100°F (38°C) x 1.17 – Adjustment factor for Alloy 825 seamless at 200°F (93°C) 7,722 psi – Collapse pressure rating for Alloy 825 tubing
