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Capillary Tubing
Capillary string for downhole control line
MEILONG TUBE provides a wide range of tubular product forms and materials mainly for the oil & gas sector. Our products have been successfully used in some of the most aggressive subsea and downhole conditions and we have a long proven track record of supplying products that meet the strict quality requirements of the Oil & Gas and geothermal energy sectors.
Improvements in the technology for the enhanced exploitation of oil and gas fields has increasingly required the use of long continuous lengths of stainless steel and nickel alloy tubulars for hydraulic control, instrumentation, chemical injection, umbilical and flowline control applications. The benefits of this tubular technology have resulted in reduced operating costs, improved recovery methods and reduced capital expenditure by connecting downhole valves and chemical injection with remote and satellite wells to a fixed or floating central operating platform.
Applications
• Downhole hydraulic control lines.
• Downhole c
MEILONG TUBE provides a wide range of capillary tubular product forms and materials mainly for the oil & gas sector. Our products have been successfully used in some of the most aggressive subsea and downhole conditions and we have a long proven track record of supplying products that meet the strict quality requirements of the Oil & Gas and geothermal energy sectors.
Improvements in the technology for the enhanced exploitation of oil and gas fields has increasingly required the use of long continuous lengths of stainless steel and nickel alloy tubulars for hydraulic control, instrumentation, chemical injection, umbilical and flowline control applications. The benefits of this tubular technology have resulted in reduced operating costs, improved recovery methods and reduced capital expenditure by connecting downhole valves and chemical injection with remote and satellite wells to a fixed or floating central operating platform.
Applications of capillary string
• Downhole hydraulic control lines.
• Downhole chemical control lines.
• Subsea control lines for hydraulic power and chemical injection.
• Smoothbore control lines used in fibre optic applications.
Production process
Coiled tubing is available in a range of different product forms depending on the customer requirements. We manufacture seam welded and redrawn, seamless tube products. The standard grades are 316L, alloy 825 and alloy 625. Other grades of stainless steel in duplex and superduplex and nickel alloy are available on request. Tubing can be supplied in the annealed or cold worked condition.
• Seam-welded and redrawn tubing.
• Seamless and redrawn tubing.
Dimensional range of capillary string (coiled tubing)
• Diameter from 3.18mm (0.125’’) to 25.4mm (1.00’’) OD.
• Wall thickness from 0.51mm (0.020’’) to 3mm (0.118”).
• OD tolerance +/- 0.005’’ (0.13mm) and +/- 10% wall thickness. Other tolerances are available on request.
• Coil lengths up to 1500m (5,000ft) without orbital joints depending on product dimensions.
• Coil lengths up to 13,500m (45,000ft) with orbital joints.
• Encapsulated, PVC coated or bare line tubing.
• Available on wooden or steel drums.
Seam-welded & redrawn tubing sizes, imperial
Alloy UNS ASTM OD WT Weight Working pressure
inch inch Lb/ft psi
316L S31603 A269 0.125 0.028 0.030 8,276
316L S31603 A269 0.125 0.035 0.035 10,533
316L S31603 A269 0.250 0.035 0.084 4,949
316L S31603 A269 0.250 0.049 0.110 7,143
316L S31603 A269 0.250 0.065 0.134 9,745
316L S31603 A269 0.375 0.035 0.133 3,182
316L S31603 A269 0.375 0.049 0.178 4,569
316L S31603 A269 0.375 0.065 0.225 6,264
316L S31603 A269 0.375 0.080 0.263 7,878
316L S31603 A269 0.500 0.049 0.246 3,336
316L S31603 A269 0.500 0.065 0.316 4,551
316L S31603 A269 0.500 0.080 0.375 5,729
316L S31603 A269 0.625 0.049 0.315 2,620
316L S31603 A269 0.625 0.065 0.407 3,571
825 N08825 B704 0.125 0.035 0.036 14,749
825 N08825 B704 0.250 0.035 0.086 6,934
825 N08825 B704 0.250 0.049 0.112 10,017
825 N08825 B704 0.250 0.065 0.137 13,652
825 N08825 B704 0.375 0.035 0.136 4,460
825 N08825 B704 0.375 0.049 0.182 6,400
825 N08825 B704 0.375 0.065 0.230 8,775
825 N08825 B704 0.375 0.080 0.270 11,032
825 N08825 B704 0.500 0.049 0.252 4,,678
825 N08825 B704 0.500 0.065 0.323 6,382
825 N08825 B704 0.500 0.080 0.384 8,023
625 N06625 B704 0.250 0.035 0.089 11,920
625 N06625 B704 0.250 0.049 0.116 17,205
625 N06625 B704 0.250 0.065 0.143 23,460
625 N06625 B704 0.375 0.035 0.141 7,660
625 N06625 B704 0.375 0.049 0.189 10,996
625 N06625 B704 0.375 0.065 0.238 15,075
625 N06625 B704 0.375 0.080 0.279 18,954
625 N06625 B704 0.500 0.049 0.261 8,031
625 N06625 B704 0.500 0.065 0.335 10,959
625 N06625 B704 0.500 0.080 0.398 13,779
625 N06625 B704 0.625 0.049 0.333 6,309
The above are tested in the condition of coiled tubing with orbital joints
All joints are X-ray tested
Control line may also be supplied without orbital joints
Certification to EN10204, 3.1
Seam-welded & redrawn tubing sizes, metric
Alloy UNS ASTM OD WT Weight Working pressure
mm mm Kg/m bar
316L S31603 A269 3.18 0.71 0.044 571
316L S31603 A269 3.18 0.89 0.051 726
316L S31603 A269 6.35 0.89 0.121 341
316L S31603 A269 6.35 1.24 0.158 493
316L S31603 A269 6.35 1.65 0.194 672
316L S31603 A269 9.52 0.89 0.192 219
316L S31603 A269 9.52 1.24 0.257 315
316L S31603 A269 9.52 1.65 0.325 432
316L S31603 A269 9.52 2.03 0.380 543
316L S31603 A269 12.7 1.24 0.355 230
316L S31603 A269 12.7 1.65 0.456 314
316L S31603 A269 12.7 2.03 0.542 395
316L S31603 A269 15.88 1.24 0.454 181
316L S31603 A269 15.88 1.65 0.587 246
825 N08825 B704 3.18 0.89 0.052 1,017
825 N08825 B704 6.35 0.89 0.124 478
825 N08825 B704 6.35 1..24 0.162 691
825 N08825 B704 6.35 165 0.198 941
825 N08825 B704 9.52 0.89 0.196 308
825 N08825 B704 9.52 1.24 0.263 441
825 N08825 B704 9.52 1.65 0.332 605
825 N08825 B704 9.52 2.03 0.389 761
825 N08825 B704 12.7 1.24 0.363 323
825 N08825 B704 12.7 1.65 0.466 440
825 N08825 B704 12.7 2.03 0.554 553
625 N06625 B704 6.35 0.89 0.129 822
625 N06625 B704 6.35 1.24 0.168 1,186
625 N06625 B704 6.35 1.65 0.206 1,618
625 N06625 B704 9.52 0.89 0.204 528
625 N06625 B704 9.52 1.24 0.272 758
625 N06625 B704 9.52 1.65 0.344 1,039
625 N06625 B704 9.52 2.03 0.403 1,307
625 N06625 B704 12.7 1.24 0.377 554
625 N06625 B704 12.7 1.65 0.484 756
625 N06625 B704 12.7 2.03 0.572 950
625 N06625 B704 15.88 1.24 0.481 435
The above are tested in the condition of coiled tubing with orbital joints
All joints are X-ray tested
Control line may also be supplied without orbital joints
Certification to EN10204, 3.1
Redrawing process of welded tubes
Long lengths can be made by seam welding formed strip but such tubing has OD & ID discontinuity and may suffer from local problems of mechanical strength or corrosion. A welded & sunk tube improves these aspects and has been proven reliable in service over several decades for offshore applications. Although more expensive than welded only tubing, the welded and redrawn tube is still relatively inexpensive compared to seamless.
Seamless tubing has cross sectional uniformity however, it is the most expensive method of manufacture and has a limitation in the continuous length that can be produced between joints. For a slight premium over the welded & sunk price, tubing can be produced by the welded & floating plug drawn process which results in a product of similar appearance to seamless but with the significant advantage of much longer continuous lengths and greatly reduced costs.
Quality assurance of capillary line
• Eddy current testing
• Hydraulically pressure testing
• Radiographically testing for all orbital joints
• Chemical composition analysis
• Mechanical properties testing
• Visual inspected
capillary string, capillary line, capillary coiled tubing