Tubing and Casing

Petrosadid: Tubing and Casing

Casing pipe lines the borehole. It is subject to axial tension by its dead weight, internal pressure by fluid purging, and external pressure by surrounding rock formations. Casing is particularly exposed to axial tension and internal pressure by the pumped oil or gas emulsion.

Tubing is pipe through which the oil or gas is transported from the wellbore. Tubing segments are generally around 30 ft. [9 m] long with a threaded connection on each end.

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Standard: API 5CT, ISO11960, API 5B, API Q1

Specification: Tubing 1.315’- 4-1/2’ Casing 4-1/2’- 20’

Steel Grade: H40, J55, K55, N80, L80-1, L80-9Cr, L80-13Cr, C90, T95, C110, Q125, V130, V140, V150

Connection:  STC,LTC,BTC


Well casing and tubing is an integral part of the oil drilling and completion process.

In general, casing provides structure and strength to the walls of the well hole so that it doesn’t collapse on itself. It also ensures that there is no seepage of oil or natural gas out of the well hole as these are brought to the surface.

We are also able to supply casing with non-API specifications for special situations, including those with semi-premium and premium connections.

Below is a list of standard API5CT specifications, all of which we supply.

Petrosadid: Tubing and Casing


Petrosadid: Tubing and Casing


Once the casing is run and held in place with cement, production tubing is run into the oil well.

Joints of tubing are connected together with couplings to make up a tubing string. Running tubing into an oil well is much the same as for running in casing, but tubing is smaller in diameter and is removable.

The production string provides a continuous bore from the reservoir to the wellhead and together with the other components of the production string, produces oil and gas at the surface.

As opposed to casing, production tubing is designed to enable quick, efficient, and safe installation, removal and re-installation.

Oil and gas is also produced more effectively through tubing than through larger-diameter production casing.

API5CT Tubing Specifications:

Petrosadid: Tubing and Casing

Product: High Collapse Casing Steel Grade: 80T,95T,110T,125T

Application: Special well with salt, mudstone and oil out sand

Product: Tubing and Casing for Steam Injection Well Steel Grade: 80H,90H,95H,100H Application: Well with Heavy Oil

Product:  Anti-H2S Tubing and Casing Steel Grade: 80S,80SS,90S,90SS,95S,95SS,110S,110SS Application: Well with H2S

Product: Anti-CO2 Tubing and Casing Steel Grade:3Cr,9Cr,13Cr,Super13Cr,22Cr,28Cr Application: Well with CO2

Product: Super High Strength Tubing and Casing Steel Grade: V130, V140, V150

Application: Deep, Super Deep Well

Product: Casing and Tubing for Low Temperature Steel Grade: 80LL, 90LL, 110L

Product: Application: Low Temperature Well

Petrosadid: Tubing and Casing

Collapse & High Collapse Requirements

OCTG basically serves to maintain the well hole integrity during drilling, completion and production lifecycle of wells. Among them, the Casing, in particular, provides resistance to collapse caused by high-strength external load. The source of external load includes, pressure coming from stratum or reservoir flow in process of exploration and development, pressure from poor drillability mud and salt layer, mud system pressure, cement or seawater pressure under conductor or line pipe.

What is Collapse

Collapse resistance is a property of pipe body and defined as the limit exceeding which pipe fails in the circumferential direction when external pressure is applied. Collapse calculation formulas were addressed in the API 5C3 or ISO 10400. Four failure modes have been defined based on failure pattern observation and mechanical rules (refer to figure below). These four domains are continuously positioned as a function of the ratio of the outside diameter to the wall thickness, or D/t ratio.

Petrosadid: Tubing and Casing

Influencing Factor

Collapse resistance is influenced by a complex combination of geometrical characteristics, material properties, applied loads, and load conditions: Geometry: Outer Diameter(D), Wall thickness(t),Ovality, Eccentricity or wall thickness variation . Mechanical properties: Yield strength, Residual stress Applied loads: Tension-Compression, Bending ,Torsion Testing parameters: Length / D of tested sample, Parasite load due to testing equipment, Pressure gradient. Our high collapse casing covers full range from 4-1/2” to 13-3/8” in O.D. Grades from 80ksi to 130ksi (refer to below table). T Series: the collapse value greater than API 5C3. TT Series: the collapse value greater than TP-T Series  for the same size.

Corrosion Resistance Casing

We provide a complete range of steel grades for all kinds of oil and gas operations. To improve the corrosion resistance for the demanding conditions of particular oil and gas wells, TPCO has developed a variety of proprietary steel grades that extend the life span of pipe products reducing corrosion rates:

Sour service

Sweet service

Corrosion Resistant Alloy (CRA)

Material selection guidelines and their applications to corrosive well.

We have created thermal service (H) grades for application at higher temperature due to working conditions Super High Strength Tubing and Casing

High strength tubing and casing include  high strength and high tenacity property used for deep and super deep well. Fracturing project always use it.

Casing and Tubing for Low Temperature

Casing and tubing for low temperature. This pipe is suitable for low temperature store and low surface temperature well situation.

Type of Premium Connection: Threaded and Coupled Connection

Connection: BGT2,TPG2,VAMTOP,BLUE,FOX,APEX Manufacturer: Baosteel, Valin, TPCO, Vallourec, Hunting Hydrill, Tenaris, JFE, TMK

Type of Premium Connection: Flush and Semi-Flush Joing Connection Connection: BG-FJ,TP-FJ,VAM-FJL Manufacturer: Baosteel, Valin, TPCO, Vallourec, Hunting Hydrill, Tenaris, JFE, TMK

Type of Premium Connection: Integral Upset Connection Connection: PH6, CS, TP-ITB Manufacturer: Baosteel, Valin, TPCO, Vallourec, Hunting Hydrill, Tenaris, JFE, TMK

Type of Premium Connection: Fast Driven Connection Connection: BG-BHC, TP-HC, BOSS, BIG OMEGA Manufacturer: Baosteel, Valin, TPCO, Vallourec, Hunting Hydrill, Tenaris, JFE, TMK

There are many types of premium connection mainly for good sealing performance, resistant to high torque and damage repairing etc. We establish strategic partner with many famous mills such as Baosteel, TPCO, valin and so on who through the international certification.

We can supply many kinds of application connections include threaded and coupled connection , flush and semi-flush joint connection without coulple. For example BGT2, TPCQ, BG-GJ, VAM series, Tenaris series, Hydrill series, JFE series, and their equivalent connections.

Integral Upset Connection

A kind of flush thread connection with pipe end upset. It can increase the ability of thread connection strength and resistance to bending. Two-step thread can improve the efficiency of field operation. Using tapered to tapered surface as the structural design of the main seal, provide good gas sealing performance; the external torque shoulder can achieve precise control; thickening of the inside and outside reverse torque shoulder can effectively prevent the plastic deformation under high compressive load.

Fast Driven Connection

Obviously, driving connection fast. Deep oil and gas exploration means longer casing strings in big sizes. Short running times and safe make-ups can be achieved from connections of BG-BHC, TP-HC, BOSS,BIG OMEGA.

Petrosadid: Tubing and Casing

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