Heavy Oil Thermal Pipe

Heavy oil well casing is used in high temperature environments in heavy oil thermal recovery wells. It is applicable for well conditions with the operating temperature of 350℃ (It is suitable for long-term continuous using oil in thermal-recovery well conditions). Heavy oil thermal pipe is mainly used as oil-string casing to inject steam into heavy oil thermal recovery wells. This steel pipe mainly relies on injecting high-temperature steam to improve the heavy oil temperature, reduce its viscosity and make heavy oil easily flow so as to facilitate the recovery of heavy oil. There are two main thermal recovery ways including steam stimulation method and steam flooding method. JST heavy oil thermal pipe is with high yield strength, tensile strength, resistance to plastic deformation and other performance.

Competitive Advantages

• 1. Heavy oil well casing features good thermal stability and strong anti-relaxation deformation ability. Under the steam injection temperature (320℃), it owns higher strength and tightness.
  2. JST heavy oil thermal pipe has high connection strength, good heat distortion resistance and reliable sealing performance. It adopts Cr-Mo steel body with high special thermal stability and strong resistance to collapsing, and special screw threads with high tensile strength and high gas tightness. This steel pipe can do the steam injection operation for six times or more, so that the life of thermal recovery wells is prolonged to its two times, better solving higher loss rate problem of thermal recovery wells. With this kind of casing, the damage rate of heavy oil thermal recovery wells decreases from 30% to 5% or less.
  3.  JST has two heat treatment lines for heavy oil thermal pipe, with annual production capacity of 150,000 tons and 50,000 tons respectively. The production range of the bigger steel pipe production line is φ114 mm to 406 mm, with the length of not more than 13.5 m, while the smaller one with φ48mm to 180 mm and the length of not more than 12.5 m.
  4. Our company owns a casing threading production line configured with two advanced QK1319-G CNC casing thread lathes and three Q1334H CNC tubing thread lathes. The line for heavy oil thermal pipe features high precision and high stiffness and has the tool nose radius compensation function (TNRC function). There are three sets of domestic advanced hydrostatic pressure equipment with the test specifications of φ60 mm to 406 mm, and with the maximum test pressure reaching 120 MPa. Two sets of pipe end magnetic particle inspection machine are used for inspecting inner and outer surfaces and near-surface cracks in any direction of steel pipe end within 500 mm. JST can annually process heavy oil thermal pipes up to 180,000 tons.

Performance Mechanical Property of Heavy Oil Well Casing

Tensile Property
Grade	Room Temperature			350℃
	Yield Strength (Mpa)	Tensile Strength (Mpa)	Ductility (%)	Yield Strength (Mpa)
JST80H	552-758	≥ 689	Refer to API 5CT	≥ 500
JST100H	690-897	≥ 793		≥ 650
JST110H	758-965	≥ 862		≥ 700

Impact Property of Heavy Oil Thermal Pipe
Grade	Room Temperature
	Longitudinal Average (J)	Horizontal Average (J)
JST80H	27	14
JST100H	34	17
JST110H	41	20

Note: Refer to API SPEC 5CT.

Creep Property of Heavy Oil Well Casing
Grade	Temperature (℃)	Steady Creep Rate (%/h)
JST80H	350℃	≤ 5*10-5
JST100H
JST110H

Note: Stress is 300 Mpa.

Parameters Data Specifications of heavy oil thermal pipe refer to EXCEL.

Maintenance

• 1. We need to pay attention to prevent steel pipes from failure. Oil casing failure mainly includes collapse, slippage, rupture, leakage, corrosion, adhesion, wear, and so on.
  2. Reduce the stress on the casing coupling surface and protect the cement sheath at the coupling.
  3. In order to prevent the instability of heavy oil thermal pipe caused by formation sand production, hollow strata and cement sheath damage. We need to take early sand prevention and late sand filling to improve the performance of cement and increase the effective thickness of cement sheath (integral joint casing).
  4. According to the stratum thermal stress, we need to design reservoir section or the place 200 m below the reservoir section. The wall thickness of heavy oil well casing (heavy oil thermal pipe) should be more than 17mm.
  5. We adopt combined steam injection and high temperature profile control measures to reduce the radial heterogeneity thermal stress load caused by steam channeling.

Packaging and Transport

• There are mainly three packaging methods for steel pipes, including bundling, vanning and oiled strapping. Pipe caps are used to protect the pipe ends.
• Heavy oil well casings are transported in bulk or in containers. Customers can choose land transportation, waterway transport or sea transportation.