Thermodiffusion zinc coating of thread joints
Thermodiffusion Zinc Coating of tubular threads effectively extends life of tubular
A simple and efficient solution to reliability problems with tubing, casing and drill pipe threaded joints is the use of thermodiffusion zinc coating (TDZ)
Thermodiffusion zinc coating is anodic relative to black metals and ensures cathodic protection of steel against corrosion
Coating has strong adhesion to base metal due to mutual diffusion of zinc and iron
Produced coating precisely repeats the item profile including threaded sections
OOO Temerso-Engineering applies thermodiffusion zinc coatings to thread connections of different sizes starting with DN48 up to DN365 inclusively
- TDZ coating is applied to tubing boxes per GOST 633-80, GOST R 53366-2009, also to tubing boxes per API 5CT and to tubing boxes with Premium threads of different types by TMK. We guarantee 20 trip cycles for tubing with V-thread TDZ-coated couplings and 10 make-up cycles for premium tubing connections
- The use of TDZ coating is practical on large-size casing collars with premium connections such as TMK UP-CS, ТМК UP-FMC and TMK UP-GF to prevent seizing during tripping operations. Temerso guarantees 4 trip cycles for casing pipe with TDZ‑coated thread connections
- TDZ coating is applied on DP tool joints of all sizes and manufactured to all standards to prevent thread wear during drilling. We guarantee at least 300 make-up cycles with recommended torque without detriment to thread connections when TDZ coating is applied on DP tool joints
Regulating and technical documentation:
TDZ coating is applied in compliance with the requirements of GOST R 9.316-2006 and technical specifications prepared by experts of OOO Temerso-Engineering
- TU 4859-002-62031850-2014 Protective thermodiffusion zinc coatings at tubing and casing thread joint elements
- TU 4859-003-62031850-2016 Protective thermodiffusion zinc coatings on drill string threaded tool joints
Advantages for customers choosing our Company:
- To date, our Company has applied TDZ coating on 1,215,000 tubing and casing couplings, 102,000 premium-connection couplings and 54,000 couplings made of L80‑13Cr grade steel
- Since 2002, we have not received A SINGLE claim concerning quality of TDZ coating from our end users
- Our Company was the first one to promote TDZ coating for tool joints, tubing and casing couplings on the Russian market
- Our Company holds 10 patents on useful models and inventions, including one patent in the USA and two patents in China concerning TDZ coatings for tubing, casing and drill pipe thread connections
Advantages of TDZ coating:
- All mechanical properties of thread connection are retained in the TDZ coating application process
- Thread connection wear resistance is improved
- Unlike phosphating, TDZ coating can be applied on steels with elevated chromium content (1 to 30 %)
- This coating can be applied on parts made of chromium-nickel alloys including non‑magnetic alloys
- TDZ coating improves corrosion resistance properties of thread connection
- Thread connection strength is improved
- Thread connection tightness is improved
When thermodiffusion zinc (TDZ) coated coupling is used on uncoated tubing pin, threaded pipe section is spared, thus pin turnaround period is increased 5–6 times
- TDZ coated coupling on uncoated tubing pin helps spare threaded pipe section, thus pin turnaround period is increased 5–6 times.
- Use of tubing strings with thermodiffusion zinc coated box ends for oil production and for injection, and at water wells will increase time between well workovers and reduce of the number of well accidents and workovers.
- Make-up torques established by regulatory documents and allowable loads on threaded joint are not altered and meet the requirements of tubing operation manual for Russian pipes and API 5C1 for tubing per API 5CT.
- Tripping operations with tubing with thermodiffusion zinc coated box ends are performed using normal tongs for particular tubing size and normal equipment. Works are performed using normal thread compounds for particular tubing size.
- Operation of tubing with thermodiffusion zinc coated box ends completely corresponds to requirements of tubing operation manual.
- It is feasible to use zinc coated box ends for tubing made of corrosion resistant steel. Often, only thermodiffusion zinc coating process ensures application of protective anti‑seize coating to thread of tubing of high alloyed steel grades with chromium content of 3 % or more.
- Ability to reliably ensure increased tightness and sufficiently high wear resistance of threaded connection makes tubing with zinc coated box ends unique for performance of such operations as hydrofrac, hydraulic casing perforation, and at different well hydraulic tests or for installation of packers.
- OOO Temerso-Engineering installs only thermodiffusion zinc coated box ends on tubing with ТС3000 inner protective coatings per TU 1390-001-62031850-2012
- Design of casing joint must ensure at least 3 make-ups and 2 break-outs without jamming while maintaining the connection sealing condition. TDZ coating helps improve this parameter to the guaranteed 4 make-up and 3 break-out cycles, including large-size tubulars.
- Casing with TDZ-coated thread connections can be run in hole using common equipment. Works are performed using normal thread compounds for particular tubing size.
- Make-up torques established by regulatory documents or allowable threaded joint loads are not altered, and meet the requirements effective norms.
- Coarse surface produced by TDZ coating increases adhesion between surface of couplings and well cement slurry.
- It is practical to use TDZ coated box ends for casing made of corrosion resistant steel. Often, only thermodiffusion zinc coating process ensures application of protective anti‑seize thread coating on casing made of high alloyed steel grades with chromium content of 3 % or more.
- TDZ coating is very effective when applied on thread and seal surfaces of casing joints used in casing drilling operations, as it improves strength and tightness of all connections in such strings
- TDZ coatings improve tool joint thread durability. TDZ coating is preserved on tool joint threads and thread sealing surfaces for at least 300 make-ups/break-outs.
- TDZ coating will eliminate the need for at least one tool joint rethreading. Use of TDZ coatings will completely pay out when drilling in remote fields, and will reduce the costs of tubular repairs and transportation to the pipe yard.
- Use of TDZ coatings allows for higher speed make-up of tool joints, which greatly reduces the rig time and lease costs.
- Consequently, the use of TDZ coating extends drill pipe service life by 1.5 to 2 times, depending on drilling conditions.
- The use of TDZ coating is practical on bottom kelly sub since its pin thread is subjected to intensive wears due to alternating make-up and break-out of drill pipe (stand) boxes. Using a kelly sub with worn-out thread can damage many drill pipe boxes.
- TDZ coating improves tool joint sealing condition, prevents tool joint thread washout, and makes drill string elements less prone to accidents.
- OOO Temerso Engineering has a solution to apply TDZ coating on joints of non‑magnetic drill collars