Frequently Asked Questions about OCTG Products
1. What OCTG products does Xenith Steel manufacture?
Xenith Steel manufactures five OCTG product types:
(1) Casing Pipe: OD 4-20in, API 5CT grades J55/K55/N80/L80/P110, STC/LTC/BTC connections.
(2) Tubing Pipe: OD 1.050-4in, API 5CT grades for production tubing.
(3) Drill Pipe: OD 2-3/8 to 6-5/8in, API 5DP grades E75/X95/G105/S135.
(4) Drill Collars: OD 3-15in, slick and spiral types for weight on bit.
(5) Tubing and Casing Couplings: OD 1.9-20in, K55/N80/L80/P110 grades.
2. What API 5CT grades are available for OCTG products?
Xenith Steel supplies eight API 5CT grades:
(1) H40: Low-strength grade for shallow wells.
(2) J55: Standard grade for moderate depth wells.
(3) K55: Similar to J55 with higher toughness.
(4) M65: Medium-strength grade for sour service.
(5) L80: Restricted hardness grade for H2S environments.
(6) N80: Higher strength for deeper wells.
(7) C90: High-strength grade for challenging conditions.
(8) P110: Highest strength grade for ultra-deep wells.
3. What thread connections does Xenith Steel offer for OCTG?
Xenith Steel offers four API thread connection types:
(1) STC (Short Thread Coupling): Standard connection for general casing and tubing applications.
(2) LTC (Long Thread Coupling): Extended engagement for improved joint strength.
(3) BTC (Buttress Thread): High axial load capacity for deep well casing.
(4) EUE (External Upset End): Tubing connections with upset ends for enhanced strength.
4. What is the difference between casing and tubing pipe?
Casing and tubing serve different well functions:
(1) Casing Pipe: Larger diameter (4-20in), structural support for wellbore, prevents formation collapse, isolates zones. Installed during drilling.
(2) Tubing Pipe: Smaller diameter (1.050-4in), conduit for production fluids from reservoir to surface. Installed inside casing after well completion.
Casing handles geological loads; tubing handles production flow.
5. What quality tests are performed on OCTG products?
Xenith Steel performs six quality tests per API 5CT:
(1) Chemical analysis for grade verification via spectrographic testing.
(2) Tensile testing for yield strength, ultimate strength, and elongation.
(3) Hardness testing (Brinell/Rockwell) for H2S service compliance.
(4) Hydrostatic pressure testing for each pipe.
(5) Non-destructive testing (UT/ET) for defect detection.
(6) Thread inspection and gauge verification for connection integrity.
6. What are the typical OCTG applications in oil and gas wells?
OCTG products serve four well stages:
(1) Drilling: Drill pipe and drill collars transmit rotary power and weight to the drill bit.
(2) Casing: Multiple casing strings protect the wellbore and isolate formations during and after drilling.
(3) Completion: Tubing pipe provides the production conduit for oil, gas, or water flow.
(4) Workover: Replacement casing and tubing for well maintenance and re-completion operations.
