Substructure for drilling rig-1

1

Stand Support

112.45.251.00

High-Strength Low-Alloy Steel (Q690), Welded & Stress-Relieved

1. Fatigue cracking at weld joints due to cyclic drilling vibration; 2. Corrosion-induced material weakening in offshore saltwater environments.

1. Conduct ultrasonic weld inspection every 6 months to detect microcracks; 2. Apply marine-grade anti-corrosion coating (DFT ≥ 250μm) for offshore applications and touch up scratches promptly.

2

Slanting Support

112.64.330.00

Alloy Steel (42CrMo), Forged & Tempered

1. Bending deformation from lateral wind loads or drill string sway; 2. Thread wear at connection points due to vibration-induced loosening.

1. Install vibration-damping washers at bolted connections; 2. Re-torque connection bolts with a calibrated torque wrench every drilling cycle to prevent uneven stress.

3

Front Stem

112.45.300.00-1

Q690 High-Strength Steel, Hot-Rolled & Precision Machined

1. Tensile fatigue from repeated drill string hoisting/lowering cycles; 2. Impact damage from accidental collision with drilling tools.

1. Monitor stem deflection during hoisting operations; replace if deflection exceeds 0.5% of total length; 2. Install protective bumpers around high-risk collision zones.

4

Slanting Stem

112.45.320.00

42CrMo Alloy Steel, Heat-Treated & Machined

1. Shear stress failure at connection points due to misaligned loads; 2. Thermal fatigue from extreme temperature fluctuations (desert/arctic drilling).

1. Ensure precise alignment during assembly to eliminate eccentric loads; 2. Inspect for thermal cracks quarterly in extreme temperature environments using magnetic particle testing.

5

Left/Right Back Stem

112.64.350.00

Q690 High-Strength Steel

1. Fatigue from continuous dynamic loads during drilling; 2. Corrosion in high-humidity or marine environments.

1. Conduct annual non-destructive testing (NDT) for fatigue cracks; 2. Use galvanized fasteners and apply anti-corrosion paint to exposed surfaces.

6

Gate Stem

112.64.290.00

42CrMo Alloy Steel

1. Wear at the gate interface due to repeated opening/closing cycles; 2. Corrosion-induced jamming in harsh drilling fluid environments.

1. Lubricate the gate interface with high-pressure, anti-corrosion grease weekly; 2. Clean the stem surface after exposure to drilling fluids and reapply lubricant.

7

Back Support

112.45.800.00

Q690 High-Strength Low-Alloy Steel

1. Compression fatigue from long-term load bearing; 2. Weld joint failure due to inadequate penetration during manufacturing.

1. Inspect weld joints annually using ultrasonic testing; 2. Ensure uniform load distribution by verifying substructure leveling monthly.

8

Support of Air Tank

112.45.100.00

Carbon Steel Q355B, Zinc-Plated

1. Corrosion from condensed moisture in the air tank; 2. Fatigue from air compressor vibration.

1. Drain condensed moisture from the air tank daily to reduce corrosion; 2. Install vibration isolators between the support and air tank to mitigate stress.

9

Drawworks Beam

112.45.92.00

Q690 High-Strength Steel, Forged & Stress-Relieved

1. Tensile fatigue from repeated drawworks operation; 2. Wear at connection points with drawworks components.

1. Monitor beam stress during heavy-load hoisting; 2. Lubricate connection points every 50 operating hours and inspect for wear.

10

Table Beam

112.45.660.00

Q690 High-Strength Steel

1. Bending deformation from uneven load distribution on the drill table; 2. Corrosion from drilling fluid splatter.

1. Ensure drill table loads are centered to avoid uneven stress; 2. Clean the beam surface regularly and reapply anti-corrosion coating as needed.

11

Set Back Beam

112.45.670.00

Q690 High-Strength Steel

1. Impact damage from drill pipe storage and retrieval; 2. Fatigue from cyclic loading of stored drill pipes.

1. Install rubber padding on the beam surface to absorb impact; 2. Inspect for impact damage and fatigue cracks weekly.

12

Front Support

112.64.68.00

Q690 High-Strength Steel

1. Impact damage from drill string movement; 2. Corrosion from exposure to environmental elements (rain, salt spray).

1. Install protective guards around the front support; 2. Apply weather-resistant anti-corrosion coating and inspect quarterly.

13

Floor man house support

112.70.430.00

Carbon Steel Q355B, Anti-Corrosion Coated

1. Corrosion from long-term exposure to outdoor environments; 2. Fatigue from structural vibration of the rig.

1. Inspect the support structure and coating annually; 2. Reinforce connections if vibration-related loosening is detected.

1

Right Upper Seat

112.64.70.00-1

Q690 High-Strength Steel, Machined & Ground

1. Wear at the contact surface due to vibration-induced relative movement; 2. Corrosion in humid or offshore environments.

1. Apply anti-wear plate to the contact surface to extend service life; 2. Inspect for corrosion and wear monthly, re-coating as needed.

2

Left Upper Seat

112.64.36.00

Q690 High-Strength Steel

1. Localized stress concentration from uneven load distribution; 2. Wear from repeated load transfer during drilling operations.

1. Ensure uniform load distribution by verifying substructure leveling quarterly; 2. Lubricate the contact surface with high-pressure grease to reduce friction.

3

Right Front Lower Base

112.64.560.00

Q690 High-Strength Low-Alloy Steel, Marine-Grade Anti-Corrosion Coated

1. Seabed scouring or soil erosion around the base (offshore/onshore); 2. Corrosion from groundwater or saltwater immersion.

1. Inspect the surrounding soil/seabed for erosion monthly; 2. Reapply anti-corrosion coating to submerged areas annually.

4

Left Front Lower Base

112.64.501.00

Q690 High-Strength Steel

1. Corrosion from environmental moisture; 2. Wear from ground movement or settlement.

1. Implement a regular corrosion maintenance program, including cleaning and coating touch-ups; 2. Monitor ground settlement and adjust base leveling as required.

5

Right Back Lower Base

112.64.550.00

Q690 High-Strength Steel

1. Fatigue from long-term load bearing; 2. Loosening of connection fasteners leading to increased stress.

1. Conduct annual NDT for fatigue cracks; 2. Re-torque connection fasteners quarterly to maintain clamping force.

6

Left Back Lower Base

112.64.520.00

Q690 High-Strength Steel

1. Corrosion from drilling fluid runoff; 2. Stress concentration from misaligned substructure assembly.

1. Divert drilling fluid runoff away from the base; 2. Verify substructure alignment annually and correct any misalignment.

7

Draw Beam of Basement

112.64.510.00

42CrMo Alloy Steel, Forged

1. Tensile fatigue from repeated load pulling during substructure installation; 2. Corrosion in enclosed basement environments with high humidity.

1. Conduct fatigue analysis and inspection annually; 2. Improve basement ventilation to reduce humidity and prevent corrosion.

1

Raise-down Unit

112.45.240.00

42CrMo Alloy Steel + High-Strength Cast Iron (Gear Housing)

1. Gear wear from insufficient lubrication; 2. Hydraulic seal failure (if hydraulic-driven) leading to pressure loss and operational failure.

1. Lubricate gears with high-pressure, anti-wear grease every 50 operating hours; 2. Inspect hydraulic seals for leaks daily and replace as soon as leaks are detected.

2

Substructure Jack up Unit

112.64.320.00

42CrMo Alloy Steel (Screw & Cylinder), Precision Machined

1. Screw wear from repeated jacking cycles and load-bearing; 2. Hydraulic fluid contamination leading to component seizure.

1. Lubricate screws with molybdenum disulfide grease before each use to reduce friction; 2. Filter hydraulic fluid regularly and replace per manufacturer’s recommendations to prevent contamination.

1

Pin φ120x295

112.45.01.03

42CrMo Alloy Steel, Quenched & Tempered (Hardness HRC45-50)

1. Wear at the contact surface due to vibration-induced movement; 2. Corrosion in humid or offshore environments.

1. Lubricate the pin surface with anti-wear grease every 30 operating hours; 2. Apply anti-corrosion coating to exposed ends and inspect monthly for wear.

2

Safety pin φ25

112.45.04

Carbon Steel 45#, Heat-Treated

1. Shear failure from overloading beyond rated capacity; 2. Corrosion leading to brittleness and reduced tensile strength.

1. Never exceed the rated shear capacity; verify load limits before use; 2. Inspect for corrosion and brittleness weekly; replace immediately if damage is detected.

3

Clip φ30

111.03.100.02

Spring Steel 65Mn, Heat-Treated

1. Fatigue from repeated opening/closing cycles; 2. Corrosion leading to loss of spring tension.

1. Inspect spring tension monthly; replace if tension is insufficient to secure pins; 2. Store spare clips in a dry environment to prevent corrosion.

4

Double taper pin φ60x200

112.64.510.02

40Cr Alloy Steel, Taper Machined

1. Wear of the taper surface due to vibration; 2. Loosening leading to increased stress on the pin and mating components.

1. Ensure proper taper fit during assembly to minimize movement; 2. Inspect for looseness monthly and re-tighten or replace as needed.

5

Safety pinφ15

112.45.35.02

Carbon Steel 45#

1. Shear failure from unexpected impact loads; 2. Wear from repeated insertion/removal during maintenance.

1. Use the correct tool for insertion/removal to avoid damage; 2. Replace safety pins after any overload or impact event.

6

Double taper pin φ110x660

112.45.05

42CrMo Alloy Steel

1. Fatigue of the taper surface from cyclic loads; 2. Corrosion in saltwater environments leading to material degradation.

1. Conduct annual NDT for fatigue cracks; 2. Apply marine-grade anti-corrosion coating in offshore applications.

7

Double taper pin φ80x350

112.45.01

40Cr Alloy Steel

1. Wear from misalignment during assembly; 2. Corrosion from drilling fluid exposure.

1. Ensure precise alignment during installation to avoid uneven wear; 2. Clean the pin after exposure to drilling fluids and reapply anti-corrosion coating.

8

Safety pinφ20

112.45.02

Carbon Steel 45#, Heat-Treated

1. Corrosion-induced weakening; 2. Shear failure from improper load distribution.

1. Inspect for corrosion weekly; 2. Ensure the pin is fully seated and properly aligned to distribute loads evenly.

9

Double taper pin φ110x500

112.45.250.02

42CrMo Alloy Steel

1. Taper surface wear from repeated load transfer; 2. Thermal fatigue from extreme temperature fluctuations.

1. Lubricate the taper surface with high-temperature grease; 2. Inspect for thermal cracks quarterly in extreme environments.

10

Double taper pin φ100x360

112.45.35.04

40Cr Alloy Steel

1. Loosening due to vibration; 2. Corrosion from moisture in enclosed spaces.

1. Use anti-vibration lock washers to secure the pin; 2. Improve ventilation in enclosed spaces to reduce moisture buildup.

11

Double taper pin φ90x340

112.45.35.03

40Cr Alloy Steel

1. Damage from improper installation (e.g., forced fitting); 2. Corrosion-induced pitting.

1. Use a hydraulic press for proper installation to avoid damage; 2. Inspect for pitting monthly and replace if severe.

12

Double taper pin φ60x250

112.45.35.01

40Cr Alloy Steel

1. Wear from vibration-induced movement; 2. Corrosion in humid environments.

1. Inspect for wear and looseness monthly; 2. Apply anti-corrosion coating to exposed surfaces.

13

Double taper pin φ40x180

112.45.01.02

40Cr Alloy Steel

1. Shear failure from overloading; 2. Wear from repeated maintenance cycles.

1. Never exceed the rated load capacity; 2. Limit unnecessary insertion/removal to reduce wear.

14

Double taper pin φ80x280

112.45.03

40Cr Alloy Steel

1. Fatigue from cyclic loads; 2. Corrosion from saltwater or drilling fluids.

1. Conduct annual fatigue inspections; 2. Clean and re-coat the pin after exposure to corrosive substances.

1

Inclined Ramp Assembly

112.64.220.00

Q355B Carbon Steel, Hot-Dip Galvanized & Anti-Slip Coated

1. Wear of the anti-slip surface from foot and equipment traffic; 2. Corrosion in offshore or high-humidity environments.

1. Inspect the anti-slip surface monthly; re-coat with anti-slip paint if wear is detected; 2. Inspect galvanization annually and touch up any damaged areas.

2

BOP Guide Rail Device

112.64.300.00

Q690 High-Strength Steel, Precision Machined

1. Wear from BOP movement during installation/removal; 2. Corrosion from drilling fluid exposure.

1. Lubricate the guide rail surface before BOP operations to reduce friction; 2. Clean the rail after each BOP movement and reapply anti-corrosion coating as needed.

3

Ladder on the right of drilling floor

112.64.203.00

Q235B Carbon Steel, Hot-Dip Galvanized (Anti-Slip Rungs)

1. Wear of rungs from constant foot traffic; 2. Loosening of connection fasteners due to vibration.

1. Inspect rungs for wear and anti-slip performance weekly; 2. Re-torque connection fasteners monthly to maintain stability.

4

Handrail general drawing

112.64.216.00

Q235B Carbon Steel, Galvanized

1. Corrosion from environmental elements; 2. Impact damage from equipment or personnel.

1. Inspect handrails and support brackets weekly for corrosion and damage; 2. Install bumpers at high-impact locations to prevent damage.

5

Safety slide

112.27.164.00

High-Density Polyethylene (HDPE) + Galvanized Steel Frame

1. Wear of the HDPE slide surface from emergency use; 2. Corrosion of the steel frame.

1. Inspect the slide surface monthly for wear and debris; 2. Inspect the steel frame annually for corrosion and re-coat as needed.

6

Ladder on the front of drill floor

112.64.201.00

Q235B Carbon Steel, Hot-Dip Galvanized

1. Impact damage from falling objects; 2. Corrosion from rain or salt spray.

1. Install a protective screen to shield the ladder from falling objects; 2. Apply weather-resistant coating to enhance corrosion resistance.

7

Drilling floor left rolling ladder

112.64.202.00

Q235B Carbon Steel, Galvanized + Nylon Rollers

1. Wear of nylon rollers from movement; 2. Loosening of roller axles due to vibration.

1. Lubricate roller axles weekly to reduce wear; 2. Inspect roller condition and axle tightness monthly.

8

Inner surrounding drawing of drill floor

112.64.400.00

Q355B Carbon Steel, Anti-Corrosion Coated

1. Corrosion from drilling fluid splatter; 2. Fatigue from drilling vibration.

1. Clean the surrounding structure regularly to remove drilling fluid residue; 2. Conduct annual NDT for fatigue cracks.