Drilling Rigs & Accessories: Wellhead, Monitoring & Downhole Survey Components

1

Wellhead Assy

Alloy steel (A182 F22/F91) main body, stainless steel (316L) internals, Inconel 625 corrosion-resistant cladding for sour wells, spiral-wound gaskets

1. Gasket wear and leakage due to pressure fluctuations and thermal cycling; 2. Corrosion of the main body in marine/sour well environments, leading to reduced structural strength.

1. Use torque wrenches for uniform flange bolt tightening, replace gaskets every 6 months; 2. For sour/marine use, conduct quarterly ultrasonic corrosion testing, touch up anti-corrosion cladding promptly if damaged.

2

Wellhead & x-mass tree

Carbon steel (A216 WCB) or alloy steel body, stainless steel (316L) valves and chokes, nitrile/fluororubber seals, anti-corrosion coating

1. Valve seat wear due to high-velocity fluid scouring and solid particle abrasion; 2. External corrosion from environmental factors (salt spray, humidity) and internal corrosion from well fluids.

1. Avoid partial valve opening to reduce scouring, inspect valve seats for wear every 500 working hours; 2. Apply anti-corrosion wax to external surfaces for onshore use, use stainless steel components for offshore, and inspect monthly.

1

SPM Pup Joints

Alloy steel (4140) pipe body, stainless steel (316L) threads, with hardfacing and corrosion-resistant coating, API standard thread connections

1. Thread wear and galling during make-up/break-out operations; 2. Pipe body corrosion in sour well/marine environments, leading to wall thickness reduction.

1. Use API-specified thread compound, control make-up torque within 85-95% of the rated value; 2. For sour service, select joints with NACE MR0175/ISO 15156 certification, conduct monthly thread inspection and anti-corrosion maintenance.

2

SPM Hammer Union

Alloy steel (42CrMo) union body, stainless steel (316) seal ring, carbon steel (1045) hammer nut, with anti-galling treatment

1. Seal ring wear and leakage due to repeated hammering during connection; 2. Thread damage on the hammer nut from improper hammering force.

1. Use a hammer of the specified weight (avoid excessive force), replace seal rings after 20 connection cycles; 2. Inspect the union thread and seal groove for damage before each use, apply anti-wear grease to threads.

1

Drilling Instruments

Aluminum alloy housing (anodized), tempered glass display, stainless steel (304) sensors, copper wiring, ABS plastic control panels

1. Sensor drift and inaccuracy due to vibration and harsh environmental conditions (high temperature, humidity); 2. Housing damage from accidental impact and corrosion in marine environments.

1. Calibrate sensors quarterly according to API Spec 17D, install shock absorbers to reduce vibration; 2. Use protective covers for marine use, ensure housing seals are intact to prevent moisture entry, inspect monthly.

2

Weight Indicator

Stainless steel (316L) pressure sensor, aluminum alloy casing, analog/digital display module, high-strength steel load cell

1. Load cell fatigue and inaccuracy due to repeated overloading and long-term use; 2. Display module failure due to voltage fluctuations and moisture intrusion.

1. Avoid exceeding the maximum load rating, conduct load cell calibration every 3 months; 2. Install a voltage stabilizer to protect the display module, keep the indicator in a dry environment, and inspect seals regularly.

3

Prameter Recorders

Stainless steel (304) housing, industrial-grade circuit board, lithium-ion battery, USB interface (stainless steel)

1. Battery capacity degradation due to high-temperature operation and frequent charging/discharging; 2. Data loss and circuit damage due to moisture and electromagnetic interference.

1. Operate within the recommended temperature range (0-60℃), avoid overcharging, replace batteries annually; 2. Use shielded cables to reduce electromagnetic interference, ensure housing is sealed tightly, store data regularly.

1

Single Point

Alloy steel (4140) housing (nitrided), neodymium magnet sensors, stainless steel (316L) electronic components, high-temperature seals

1. Sensor damage due to high downhole temperature (above 150℃) and pressure; 2. Housing wear from contact with wellbore walls and solid particles.

1. Select models with temperature/pressure ratings exceeding downhole conditions (safety margin ≥20%), inspect sensors before each run; 2. Install centralizers to reduce wellbore contact, avoid running in highly deviated well sections at high speed.

2

Multi-point

Titanium alloy housing (lightweight and corrosion-resistant), fiber optic sensors, high-temperature lithium battery, ceramic pressure-resistant components

1. Data transmission failure due to fiber optic cable damage; 2. Battery failure due to prolonged exposure to high downhole temperatures.

1. Inspect fiber optic cables for cracks and wear before use, handle with care to avoid bending; 2. Limit downhole running time within the battery's high-temperature service life, pre-test battery performance before each operation.

3

MWD

Alloy steel (25CrNiMo) pressure housing, electromagnetic sensors, mud pulse generator (tungsten carbide), stainless steel (316L) internals

1. Mud pulse generator wear due to high-velocity mud scouring and solid particle abrasion; 2. Sensor interference from downhole magnetic anomalies.

1. Maintain mud solid content ≤0.1% to reduce generator wear, inspect the generator nozzle before each run; 2. Conduct pre-survey magnetic calibration, avoid running in areas with strong magnetic interference, and correct data accordingly.

4

LWD

Nickel-based alloy (Inconel 718) housing, gamma ray sensors, neutron detectors, high-temperature circuit boards

1. Detector efficiency degradation due to long-term radiation exposure; 2. Housing corrosion in sour well environments with H₂S and chloride ions.

1. Calibrate detectors every 6 months, replace when efficiency drops below 90%; 2. For sour well use, select housings with NACE MR0175/ISO 15156 certification, conduct post-operation corrosion inspection.

1

Slick line winch

Carbon steel (Q235) frame (anti-corrosion painted), alloy steel (42CrMo) drum, stainless steel (316) gears, rubber vibration isolators, electric motor (aluminum alloy housing)

1. Drum surface wear due to friction with the slick line; 2. Gear wear and jamming due to contamination by sand and moisture, vibration during operation.

1. Lubricate the slick line regularly, inspect drum surface wear every 100 operation hours, replace if wear grooves exceed 0.5mm; 2. Keep the winch gearbox sealed, replace lubricating oil every 500 working hours, install vibration isolators to reduce operational shock.