Pile Remedial Services
PILE REFUSAL REMEDIAL SERVICES
OCS provides personnel and equipment for pile remediation using ‘Jetting and Airlift’ and/or Drilling techniques. Drilling can be either ‘Pile top drilling’ or ‘drilling off the boom’.
Jetting and Airlift
Air lift works on the below principle:
The jetting/airlifting string is static during remedial operations. The system relies on high pressure water through nozzles located in the jetting head to break up the formation and an airlift to remove formation materials.
Principle equipment employed for Jetting and Airlifting:
- Jetting / Airlifting String
- Water winning and pressure pumps.
- Air compressors
- Miscellaneous hoses and fittings.
- Jet String make up rack.
- Access platform on the top of the pile.
OCS Air-Lift Spreads consists of the following:
1. 40ft Open Top Container consists of:
- 10” Pipe Flanged strings (fitted with 2 x 2” Water Jet pipe &1 x 2” Compressed air line)
- 40ft LG x 10” dia Jetting Head Section (Type 4)
- 40ft LG x 10” dia Jetting Intermediate Section (Type 2)
- 40ft LG x 10” dia Jetting Intermediate Section (Type 3)
- 40ft LG x 10” dia Top Section (Type 1)
- Lifting Cap for jetting and airlift string
- Centralizers
- 2” dia x 500 psi Jetty Hose in 200 ft LG04 ea
2. 20ft High Cube Container consists of:
- 1200 gpm – 250 Psi Jet Pump
- Centralizers
- Neoprene Rubber, 5mm WT x 508mm OD x 280mm ID
- Pipe sleeve, 2-1/2″ dia x 5mm WT x 1000mm LG
- 6” dia to 2” dia Water Distribution Manifold
- 8” ANSI 150lb Foot Valve Cast Iron
- Misc Hose Assembly
- Venture System Device
- 8″ dia to 6″ dia reducer (#300 rating)
- 8” dia x 1ft LG pup piece
- Water Filled Pressure Gauge (500 Psi)
- 6” dia x 1ft LG pup piece
Drilling
Pile Top Drilling Works on the below principle:
OCS employs Drilling off The Boom (DOTB) technique. The drilling assembly (comprises of the power swivel, drill string and bottom hole assembly) is connected to the vessel crane. Control tugger winches is connected to the power swivel to maintain the power swivel orientation during the swivelling operations.
Drilling off the Boom technique eliminates the requirement of an extensive drilling rig spread. The drilling assembly can be mobilized and set-up on the main installation vessel in the event of a pile refusal and/or relief drilling is expected. The key working principal for Drilling off the Boom comprises off;
- Drilling assembly rigged up onto the vessel crane and lowered into the pile top.
- The Bottom hole assembly rotating bit cuts and breaks up the soil plug formation.
- Cuttings from the formation is airlifted to the surface.
Principle equipment for Drilling:
- Drill String, Bottom hole assembly centralisers, roller cutters.
- Power Swivel and Hydraulic power pack.
- Drill string make up frames.
- Access platform on top of the pile
OCS Drilling Spreads consists of the following:
- Drilling Equipment assembly
- 1 unit Power Swivel and Crossover
- 13-3/8” Drill Pipe Strings. Mobilized length to suit water depth and drill depth
- HT100 Tongs and Hydraulic Jack,
- Bottom hole assembly with drilling bit, BHA cross over, BHA collar
- Tongs make up assembly.
- Elevator / clamps to lift up drill strings.
Pile Refusal Remedial Pre-Qualification Document: Download
- Drilling Equipment assembly