Project Tag: Surface Dive Stage w/ LARS

Pipeline Abandonment

Global mobilized a four point mooring system and a deep air diving system onto a landing craft. The vessel was then moored 40ft from the leg of a production platform and directly over a sub sea oil and gas manifold. This required anchor operations to conducted in 3 pipeline corridors and near an active production platform. The project involved installing several hot tap installations and disassembling and re-assembling various spool pieces of the subsea manifold,which aid in the ability to utilitize cleaning pigs in both lines from the platform. All this was done without interrupting flow thought the manifold or operations on the production platform that it is connected to. This project was performed in Cook Inlet that is typical has zero visibility and tidal current in the excess of six knots

FPSO Ship Husbandry

Global provided surface supplied dive team and Inspection Class ROV to conduct visual surveys of the FPSO buoy and components as well as perform light construction and ship husbandry on the hull of the BW Pioneer. Tooling included barnacle busters and high pressure water blasters to remove marine growth.

USCG – Orphan Well Leaker

Mobilized surface dive spread and light construction vessel(s) to conduct site clearance operations on a leaking well at Main Pass 25. Conducted diver and sonar (Mesotech 1000) survey of bottom within 100′ radius of well center. Identified and removed (3) 2″ pipelines and misc. debris from bottom in preparation of lift boat arriving on site to perform well abandonment operations.

High Elevation Relief Reservoir Maintenance

We were hired to install blanking flanges on the upstream end of a high altitude dam in 150 ffw so our client could perform maintenance on the three valves in the outlet works piping of Relief Reservoir.

This remote reservoir is located in the Sierra Nevada Mountains at an elevation of 7,300 ft with no road access to the facility. All equipment and materials for this site is brought in by helicopter or mules. Due to the high elevation and depth of dive operations mixed gas diving was the primary form of diving employed to maximize working bottom time. Due to the greater decompression requirements of mixed gas techniques decompression chambers are utilized to ensure the diver’s safety.

A heavy lift helicopter (Sky Crane) was brought in to transport sectional barge pieces since the the crest of the dam was not wide enough for the dive equipment. Each piece was 15 ft by 7 1/2 ft and weighed over 8,500 pounds. Together they created a 30 ft by 45 ft dive barge. The heavy lift helicopter then lifted two decompression chambers and a dive van from the staging area in Kennedy Meadows to Relief Reservoir,a five minute flight.

Helicopter operations included a comprehensive security plan as the staging area is a high traffic tourist site for pack trains and hikers.

Platform Decommissioning

Working aboard the D/B Superior Performance,we provided mixed gas diving support to WWCI for the removal of an 8-pile platform jacket. Diving operations were conducted to a depth of 218 fsw. Due to internal obstructions,divers utilized diamond wire saw tooling to cut two of the jacket legs. The remaining legs were cut utilizing underwater burning rod.

Dix Dam Face Slab Repair

Upon completion in the mid 1920’s,Dix Dam was the largest rock filled dam in the world standing approximately 287 feet above the riverbed. It was built in the private sector by it’s current owner,Kentucky Utilities Company,to create a reservoir for operating a hydroelectric generating station.

Global was selected to perform and manage repair work to an existing earth filled dam. Divers removed debris including cars,trees,and sediment from several areas of the dam and then these areas were surveyed using sonar and tactile methods. Damaged areas of the face slab were covered using sheet membrane secured to the face of the dam. Work took place in up to 140 feet of water.

Seawater Intake Lines – Modification & Cleaning

Global Diving & Salvage,Inc was the prime contractor / project manager responsible for the modification and cleaning of the SeaLife Center’s intake lines. The first phase of the project was to install a pig launcher system; tasks included dewatering the Center’s wet well,installing an isolation valve between the well’s chambers,and saw cutting new access holes in the pump room floor.

The second phase of the project consisted of the dive crew cutting a 24 inch HDPE pipe and lifting it out of the soft bottom material to allow for an ROV inspection of the intake pipe. The inspection was short lived as the pipe was impassable due to marine growth and sediment. In order to clean the lines,several cleaning pigs were launched to remove the blockage. A new intake screen and support structure was installed along with a remotely operated pig catcher.

Dive crews worked off of a barge with a 150 ton crane and four point mooring system that was strategically anchored over the buried intake support functions. A deep gas dive system was utilized to accommodate dive operations in up to 260′ of seawater. The final quality control inspection was performed by an ROV flying over 200′ up the pipe to inspect for marine growth and debris.

South Timbalier 196 B – Platform Removal

We provided surface diving support aboard the D/B Superior Performance to assist,as needed,with the removal of the topside package and platform jacket. Dive work was performed down to 105 fsw using standard surface diving procedures.

The platform was initially cut free from the jacket then the legs were cut 15 feet below mud line using explosives. After all the legs had been severed,the platform toppled onto its side so that the D/B Superior Performance could pick up the structure,approximately 710 metric tons,and set it on the materials barge for transport to shore and proper disposal.

Conductor Removal

A surface dive crew aboard Stabbert Maritime’s DSV DPII Ocean Carrier cut off a 24″ conductor stub 5 ft below the mud line utilizing a diamond wire saw. The entire project was completed in under 16 hours.

J/U Pride Wyoming Rig Salvage

The Pride Wyoming,a Bethlehem JU-250-MS design mat rig,was jacked up on location at SS 283A when Hurricane Ike passed in September 2009. The rig was destroyed,leaving debris in three separate blocks. WWCI contracted Global Diving & Salvage,Inc. to assist in the prep,salvage and site clearance of all rig components including ancillary debris removal.