05.07.2009
In theory, jetting consists of fluidizing the seabed soil so that the heavier pipeline sinks in.
The jetting plough is placed over the pipeline and high pressure water jets from nozzles blast the surrounding soil away from the pipeline.
Jetting disperses the local soil away from the pipeline and creates a wide trench. In most
cases, the soil is not returned immediately and the pipeline gets covered in time depending on the bottom sediment load.
Jetting is done in sands and soft clays, but in hard clays ploughing may be required.
Sorry, this entry is only available in עברית.
A type of stratigraphic trap. The termination by thinning or tapering out (“pinching out”) of a reservoir against a nonporous sealing rock creates a favorable geometry to trap hydrocarbons, particularly if the adjacent sealing rock is a source rock such as a shale. The disappearance of a porous, permeable formation between two layers of impervious rock over a horizontal distance
A small scale test or trial operation / plant that is used to assess the suitability of a method for commercial application
Long and heavy steel pylon driven into the seabed; a system of piles is used as foundation for anchoring a fixed platform or other offshore structures
Small-diameter pipeline, fixed to a larger pipeline, used to transport a product other than that of the main line
A pig is a device inserted into a pipeline which travels freely through it, driven by the product flow to do a specific task within the pipeline. These tasks fall into a number of different areas: (a) Utility pigs which perform a function such as cleaning, separating products in-line or dewatering the line; (b) Inline inspection pigs which are used to provide information on the condition of the pipeline and the extent and location of any problem (such as corrosion for example) and (c) special duty pigs such as plugs for isolating pipelines. During the construction of the line, pigs can be used to remove debris that accumulates. Testing the pipeline involves hydro-testing and pigs are used to fill the line with water and subsequently to dewater the line after the successful test. During operation, pigs can be used to remove liquid hold-up in the line, clean wax off the pipe wall or apply corrosion inhibitors for example. They can work in conjunction with chemicals to clean pipeline from various build-ups. Inspection pigs are used to assess the remaining wall thickness and extent of corrosion in the line, thus providing timely information for the operator regarding the safety and operability of the line. Pigs (or more specifically) plugs can be used to isolate the pipeline during a repair. >
System used to assist propelling a pig into a flowline for use in cleaning a subsea flowline. Equipment designed to launch and receive pigs