two pipeline in the same trench 1

[robb4]

Dear all,

I'm involved into design of pipeline system composed by 2 gas pipeline.

I have a small on shore section (500m) and I'm thinking about the possibility to bury both pipeline in the same trench (the route in that section is the same).

Considering that the cathodic protection system is the same for both pipeline (sacrificial anodes, same system used in offshore section) is there any problem / limitation to do that? (such as installation issue, HSE requirements)

Thank for your help.

 

[ss770640]

Robb4,

i work within subsea pipe lay industry for a leading contractor.

A Bundled pipeline solution is definitely the most cost effective. Use sacrificial anodes on the main line only and attach to piggyback line with spot welds (or other) at predetermined spacing to provide continuity. The current attenuation should be a derivative of normal anode calcs/code requirements and shouldnt matter if only a 500m section is onshore. (if anything, being outwith saltwater makes protection more likely)

Offshore code such as DNV-FS-101 or PD 8010 will provide further guidance. Don't use the Dutch code NEN 3650.

Have the insuring body approve your calcs.

BEng(Hons) CEng (UK) MIMECHE

 

[pipelyer]

http://www.saddletech.ca/standard.htm

Here is a effect weight used in swamp conditions.
Far superior to the bolt on Cement Weights