Non-contact inspection and its special device at marine-bottom pipeline cathode protecting state

Abstract

A method for detecting cathode protection state of submerged pipeline by noncontacting means includes setting state of submerged pipeline as per influence factor possible parameter scope of cathode protection electric field, using boundary element manner to make analog test and setting up cathode protection electric field-influence factor databank, inverting and confirming an aging state of surface protective layer on said pipeline as well as obtaining protective potential and protective current density distribution at surface of said pipeline by utilizing data collection system to obtain electric field distribution near said pipeline and utilizing prepared databank.

Description

Technical field: [0001] The invention relates to underwater detection operations of marine engineering, in particular to a non-contact detection method and a proprietary device for cathodic protection status of submarine pipelines. Background technique: [0002] With the rapid development of offshore oil and gas resources development, my country has built a large number of submarine oil and gas pipelines in major offshore economic exclusive zones and oil and gas fields. If some form of damage occurs to the submarine pipeline, it will lead to the shutdown of oil and gas fields and the pollution of the marine environment, and may also cause casualties. The direct economic loss and indirect loss are huge. At present, some oil and gas pipelines in my country are close to reaching their designed service life, and it is urgent to detect and evaluate their cathodic protection status to provide safety guarantee for offshore oil and gas development. In the current underwater cathodi...

AI Technical Summary

Problems solved by technology

In the current underwater cathodic protection potential detection method for submarine pipelines, one end of the detection system needs to be electrically connected to the submarine pipeline (such as the riser of an offshore oil and gas platform), and the other end is carried by a diver to measure its protection along the pipeline route with a reference electrode. Potential, this is only suitable and feasible in the case of small water depth and close to the platform; but for submarine pipelines with a water depth of tens of meters or even hundreds of meters, and a length ranging from tens of kilometers to hundreds of kilometers Generally speaking, when this detection system is far away from the oil and gas platform, it will face many insurmountable problems such as the need to carry signal cables that are too long, the cost is high, the effective shipboard space of the working ship is large, the signal attenuation is serious, and the operation is inconvenient.

Images