METHOD FOR STARTING AND STOPPING OF OFFSHORE AIRLIFT AND SYSTEM FOR ITS IMPLEMENTATION Russian patent published in 2009 - IPC E21C50/00 E21C45/00 F04F1/20 

FIELD: mining.

SUBSTANCE: group of inventions relates to mechanical engineering and can be used directly in development of subsea mineral deposits, where mineral components are pumped out by airlift. Method for starting and stopping of offshore airlift, where starting process includes compressed air supply via pressure pipeline from compressor to mixer of lifting pipe, while stopping process includes stopping of compressed air supply via pressure pipeline from compressor to mixer of lifting pipe, compressed air supply from compressor to upper part of said offshore airlift's lifting pipe and its discharging to atmosphere, as well as compressor stopping. In the course of offshore airlift starting process amount of sea water supply to lifting pipe of offshore airlift is pre-defined, connection between upper part of lifting pipe and atmosphere is closed, compressed air is supplied into upper part of lifting pipe of offshore airlift, sea water is displaced from lifting pipe to ocean through connecting pipe, compressed air supply into upper part of lifting pipe is stopped after the required air pressure in said pipe is achieved, connection of lifting pipe with ocean through connecting pipe is closed, connection between upper part of lifting pipe with atmosphere is restored with simultaneous supply of compressed air into mixer of lifting pipe. After that, connection between lifting pipe and ocean is provided through connecting pipe, amount of sea water supplied into lifting pipe is monitored, measured pressure value is compared with pre-defined target value and balanced with it through adjustment of sea water flowrate in said connecting pipe. And when water-air mix is spread over the entire length of lifting pipe, unrestricted supply of sea water through connecting pipe to lifting pipe is restored. And in the course of offshore airlift stopping process, pressure value in upper part of lifting pipe is pre-defined, then this value is monitored during compressed air supply from compressor to upper part of offshore airlift's lifting pipe, measured pressure value is compared with pre-defined value and as soon as they become equal said compressor is stopped. After that, connection between lifting pipe and ocean through connecting pipe is closed and connection of upper part of lifting pipe with atmosphere is opened again.

EFFECT: improvement of offshore airlift starting and stopping method.

2 cl, 3 dwg