MANDREL WITH SIDE POCKET THAT MAINTAINS OPERATION CAPABILITY AFTER SUBJECTED TO FLUSH OF CEMENT SLURRY Russian patent published in 2008 - IPC E21B33/14 

FIELD: oil and gas production industry.

SUBSTANCE: package of inventions is related to well completion method and devices, i.e. to methods of well completion with mandrel provided with side pocket that maintains operation capability after subjected to flush of cement slurry and cementing plug to flush cement slurry via tubing string. The method includes tubing string provided with, at least, one mandrel with side pocket and RIH with tubing string. Cement slurry is displaced via tubing string and mandrel to annular space around tubing string and main part of the cement slurry inside the mandrel is removed by moving cementing plug along the mandrel by means of drive fluid pressure. Additional part of cement slurry located in the mandrel is washed out by turbulised flow of drive fluid use to move cementing plug. Mandrel is provided with oblongated pipe that is provided with asymmetrical connecting converters on distral ends, asymmetrical passage in the cavity of stated pipe between connecting converters, cylinder chamber located in the pipe cavity between connecting converters alongside of pipe passage and of length less than half of pipe passage length, normally available production flow passage located in the pipe cavity from cylinder chamber to the nearest connecting converter and insert that creates turbulence of drive fluid and takes main unused part of the pipe cavity, located beyond the passage, cylinder chamber and production flow passage. Cementing plug contain front set of cups fastened to the plug case, rear set of cups fastened to the plug case at the distance from front set of cups that practically corresponds a length of link that connects tubing joints and centraliser fixed on the case between front and rear sets of cups. Ensures increase of method performance due to possible cleaning of mandrel with side pocket from cement slurry and its further use for gaslift operation of the well.

EFFECT: improved performance of well completion method.

12 cl, 5 dwg