| 摘要 |
FIELD: oil-and-gas industry.SUBSTANCE: external rig composed of packer, outer string, at least one outer outlet between packer and filter is lowered into well. Inner string includes crossover for selective passage of gravel to outer outlet. Backflow flows through said filter and crossover into top annulus. Proceeding from inner string displacement relative to packer, position of fluid injection into well through bottom annulus is defined. Defined is circulation position whereat gravel is filled in bottom annulus while backflow flows through the filter into top annulus. Reversing position whereat gravel in inner string above crossover can be forced back to the surface. Valve assy is mounted nearby inner string bottom end, open in lowering into well. To close said valve assy, larger number of jobs is required other than single force application in one direction.EFFECT: ruled out swabbing effect and fluid absorption in bed.23 cl, 62 dwg |
