PROCEDURE FOR STABILISED OPERATION OF WATERED FIERY SEAM Russian patent published in 2011 - IPC E21B43/14 

FIELD: gas-and-oil producing industry.

SUBSTANCE: at moment of borehole watering in given seam there is performed temporary mudding in upper watered fiery seam. Further, a flow string is lifted from the borehole; the borehole is after-drilled with a bit of diametre smaller, than diametre of the flow string, to dense rock in a sub-face of a lower fiery seam. A blind flow string is lowered into the borehole. In its head this string is equipped with a packing-suspended system facilitating location of a shoe of the blind flow string in dense rock of the sub-face of the lower fiery seam, while location of its head is in a lower part of the flow string. The blind flow string is cemented and perforated at the level of the lower fiery seam. A sub-packer shank end of diametre smaller, than diametre of the flow string, is lowered to the lower fiery seam. Also, a head of the sub-packer shank end is positioned above the head of the blind flow string. During lowering there is installed a sub in the head of the sub-packer shank end; the flow string with a packer; a behind-the packer valve installed on this string is connected to this sub. The behind-the-packer valve is arranged 10-20 m above a roof of the upper fiery seam, while the packer is installed below the sub-face of the upper fiery seam. Mudding of the upper watered fiery seam is removed, and fiery seams are developed and tested. Through perforations in the blind flow string gas is withdrawn from the lower fiery seam to the sub-packer shank end and further to the flow string where it is mixed with gas and fluid from the watered upper fiery seam in an internal cavity of the behind-the-packer valve. Gas with fluid is supplied along the flow string to the sell head and further into a loop.

EFFECT: stabilised operation of watered upper production fiery seam due to supply of gas from lower production fiery seam in same borehole possessing seam power higher, than upper production fiery seam.

1 dwg