METHOD OF RECOVERY OF YIELD AND BRINGING TO OPERATION OF TEMPORARILY SHUT-IN WELLS WITH COMPLICATED STRUCTURE OF COLLECTORS UNDER CONDITIONS OF ABNORMALLY LOW BED PRESSURE AND HEAVY WATERING Russian patent published in 2009 - IPC E21B43/00 E21B43/32 

FIELD: oil and gas production.

SUBSTANCE: method of recovery of yield and bringing to operation of temporarily shut-in wells with complicated structure of collectors under conditions of abnormally low bed pressure and heavy watering including repair, insulating, and exposure of producing bed consists in following: initially, sand plug is washed up to first over current gas-water contact (GWC) of clay interlayer but not 5-7 m from current GWC; producing string is callipered. The shank end out of casing tubes of smaller diametre is lowered into the producing string up to the head of the washed sand plug; also the head of the shank end is arranged 20 m above the top of the producing bed. The shank end is cemented with cement grout and a cement sleeve is left 1-2 m above the shoe of the shank end. Upon completion of waiting-on-cement period WCC the cement sleeve is drilled and the sand plug is washed to depth 1-2 m below current GWC. Water insulating composition at volume 15-20 m³ is pumped through existing interval of perforation; composition is forced through into depth of the producing bed creating a water insulating screen with cement grout of volume 3-5 m³; a cement sleeve 1-2 m above the shoe of the shank end is left at the bottomhole. Upon WCC perforating is performed for operation of two columns, the producing column and the shank end in interval above the second over the current GWC clay interlayer up to the top of the producing bed; gas discharge is initiated. Composition containing Portland cement, super-plasticiser C-3, polyvinyl alcohol and polypropylene fibre is used as cement grout; while for perforation either a high-power cumulative perforator or hydraulic jet are used.

EFFECT: insulating fluid entry, ensuring pressure tightness of producing column and additional gas withdrawal from earlier shut-in wells.

1 ex, 4 dwg