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

摘要

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 including repair, insulating, and exposure of producing bed consists in following: initially, sand plug is washed for depth 2-3 m below current gas-water contact (GWC); producing string is callipered, shank end out of casing tubes of smaller diametre is lowered into producing string up to head of washed sand plug; head of shank end is arranged 20 m above top of producing bed. The shank end is cemented with cement grout; upon waiting-on-cement completion (WCC) two columns, the producing column and the shank end are perforated in interval below the first over current GWC clay interlayer to depth 2-3 m below current GWC. Water insulating composition at volume 15-20 m³ is pumped through perforated openings made for water insulation; 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 first over the current GWC clay interlayer 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