METHOD FOR ISOLATION OF RESERVOIR WATER INFLOW IN WELL WITH BUCKLED FLOW STRING UNDER CONDITIONS OF ABNORMALLY LOW RESERVOIR PRESSURES Russian patent published in 2010 - IPC E21B43/32 E21B29/10 

FIELD: oil and gas production.

SUBSTANCE: sand plug is washed down to lower perforation holes of existing interval of perforation, and buckling of flow string is eliminated. Then tail of smaller diametre pipes is lowered in inner cavity of flow string to head of washed sand plug, with arrangement of tail head by 20 m higher than reservoir roof, which is cemented by mortar, leaving cement sleeve in inner cavity of tail down to depth of upper holes of existing perforation interval. After cement hardening, tail and flow string are perforated in interval of above dehydrated part of reservoir to its roof. Lifting string is lowered into well, gas inflow is caused from reservoir, and well is flared, gas dynamics research is carried out, and well is put in operation. At the same time cement mortar consists of portland cement, superplasticiser C-3, polyvinyl alcohol and polypropylene fibre.

EFFECT: liquidation of reservoir water inflow and elimination of flow string buckling conditions, provision of water-free operation of wells.

3 dwg