METHOD FOR CEMENTATION OF WELLS Russian patent published in 1998 - IPC

FIELD: oil and gas production industry. SUBSTANCE: this can be used in construction of wells. According to method, injected into casing pipe string are following liquids: buffer liquid, plugging solution, displacing liquid with subsequent displacement into annular space of buffer liquid and then plugging solution. Operation of displacing buffer liquid and plugging solution into annular space is carried out in turbulent mode until reaching maximal permissible values of pressure for casing pipe string and ground occurring around walls of well. Upon that, displacement of remaining proportion of plugging solution is performed in mode which corresponds to structural flow of liquid in annular space. Plugging solution can be used with usual water-mix ratio. At successive injection, water-mix ratio can be reduced. Application of aforesaid method allows for creating reliable zone of isolation with material being cemented at operating object. EFFECT: higher efficiency. 2 cl, 2 dwg