METHOD FOR WATERPROOFING ANNULAR SPACE OF PROCESS WELLS Russian patent published in 2024 - IPC E21B33/14 C09K8/508 

FIELD: mining.

SUBSTANCE: invention relates to a method for waterproofing annular space of process wells constructed in conditions of a developed cryolithozone. Method involves pouring a fluid gel composition into the annular space of the well. Production string is placed in the well. String is equipped with a conductor at the mouth and a filter with a settler at the lower end. After the filter with a settler, there is a gravel coating, on top of which a layer of cement mortar is arranged in the annular space to the lower boundary of the cryolithozone. After that, the fluid composition is poured in a heated form, which fills the entire annular space of the well in the cryolithozone up to the day surface. Fluid gel composition consists of polyvinyl alcohol 2.0–10.0%, boric acid 0.2–1.0%, sawdust, drilling mud, 5.0–30.0%, water – the rest. As a result of cooling in the well, the fluid gel composition is converted into a viscoelastic, waterproofing and reinforcing material.

EFFECT: improving reliability of well design, excluding formation of ice plugs in annular space, reduction of labour intensity and terms of performance of works on construction of wells and device of waterproofing, exclusion of possibility of damage of production polymer string with drill pipes.

1 cl, 1 dwg