Method and composition for limiting permeability of a matrix to limit liquid and gas inflow

A sealing composition comprising a coagulable polymer emulsion or colloid contactable with at least one selected additive which interacts with said polymer emulsion or colloid to form a coagulated mass for forming a sealing barrier against liquid or gas inflow through a porous matrix, wherein said polymer emulsion or colloid contains at least one further selected additive including one or a combination of radiation stabilisers to confer radiation resistance on said sealing barrier.

A sealing composition comprising a coagulable polymer emulsion or colloid contactable with at least one selected additive which interacts with said polymer emulsion or colloid to form a coagulated mass for forming a sealing barrier against liquid or gas inflow through a porous matrix, wherein said polymer emulsion or colloid contains at least one further selected additive including one or a combination of radiation stabilisers selected from the group consisting of carbon black, zinc oxide both in particulate form and essentially insoluble in water;

• ortho di-substituted phenols, hydroxyphenyl propionates, hydroxybenzyl compounds, aromatic amines, sterically hindered amines, phosphites and organic sulphur compounds to confer radiation resistance on said sealing barrier, said radiation stabiliser or combination of radiation stabilisers being present in the latex emulsion or colloid in proportion less than 1 wt %.

A method for forming a radiation resistant containment barrier which limits or reduces liquid or gas inflow through a porous matrix, comprising delivering to said porous matrix by injection a coagulable polymer emulsion or colloid for contacting with at least one selected additive which interacts with said polymer emulsion or colloid to form a radiation resistant containment barrier to reduce liquid and/or gas inflow through the porous matrix, said coagulable polymer emulsion or colloid containing at least one selected additive including one or a combination of radiation stabilisers to confer radiation resistance on said containment barrier;

• wherein said sealing barrier is formed by contacting said polymer emulsion or colloid with a further selected additive to cause coagulation of said polymer emulsion or colloid to form said sealing barrier;
• and wherein said containment barrier is mechanically resistant to a radiation level of at least 1 MRad.