Melamine-aldehyde sealing agents and method of making the same

Claim 1

METHOD OF PREPARING A SEALING AGENT FOR SEALING POROUS FORMATIONS WHICH COMPRISES REACTING MELAMINE WITH A REACTANT SELECTED FROM THE GROUP CONSISTING OF FORMALIN AND FURFURAL UNDER CONDENSATION CONDITIONS TO FORM A THERMOSETTING RESIN, THE WEIGHT PROPORTION OF MELAMINE TO THE SECOND-NAMED REACTANT BEING WITHIN THE RANGE OF ONE TO 1/6-20 WHEN SAID SECOND-NAMED REACTANT IS FORMATION AND ONE TO 108 WHEN SAID SECOND-NAMED REACTANT IS FURFURAL; CONTINUING THE REACTION UNTIL THE RESIN HAS REACHED AN INTERMEDIATE PLASTIC SOLID STAGE AT WHICH IT IS DISPERSIBLE BY STIRRING IN WATER WITHOUT THE AID OF AN EMULSIFYING AGENT TO FORM A NON COLLOIDAL SUSPENSION STABLE FOR AT LEAST FIVE HOURS; STOPPING THE REACTION WHEN SAID INTERMEDIATE PLASTIC SOLID STAGE IS REACHED WHEREBY TO OBTAIN A PARTIALLY CONDENSED RESIN CAPABLE OF FURTHER CONDENSATION TO A HARD INFUSIBLE STAGE UPON APPLICATION HEAT SAID PARTIALLY CONDENSED RESIN COMPRISING, WHEN SAID SECOND-NAMED REACTANT IS FORMALIN, A DISTINGUISHABLE AGGLOMERATED RESIN MASS; DISINTEGRATING, WHEN SAID SECOND-NEMED REACTANT IS FORMALIN, SAID RESIN MASS; AND DISPERSING THE RESIN WHILE STILL SOFT SOLELY BY STIRRING IN WATER THEREBY FORMING, AS THE DESIRED PRODUCT, A NONCOLLOIDAL AQUEOUS SUSPENSION WHICH, WHEN FORCED INTO A BED OF 10 MESH SAND, WILL FORM A RESIN SHEATH AT THE FACE OF THE BED CAPABLE OF THERMOSETTING TO A HARD LAYER SUBSTANTIALLY IMPREVIOUS TO DRILLING FLUID.