Barite-quartz and calcite-quartz filter cake removal method
Abstract:
A method is described for removing a barite-quartz and a calcite-quartz filter cake from a well bore. The method involves contacting the filter cake with a first composition comprising NH4F, NaBrO3, NH4Cl, and NaNO2. The NH4Cl and NaNO2 react exothermically, and the heat produced drives the endothermic reaction of NH4F and NaBrO3, which produces HF for dissolution of the quartz in the filter cake. Filter cake comprising barite may be further treated with a second composition comprising a converting agent and a chelating agent. Filter cake comprising calcite may be treated with a first composition having an excess of NH4Cl and NaBrO3, which react to produce HCl for calcite dissolution.
Public/Granted literature
Information query
Patent Agency Ranking
0/0