HIGH STRENGTH DISSOLVABLE COMPOSITIONS FOR USE IN SUBTERRANEAN WELLS

摘要

A polymetaphosphate composition and method for temporarily sealing a perforation in a wellbore to facilitate a treatment therein and a well tool which can include a flow path, and a flow blocking device which selectively prevents flow through the flow path. The well tool can include a polymetaphosphate composition. A method of constructing a downhole well tool can include forming a structure of a solid mass comprising a polymetaphosphate composition, and incorporating the structure into the well tool.

主权项

1. A method of plugging the perforations in a casing which has been set in a wellbore which penetrates a subterranean formation comprising:
(a) flowing down said casing a wellbore fluid having dispersed therein a plurality of substantially spherical high strength degradable compositions being sized to seal said perforations and being comprised of polymetaphosphates of the formula
AXH2P04.2H20+BMO +2(NH4)2HP04−>(1/n)[XM(P03)3]n+ammonia+water wherein A and B are numbers of moles of reactants and the ratio of A:B is in the range of from about 1:1 to about 6:1, X is selected from Li, Na or K, M is selected from Be, Mg, Ca, Zn, Pb, Cu or Ni and n is from about 1 to about 100 or greater; and (b) continuing the flow of said wellbore fluid until at least a portion of said perforations are sealed by said structures.