Well treatment fluids composition
A well treatment fluid composition that includes a tetrakis(hydroxyorgano)phosphonium salt and 1,3-dimethylol-5,5-dimethylhydantoin. Methods for preparing a well treatment fluid composition and treating a subterranean formation are also presented.
1. A method for preparing a well treatment fluid composition comprising the steps of:
obtaining a composition comprising a tetrakis(hydroxyorgano)phosphonium salt, 1,3-dimethylol-5,5-dimethylhydantoin, and optionally one or more members selected from the group consisting of:
oxidizing viscosity breakers,
quaternary ammonium compounds, and
polymers of an unsaturated carboxylic acid or copolymers of an unsaturated carboxylic add with a sulphonic acid, said polymers or copolymers being terminated by a mono- or di-phosphonated unsaturated carboxylic add group or having such monomers incorporated into the polymer backbone,
wherein the composition achieves a reduction of bacteria to give a total kill at 5 hour contact time; and
diluting the composition to form a diluted composition.
2. The method of claim 1 , wherein the tetrakis(hydroxyorgano)phosphonium salt is selected from the group consisting of
tetrakis(hydroxymethyl)phosphonium sulphate,
tetrakis(hydroxymethyl)phosphonium chloride,
tetrakis(hydroxymethyl)phosphonium phosphate,
tetrakis(hydroxymethyl)phosphonium nitrate, and
tetrakis(hydroxymethyl)phosphonium oxalate.
3. The method of claim 1 , wherein the composition includes an oxidizing viscosity breaker and the breaker is selected from the group consisting of hydrogen peroxide, sodium persulfate, encapsulated ammonium persulfate, and sodium chlorite.
4. The method of claim 1 , wherein the mass ratio between the THP salt and 1,3-dimethylol-5,5-dimethylhydantoin is about 1:0.5 to about 1:25.
5. The method of claim 4 further including comprising at least one oxidizing viscosity breaker.
6. The method of claim 1 , wherein the composition contains less than 0.2% free formaldehyde after 4 months storage at 50° C.
7. The method of claim 4 , wherein the composition contains less than 0.2% free formaldehyde after 4 months storage at 50° C.
8. A method for treating a subterranean formation comprising the step of introducing a composition into the formation, wherein the composition comprises a tetrakis(hydroxyorgano)phosphonium salt, 1,3-dimethylol-5,5-dimethylhydantoin, and optionally one or more members selected from the group consisting of:
oxidizing viscosity breakers,
quaternary ammonium compounds, and
polymers of an unsaturated carboxylic acid or copolymers of an unsaturated carboxylic add with a sulphonic acid, said polymers or copolymers being terminated by a mono- or di-phosphonated unsaturated carboxylic add group or having such monomers incorporated into the polymer backbone,
wherein the composition achieves a reduction of bacteria to give a total kill at 5 hour contact time.
9. The method of claim 8 , wherein the tetrakis(hydroxyorgano)phosphonium salt is selected from the group consisting of
tetrakis(hydroxymethyl)phosphonium sulphate,
tetrakis(hydroxymethyl)phosphonium chloride,
tetrakis(hydroxymethyl)phosphonium phosphate,
tetrakis(hydroxymethyl)phosphonium nitrate, and
tetrakis(hydroxymethyl)phosphonium oxalate.
10. The method of claim 8 , wherein the composition includes an oxidizing viscosity breaker and the breaker is selected from the group consisting of hydrogen peroxide, sodium persulfate, encapsulated ammonium persulfate, and sodium chlorite.
11. The method of claim 8 , wherein the mass ratio between the THP salt and 1,3-dimethylol-5,5-dimethylhydantoin is about 1:0.5 to about 1:25.
12. The method of claim 11 further including comprising at least one oxidizing viscosity breaker.
13. The method of claim 8 , wherein the composition contains less than 0.2% free formaldehyde after 4 months storage at 50° C.
14. The method of claim 11 , wherein the composition contains less than 0.2% free formaldehyde after 4 months storage at 50° C.