Methods and compositions for crosslinking polymers with boronic acids

A method of reusing a viscosified treatment fluid comprising:

• providing a first viscosified treatment fluid that comprises water and a first crosslinked gelling agent, the first crosslinked gelling agent being formed from a reaction comprising a gelling agent and a boronic acid crosslinking agent comprising a compound having the formula:
• wherein
• X is a Lewis base;
• R1 and R4 are selected from the group consisting of:
• heteroatoms, organic fragments, and combinations thereof, wherein R1 and R4 can be the same or different;
• —B(OR3)2 is a boronic acid group;
• R3 is selected from the group consisting of:
• hydrogen, an alkyl group, an aryl group, and a combination thereof;
• n is a positive integer greater than or equal to one;
• adjusting the pH of the first viscosified treatment fluid;
• allowing at least a portion of the first crosslinked gelling agent in the first viscosified treatment fluid to delink to form delinked gelling agents;
• crosslinking at least two delinked gelling agents to form a second crosslinked gelling agent to form a second viscosified treatment fluid;
• and
• using the second viscosified treatment fluid in a chosen application.

A method of reusing a viscosified treatment fluid comprising:

• providing a first viscosified treatment fluid that comprises water and a first crosslinked gelling agent, the first crosslinked gelling agent being formed from a reaction comprising a gelling agent and a boronic acid crosslinking agent comprising a compound having the formula:
• adjusting the pH of the first viscosified treatment fluid;
• allowing at least a portion of the first crosslinked gelling agent in the first viscosified treatment fluid to delink to form delinked gelling agents;
• crosslinking at least two delinked gelling agents to form a second crosslinked gelling agent to form a second viscosified treatment fluid;
• and
• using the second viscosified treatment fluid in a chosen application.