Delayed breaker composition
AssigneeHalliburton Energy Services, Inc.
InventorsMichael W. Sanders, James Ogle
Life of this patent
Estimating the term…
Abstract
A downhole fluid composition having a saccharide gelling agent, an oxidative breaker, and a sequestering agent. The sequestering agent is hydrocarbon miscible and inert to oxidation by the oxidative breaker. The sequestering agent sequesters the oxidative breaker or an activator for the oxidative breaker, whereby oxidation of the gelling agent is inhibited. The downhole fluid may also include a proppant. Upon contacting hydrocarbons downhole or reaching a predetermined temperature, the sequestering agent releases the oxidative breaker or activator thereby oxidizing the saccharide gelling agent.
Claims10
A method comprising:
- pumping an aqueous base fluid having a saccharide gelling agent into a wellbore;
- introducing a delayed breaker composition for the saccharide gelling agent into the wellbore, the delayed breaker composition consisting essentially of
- an oxidative breaker;
- and
- a sequestering agent, the sequestering agent being hydrocarbon miscible and inert to oxidation by the oxidative breaker, the sequestering agent being selected from group of mineral oils, natural oils, C2-C40 alkanes, synthetic oils, waxes, and mixtures thereof, wherein the oxidative breaker is dissolved in the
- sequestering agent, and wherein the sequestering agent sequesters the oxidative breaker whereby oxidation of the gelling agent is inhibited;
- and wherein the delayed breaker composition does not comprise a surfactant;
- allowing the delayed breaker composition to contact a hydrocarbon within the wellbore thereby releasing the oxidative breaker;
- allowing the oxidative breaker to contact and break the saccharide gelling agent.
A method comprising:
- introducing a downhole fluid composition into a wellbore, the composition comprising:
- an aqueous phase having a saccharide gelling agent,
- a second phase having an oxidative breaker dissolved in a sequestering agent, the sequestering agent being hydrocarbon miscible and inert to oxidation by the oxidative breaker, the sequestering agent being selected from group of mineral oils, natural oils, C2-C40 alkanes, synthetic oils, waxes, and mixtures thereof, and wherein the oxidative breaker is dissolved in the sequestering agent,
- and wherein the composition does not contain a surfactant,
- allowing the delayed breaker composition to contact a hydrocarbon within the wellbore thereby releasing the oxidative breaker;
- allowing the oxidative breaker to contact and break the saccharide gelling.
Dependencies are inferred from the claim text.