Methods for wellbore strengthening
AssigneeSchlumberger Technology Corporation
InventorsSteven Young, Aaron Blue, Josh Sheldon
Life of this patent
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Abstract
A wellbore fluid may include an oleaginous fluid forming a continuous phase; a non-oleaginous fluid forming a discontinuous phase; at least one emulsifier stabilizing an emulsion of the non-oleaginous continuous phase within the oleaginous continuous phase; and at least one viscosifier dispersed into the oleaginous continuous phase in a concentration of at least 4 ppb; wherein upon subjecting the wellbore fluid to shear rate of at least 10,000 s−1, the emulsion is disrupted and the non-oleaginous fluid contacts the at least one viscosifier, thereby solidifying the wellbore fluid.
Claims16
A wellbore fluid comprising:
- an oleaginous fluid forming a continuous phase;
- a non-oleaginous fluid forming a discontinuous phase;
- at least one emulsifier stabilizing an emulsion of the non-oleaginous continuous phase within the oleaginous continuous phase;
- at least one viscosifier dispersed into the oleaginous continuous phase in a concentration of at least 4 ppb;
- and
- at least one crosslinker selected from the group consisting of a zirconium salt or an iron salt to crosslink the viscosifier dispersed in the oleaginous continuous phase,
- wherein upon subjecting the wellbore fluid to shear rate of at least 10,000 s−1, the emulsion is disrupted and the non-oleaginous fluid contacts the at least one viscosifier, thereby solidifying the wellbore fluid;
- wherein the wellbore fluid comprises at least one hydratable non-organophillic clay present in a concentration that ranges from 10 pp to 20 ppb.
A method of reducing loss of a wellbore fluid in a wellbore to a formation, the method comprising:
- pumping a wellbore fluid into the wellbore, the wellbore fluid comprising:
- an oleaginous fluid forming a continuous phase;
- a non-oleaginous fluid forming a discontinuous phase;
- at least one emulsifier stabilizing an emulsion of the non-oleaginous continuous phase within the oleaginous continuous phase;
- and
- at least one viscosifier dispersed into the oleaginous continuous phase in a concentration of at least 4 ppb;
- subjecting the wellbore fluid to shear forces generated by pumping the wellbore fluid into the formation through a nozzle in a drill bit, thereby exposing the at least one viscosifier to the non-oleaginous fluid, wherein the wellbore near the drill bit is at a temperature of at least 65.6° C.;
- and
- allowing the wellbore fluid to solidify;
- wherein the wellbore fluid comprises at least one hydratable non-organophillic clay present in a concentration that ranges from 10 pp to 20 ppb.
Dependencies are inferred from the claim text.