# US 11,441,367 B2 · Direct emulsions and methods of use > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,367 B2 - Document ID: US11441367B2 - Status: Granted - Kind: B2 - Application number: 15/952,137 - Filed: 2018-04-12 - Published: 2018-10-18 - Granted: 2022-09-13 - Earliest claimed: 2017-04-12 - Assignees: Schlumberger Technology Corporation - Applicants: M-I L.L.C. - Inventors: Carlos Rodriguez - Web page: https://patentgrep.com/patent/US11441367B2 ## CPC - E21B 21/003: {Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138)} - C09K 8/032: {Inorganic additives} - C09K 8/05: containing inorganic compounds only, e.g. mixtures of clay and salt - C09K 8/265: {containing inorganic additives} - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract A method comprising drilling through a plurality of differing zones of a subterranean formation using a drilling fluid comprising a non-oleaginous continuous phase, an oleaginous discontinuous phase and at least a first salt dissolved into the non-oleaginous continuous phase. The amount of the at least first salt dissolved into the non-oleaginous continuous phase is maintained such that a density of the drilling fluid varies by no more than 10% while drilling through the plurality of zones. ## Claims ### Claim 1 A method comprising: drilling through a plurality of differing zones of a subterranean formation using a drilling fluid comprising: a non-oleaginous continuous phase in an amount from 40 vol % to 95 vol %; an oleaginous discontinuous phase in an amount from 5 vol % to 60 vol %; a saponite clay; a surfactant in an amount from 0.1 wt % to 8.0 wt %; and at least one first salt dissolved into the non-oleaginous continuous phase, wherein an amount of the at least one first salt dissolved into the non-oleaginous continuous phase is maintained such that a density of the drilling fluid varies by no more than 10% while drilling through the plurality of differing zones, the at least one first salt is selected from a group consisting of sodium chloride, calcium chloride, potassium chloride, sodium formate, potassium formate, cesium formate, sodium bromide, potassium bromide, calcium bromide, zinc bromide, zinc chloride, calcium nitrate, potassium acetate, calcium sulfate dehydrate, and combinations thereof, and a density of the drilling fluid ranges from about 8.0 ppg to about 11.0 ppg. ### Claim 2 (depends on 1) The method of claim 1, wherein the non-oleaginous continuous phase is an aqueous phase selected from the group consisting of fresh water, sea water, brine, and mixtures thereof. ### Claim 3 (depends on 2) The method of claim 2, wherein the non-oleaginous continuous phase is substantially saturated with the at least one first salt. ### Claim 4 (depends on 1) The method of claim 1, wherein the oleaginous discontinuous phase is selected from the group consisting of natural and synthetic oils. ### Claim 5 (depends on 1) The method of claim 1, wherein at least one zone of the subterranean formation comprises at least one second salt, wherein the at least one first salt and the at least one second salt are the same salt. ### Claim 6 (depends on 1) The method of claim 1, wherein the subterranean formation comprises swellable clay. ### Claim 7 (depends on 1) The method of claim 1, wherein drilling through the plurality of differing zones of the subterranean formation occurs without changing the drilling fluid used during the drilling. ### Claim 8 (depends on 1) The method of claim 1, wherein drilling through the plurality of differing zones of the subterranean formation occurs without running a casing into an upper zone. ### Claim 9 (depends on 1) The method of claim 1, wherein the at least one salt is sodium chloride and present in the drilling fluid at a concentration of 60.67 lb/bbl to 62.87 lb/bbl. ### Claim 10 A method comprising: drilling into at least an upper zone of a subterranean formation having at least one first salt therein with a drilling fluid comprising: a non-oleaginous continuous phase in an amount from 40 vol % to 95 vol %; an oleaginous discontinuous phase in an amount from 5 vol % to 60 vol %; a saponite clay; a surfactant in an amount from 0.1 wt % to 8.0 wt %; and at least one second salt dissolved into the non-oleaginous continuous phase, wherein, during the drilling, an amount of the at least one second salt dissolved into the non-oleaginous continuous phase is maintained such that a density of the drilling fluid varies by no more than 10% during the drilling, the non-oleaginous continuous phase is an aqueous phase, an amount of the at least one second salt dissolved in the aqueous phase is up to 4 wt % of saturation, the at least one second salt is selected from the group consisting of sodium chloride, calcium chloride, potassium chloride, sodium formate, potassium formate, cesium formate, sodium bromide, potassium bromide, calcium bromide, zinc bromide, zinc chloride, calcium nitrate, potassium acetate, calcium sulfate dehydrate, and combinations thereof, and a density of the drilling fluid ranges from about 8.0 ppg to about 11.0 ppg; and drilling into at least one selected from an intermediate zone and a lower zone of the subterranean formation using the drilling fluid. ### Claim 11 (depends on 10) The method of claim 10, wherein the aqueous phase is selected from the group consisting of fresh water, sea water, brine, and mixtures thereof. ### Claim 12 (depends on 10) The method of claim 10, wherein the at least one first salt and the at least one second salt are the same salt. ### Claim 13 (depends on 10) The method of claim 10, wherein the at least one selected from the intermediate zone and the lower zone of the subterranean formation has a lower pressure than the upper zone. ### Claim 14 (depends on 10) The method of claim 10, wherein drilling through the at least one selected from the intermediate zone and the lower zone occurs without changing the drilling fluid used during the drilling. ### Claim 15 (depends on 10) The method of claim 10, wherein drilling through the at least one selected from the intermediate zone and the lower zone occurs without running a casing into the upper zone. ### Claim 16 A method comprising: drilling into at least an upper zone of a subterranean formation having swellable clays therein with a drilling fluid comprising: a non-oleaginous continuous phase in an amount from 40 vol % to 95 vol %; an oleaginous discontinuous phase in an amount from 5 vol % to 60 vol %; a saponite clay; a surfactant in an amount from 0.1 wt % to 8.0 wt %; and at least one salt dissolved into the non-oleaginous continuous phase, wherein an amount of the at least one salt is selected to be dissolved into the non-oleaginous continuous phase such that a reactivity of the swellable clay is reduced and the at least one salt is selected from the group consisting of sodium chloride, calcium chloride, potassium chloride, sodium formate, potassium formate, cesium formate, sodium bromide, potassium bromide, calcium bromide, zinc bromide, zinc chloride, calcium nitrate, potassium acetate, calcium sulfate dehydrate, and combinations thereof; and drilling into at least one selected from an intermediate zone and a lower zone of the subterranean formation having a lower pressure than the upper zone using the drilling fluid. ### Claim 17 (depends on 16) The method of claim 16, wherein the at least one salt is sodium chloride or potassium chloride. ### Claim 18 (depends on 16) The method of claim 16, wherein drilling through the at least one selected from the intermediate zone and the lower zone occurs without changing the drilling fluid used during the drilling. ### Claim 19 (depends on 16) The method of claim 16, wherein drilling through the at least one selected from the intermediate zone and the lower zone occurs without running a casing into the upper zone.