Emulsion preventer for completion brines
AssigneeM-I L.L.C.
InventorsChangping Sui, Pawilai Chinwangso, Hui Zhang, Steven Young
Life of this patent
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Abstract
Emulsion-preventing compositions may contain one or more sorbitan esters; and one or more non-ionic surfactants; where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5. Methods may include contacting an emulsion with a treatment fluid, the treatment fluid containing one or more sorbitan esters and one or more non-ionic surfactants, where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5; and separating the emulsion into an aqueous phase and an oleaginous phase.
Claims14
A method comprising:
- emplacing a wellbore fluid into a wellbore, the wellbore fluid comprising:
- a base fluid;
- one or more sorbitan esters;
- and
- one or more nonionic surfactants;
- wherein the volumetric ratio of the one or more sorbitan esters to the one or more nonionic surfactants is in the range of 1:1 to 1:5,
- wherein the wellbore fluid meets at least two of the following three criteria:
- (1) Biodegradation
- a) >60% in 28 days as measured by OECD 306 or any other OSPAR-accepted marine protocols,
- b) or in the absence of valid results for such tests:
- i. >60% in 28 days as measured by OECD 301B, 301C, 301D, 301F, 310, Freshwater BODIS or
- ii. >70% in 28 days as measured by OECD 301A, 301E;
- (2) Bioaccumulation
- a) a bioconcentration factor of less than 100;
- b) log Pow≤3 and molecular weight>700, or
- c) if the conclusion of a weight of evidence expert judgment under Appendix 3 of OSPAR Agreement 2008-5 is positive;
- and
- (3) Aquatic Toxicity
- a) LC50>10 mg/l or EC50>10 mg/l.
A method comprising:
- contacting an emulsion with a treatment fluid, the treatment fluid comprising:
- one or more sorbitan esters, and
- one or more nonionic surfactants,
- wherein the volumetric ratio of the one or more sorbitan esters to the one or more nonionic surfactants is in the range of 1:1 to 1:5;
- and
- separating the emulsion into an aqueous phase and an oleaginous phase,
- wherein the treatment fluid meets at least two of the following three criteria:
- (1) Biodegradation
- a) >60% in 28 days as measured by OECD 306 or any other OSPAR-accepted marine protocols,
- b) or in the absence of valid results for such tests:
- i. >60% in 28 days as measured by OECD 301B, 301C, 301D, 301F, 310, Freshwater BODIS or
- ii. >70% in 28 days as measured by OECD 301A, 301E;
- (2) Bioaccumulation
- a) a bioconcentration factor of less than 100;
- b) log Pow≤3 and molecular weight >700, or
- c) if the conclusion of a weight of evidence expert judgment under Appendix 3 of OSPAR Agreement 2008-5 is positive;
- and
- (3) Aquatic Toxicity
- a) LC50>10 mg/l or EC50>10 mg/l.
A method, comprising:
- emplacing a wellbore fluid into a wellbore, the wellbore fluid comprising:
- a base fluid;
- a surfactant package comprising:
- one or more sorbitan esters present in the surfactant package in an amount ranging from about 5 to about 50 vol % of the surfactant package;
- and
- one or more nonionic surfactants present in the surfactant package in an amount ranging from about 50 to about 95 vol % of the surfactant package, the one or more nonionic surfactants comprising at least an alkyl glycoside of the general formula:
- where X is a number from 1 to 4;
- and Y ranges from 4 to 25.
Dependencies are inferred from the claim text.