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US 5,401,786 AGranted
Additive composition for oil well cementing formulations
AssigneeBASF SE
InventorSridhar Gopalkrishnan
Life of this patent
Estimating the term…
Abstract
An oil and gas well cementing composition has styrene/butadiene latex and a combination of nonionic and anionic surfactants for improved physical properties, especially fluid loss.
Claims23
an oil and gas well cementing composition consisting essentially of:
- a) cement;
- b) styrene/butadiene latex in an amount of from about 5% to about 30% by weight of said cement;
- c) from about 0.05% to about 2% by weight of a nonionic surfactant stabilizer additive which is an alkylphenol ethoxylate of the following formula:
- R--C.sub.6 H.sub.5 --[CH.sub.2 --CH.sub.2 --O].sub.n H
- wherein R is butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl, said alkylphenol ethoxylate having a molecular weight of from about 1000 to about 3000 such that n equals from about 25 to about 50;
- d) from about 0.01% to about 2% by weight of at least one anionic surfactant stabilizer additive selected from the group consisting of polyacrylic acid homopolymer consisting of repeat units of the formula:
- ##STR3## wherein x is an alkali metal or hydrogen, and n is a number such that the molecular weight of said homopolymer is from about 1000 to about 250,000;
- and
- e) water in an amount such that the total quantity of water is from about 30% to about 60% by weight of said cement, and wherein
- said composition has a fluid loss of less than about 60 mL/30 minutes.
7 more elements
An aqueous oil and gas well cementing composition consisting essentially of:
- cement;
- a styrene/butadiene latex in an amount of from about 5% to about 30% by weight of said cement;
- water in an amount from about 30% to about 60% by weight of said cement;
- and
- a stabilizer package consisting essentially of a nonionic component and an anionic component, wherein
- (i) said nonionic component is present from about 0.05% to about 2% by weight and is a nonionic octylphenol ethoxylate having a weight average molecular weight of from about 1500 to about 2200, and having between about 30 to about 40 moles of ethylene oxide per mole of octylphenol;
- and wherein
- (ii) said anionic component is present from about 0.01% to about 2% by weight and is a polyacrylic acid homopolymer consisting
- of repeat units of the formula:
- ##STR4## wherein x is an alkali metal or hydrogen, and n is a number such that the weight average molecular weight of said polyacrylic acid homopolymer is about 15,000;
- and wherein
- said stabilizer package is present in an amount to impart low fluid loss characteristic to said composition of less than 60 mL/30 minutes.
9 more elements
Dependencies are inferred from the claim text.