| 摘要 |
A cement composition for cementing the annulus between a well casing and a borehold comprises:… (a) a hydraulic cement;… (b) water; and… (c) a gas generating composition which is one of the following:… I. a nitrogen gas generating material selected from hydrazine, hydrazine sulfate, carbazide, and any mixture of two or more thereof;… an oxidizing agent selected from hydrogen peroxide, sodium peroxyborate tetrahydrate, sodium peroxyborate monohydrate, potassium dichromate, and any mixture of two or more thereof; and… a reaction rate control material selected from sodium sulfate, calcium sulfate hemihydrate, copper sulfate hemihydrate, copper sulfate, calcium hydroxide, and any mixture of two or more thereof;… II. a nitrogen gas generating material selected from hydrazine, hydrazine sulfate, carbazide, and any mixture of two or more thereof;… an oxidizing agent selected from calcium peroxide, zinc peroxide, or a mixture thereof; and… a reaction rate control material comprising copper sulfate;… III. a nitrogen gas generating material selected from an ammonium salt of an organic or inorganic acid, hydroxylamine sulfate, carbamide, azodicarbonamide, and any mixture of two or more thereof;… an oxidizing agent selected from hydrogen peroxide, sodium peroxyborate tetrahydrate, sodium peroxyborate monohydrate, and any of two or more thereof;… a reaction rate control material comprising copper sulfate;… IV. a nitrogen gas generating material comprising azodicarbonamide;… an oxidizing agent comprising calcium peroxide; and… a reaction rate control material comprising copper sulfate; and… V. any combination of two or more of I, II, III and IV. |
