A concrete durability protection method is provided, including following steps: Step one: rinsing the concrete surface; Step two: spraying agent A material or alternately spraying agent B material and agent A material at the wet surface of the concrete; Step three: repeating step two. The beneficial effects of the present invention include: nanoscale active silicate penetrates into the concrete surface layer within a certain depth and reacts with free calcium ions within the concrete to form C—S—H crystalline, thereby improving the compactness of the concrete surface layer within a certain depth, repairing defects in the concrete surface layer within a certain depth, such as the capillary interstices, pores, microcracks, etc., so as to effectively improve the durability of concrete. The unreacted nanoscale active silicate material has permanent activity. It could recover its activity when the concrete absorbs moisture, and continue to react with free calcium ions in the concrete to quickly form C—S—H crystals, realizing the permanent concrete durability protection.

Synthesis and application of an alcohol amine with an extended main carbon chain are provided, belonging to the field of chemical building materials. Under the action of a catalyst, tertiary amine is subjected to a two-step substitution reaction, a hydrolytic reaction and a reducing reaction to obtain a novel alcohol amine (NAA). The novel alcohol amine as provided may have a better grinding aid effect than triethanolamine while is added into cement as a cement grinding aid, and thus has a wide application prospect.

Synthesis and application of an alcohol amine with an extended main carbon chain are provided, belonging to the field of chemical building materials. Under the action of a catalyst, tertiary amine is subjected to a two-step substitution reaction, a hydrolytic reaction and a reducing reaction to obtain a novel alcohol amine (NAA). The novel alcohol amine as provided may have a better grinding aid effect than triethanolamine while is added into cement as a cement grinding aid, and thus has a wide application prospect.

A rheology modifying agent that develops a rheology modifying effect over a wide temperature region is provided. A rheology modifying agent comprising two or more types of compounds represented by the following general formula (1):

##STR00001##

wherein X is a group represented by R.sup.1a or R.sup.1b—[CONH—CH.sub.2CH.sub.2CH.sub.2].sub.n—; R.sup.1a is an alkyl group with 14 or more and 22 or less carbons or an alkenyl group with 14 or more and 22 or less carbons; R.sup.1b is an alkyl group with 13 or more and 21 or less carbons or an alkenyl group with 13 or more and 21 or less carbons; n is an integer of 1 or more and 3 or less; each of R.sup.2 and R.sup.3 is independently an alkyl group with 1 or more and 4 or less carbons or a group represented by —(C.sub.2H.sub.4O).sub.pH; and p is an average number of added moles and a total for R.sup.2 and R.sup.3 is a number of 0 or more and 5 or less,

wherein the two or more types of compounds differ in X in the general formula (1) and

at least one of the two or more types of compounds is a compound in which R.sup.1 of X in the general formula (1) is an alkenyl group.

A rheology modifying agent that develops a rheology modifying effect over a wide temperature region is provided. A rheology modifying agent comprising two or more types of compounds represented by the following general formula (1):

##STR00001##

wherein X is a group represented by R.sup.1a or R.sup.1b—[CONH—CH.sub.2CH.sub.2CH.sub.2].sub.n—; R.sup.1a is an alkyl group with 14 or more and 22 or less carbons or an alkenyl group with 14 or more and 22 or less carbons; R.sup.1b is an alkyl group with 13 or more and 21 or less carbons or an alkenyl group with 13 or more and 21 or less carbons; n is an integer of 1 or more and 3 or less; each of R.sup.2 and R.sup.3 is independently an alkyl group with 1 or more and 4 or less carbons or a group represented by —(C.sub.2H.sub.4O).sub.pH; and p is an average number of added moles and a total for R.sup.2 and R.sup.3 is a number of 0 or more and 5 or less,

wherein the two or more types of compounds differ in X in the general formula (1) and

at least one of the two or more types of compounds is a compound in which R.sup.1 of X in the general formula (1) is an alkenyl group.

The present application provides a gas-generating aqueous fluid containing a gas-generating compound like an azo compound, and an organic amine like a primary, secondary or tertiary amine, a hydrazine, a hydrazide, or a semicarbazide. The aqueous fluid may also a viscosifier, and a foaming surfactant. The present application also provides a method of using the gas-generating composition to modulate density of a wellbore fluid for use in downhole applications. The method optionally includes adding an oxidizer to the wellbore fluid.

The present application provides a gas-generating aqueous fluid containing a gas-generating compound like an azo compound, and an organic amine like a primary, secondary or tertiary amine, a hydrazine, a hydrazide, or a semicarbazide. The aqueous fluid may also a viscosifier, and a foaming surfactant. The present application also provides a method of using the gas-generating composition to modulate density of a wellbore fluid for use in downhole applications. The method optionally includes adding an oxidizer to the wellbore fluid.

Disclosed is a method for using a secondary or tertiary alkanolamine for grinding cement, the method including: forming an inorganic acid salt of the alkanolamine; and adding the salified alkanolamine to a grinder.

Disclosed is a method for using a secondary or tertiary alkanolamine for grinding cement, the method including: forming an inorganic acid salt of the alkanolamine; and adding the salified alkanolamine to a grinder.

Sealing composition for plugging and abandoning a wellbore and methods of plugging and abandoning a wellbore are disclosed. Embodiments of a method for plugging and abandoning a wellbore may include introducing a sealing composition into a wellbore and curing the sealing composition to form a plug. The sealing composition may include from 1 weight percent to 20 weight percent of a curing agent, based on the total weight of the composition, and from 20 weight percent to 97 weight percent of an epoxy resin system, based on the total weight of the composition. The epoxy resin system may include an epoxy resin having the formula (OC.sub.2H.sub.3)—CH.sub.2—O—R.sup.1—O—CH.sub.2—(C.sub.2H.sub.3O), where R.sup.1 is a linear or branched hydrocarbyl having from 4 to 24 carbon atoms; and a reactive diluent having the formula R—O—CH.sub.2—(C.sub.2H.sub.3O), where R is a hydrocarbyl having from 12 to 14 carbon atoms.