A method of optimizing system parameters in a crude unit to reduce corrosion and corrosion byproduct deposition in the crude unit is disclosed and claimed. The method includes measuring or predicting properties associated with the system parameters and using an automated controller to analyze the properties to cause adjustments in the chemical program to optimize the system parameters. Adjusting the system parameters effectively controls corrosion in the crude unit by reducing the corrosiveness of a fluid in the process stream and/or by protecting the system from a potentially corrosive substance. System parameter sensing probes are arranged at one or more locations in the process stream to allow accurate monitoring of the system parameters in the crude unit.

The invention relates to a composition for inhibiting corrosion of the upper part (or roof) of a pipeline for conveying wet hydrocarbons, i.e. hydrocarbons comprising a variable amount of water, said composition comprising at least one Amine 1 with vapor pressure greater than or equal to 10 mmHg, and at least one. Amine 2 with vapor pressure greater than or equal to 0.1 mmHg and strictly less than 10 mmHg. The invention also relates to the use of such a composition, and also to the method of inhibiting top-of-line corrosion employing said inhibitor composition.

The invention relates to a composition for inhibiting corrosion of the upper part (or roof) of a pipeline for conveying wet hydrocarbons, i.e. hydrocarbons comprising a variable amount of water, said composition comprising at least one Amine 1 with vapor pressure greater than or equal to 10 mmHg, and at least one. Amine 2 with vapor pressure greater than or equal to 0.1 mmHg and strictly less than 10 mmHg. The invention also relates to the use of such a composition, and also to the method of inhibiting top-of-line corrosion employing said inhibitor composition.

An asphaltene dispersant composition is provided. The composition may contain an alkylphenol copolymer having the following repeating units (A) and (B):

##STR00001##

wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

An asphaltene dispersant composition is provided. The composition may contain an alkylphenol copolymer having the following repeating units (A) and (B):

##STR00001##

wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

A paraffin inhibitor composition that exhibits stable properties at low temperature is provided. The composition may contain, for instance, an alkylphenol copolymer having the following repeating units (A) and (B):

##STR00001##

wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.16-C.sub.40 alkyl.

An alkylphenol copolymer, such as for use in a petroleum composition, is provided. The alkylphenol copolymer has the following repeating units (A) and (B):

##STR00001##

wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

An alkylphenol copolymer, such as for use in a petroleum composition, is provided. The alkylphenol copolymer has the following repeating units (A) and (B):

##STR00001##

wherein, x is an integer from 1 to 200; y is an integer from 2 to 200; R.sub.1 is a straight or branched C.sub.1-C.sub.15 alkyl; and R.sub.2 is a straight or branched C.sub.2-C.sub.40 alkyl, wherein R.sub.2 is different than R.sub.1.

In one embodiment, an alkylphenol copolymer is disclosed wherein the copolymer comprises at least one alkylphenol monomer and the alkylphenol copolymer exhibits the following: an oscillation displacement of greater than 0 at a temperature of 5 C. in a first oscillation temperature sweep and an oscillation displacement in a second oscillation temperature sweep within 25% of the oscillation displacement in the first oscillation temperature sweep at a temperature of 5 C. In a further embodiment, a petroleum composition is disclosed wherein the composition comprises a petroleum source and a macromolecular compound wherein the macromolecular compound exhibits the following: an oscillation displacement of greater than 0 at a temperature of 10 C. in a first oscillation temperature sweep, and an oscillation displacement in a second oscillation temperature sweep within 25% of the oscillation displacement in the first oscillation temperature sweep at a temperature of 10 C.

Methods for making sulfide scavenging compositions are provided. The method comprises reducing a settling velocity of the sulfide scavenging composition in a fluid stream by adjusting the specific gravity of the sulfide scavenging composition to within about fifteen percent or less of the specific gravity of the fluid stream. Sulfide scavengers using the above method are also disclosed. Methods for removing sulfides from fluid streams are also provided. The methods include adding the above sulfide scavengers to fluid streams.