Cross-reference to related application This application claims the benefits of Malaysian

Application No. PI 20093108 filed 27 July 2009.

Field of invention The present invention relates to an improved thermo- chemical formulation that removes organic deposits and prevents the formation of emulsion simultaneously.

Background of the invention

Petroleum or crude oil is a naturally occurring, toxic, flammable liquid that can be found in various geologic formations under the surface of the earth. Crude oil comprises of a series of hydrocarbons such as alkanes, naphtenes, and aromatic compounds as well as phenols, carboxylic acids, and metals. A major fraction of sulfur and nitrogen compounds may be present as well. The carbon number of these components have a range from 1 (methane) to 50 or more (ashphaltenes) .

Petroleum is recovered primarily through oil drilling, where oil wells are drilled into geologic formations to pump out the oil. After the ^' oil is pumped to the surface, the oil is then transported to the refineries. In the refineries, the recovered crude oil is separated, most easily by boiling point, processed and refined into different types of petroleum products and be made into fuels.

Among the challenges faced by the operators in the refineries is the formation of organic deposites, e.g. wax in the pipelines. These organic deposits have a significant effect on oil production efficiency. When warm oil flows through a pipeline with cold walls, wax will precipitate and adhere to the walls. This in turn will reduce the pipeline's cross-sectional area. Without proper counter measures, buildup in pipelines can cause increased pressure, resulting in reduced throughput and efficiency. In more extreme cases, pipelines/processing facilities can plugged up, halt production and lead to potentially huge financial losses.

The formation of emulsion is also one of the major issues associated with both oil-field production and refinery environments . The emulsion may be a natural emulsion due to the presence of naturally occurring emulsifying agents, or the emulsion may be an artifact of the use of additives or recovery processes.

Emulsions are undesirable due to the volume of dispersed water. It can interfere with refining operations, induce corrosion, increase heat capacity and reduce the handling capacity of refining equipments and pipelines. This, in turn will increase the operating and capital costs. Moreover, the characteristics and physical properties of crude oil change significantly upon emulsification. The applicant, in their parent PI 20093108 discloses a method and thermo-chemical system for removing organic deposits in oil well bore, and oil production and transportation tubing and pathway. It uses a fluid formulation or combination of formulations, which can generate sufficient heat and have the capability of dissolving and dispersing the organic deposits in a way that they remain in solution/suspension to prevent their re- deposition and are easily removed.

However, due to the solvent content in the formulations, emulsion formation takes place at the surface facilities. There arises a need to use demulsifiers / emulsion breakers to break the formed emulsions. The emulsion breaking/demulsification process is usually carried out using the following methods: thermal, electrical, mechanical or chemical. Other methods such as filtration, pH adjustment, membrane separation, and heat treatment techniques may also be used. The most common method of demulsification in both oil field and refinery application is the combination of heat and application of chemical design to neutralize and eliminate the effects of emulsifying agents.

However, as stated in "Oilfield Processing of Petroleum: Crude oil", Francis S. Manning, Richard E. Thompson, page 118, there is a possibility of overdosing i.e. adding too much demulsifiers, which can produce new emulsions that are often more difficult to break than the original ones. Also, it is seldom economical to use chemicals alone to break emulsions. Usually electricity or heat is used to reduce the dosage and hence the cost of the chemicals. Furthermore, the formulated chemicals may cause problems to the environment.

In view of that, it may not feasible to use demulsifiers the long run. Also, it will decrease the percentage of recovery from crude oil.

Accordingly, the aim of the present invention is to provide an improved thermo-chemical formulation that removes organic deposits and prevents the formation of emulsion simultaneously.

Summary of the invention The present invention relates to an improved . thermo- chemical formulation that removes organic deposits and prevents the formation of emulsion simultaneously.

The formulation comprises of the combination of two formulations: Active-01 [xylene, acetic acid, Solvessol 150, and linear alkyl benzene sulfonic acid (LABSA) ] and Active-02 _ [Solvessol 150 and N-butyl amine] .

Detailed description of the invention

The present invention provides an improved thermo- chemical formulation that has the ability to remove wax or organic deposits at oil well bore and prevent the formation of emulsion at the crude oil terminal simultaneously. The present invention uses a combination of the action of heat and solvents to remove organic deposits and active ingredients to break emulsion more effectively.

The improved thermo-chemical formulation disclosed herein comprises the combination of at least two formulations. One of the formulations i.e. Active-01, is a solution containing organic acids in organic solvents while the second formulation i.e. Active-02, is a solution containing organic bases in organic solvents.

Organic acids such as linear alkyl benzene sulfonic acids (LABSA) , acetic acid, lactic acid, formic acid, citric acid, oxalic acid and uric acid were found to be suitable for the purpose of the present invention.

Organic bases such as alkyl amines, pyridine,, imidazole, benzimidazole, histidine, phosphazene bases, hydroxides of some organic cations were found to be suitable for the purpose of the present invention. Alkyl amines may include ethyl amine, propyl amine, butyl amine, and pentyl amine.

Organic solvents such as xylene, solvesso 150, pentane, cyclopentane, hexane, cyclohexane, benzene, toluene, 1,4- Dioxane, chloroform, diethyl ether, dichloromethane (DCM) , tetrahydrofuran (THF) , ethyl acetate, acetone, dimethylformamide (DMF) , acetonitrile (MeCN) , dimethyl sulfoxide (DMSO), formic acid, n-butanol, isopropanol (IPA) , n-propanol, ethanol, methanol, acetic acid and water may be used in the present invention. In Active-01 formulation, organic acids and organic solvents are used for application. More preferably, organic acids i.e. LABSA and acetic acid and organic solvents i.e. xylene and solvesso 150 are used in Active-01.

The acceptable concentration of Active-01 used in the present invention is. in a range of about 33% to 83%. More specifically, the optimum concentration of Active-01 is 66%. In Active-01 formulation, the concentration of LABSA, acetic acid, xylene and solvesso 150 is about 11%, 25%, 50% and 14% respectively .

On the other hand, organic bases and organic solvents are applied in Active-02 formulation. More preferably, organic base i.e. N-butyl amine and organic solvent i.e. solvesso 150 are used in Active-02.

The acceptable concentration of Active-02 used in the present invention is in a range of about 16% to 66%. More specifically, the optimum concentration of Active-02 is 33%. In Active-02 formulation, . the concentration of N-butyl amine and. solvesso 150 is about 70% and 30% respectively.

The present invention has been improved compared to PI 20093108 by reducing the percentage of the solvents and adding more active ingredients that can act as an emulsion breaker. Furthermore, no additives such as corrosion inhibitors and surfactants are needed/added in the present invention as compared to the formulations disclosed in PI 20093108. Chemical % Quantity in 1L % Quantity in 1L

Improved Solid Current Solid Buster Buster

(PI 20093108)

Active-01

Xylene (Solvent 2) 50%

Acetic Acid (Organic Acid 25%

2)

Solvesso 150 (Solvent 1) 14% 19.9%

LABSA (Organic Acid 1) 11%. 75%

Sinotherm 4%

Masking Agent (Sinotherm 0.1% NP1214)

Corrosion Inhibitor 1%

(Nevamine AX6004)

Active-02

N-butyl Amine (Organic 70% 79.9% Base)

Solvesso 150 (Solvent 1) 30% 20%

Masking Agent (Sinotherm 0.1%

NP1214)

Table 1 Comparison between- the improved thermo-chemical formulation and the current formulations disclosed in PI 20093108.

In the present invention, the combination of Active-01 and Active-02 formulations gives the effect in removing wax or organic deposits and breaking emulsion simultaneously.

When the two formulations are combined, organic acid in Active-01 reacts with the organic base in Active-02 in organic solvents. More specifically, LABSA in Active-01 reacts with N-butyl amine in Active-02, wherein sufficient heat is formed from the reaction to melt wax and create ester simultaneously. The resulted/formed ester functions as an emulsion breaker. In addition, acetic acid in Active-01 also has the same ability in breaking emulsion. Organic solvents i.e. Sol essol 150 is used to give solvency effect whereas xylene is used to remove asphaltene deposits. By varying the percentage of solvents, the maximum achievable temperature will also vary. In this way, the wax can be melted if the maximum temperature is above the melting point of the wax. As disclosed in the present invention, the combination of Active-01 in concentration of 66% and Active- 02 in concentration of 33% is able to give the maximum temperature i.e. 92 °C in melting wax or organic deposits and create ester to break emulsion simultaneously.

The following examples serve to illustrate the advantages of the present invention.

Comparative Example 1

The comparison between crude oil, emulsion water obtained after TK-38S crude oil was treated different solvents:

Emulsion Stability Test

Solvents Percentage (%)

Crude oil Emulsion Water

Blank Severe

emulsion

Original SDTT 8% 40% 52% (Current Solid Buster

In PI 20093108)

Xylene 4.5% 95.5% —

Mutual Solvent 5.5"5 9-4.5% —

Acetic Acid 1% 99% —

Improved Formulation 30% - 70% The sample applied in the test mentioned above is a TK- 38S emulsion sample. This TK-38S crude oil sample is a biodegraded type of crude with total acid number (TAN) from- about 0.93 to 1.06 mg KOH/g crude oil. According to the result shown above, it is obvious that the improved formulation gave the . highest yield of crude oil and . no emulsion appeared in the oil obtained. Thus, the improved formulation has the best effect in removing organic deposits and breaking emulsion in TK-38S crude oil.

Comparative Example 2

The comparison between crude oil, emulsion and water obtained after TK-38L crude oil was treated with different solvents:

Emulsion Stability Test

Solvents Percentage (%)

Crude oil Emulsion Water

Blank Severe

emulsion

Original SDTT 25% 35% 40% (Current Solid Buster

In PI 20093108)

Xylene 0.5% 99.5% -

Mutual Solvent 0.5% 99.5% -

Acetic Acid 0.5% 99.5% -

Improved Formulation 30% - 70% The sample applied in the test mentioned above is a TK- 38L emulsion sample. This TK-38L crude oil sample is a biodegraded type of crude with total acid number (TAN) of 1.06 mg KOH/g crude oil. According to the result shown above, it is obvious that the improved formulation gave the highest yield of crude oil and no emulsion appeared in the oil obtained. Thus, the improved formulation has the best effect in removing organic deposits and breaking emulsion in TK-38L crude oil .

While specific features have been disclosed and described in this specification, it should be understood that other alternatives, modifications, substitutions, variations and substantial eguivalents might be apparent to those skilled in the art. Such changes and modifications can be made without departing from the scope of the invention to adapt it to various conditions. Thus, the appended claims as filed are intended to embrace all embodiments that fall within the scope of the following claims.