Lactate esters application in oil exploration

Lactate esters’ application in oil exploration

Lactate esters is a green biological product which was synthesized from pure natural and renewable resources such as corn, has the characteristics of renewable, degradable, high boiling point, low volatility, favorable smell and good biocompatibility. In the oil industry, lactate esters mainly used in two areas: 1) as a kind of chemical additives, lactate esters mixed with other chemicals is used to improve oil recovery rate,  2) as a kind of environmental protection solvent, lactate esters blending with other products is used to clean the oil pipeline.

 

I. Lactate esters improve oil recovery rate

1. Three stages of oil recovery：

Extracting oil from oil layer can be divided into three stages: 1) Primary oil recovery (POR), extracting oil relying on the formation of natural forces, oil recovery rate is below 30%, 2) Secondary oil recovery (SOR), extracting oil using the water injection, gas injection technology to add oil reservoir energy, oil recovery rate can be increased to 40%~50%, 3) Enhanced Oil Recover (EOR), Using physical chemical and biological technology to strengthen the exploitation of remaining reserves, can make the original recovery to 80%~ 85%.

Enhanced Oil Recover (EOR), can be divided into four categories, one is the thermal driving, including steam drive, combustion of oil in-situ, two is miscible driving, including CO2 miscible, hydrocarbon miscible and other inert gases miscible driving, Three is chemical driving, including polymer driving, surfactant driving, alkaline water driving, and concentrated acid injection driving, Four is microbial oil recovery, including biological microorganisms, microbial surfactant driving.

According to the production operation process, oil recovery using chemical agent can be divided into: chemical agent for improving the recovery efficiency, wax and wax remover, chemical agent for fracturing fluid, chemical agent for acidizing fluid, chemical agent for water plugging or "profile", chemical agent for oil well acid-protecting, chemical agent for preventing damage on address.

2. Lactate esters’ application in oil recovery

    Lactate ester is mainly used in the third stage: Enhanced Oil Recover (EOR), is mainly used in the third oil recovery methods, that is, surfactant flooding or concentrated acid injection driving in the chemical driving. Lactate ester may be as a kind of acidizing fluid additive used in conjunction with other chemicals.

3. Actual application steps of lactate ester in oil recovery

Firstly, Injecting temporary plugging agent plug the upper of drilling well.

Second, injecting into strong acid to lower level in order to corrode rock, which will form large channel.

Thirdly, injecting into lactic acid ester to the bottom, lactate ester dissolve into carboxylic acid and water under high temperature high press, 

carboxylic acid gets reaction with calcium and magnesium icon, which can open a lot of small holes.

Acheivement:improve the reservoir permeability and expand the oil drainage area, increase oil production capability. 

Finally,this product degrade into carbon dioxide and water, it is safe and environment friendly. 

 

II. Lactate ester clean oil pipeline

The characteristics of lactate ester as solvent in cleaning industry:

1. Good environmental performance: It’s non-toxic, environmental, biodegradable, washing waste water can be directly discharge to environment.

2. Strong solvent power: Strong solvency in resin, grease and water-soluble dirt.

3. Perfect wetting ability: Good wetting ability on the surface to be cleaned. The surface has good hydrophily after cleaned. It possesses many diverse properties: disperse, emulsify, foam, wetting, solubilizing and so on.

4. Good compatibility: Lactate esters can miscible with water, and has good compatibility with other organic solvent. It can be well combined with other cleaning composition in system.

5. High price ratio: Compared with other organic agent, lactate esters is low loss and cost-effective, and has no adverse effect on the object to be cleaned.

 

III. Lactate esters’ brief introduction

1. Methyl Lactate:  

Description:

Methyl-L-lactate is the methyl ester deriving from lactic acid which is produced

through the bio-fermentation of corn and is featured in high optical purity, 

colorless clear liquid, light characteristic odor, it’s miscible with  most organic 

solvents, and can completely dissolve in water.

 

Product Information:

Trade Name	Methyl lactate
CAS No.	27871-49-4
HS No.	2918110000
Hazard Grade	3 (Packing group III)
Molecular formula	C4H8O3

 

Technical Index 

Item	Standard
Assay(GC)	Min. 99.0%
Optical Purity	Min. 99.5%
color	Max. 50apha
Acid Value	Max. 0.1%
methanol	Max. 0.5%
Water content(Karl fisher)	Max. 0.2%
Density(25 °C)	1.09
Refractive Index(20 °C)	1.410~1.418

 

 

2. Ethyl lactate

Description 

Colorless clear liquid, an ethyl ester of the DL-lactic acid that derives from

bio-fermentation of sugar-like carbohydrate, it has a particular odor that is like rum, fruit and better, it is soluble in most organic solvents, but partly hydrolyzes when mixing with water.

 

Product Information

Trade Name	Ethyl DL-lactate
CAS No.	97-64-3
HS No.	2918110000
Hazard Grade	3 (Packing group III)
Molecular formula	C5H10O3

 

Technical Index 

Item	Standard
Assay(GC)	Min. 99.0%
color	Max. 20apha
Acid Value	Max. 1.0
Ethanol	Max. 0.3
Water content(Karl fisher)	Max. 0.2
Density(25 °C)	1.030~1.038
Refractive Index(20 °C)	1.410~1.420