CN1275430A - Lignin sulfonate surfactant for oil field, its preparation process and use in tertiary oil recovery - Google Patents

Abstract

The alkali paper-making waste liquor-lignin and phenols are used as raw material, and the condensation reaction method is adopted to make modification and solfonation of lignin to obtain modified lignosulfonate, and the surface and interface properties of said lignosulfonate can be greatly raised. Said lignosulfonate can be compounded with alkyl solfonate surfactant, it possesses good cooperative effect, and can be combined with crude oil to form an ultra-low interfacial tension with 10 (-3) mN/m order in a wide active agent alkali and salinity range, and its laboratory oil displacement test shows that the oil displacement efficiency can be raised by above 15% OOIP as compared with water drive, and as compared with simpel alkyl sulfonate, its cost can be saved by 30-60%. It can be used as compounding agent in tertiary oil recovery.

Description

Lignosulfonate surfactant for oil field, preparation method thereof and application thereof in tertiary oil recovery

The invention relates to a surfactant for oil field (oil displacement), its preparation and application, in particular to an alkylbenzene sulfonate surfactant for oil field, its preparation method and its application as a compound agent in tertiary oil recovery.

When the oil field enters a high water-content oil production stage, in order to further improve the oil extraction efficiency and meet the requirements of industrial production, the tertiary oil extraction technology plays an important role in ensuring the stability and high yield of the oil field. Around tertiary oil recovery technology, the ternary combination flooding method has been widely adopted and achieves good effects. At present, various matching technologies of the technology become mature, but the cost is further reduced, so that the economic clearance of the ternary combination flooding is a main public target of the technology, and the development of novel, efficient and cheap oil displacement agents is urgent.

Lignin is a by-product produced in paper making, and is usually discharged in the form of waste liquid, which is not only a waste of resources, but also a certain pollution to the environment. Therefore, the method has certain economic and social benefits for fully utilizing the waste water. The annual production of paper pulp in China is more than 600 million tons, wherein the alkaline papermaking accounts for 70-75%, so that the alkali lignin has wide sources and low price and can meet the requirement of tertiary oil recovery to a certain extent.

The invention aims to provide a novel, efficient and low-cost lignosulfonate surfactant which can be applied to oil fields;

another object of the present invention is to provide a simple and practical method for preparing the above lignosulfonate surfactant;

the invention also aims to provide the application of the lignosulfonate surfactant as a compound agent in the ternary combination flooding in tertiary oil recovery.

In order to achieve the purpose of the invention, the invention provides a modified lignosulfonate.

The conventional lignosulfonate is the most commonly used surfactant, but because of its poor surface activity, it is mainly used as a dispersant for liquid-solid dispersion systems, and usually, the surface tension of its aqueous solution is about 50mN/m, and the critical micelle concentration is high. For these reasons, it is difficult to reduce the oil-water interfacial tension by using a common lignosulfonate, and it is necessary to modify the lignosulfonate. In view of the fact that lignosulfonates have too high a water solubility, lipophilic components are introduced into the structure.

Lignin has the following structural units:

because of the existence of the phenolic hydroxyl, not only the hydrogen on the hydroxyl is very active, but also the ortho-position and para-position of a benzene ring become active under the action of the hydroxyl, so long-carbon chain alkyl can be introduced by alkylation of the phenolic hydroxyl; alkyl groups may also be introduced by the Mannich reaction; the alkyl group may also be introduced indirectly by introducing an alkylphenol by a condensation reaction.

Their chemical reaction is as follows:

(1) an alkylation method:

(2) mannich reaction method:

(3) condensation reaction method:

the modified lignosulfonate prepared by the three methods can greatly improve the surface activity of the lignosulfonate. But the alkylation method (1) has long route and high cost, the Mannich reaction method (2) has higher price of aliphatic amine and still higher cost, and the condensation reaction method (3) has better industrial prospect, and after production, the sale price of the product can be controlled within the specified price.

Based on the above inventive idea, the following technical scheme is proposed:

the invention is firstly a lignosulfonate surfactant prepared by the following method, which comprises the following steps:

a) taking lignin, phenol and formaldehyde as raw materials;

b) condensation, the three raw materials are subjected to condensation reaction for 2 to 5 hours at the temperature of 100 ℃ and 150 ℃;

c) sulfonation-sodium sulfite is continuously added to sulfonate the condensation product at the temperature of 140 ℃ and 155 ℃ for 1-4 hours;

d) drying-filtering the sulfonated product, and drying at 70-90 deg.C to obtain the final product.

The technical scheme of the invention also comprises: the method for preparing the lignosulfonate surfactant comprises the following steps of:

a) taking lignin, phenol and formaldehyde as raw materials;

b)condensation, the three raw materials are subjected to condensation reaction for 2 to 5 hours at the temperature of 100 ℃ and 150 ℃;

c) sulfonation-sodium sulfite is continuously added to sulfonate the condensation product at the temperature of 140 ℃ and 155 ℃ for 1-4 hours;

d) drying-filtering the sulfonated product, and drying at 70-90 deg.C to obtain the final product.

In the above production method, the phenol in the step a) is C₆-C₁₀The alkylphenol of (1).

In the above production method, the phenol in the step a) is preferably nonylphenol.

In the above preparation method, the condensation reaction temperature in step b) is 120-.

In the above production method, the condensation reaction time in the step b) is preferably controlled to 3 hours.

In the above preparation method, the sulfonation temperature in step c) is 150 ℃, the sodium sulfite concentration is 4% (wt), and the molar ratio is 1.05: 1.

In the above preparation method, the drying temperature in step d) is preferably 70-90 ℃.

The technology of the invention further comprises the application of the lignosulfonate surfactant as a compound agent in tertiary oil recovery.

The invention comprises the following figures:

FIG. 1 is a block diagram of a process for preparing a lignosulfonate in accordance with the present invention;

FIG. 2 is a interfacial tension curve for the formulation of lignosulfonate with alkylbenzenesulfonate in accordance with the present invention.

The technical contents of the present invention and the significant technical effects brought by the technical contents will be described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

According to the scheme shown in FIG. 1, 150 kg of sodium sulfite was added to a plurality of water, and stirred well until it was completely dissolved, and then 700 kg of lignin was gradually added thereto and stirred for 1 hour. 140 kg of 37% formaldehyde was slowly added dropwise thereto, and the mixture was stirred for 10 minutes. Thereafter, 70 kg of nonylphenol was added and stirred for 10 minutes. The mixed reaction solution was introduced into a 100L autoclave, heated in an oil bath, and reacted for 3 hours at a temperature of 130 ℃. After that, filtration and drying at 80 ℃ for 6 hours gave about 1 ton of the product lignosulfonate. Example 2

The lignosulfonate was prepared in the same manner as in example 1, except that the reaction temperature of the raw materials in the autoclave was controlled at 110 ℃ for 5 hours. Example 3

The lignosulfonate was prepared in the same manner as in example 1, except that the reaction temperature of the raw materials in the autoclave was controlled at 150 ℃ for 2 hours. Example 4

The procedure of example 1 was repeated, except that the amount of sodium sulfite was 150 kg, the amount of lignin was 700 kg, 686 kg of nonylphenol and 140 kg of formaldehyde were added, to obtain lignosulfonate.

Example 5

The procedure of example 1 was repeated, except that octylphenol was used instead of the phenol compound in an amount of 655 kg, to obtain lignosulfonate in the same manner as in example 1. Example 6

The procedure of example 1 was repeated, except that heptol was used in an amount of 610 kg instead of the phenol-based substance, to obtain lignosulfonate in the same manner as in example 1. Example 7

The same procedure as in example 1 was repeated except that the lignin used was wood pulp alkali lignin, and the waste liquid from the paper mill was treated and then charged into the reactor, to obtain lignosulfonate in the same manner as in example 1.

The above implementationThe example product, calculated, costs about 0.3 ten thousand yuan/ton. The product is compounded with other active agents to form 10^-3The ultra-low interfacial tension (the experimental apparatus is a Model-500 type rotary drop interfacial tension apparatus produced by the American university of Texas) with the mN/m order of magnitude is used for an oil displacement test after being compounded, can achieve higher recovery ratio and meet the application requirement of the invention. Example 8

Application of lignosulfonate as compounding agent in tertiary oil recovery

The lignosulfonate (WNS) produced in the above example and alkylbenzene sulfonate (ORS) were compounded in a ratio of 3: 1, and the fixed NaOH concentration in the system was 1.2 wt%. FIG. 2 is a tableWhen the concentration of the active agent is 0.6 wt%, the system can form 10 with Daqing crude oil^-3-10^-4Ultra-low interfacial tension of the order of mN/m. Meanwhile, as can be seen from fig. 2, the interfacial tension effect of the WNS/ORS-3: 1 compound system is obviously superior to that of a single ORS active agent system, which indicates that the WNS product and ORS have better synergistic effect.

The product of the invention is subjected to an indoor natural core oil displacement experiment, the method is to perform an indoor oil displacement experiment of a lignosulfonate composite system on Daqing naturalcores with the diameter of 2.5cm multiplied by 10cm, and the experimental result is shown in table 1. It can be seen from table 1 that the oil displacement efficiency is improved by more than 15% (OOIP) compared with water flooding, wherein the product oil displacement experimental result of the WNS and ORS composite system of example 7 is improved by 20.00% (OOIP) compared with water flooding, which indicates that the two active agents have higher synergistic effect and the composite system has better compatibility with Daqing oil water.

TABLE 1 indoor oil displacement test results

	Active agent Total concentration of (wt% commercial product)	Comparative example	NaOH Concentration of (wt％)	Polymer and method of making same Concentration of (ppm)	Follow-up slug Concentration of Polymer (ppm)	Specific water flooding lifter High recovery ratio (％OOIP)
							Example 1	0.6	WNS∶ORS＝3∶1	1.2	1200	800	16.27
Example 4	0.8	WNS∶ORS＝3∶1	1.2	1200	800	18.32
							Example 5	0.6	WNS∶ORS＝3∶1	1.2	1800	800	18.90
Example 7	0.8	WNS∶ORS＝3∶1	1.2	1800	800	20.00

According to the invention, although the single industrial lignosulfonate can not form ultra-low interfacial tension with Daqing crude oil, the lignosulfonate can generate better synergistic effect with a plurality of active agents, particularly with alkylbenzene sulfonate surfactants, and can form 10 with the Daqing crude oil within a wider range of the active agents, alkali and mineralization degree^-3The ultra-low interfacial tension of mN/m order of magnitude, the indoor oil displacement experimental result shows that the oil displacement efficiency is improved by 15 percent OOIP compared with water displacement, and the oil displacement efficiency is 30 to 60 percent saved when being the same as the oil displacement efficiency of singly using ORS-41. If the cost is the same, the recovery ratio can be improved by 3-5 percent (OOIP).

Claims (8)

1. A lignosulfonate surfactant having a molecular weight of 380-500 prepared by a method comprising the steps of;

a) taking lignin, phenol and formaldehyde as raw materials;

b) condensation, the three raw materials are subjected to condensation reaction for 2 to 5 hours at the temperature of 100 ℃ and 150 ℃;

c) sulfonation-sodium sulfite is continuously added to sulfonate the condensation product at the temperature of 140 ℃ and 155 ℃ for 1 to 4 hours;

d) drying-filtering the sulfonated product, and drying at 70-90 deg.C to obtain the final product.

2. The lignosulfonate surfactant according to claim 1, wherein the phenol in step a) of the preparation method is C₆-C₁₀The alkylphenol of (1).

3. The lignosulfonate surfactant according to claim 1, wherein the phenol in step a) of the preparation method is nonylphenol.

4. The lignosulfonate surfactant as claimed in claim 1, wherein the condensation reaction temperature in step b) of the preparation method is 120-130 ℃ and the reaction time is controlled to be 3 hours.

5. The lignosulfonate surfactant according to claim 1, wherein in step c) of the preparation method the sulfonation temperature is 150 ℃, the sodium sulfite concentration is 4% (wt) andthe molar ratio is 1.05: 1.

6. The lignosulfonate surfactant according to claim 1, wherein the drying temperature in step d) of the preparation method is 70-90 ℃.

7. A method of preparing a lignosulfonate surfactant according to claim 1, comprising the steps of:

a) taking lignin, phenol and formaldehyde as raw materials;

b) condensation, the three raw materials are subjected to condensation reaction for 2 to 5 hours at the temperature of 100 ℃ and 150 ℃;

c) sulfonation-sodium sulfite is continuously added to sulfonate the condensation product at the temperature of 140 ℃ and 155 ℃ for 1-4 hours;

d) drying-filtering the sulfonated product, and drying at 70-90 deg.C to obtain the final product.

8. Use of the lignosulfonate surfactant of claim 1 as a combination in enhanced oil recovery.