A foaming agent composition

Abstract

The present invention provides a foaming agent composition, which comprises a biological macromolecule, a main foaming agent, decyl glucoside, and an auxiliary agent comprising one or more of cetearyl glucoside, coconut glucoside, and lauryl glucoside. The foaming agent composition can not only produce foam with a volume 4.7 times that of the original foaming system, but also has a foam liquid separation half-life of more than 17 hours, effectively solving the application shortcomings of current water-based foam agents. At the same time, the composition also has biological affinity and a wide range of material sources, and is environmentally friendly and economical.

Description

Technical Field

[0001] The invention belongs to the technical field of surface chemistry and polymer materials, and in particular relates to a foaming agent composition. Background Art

[0002] The extraction of oil can be divided into three different stages. The first stage is primary oil recovery, in which the natural fluid pressure and rock expansion of the reservoir push the crude oil to the oil well. This method can recover 30% of the crude oil. The next stage is secondary oil recovery. In this method, the oil is transferred to the production well using techniques such as water flooding or pressurized immiscible gas injection, thereby improving the oil recovery rate. However, the extraction of the remaining oil in the reservoir with complex geological structures remains a challenge. To solve this problem, foam has been introduced as a miscible fluid in the application of enhanced oil recovery. Foam has shown great potential in improving the surface sweep efficiency and vertical sweep efficiency, thereby significantly improving the recovery rate of oil and gas reservoirs. Foam is a two-phase system (i.e., flowing bubbles and trapped bubbles) formed by different surfactants and a gas phase (which can be air, N2 or CO2). Physically, the flowing bubbles cause flow resistance, while the trapped bubbles block some flow channels and reduce the relative permeability of the gas. In addition, foam can significantly improve oil washing efficiency by reducing residual oil saturation by using surfactants to reduce water-oil interfacial tension (IFT), that is, reducing IFT to ultra-low values. A large number of experimental measurements have shown that the presence of oil has an adverse effect on the propagation dynamics of foam in porous media. After entering the larger pores and throats in the porous media, the flow resistance of the foam increases due to the Jamin effect, and then it turns to gradually enter the smaller pores and throats with higher oil saturation, thereby improving the recovery factor.

[0003] The basic principle of foam flooding technology is to add a certain amount of foaming agent and foam stabilizer to the injected water, and inject gas and liquid at the same time to make the injected fluid form foam in the underground pores, thereby increasing the viscosity of the injected fluid and preventing gas cross-flow in the formation, thereby generating strong foam sheets in the high permeability area to improve the sweep efficiency of heterogeneous reservoirs. However, the application of foam in porous media still faces some challenges, such as the thermal and mechanical stability of the foam, the optimal surfactant concentration for maximum stability, the interaction mechanism of the foam-oil interface, and the in-situ generation and expansion of the foam. There are three interdependent conditions for foam instability: (1) foam drainage, under the action of gravity, the liquid separates from the bubble surface and is hindered by capillary force and shear stress on the bubble surface; (2) liquid film rupture; (3) gas diffusion between bubbles caused by uneven bubble size distribution. The above problems can be improved by increasing the amount of foaming agent, but it is accompanied by an increase in cost. In addition, the divalent ions in the formation water have a great impact on conventional ionic surfactants, which is mainly reflected in the compression of the molecular double layer, making the dispersion of the surfactant worse and the interfacial activity reduced. Adding a foam stabilizer (or auxiliary agent) other than a foaming agent can improve foam performance. A common practice is to add a polymer to increase the viscosity of the water phase and slow down the liquid precipitation rate through viscosity. The network of the polymer stretched in the solvent water can increase the strength of the liquid film and improve the stability of the foam. However, common polyacrylamide (PAM) polymers have the disadvantages of too large molecular weight, weak hydration ability and shear resistance, and cannot effectively solve the problem of premature foam instability. Summary of the invention

[0004] In view of the above problems, the present invention provides a foaming agent composition having good stability. The technical solution of the present invention is as follows:

[0005] A foaming agent composition, calculated by weight percentage, consists of the following substances:

[0006] Wetting rubber, 20wt% to 40wt%;

[0007] Decyl glucoside, 30 wt% to 50 wt%;

[0008] The total content of Wenlun gum and decyl glucoside is 70wt% to 90wt%;

[0009] The balance is at least one of cetearyl glucoside, coconut glucoside and lauryl glucoside.

[0010] As a specific embodiment of the present invention, the Wenlun glue has a weight average molecular weight of 350000 g / mol to 670000 g / mol. Preferably, the Wenlun glue has a weight average molecular weight of 350000 g / mol to 600000 g / mol, within which range its thermal stability is better, and further preferably, the Wenlun glue has a weight average molecular weight of 500000 g / mol, which has excellent stability.

[0011] As a specific embodiment of the present invention, the content of cetearyl glucoside, coconut glucoside and lauryl glucoside is no more than 20wt%.

[0012] Beneficial effects of the present invention:

[0013] The foaming agent composition provided by the present invention, which includes a nonionic surfactant and a biomacromolecule Wenlun gum, has good dispersibility in oil field injection water, and the foaming system can be directly prepared with oil field injection water. The foaming agent foam stabilization mechanism is as follows: (1) Wenlun gum, as a foam stabilizer, is itself a microbial extracellular secretion, and there are a large number of hydrophilic groups in its molecular structure, which endows Wenlun gum with extremely strong water absorption and water retention; (2) Wenlun gum itself can produce considerable viscosity, which can further reduce the liquid separation rate through viscosity and enhance the strength of the foam film; (3) All nonionic surfactants used in the present invention are alkyl polysaccharides, which have rich hydrophilic groups and can form hydrogen bonds with solvent water and Wenlun gum to produce a stable structure-activity relationship. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A comparison chart of the foam liquid separation half-life and foam volume of each foaming agent composition;

[0015] Figure 2 Microscopic graphs of the foam produced for each foaming agent composition over time;

[0016] Figure 3 This is a solid image of foam produced by the foaming agent composition of Example 1 after stirring at a rotation speed of 3000 rad / min for 60 seconds;

[0017] Figure 4 This is a solid image of foam produced by the foaming agent composition of Example 3 after stirring at a rotation speed of 3000 rad / min for 60 seconds;

[0018] Figure 5 This is a graph showing the change in the half-life of the foaming liquid after the foaming agent composition of Comparative Example 1 is aged at 120° C. for different periods of time;

[0019] Figure 6 This is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Comparative Example 2 is aged at 120° C. for different periods of time;

[0020] Figure 7 This is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Comparative Example 3 is aged at 120° C. for different periods of time;

[0021] Figure 8 This is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Comparative Example 2 is aged at 120° C. for different periods of time;

[0022] Fig. 9 This is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Example 1 is aged at 120° C. for different periods of time;

[0023] Fig.10 is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Example 4 is aged at 120° C. for different periods of time;

[0024] Fig.11 is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Example 2 is aged at 120° C. for different periods of time;

[0025] Fig.12 is a graph showing the change in the foam liquid separation half-life after the foaming agent composition of Example 3 is aged at 120° C. for different periods of time;

[0026] Fig.13 Comparison of the properties of the foams prepared in Examples 3-6 having different percentages of Wenlun gum / decyl glucoside. DETAILED DESCRIPTION

[0027] In order to make the technical solutions and technical advantages of the present invention more clear, the technical solutions in the implementation process of the present invention will be clearly and completely described below in combination with embodiments and drawings.

[0028] The Wenlun glue used in the present invention was purchased from Zhengzhou Kaizhiyu Food Additive Co., Ltd. (industrial grade), decyl glucoside, coconut glucoside, lauryl glucoside and cetearyl glucoside were purchased from Jiangsu Wanqi Biotechnology Co., Ltd. (daily chemical grade, effective content 50%), and the remaining drugs were all industrial grade unless otherwise specified;

[0029] The brine mentioned in the present invention refers to simulated water with a mineralization of 85000 ppm, which is composed of 82000 ppm NaCl, 1500 ppm CaCl2 and 1500 ppm MgCl2. The purpose of configuring the foaming agent composition with simulated water is to make the performance test conditions closer to the application environment.

[0030] Example 1

[0031] The foaming agent composition comprises: about 35 parts by weight of wenan gum with a molecular weight of 600,000 g / mol; about 45 parts by weight of decyl glucoside; about 8 parts by weight of coconut glucoside; about 8 parts by weight of lauryl glucoside and about 4 parts by weight of cetearyl glucoside.

[0032] Example 2

[0033] The foaming agent composition comprises: about 20 parts by weight of Wenlun gum with a molecular weight of 400000 g / mol, about 50 parts by weight of decyl glucoside, about 15 parts by weight of coconut glucoside and about 15 parts by weight of lauryl glucoside.

[0034] Example 3

[0035] The foaming agent composition comprises: about 40 parts by weight of Wenlun gum with a molecular weight of 500000 g / mol, about 50 parts by weight of decyl glucoside, about 8 parts by weight of lauryl glucoside and about 2 parts by weight of cetearyl glucoside.

[0036] Example 4

[0037] The foaming agent composition comprises: about 35 parts by weight of Wenlun gum with a molecular weight of 350,000 g / mol, about 50 parts by weight of decyl glucoside, about 6 parts by weight of lauryl glucoside and about 9 parts by weight of cetearyl glucoside.

[0038] Comparative Example 1

[0039] The foaming agent composition comprises: about 35 parts by weight of 3 million molecular weight polyacrylamide, about 45 parts by weight of decyl glucoside, about 8 parts by weight of coconut glucoside, about 8 parts by weight of lauryl glucoside and about 4 parts by weight of cetearyl glucoside.

[0040] Comparative Example 2

[0041] The foaming agent composition comprises: about 20 parts by weight of wenmeng gum with a molecular weight of 670000 g / mol, about 50 parts by weight of decyl glucoside, about 15 parts by weight of lauryl glucoside and about 15 parts by weight of cetearyl glucoside.

[0042] Comparative Example 3

[0043] The foaming agent composition comprises: about 40 parts by weight of xanthan gum, about 40 parts by weight of decyl glucoside, about 10 parts by weight of coco-glucoside, about 5 parts by weight of coco-glucoside and about 5 parts by weight of lauryl glucoside.

[0044] Comparative Example 4

[0045] The foaming agent composition comprises: about 35 parts by weight of 1 million molecular weight polyacrylamide, about 45 parts by weight of decyl glucoside, about 8 parts by weight of coconut glucoside, about 8 parts by weight of lauryl glucoside and about 4 parts by weight of cetearyl glucoside.

[0046] Comparative Example 5

[0047] The foaming agent composition comprises: about 10 parts by weight of Wenlun gum with a molecular weight of 500000 g / mol, about 50 parts by weight of decyl glucoside, about 8 parts by weight of lauryl glucoside and about 2 parts by weight of cetearyl glucoside.

[0048] Comparative Example 6

[0049] The foaming agent composition comprises: about 35 parts by weight of Wenlun gum with a molecular weight of 350,000 g / mol, about 15 parts by weight of decyl glucoside, about 6 parts by weight of lauryl glucoside and about 4 parts by weight of cetearyl glucoside.

[0050] Test Case

[0051] The test examples mentioned in the present invention all refer to the foam generated by a foaming agent composition solution with a mass concentration of 0.4wt% and a simulated water configuration with a mineralization degree of 85000ppm, composed of 82000ppm NaCl, 1500ppm CaCl2 and 1500ppm MgCl2, after being stirred for 60s at a speed of 3000rad / min using a Waring stirrer.

[0052] Test Example 1 (Comprehensive Foam Performance)

[0053] Please refer to Figure 1 , Figure 1 The foam volume and foam liquid separation half-life of Examples 1-4 and Comparative Examples 1-4 with an effective content of 0.4wt% prepared with saline are shown after stirring for 60s at a speed of 3000rad / min using a Waring stirrer. It can be seen that the foam liquid separation half-life of Comparative Examples 1, 3 and 4 is less than 5h, while the foam liquid separation half-life prepared by Comparative Example 2 and Examples 1-4 containing warm wheel glue is more than 10h, and the liquid separation half-life of the foams of Examples 1-4 provided by the present invention is more than 15h. The foams prepared in Example 3 have the longest foam liquid separation half-life (20h), and the foams prepared in Example 4 have the largest initial foam volume (520mL). The above performance comparison fully illustrates the excellent performance of the foaming agent composition provided by the present invention.

[0054] Test Example 2 (Foam Micromorphology)

[0055] Please refer to Figure 2, Figure 2 The foam particle size change, foam liquid film thickness and foam decay process (from left to right, 0 hours, 2 hours and 6 hours after foaming) of the foam produced by the test examples 1-4 and comparative examples 1-4 with an effective content of 0.4wt% after stirring at a speed of 3000rad / min for 60s are listed and compared. Compared with the faster drainage of the foam in comparative examples 1-4, the decrease in the foam liquid film thickness and the increase in the foam particle size caused by the aggregation, the foam in the examples 1-4 has a slower drainage within 0-6h, a stable foam liquid film thickness and slow bubble aggregation. The above performance comparison fully illustrates that the foaming agent composition provided by the present invention has a strong water retention.

[0056] Test Example 3 (actual foam image)

[0057] Figure 3 The foam entity and the foam decay process of Example 1 with an effective content of 0.4 wt % after stirring for 60 s at a speed of 3000 rad / min using a Waring stirrer are shown. The foam liquid separation half-life is 16.5 h, which is the shortest foam liquid separation half-life among the embodiments provided by the present invention. Figure 1 It can be seen that even as the foaming agent composition providing the shortest liquid separation half-life in the present invention, Example 1 is still much better than Comparative Examples 1-4 in terms of foam stabilization performance.

[0058] Figure 4 The foam entity produced by Example 3 with an effective content of 0.4 wt% after stirring for 60 s at a speed of 3000 rad / min using a Waring stirrer has a foam liquid separation half-life of 20 h. Figure 3 and Figure 4 From the amount of liquid precipitated from the foam 20 h after bubbling, it can be clearly observed that 100 mL of the foam of Example 1 has passed the liquid precipitate half-life, while the foam prepared in Example 3 has just reached the liquid precipitate half-life.

[0059] Test Example 4 (Relationship between Foam Performance and Aging Time)

[0060] Figure 5 The foaming performance of the foaming agent composition solution of Comparative Example 1 with an effective content of 0.4 wt% at 120°C is shown as a function of aging time. The foaming volume is reduced from 370 mL in the unaged state to 227 mL after aging for 33 days, and the foaming performance is greatly reduced. The foam liquid separation half-life is reduced from the initial 1 hour to 0.33 hours (about 20 minutes).

[0061] Figure 6The foaming performance of the foaming agent composition solution of Comparative Example 4 with an effective content of 0.4 wt% at 120°C is shown as a function of aging time. The foaming volume decreases from 400 mL in the unaged state to 195 mL after aging for 33 days, and the foaming performance is greatly reduced. The foam liquid separation half-life is reduced from the initial 3 hours to 0.6 hours.

[0062] Figure 7 The foaming performance of the foaming agent composition solution of Comparative Example 3 with an effective content of 0.4 wt% at 120°C is shown as a function of aging time. The foaming volume decreases from 390 mL in the unaged state to 326 mL after aging for 33 days, and the foam liquid separation half-life decreases from the initial 8 hours to 1.2 hours, with a significant loss in foaming performance.

[0063] Figure 8 The foaming performance of the foaming agent composition solution of Comparative Example 2 with an effective content of 0.4wt% at 120°C is shown. The foaming volume is reduced from 410mL in the unaged state to 355mL after aging for 33 days, and the foam liquid half-life is reduced from the initial 10.5 hours to 5.2 hours, and the foaming performance is greatly reduced. The foaming agent composition of Comparative Example 2 contains Wenlun gum, which is a composition containing biomacromolecules, and its performance is better than that of Comparative Example 3 containing xanthan gum and Comparative Examples 1 and 4 containing polyacrylamide.

[0064] Fig. 9 The figure shows the change of the foam liquid half-life of the foam composition solution of Example 1 with an effective content of 0.4wt% at 120°C with aging time. The foaming volume decreased from 450mL in the unaged state to 411mL after aging for 33 days, with no significant loss, but the foam liquid half-life decreased from the initial 17 hours to 7 hours. Figure 5 and Figure 1 It can be found that the performance of the foaming agent composition of Example 1 after aging for 33 days is still better than that of the foaming agent composition of Comparative Example 1 and the foaming agent composition of Comparative Example 4 under the unaged condition.

[0065] Fig.10 The change of the foam liquid half-life of the foaming agent composition solution of Example 4 with an effective content of 0.4 wt% at 120°C with aging time is shown. The foaming volume is reduced from 520 mL in the unaged state to 435 mL after aging for 33 days, with no significant loss, but the foam liquid half-life is reduced from the initial 18 hours to 7.3 hours.

[0066] Fig.11The change of the foam liquid half-life of the foaming agent composition solution of Example 2 with an effective content of 0.4 wt% at 120°C with aging time is shown. The foaming volume is reduced from 480 mL in the unaged state to 420 mL after aging for 33 days, with no significant loss, but the foam liquid half-life is reduced from the initial 17.5 hours to 8.2 hours.

[0067] Fig.12 The foaming agent composition solution of Example 3 with an effective content of 0.4 wt% at 120°C shows the change of the foaming liquid half-life with aging time. The foaming volume is reduced from 500 mL in the unaged state to 460 mL after aging for 33 days, without a significant loss, but the foaming liquid half-life is reduced from the initial 20 hours to 9.2 hours. The foaming agent composition of Example 3 has the best foaming performance among all comparative examples and examples.

[0068] Test Example 5 (Performance Changes of Decyl Glucoside and Weinlun Gum with Different Weights)

[0069] Fig.13 The foaming performance of the foaming agent composition of Example 3, Example 4, Comparative Example 5 and Comparative Example 6 with an effective content of 0.4wt% is shown. Example 3 and Comparative Example 5 have the same foaming agent composition, but there is a difference in the content of each component. The content of Wenlun gum in Comparative Example 5 is 10wt%, and the total content of Wenlun gum and decyl glucoside is 60wt%, resulting in Comparative Example 5 having a liquid precipitation half-life of only 5h, which is 15h shorter than the liquid precipitation half-life of Example 3. Similarly, in Example 4 and Comparative Example 6, the content of decyl glucoside in Comparative Example 6 is 15wt%, and the total content of Wenlun gum and decyl glucoside is 50wt%, resulting in a foaming volume of 140mL less than that of Example 4, and a half-life of 10 hours less than that of Example 4.

[0070] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A foaming agent composition, characterized in that In terms of mass percentage, it is composed of the following substances: Weinlun rubber, 20wt% to 40wt%, weight average molecular weight 350000 g / mol to 670000 g / mol; Decyl glucoside, 30 wt% to 50 wt%; The total content of Wenlun gum and decyl glucoside is 70wt% to 90wt%; The balance is at least one of cetearyl glucoside, coconut glucoside and lauryl glucoside.

2. The foaming agent composition according to claim 1, characterized in that: The Wenlun rubber has a weight average molecular weight of 350000 g / mol to 600000 g / mol.

3. The foaming agent composition according to claim 2, characterized in that: The Wenlun rubber has a weight average molecular weight of 500000 g / mol.

4. The foaming agent composition according to claim 1, characterized in that The content of cetearyl glucoside, coconut glucoside and lauryl glucoside is not more than 20wt%.

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