Ultrahigh-salinity-resistant foam scrubbing agent for deep coal-bed gas well as well as preparation method and application of foam scrubbing agent

Abstract

The invention discloses an ultrahigh-salinity-resistant foam scrubbing agent for a deep coal-bed gas well as well as a preparation method and application thereof, and relates to the technical field of oil-gas field development. The foam scrubbing agent is prepared from the following raw materials: 10%-20% of dodecyl amide propyl dimethyl tertiary amine, 5%-15% of tetradecyl amide propyl dimethyl tertiary amine, 15%-30% of hydrogen peroxide and 35%-70% of pure water. The preparation method comprises the following steps: adding dodecyl amide propyl dimethyl tertiary amine, tetradecyl amide propyl dimethyl tertiary amine and water into a reaction kettle, stirring and heating until the materials are completely dissolved, uniformly stirring, and slowly dropwise adding hydrogen peroxide. And preserving heat for 3 hours, and cooling to 40 DEG C to obtain a finished product. The foam scrubbing agent can be used as an ultrahigh-salinity-resistant foam scrubbing agent for a deep coal-bed gas well, and is good in chemical stability and thermal stability, non-combustible, non-corrosive and convenient to implement.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas field development, and particularly relates to an anti-ultra-high salinity foam drainage agent for deep coalbed methane wells, a preparation method thereof, and an application thereof. Background Art

[0002] Due to the existence of tensile faults in the coal reservoir around the wellbore of deep coalbed methane wells, it is easy to communicate with the aquifer or the water-permeable rock layers at the top and bottom of the coal reservoir. As a result, the water production of the coalbed methane well is too large. During the development of coalbed methane, there is often an excessive liquid production in the gas well, causing the gas well to be flooded, affecting the normal development and production of the gas well. At the same time, the water production from the reservoir has become a key problem restricting the normal production of deep coalbed methane wells.

[0003] Foam drainage gas production is a drainage gas production technology that has developed rapidly and been widely adopted at home and abroad in recent years. It has the advantages of simple equipment, convenient construction, low cost, wide application range, long service life, and does not affect the normal production of gas wells. The principle of foam drainage gas production is: by adding a functional surfactant with foaming ability into the wellbore, a large number of low-density water-containing foams are generated during the vertical flow of the gas-liquid two-phase. A large number of water-containing foams carry the formation water from the bottom of the well to the ground along with the gas flow, improving the vertical liquid-lifting ability of the gas flow to achieve the purpose of drainage gas production.

[0004] When the salinity of the formation water increases, due to the salting-out effect of the surfactant, the foaming and liquid-carrying abilities of the foam drainage agent are greatly reduced, making the foam drainage agent unable to achieve the ideal effect of drainage gas production.

[0005] Currently, most anti-salt and anti-salinity foam drainage agents use traditional betaine surfactants and foam stabilizers for compatibility to improve the foam stability of foam drainage. For example, the components of the salt-tolerant and methanol-resistant foam drainage agent disclosed in Patent CN102212348A are: 20-40% of coconut oil amide propyl betaine, 45-65% of amine oxide, 5-20% of α-olefin sulfonate, 5-15% of triethanolamine, 0.2-2% of fluorocarbon surfactant, and 0-5% of methanol, and its anti-mineral water ability only reaches 180 g / L. The components of the foam drainage agent composition for high salinity drainage gas production and its preparation method and application disclosed in Patent CN106590583A are: 1 part of long-chain polyether nitrogen-containing compound and 0.5-20 parts of α-olefin sulfonate, and it is only applicable to gas wells with a salinity lower than 250 g / L. However, the salinity of the formation water in deep coalbed methane wells is higher than 250 g / L and reaches 300 g / L.

[0006] Therefore, it is necessary to develop a foam drainage agent with strong resistance to high salinity formation water for deep coalbed methane wells. Summary of the Invention

[0007] The present application provides an anti - ultra - high salinity foam drainage agent for deep coalbed methane wells, a preparation method thereof, and an application thereof, so as to solve the technical problem that the existing foam drainage agents cannot be applied to the formation water salinity of deep coalbed methane wells.

[0008] In the first aspect, the present application provides an anti - ultra - high salinity foam drainage agent for deep coalbed methane wells. The raw materials of the foam drainage agent include: dodecylamide propyl dimethyl tertiary amine, tetradecylamide propyl dimethyl tertiary amine, hydrogen peroxide, and pure water.

[0009] Optionally, by weight percentage, the raw materials of the foam drainage agent include:

[0010]

[0011] In the second aspect, the present invention also provides a preparation method of the anti - ultra - high salinity foam drainage agent for deep coalbed methane wells described in the first aspect, including the following steps:

[0012] Mix dodecylamide propyl dimethyl tertiary amine, tetradecylamide propyl dimethyl tertiary amine, and water;

[0013] Heat the mixture to a set temperature. After the mixture melts, add hydrogen peroxide;

[0014] After maintaining the temperature for a set duration, cool down to obtain the anti - ultra - high salinity foam drainage agent for deep coalbed methane wells.

[0015] Optionally, the set temperature is 60°C to 70°C.

[0016] Optionally, adding hydrogen peroxide specifically includes: dropping hydrogen peroxide into the mixture.

[0017] Optionally, the dropping time of hydrogen peroxide is not more than 3.5 h.

[0018] Optionally, the set duration is 3 h.

[0019] Optionally, the cooling specifically includes: cooling down to 40°C.

[0020] In the third aspect, the present invention also provides an application of the anti - ultra - high salinity foam drainage agent for deep coalbed methane wells described in the first aspect. The foam drainage agent is used as an anti - ultra - high salinity foam drainage agent for deep coalbed methane wells.

[0021] Optionally, the foam drainage agent is used as an anti - ultra - high salinity foam drainage agent for deep coalbed methane wells, specifically including: adding the foam drainage agent into the wellbore at a concentration of 0.3% to 1% to effectively drain the high - salinity formation water in the gas well wellbore.

[0022] The above - mentioned technical solution provided by the present invention has the following advantages compared with the prior art:

[0023] The present invention provides an anti - ultra - high salinity foam - discharging agent for deep coal - bed methane wells, a preparation method thereof and an application thereof. The foam - discharging agent has simple components, good chemical stability and thermal stability, is non - flammable, has no corrosion effect, and is convenient to implement. It can be used in deep coal - bed methane wells with formation water salinity within 300 g / L and has a wide application range. Brief Description of the Drawings

[0024] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 A picture for obtaining the drainage half - life of the water sample by using the anti - ultra - high salinity foam - discharging agent for deep coal - bed methane wells provided in Example 3;

[0027] Figure 2 A picture for obtaining the foaming volume of the water sample by using the anti - ultra - high salinity foam - discharging agent for deep coal - bed methane wells provided in Example 3;

[0028] Figure 3 A picture for obtaining the well density of the water sample by using the anti - ultra - high salinity foam - discharging agent for deep coal - bed methane wells provided in Example 3. Detailed Embodiments

[0029] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0030] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0031] In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" specifically refer to the drawing directions in the drawings. Additionally, in the description of the specification of the present application, the terms "including", "comprising", etc. mean "including but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. In this text, "at least one" means one or more, and "multiple" means two or more. "At least one kind", "at least one item (piece) below" or similar expressions refer to any combination of these items, including any combination of single item (piece) or plural items (piece). For example, "at least one item (piece) among a, b, or c", or, "at least one item (piece) among a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0032] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present application can be obtained through market purchase or can be prepared by existing methods.

[0033] In a first aspect, the present application provides a foam drainage aid for deep coalbed methane wells, and the raw materials of the foam drainage aid include:

[0034] Dodecylamidopropyldimethyl tertiary amine, tetradecylamidopropyldimethyl tertiary amine, hydrogen peroxide, and pure water.

[0035] In an alternative embodiment, by weight percentage, the raw materials of the foam drainage aid include:

[0036]

[0037] In a second aspect, based on a general inventive concept, the present invention also provides a method for preparing an anti-ultra-high salinity foam drainage agent for deep coalbed methane wells as described in the first aspect, comprising the following steps:

[0038] Mix dodecylamidopropyldimethyl tertiary amine, tetradecylamidopropyldimethyl tertiary amine and water;

[0039] Heat the mixture to a set temperature, and after the mixture melts, add hydrogen peroxide;

[0040] After maintaining the temperature for a set duration, cool down to obtain the anti-ultra-high salinity foam drainage agent for deep coalbed methane wells.

[0041] In an optional embodiment, the set temperature is 60°C to 70°C.

[0042] In the above embodiment, the set temperature can be selected from 60°C, 62°C, 64°C, 65°C, 67°C or 70°C.

[0043] In an optional embodiment, adding hydrogen peroxide specifically includes: dropping hydrogen peroxide into the mixture.

[0044] In an optional embodiment, the dropping time of the hydrogen peroxide is not more than 3.5 h.

[0045] In an optional embodiment, the set duration is 3 h.

[0046] In an optional embodiment, the cooling specifically includes: cooling down to 40°C.

[0047] In a third aspect, based on a general inventive concept, the present invention also provides an application of the anti-ultra-high salinity foam drainage agent for deep coalbed methane wells as described in the first aspect, and the foam drainage agent is used as an anti-ultra-high salinity foam drainage agent for deep coalbed methane wells.

[0048] In an optional embodiment, the foam drainage agent is used as an anti-ultra-high salinity foam drainage agent for deep coalbed methane wells, specifically including: adding the foam drainage agent into the wellbore at a concentration of 0.3% to 1%, and effectively discharging the high-salinity formation water in the wellbore of the deep coalbed methane well.

[0049] The following further elaborates the present application in combination with specific examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods without specific conditions noted in the following examples are generally determined according to industry standards. If there are no corresponding industry standards, they are carried out according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0050] Example 1

[0051] This example provides a foam drainage aid for deep coalbed methane wells with resistance to ultra-high salinity, and its raw material composition includes:

[0052]

[0053]

[0054] The preparation method specifically includes the following steps:

[0055] Add 100 kg of dodecylamidopropyl dimethyl tertiary amine, 50 kg of tetradecylamidopropyl dimethyl tertiary amine, and 700 kg of water into the reaction kettle, stir and heat to 65 °C. After the raw materials are completely melted, stir evenly and slowly drop 150 kg of hydrogen peroxide.

[0056] The dropping rate of the hydrogen peroxide is controlled to be dropped within 3.5 h. After keeping warm for 3 h, cool down to 40 °C to obtain the foam drainage aid for deep coalbed methane wells with resistance to ultra-high salinity.

[0057] Example 2

[0058] This example provides a foam drainage aid for deep coalbed methane wells with resistance to ultra-high salinity, and its raw material composition includes:

[0059]

[0060] The preparation method specifically includes the following steps:

[0061] Add 150 kg of dodecylamidopropyl dimethyl tertiary amine, 100 kg of tetradecylamidopropyl dimethyl tertiary amine, and 500 kg of water into the reaction kettle, stir and heat to 70 °C. After the raw materials are completely melted, stir evenly and slowly drop 250 kg of hydrogen peroxide.

[0062] The dropping rate of the hydrogen peroxide is controlled to be dropped within 3.5 h. After keeping warm for 3 h, cool down to 40 °C to obtain the foam drainage aid for deep coalbed methane wells with resistance to ultra-high salinity.

[0063] Example 3

[0064] This example provides a foam drainage aid for deep coalbed methane wells with resistance to ultra-high salinity, and its raw material composition includes:

[0065]

[0066] The preparation method specifically includes the following steps:

[0067] Add 200 kg of dodecylamidopropyldimethylamine, 100 kg of tetradecylamidopropyldimethylamine, and 400 kg of water to the reaction kettle. Stir and heat to 65 °C. After the raw materials are completely melted, stir evenly and slowly dropwise add 300 kg of hydrogen peroxide.

[0068] The dropping rate of the hydrogen peroxide is controlled to be added dropwise within 3.5 h. After keeping warm for 3 h, cool down to 40 °C to obtain the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity.

[0069] Use the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity obtained in Examples 1 to 3 to test the self-prepared mineralized water and well water samples. The test process is as follows:

[0070] First, prepare mineralized water with different salinities. The different salinities, their corresponding densities, and the performance tests of Example 3 in mineralized water with different salinities are shown in Table 1:

[0071] Table 1 Densities corresponding to formation water with different salinities and test results of Example 3

[0072] Serial number Water sample salinity <![CDATA[Corresponding density (g / cm 3 )]]> Foaming volume (ml) Drainage half-life (S) Liquid-carrying rate (%) 1 40 g / L 1.034 795 561 92.3 2 80 g / L 1.058 785 560 92.0 3 100 g / L 1.071 785 520 89.8 4 200 g / L 1.162 780 495 86.7 5 250 g / L 1.160 778 470 84.6 6 300 g / L 1.204 765 430 82.7

[0073] Use the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity in Examples 1 to 3 to test the self-prepared high-salinity water sample and the water sample of Well Jishen 8-8 in a certain gas production management area of a certain company. The test results are shown in Tables 2 to 4.

[0074] Table 2 Test data of Example 1 in the water sample of Well Jishen 8-8 and the self-prepared high-salinity water sample

[0075]

[0076] Table 3 Test data of Example 2 in the water sample of Well Jishen 8-8 and the self-prepared high-salinity water sample

[0077]

[0078] Table 4 Test data of Example 3 in the water sample of Well Jishen 8-8 and the self-prepared high-salinity water sample

[0079]

[0080] When using the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity provided in Example 3 to test the water sample of Well Jishen 8-8 in a certain gas production management area of a certain company, the pictures of the water sample are as Figures 1 - 3 shown, where Figure 1 is the picture of the liquid drainage half-life during the test, Figure 2 is the picture of the foaming volume during the test, Figure 3 is the picture of the density of the well water sample during the test.

[0081] In summary, the foam drainage aid for deep coalbed methane wells provided in the present invention has simple composition, good chemical stability and thermal stability, is non-flammable, has no corrosion effect, is convenient to implement, can be used for deep coalbed methane wells with formation water salinity within 300 g / L, and has a wide application range.

[0082] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A foam drainage aid for deep coalbed methane wells, characterized in that, The raw materials of the foam drainage agent include: dodecylamidopropyldimethyl tertiary amine, tetradecylamidopropyldimethyl tertiary amine, hydrogen peroxide and pure water.

2. The foam drainage aid for deep coalbed methane wells according to claim 1, wherein By weight percentage, the raw materials of the foam drainage agent include: Dodecylamidopropyldimethyl tertiary amine 10% - 20% Tetradecylamidopropyldimethyl tertiary amine 5% - 15% Hydrogen peroxide 15% - 30% The balance is pure water.

3. The preparation method of the foam drainage aid for deep coalbed methane wells according to any one of claims 1 to 2, characterized in that, It includes the following steps: Mix dodecylamidopropyldimethyl tertiary amine, tetradecylamidopropyldimethyl tertiary amine and water; Heat the mixture to the set temperature. After the mixture melts, add hydrogen peroxide; After maintaining the set duration, cool down to obtain the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity.

4. The preparation method according to claim 3, characterized in that, The set temperature is 60°C - 70°C.

5. The preparation method according to claim 3, characterized in that, Adding hydrogen peroxide specifically includes: dropping hydrogen peroxide into the mixture.

6. The preparation method according to claim 5, characterized in that, The dropping time of the hydrogen peroxide is not more than 3.5 h.

7. The preparation method according to claim 3, wherein The set duration is 3 h.

8. The preparation method according to claim 3, characterized in that, The cooling specifically includes: cooling down to 40°C.

9. Use of the foam drainage aid for deep coalbed methane wells against ultra-high salinity according to any one of claims 1 to 2, characterized in that, The foam drainage agent is used as the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity.

10. The application according to claim 9, wherein The foam drainage agent is used as the foam drainage agent for deep coalbed methane wells with resistance to ultra-high salinity. Specifically, the foam drainage agent is added to the wellbore at a concentration of 0.3% - 1% to effectively discharge the high-salinity formation water in the wellbore of the gas well.

Images