CN111269703B - Intelligent steering agent for coal bed gas exploitation and preparation method thereof - Google Patents

Abstract

The invention discloses an intelligent steering agent for coal bed gas exploitation and a preparation method thereof, wherein the intelligent steering agent comprises the following components in percentage by weight: 5 to 15 percent of glucosamine hydrochloride, 10 to 20 percent of N-methyl-D-glucosamine hydrochloride, 1 to 20 percent of water-soluble regulator, 0.2 to 0.5 percent of surfactant, 0.1 to 0.2 percent of dispersing mutual solvent, 5 to 20 percent of acrylamide, 1 to 10 percent of N, N-methylene bisacrylic acid amine, 5 to 10 percent of accelerator and 50 to 60 percent of water. The intelligent steering agent is in a liquid state under the ground condition, has low viscosity and good injectability; after the intelligent steering agent is injected into a coal bed, the intelligent steering agent can be subjected to temperature stimulation to change from a liquid state to a solid state under the low-temperature condition of a coal reservoir, the phase change time can be adjusted by adjusting the temperature, other temporary plugging agents are not needed to be added, and the formed solid phase temporary plugging is a non-porous longitudinal plane plugging and a transverse volume plugging, so that the plugging strength is high and no gap exists.

Description

A kind of intelligent steering agent for coalbed methane exploitation and preparation method thereof

technical field

The invention relates to a preparation method of an intelligent steering agent used in coalbed methane temporary blockage diversion, and belongs to the technical field of coalbed methane exploitation.

technical background

At present, the overall progress of the domestic coalbed methane industry is slow. Technical bottlenecks such as efficient development of low-rank coalbed methane, production increase and efficiency improvement in developed areas, and comprehensive development of deep coalbed methane and coal-measure gas have not yet been broken through. Surface coalbed methane wells generally have low and unstable production. The problem that the existing technology is difficult to support the rapid development of the industry still needs to be solved.

At present, there are very few temporary plugging agents used in the temporary plugging and diversion of coalbed methane. They are mainly solid phase particles or fibrous temporary plugging agents under ground conditions. The existing problems are: it is difficult to realize the uniform carrying of the carrier fluid; Pores are blocked by particles, and there are pores between particles, which may be incomplete or impossible to block; it is easy to cause damage to the reservoir, etc. Therefore, combined with the common characteristics of coal reservoirs such as softness, large surface area, strong adsorption, low pressure, and natural fracture system development, a smart steering agent for coalbed methane mining was developed. Liquid state, after being injected into the coal seam, it will change from a liquid state to a solid state due to temperature stimulation, forming a non-porous longitudinal plane blockage and a horizontal volume blockage on the coal seam, and then it can completely change from a solid state to a liquid state under certain temperature and time conditions shape, can flow back smoothly, and is convenient for construction and high in plugging strength.

Contents of the invention

The object of the present invention is to provide an intelligent steering agent for coalbed methane exploitation, the intelligent steering agent is in a liquid state under ground conditions, and changes from a liquid state to a solid state in a coal seam, with controllable phase transition time and high strength , strong pressure bearing capacity, good steering effect, and good application prospects.

Another object of the present invention is to provide a method for preparing an intelligent steering agent, which has a simple preparation process, strong controllability, and is suitable for large-scale production.

The present invention solves its technical problem and adopts the following technical solutions to realize:

The present invention proposes an intelligent steering agent, comprising: 5-15% of glucosamine hydrochloride, 10-20% of N-methyl-D-glucosamine hydrochloride, and 1-20% of water-soluble regulator in terms of weight percentage. 20%, surfactant 0.2～0.5%, dispersing mutual solvent 0.1～0.2%, acrylamide 5～20%, N,N methylene bisacrylamine 1～10%, accelerator 5～10%, water 50～ 60%,

The water-soluble regulator is lactic acid, acetic acid, tartaric acid, malic acid, fumaric acid, etc.;

The surfactant is polyoxyethylene alkylphenol ether, sodium alkylarylsulfonate, sodium dodecylbenzenesulfonate;

The dispersing mutual solvent is isopropanol, ethylene glycol monobutyl ether, sodium oleate, hexenyl bis stearamide;

The accelerator is triethanolamine, formaldehyde, tetramethylthiourea, cinnamaldehyde, p-chlorobenzoic acid, vanillin and the like.

The preparation process of the intelligent steering agent is as follows: first take a certain amount of water, then add glucosamine hydrochloride, N-methyl-D-glucosamine hydrochloride, water-soluble regulator, surfactant, Disperse the mutual solvent, then stir it evenly to make the main agent of the intelligent steering agent; mix acrylamide, N,N methylenebisacrylamide and accelerator in a certain proportion to make the auxiliary agent of the intelligent steering agent.

The on-site pumping method and process of the intelligent steering agent are as follows: the main agent and the auxiliary agent of the intelligent steering agent should be injected separately, the main agent is injected from the higher displacement of the sand mixer, and the auxiliary agent is injected by the small displacement of the pump; according to the fracturing design, Inject the first stage of fracturing fluid to open the first fracture; inject the intelligent steering agent and auxiliary agent according to the required ratio to mix in the wellbore and enter the fracture to form a temporary plug;

Compared with the existing coalbed methane temporary plugging and diverting agent technology, the present invention has the following beneficial effects:

(1) The intelligent steering agent is in a liquid state under ground conditions, with low viscosity and good injectability;

(2) After the intelligent steering agent is injected into the coal seam, it can be stimulated by the temperature to change from a liquid state to a solid state under the low temperature condition of the coal reservoir. The phase change time can be adjusted by adjusting the temperature without adding other temporary plugging agents. Phase temporary blockage is non-porous longitudinal plane blockage and transverse volume blockage, with high blockage strength and no gaps;

(3) The intelligent steering agent can completely liquefy from a solid state to a liquid state under certain temperature and time conditions. The liquefied liquid has low viscosity and is easy to flow back without causing residual damage to the coal seam.

Description of drawings

Figure 1 is the adsorption and desorption curve of coal after soaking in intelligent steering agent.

Detailed ways

Example 1

First take 5g of lactic acid in 69.4g of aqueous solution, then add glucosamine hydrochloride (15g), N-methyl-D-glucosamine hydrochloride (10g), sodium alkylarylsulfonate (0.4 g), isopropanol (0.2g) were stirred and mixed evenly, and reacted under nitrogen protection at 80°C for 6 hours, and the main agent of the intelligent steering agent was prepared; ), triethanolamine (10g) were stirred and mixed evenly, and reacted at 60° C. for 5 hours to prepare the auxiliary agent.

Prepare the prepared intelligent steering main agent and auxiliary agent according to the mass ratio of 100:4, mix them evenly and put them in a 40°C water bath to heat, observe the phenomenon every 1 minute, and record the starting time of curing, the time of complete gelation and curing, and the beginning of liquefaction time and liquefaction rate. The intelligent steering agent under this ratio starts to solidify after 13 minutes, completely changes from a liquid state to a solid state after 26 minutes, starts to liquefy at 60 minutes, and reaches a liquefaction rate of 42.9% at 220 minutes, and completely liquefies in about 60 days.

Example 2

First take 5g of lactic acid in 69.4g of aqueous solution, then add glucosamine hydrochloride (15g), N-methyl-D-glucosamine hydrochloride (10g), sodium alkylarylsulfonate (0.4 g), isopropanol (0.2g) were stirred and mixed evenly, and reacted under nitrogen protection at 80°C for 6 hours, and the main agent of the intelligent steering agent was prepared; ), triethanolamine (10g) were stirred and mixed evenly, and reacted at 60° C. for 5 hours to prepare the auxiliary agent.

Prepare the prepared intelligent steering main agent and auxiliary agent according to the mass ratio of 100:6, mix evenly and put it in a 40°C water bath to heat, observe the phenomenon every 1 minute, and record the starting time of curing, the time of complete gelation and curing, and the beginning of liquefaction time and liquefaction rate. The intelligent steering agent under this ratio starts to solidify after 9 minutes, completely changes from a liquid state to a solid state after 19 minutes, and starts to liquefy at 55 minutes, and the liquefaction rate reaches 50% at 165 minutes, and the liquefaction rate does not increase in the next 30 minutes. In the follow-up observation, it was found that the intelligent steering agent under this ratio was completely liquefied in about 60 days.

Example 3

First take 5g of lactic acid in 69.4g of aqueous solution, then add glucosamine hydrochloride (15g), N-methyl-D-glucosamine hydrochloride (10g), sodium alkylarylsulfonate (0.4 g), isopropanol (0.2g) were stirred and mixed evenly, and reacted under nitrogen protection at 80°C for 6 hours, and the main agent of the intelligent steering agent was prepared; ), triethanolamine (10g) were stirred and mixed evenly, and reacted at 60° C. for 5 hours to prepare the auxiliary agent.

Prepare the prepared intelligent steering main agent and auxiliary agent according to the mass ratio of 100:8, mix them evenly and put them in a 40°C water bath to heat, observe the phenomenon every 1 minute, and record the starting time of curing, the time of complete gelation and curing, and the beginning of liquefaction time and liquefaction rate. The intelligent steering agent under this ratio starts to solidify after 5 minutes, completely changes from a liquid state to a solid state after 11 minutes, and begins to liquefy at 50 minutes. The liquefaction rate reaches 52.6% at 170 minutes and does not increase in the next 20 minutes. In the follow-up observation, it was found that the intelligent steering agent under this ratio was completely liquefied in about 55 days.

Example 4

First take 5g of lactic acid in 69.4g of aqueous solution, then add glucosamine hydrochloride (15g), N-methyl-D-glucosamine hydrochloride (10g), sodium alkylarylsulfonate (0.4 g), isopropanol (0.2g) were stirred and mixed evenly, and reacted under nitrogen protection at 80°C for 6 hours, and the main agent of the intelligent steering agent was prepared; ), triethanolamine (10g) were stirred and mixed evenly, and reacted at 60° C. for 5 hours to prepare the auxiliary agent.

Prepare the prepared intelligent steering main agent and auxiliary agent according to the mass ratio of 100:10, mix them evenly and put them in a 40°C water bath to heat, observe the phenomenon every 1 minute, and record the starting time of curing, the time of complete gelation and curing, and the beginning of liquefaction time and liquefaction rate. The intelligent steering agent under this ratio starts to solidify after 3 minutes, completely changes from a liquid state to a solid state after 7 minutes, and begins to liquefy at 40 minutes. The liquefaction rate reaches 54.2% at 160 minutes and does not increase in the next 20 minutes. In the follow-up observation, it was found that the intelligent steering agent under this ratio was completely liquefied in about 50 days.

Table 1 Record table of solidification and liquefaction experiment of intelligent steering agent at 40°C

Table 2 Example 1 intelligent steering agent liquefaction experiment record table

time (min) Liquefaction rate (%) 60 2.4 90 7.1 100 9.5 110 11.9 120 14.3 130 19 140 21.4 150 23.8 160 28.6 170 31 180 33.3 190 35.7 200 38.1 210 40.5 220 42.9

Table 3 Example 2 intelligent steering agent liquefaction experiment record table

Table 4 Example 3 intelligent steering agent liquefaction experiment record table

time (min) Liquefaction rate (%) 50 4.8 60 9.7 70 23.5 80 33.7 90 35.7 100 38 110 40.1 120 42.5 130 45.8 140 47.9 150 50.2 160 51.3 170 52.6 180 52.6 190 52.6

Table 5 Example 4 intelligent steering agent liquefaction experiment record table

Test case

Select the intelligent diverting agents of test examples 1 to 4, and use a pipeline with a diameter of 5mm to evaluate the pressure bearing capacity of the pipeline. Experimental temperature: 40°C, pipeline length: 30cm, 75cm, 150cm, first heat the pipeline to the corresponding temperature, inject the intelligent steering agent at a displacement of 0.1ml/min, make it solidify in the pipeline, and gradually increase the pressure to a certain value , the solidified solid will flow out, and the pressure value at this time is the pressure bearing capacity of the smart steering agent.

Table 6 Record table of pressure bearing capacity of intelligent steering agent

Test case

The liquefied liquid in Test Example 4 was selected to soak the pulverized coal, and the effect of soaking in the liquefied liquid of the intelligent steering agent on the adsorption and desorption capacity of coal was tested using the automatic adsorption gas content testing system. The experimental results are shown in Figure 1.

It can be found from Table 1 that under the same temperature conditions, with the increase of the main and auxiliary agent ratio of the intelligent steering agent, the initial curing time, complete curing time and initial liquefaction time are gradually shortened, indicating that the phase transition of the intelligent steering agent The time can be adjusted by adjusting the ratio of main and auxiliary agents in the formula; from Table 2 to Table 5, it can be seen that the liquefaction rate of the smart steering agent with the ratio in 4 is about 50% in a short time, and its complete liquefaction The time is 50-60 days, and they can be completely liquefied without any damage to the formation. It can be seen from Table 6 that with the increase of the ratio of the main and auxiliary agents of the intelligent steering agent, its pressure-bearing capacity has a slight increase. The 4 kinds of intelligent steering agents in the pipeline can all withstand the pressure of about 12MPa, and the plugging strength is good; from Figure 1, it can be seen that after being soaked in the liquefaction liquid of the intelligent steering agent, the adsorption curve and desorption curve of coal move slightly downward , indicating that the amount of adsorption and desorption of coal after soaking in the liquefied liquid of the intelligent steering agent decreases slightly, but the reduction is very small, that is, the immersion of the intelligent steering agent in the liquefied liquid has almost no effect on the adsorption and desorption capacity of the pulverized coal.

In summary, a kind of intelligent diverting agent for coalbed methane exploitation provided by the present invention comprises glucosamine hydrochloride, N-methyl-D-glucosamine hydrochloride 1, water-soluble regulator, surface active Agents, dispersing mutual solvents, acrylamide, n,n methylene bisacrylamide, accelerators, etc. are configured as raw materials. It is in a liquid state at room temperature, and begins to change from a liquid state to a solid state at a certain temperature and time. Under the condition of time, it can completely change from a solid state to a liquid state. The liquefied liquid will not cause damage to the coal reservoir, can be flowed back smoothly, and is convenient for construction.

The examples described above are some examples of the present invention, not all examples. The detailed description of the implementation of the invention is not intended to limit the scope of the invention as claimed, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other examples obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Claims (5)

1. An intelligent steering agent for coalbed methane exploitation, characterized in that, by weight percentage, it comprises: 5-15% of glucosamine hydrochloride, 10-15% of N-methyl-D-glucosamine hydrochloride 20%, water-soluble regulator 1-20%, surfactant 0.2-0.5%, dispersing mutual solvent 0.1-0.2%, acrylamide 5-20%, N,N methylenebisacrylamine 1-10%, promoting 5-10% of surfactant, 50-60% of water, and the surfactant is one of polyoxyethylene alkylphenol ether, sodium alkylarylsulfonate and sodium dodecylbenzenesulfonate. 2. A kind of intelligent steering agent for coalbed methane exploitation according to claim 1, characterized in that, the water-soluble regulator is one of lactic acid, acetic acid, tartaric acid, malic acid, and fumaric acid. 3. a kind of intelligent steering agent for coalbed methane exploitation according to claim 1, is characterized in that, described dispersion mutual solvent is Virahol, ethylene glycol monobutyl ether, sodium oleate, hexenyl bis A kind of stearamide. 4. a kind of intelligent steering agent for coalbed methane exploitation according to claim 1, is characterized in that, described promotor is triethanolamine, formaldehyde, tetramethylthiourea, cinnamaldehyde, p-chlorobenzoic acid, One of the vanillin. 5. The preparation method of a kind of intelligent steering agent for coalbed methane exploitation described in any one of claims 1-4, it is characterized in that, comprises the following steps: first get a certain amount of water, then add glucose respectively wherein Amine hydrochloride, N-methyl-D-glucosamine hydrochloride, water-soluble regulator, surfactant, dispersing mutual solvent, and then stir evenly to make the main agent of intelligent steering agent; acrylamide, N,N Methylenebisacrylic acid amine and accelerator are mixed in a certain proportion to make intelligent steering agent auxiliary agent.

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