1. A novel super-elastic nano-micron deep profile control and water shutoff material is characterized by comprising the following components in parts by weight: 50-60 parts of water, 5-20 parts of surfactant, 10-20 parts of oil phase, 5-10 parts of SEBS and 1-5 parts of cross-linking agent.

2. A novel super-elastic nano-micron deep profile control water shutoff material as claimed in claim 1, wherein said cross-linking agent is one or more of dicumyl peroxide, di-tert-butylperoxydiisopropylbenzene, 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane.

3. The novel super-elastic nano-micron deep profile control water shutoff material according to claim 1, wherein the oil phase is one or more of white oil, naphthenic oil and hydrogenated naphthenic oil.

4. The novel super-elastic nano-micron deep profile control and water shutoff material according to claim 1, wherein the surfactant is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, span, tween and octylphenol polyoxyethylene ether.

5. The novel super-elastic nano-micron deep profile control water shutoff material according to claim 1, wherein the particle size of the water shutoff material is 100 nm-1 μm.

6. A preparation method of a novel super-elastic nano-micron deep profile control and water shutoff material is characterized by comprising the following steps:

s1, adding an oil phase into SEBS, heating, stirring and dissolving to obtain an S1 oil phase, and keeping the temperature for later use;

s2, stirring and dissolving water and a surfactant to obtain a water phase;

s3, heating the water phase obtained in the step S2, preserving heat, adding the S1 oil phase into the water phase system in a dropwise adding mode, stirring at a high speed for emulsification, and stirring at a low speed;

and S4, dissolving a cross-linking agent in xylene, adding the solution into the emulsified system of S3, carrying out heat preservation reaction, then heating for reaction, and cooling to room temperature.

7. The preparation method of the novel super-elastic nano-micron deep profile control and water shutoff material according to claim 6, wherein in the step S1, the temperature is raised to 50-60 ℃.

8. The preparation method of the novel super-elastic nano-micron deep profile control and water shutoff material according to claim 6, characterized in that in the step S3, the temperature of the water phase is raised to 50-60 ℃, the high-speed stirring speed is controlled to be 2000-4000 r/min, the time is controlled to be 30-60 min, and the low-speed stirring speed is controlled to be 500-700 r/min.

9. The preparation method of the novel superelastic nano-micron deep profile control and water shutoff material according to claim 6, wherein in the step S4, the temperature keeping reaction is specifically to maintain the temperature at 50-60 ℃ and react for 2-5 hours, and the temperature raising reaction is specifically to maintain the temperature at 80-90 ℃ and react for 5-10 hours.

Background

Along with the continuous water injection exploitation of various large oil fields in China, the water content of oil wells is increased year by year, the traditional jelly, swelling particles and other inorganic plugging agents can only act on the near well zone of the water injection wells, and cannot reach the seepage section of the medium and far wells with rich formation residual oil. In order to solve the problem, in recent years, polymer microsphere deep profile control and flooding technologies are tested in various oil fields in succession, and good effects of water reduction and oil increase are achieved. The initial particle size of the polymer microspheres can reach nano-micron level, the polymer microspheres can smoothly enter the deep part of an oil reservoir through a near wellbore area, the volume of the polymer microspheres expands under the action of the temperature and the mineralization degree of formation water, and the polymer microspheres can be plugged and stacked at the narrow and small pore throat part of the formation, so that the liquid flow at the deep part of the oil reservoir generates phase inversion, the water wave and volume of injection are enlarged, and the effect of precipitation and oil increase is achieved.

However, the traditional polymer microsphere material is hydrogel formed by taking polyacrylamide as a main body and adding a certain cross-linking agent, has relatively low pressure resistance and poor pore throat shearing resistance, and is easily sheared into fragments through a relatively narrow pore throat under the pressure of water injection, so that the subsequent plugging effect is lost. In addition, under the action of the temperature and the mineralization degree of the formation water, the hydrogel is hydrated and expanded, the pressure resistance of the hydrogel is further reduced, the water resistance effect generated by subsequent water injection is weakened, and the effective period is relatively short.

In order to overcome the defect that the traditional polymer microsphere is relatively low in plugging strength, people adopt a rubber material with better elastic deformation recovery capability to replace polyacrylamide to prepare spheroidal particles, the elasticity of the rubber is superior to that of hydrogel, but the preparation forming capability of the rubber is weaker, large refining forming equipment is needed, the prepared particles are larger and at the minimum in millimeter level, the initial particle size is too large, so that the particles are difficult to enter the deep part of an oil reservoir for profile control and water plugging, the technical problem which troubles technical personnel for a long time is solved, and the application range of the particles is greatly limited.

Disclosure of Invention

The invention provides a novel hyperelastic nano-micron deep profile control and water shutoff material and a preparation method thereof, and solves the problems that in the prior art, rubber water shutoff material particles are large and difficult to enter deep oil reservoirs for profile control and water shutoff, and the traditional polyacrylamide microsphere has poor pressure resistance and low plugging strength.

The technical scheme of the invention is as follows:

a novel hyperelastic nano-micron deep profile control and water shutoff material comprises the following components in parts by weight: 50-60 parts of water, 5-20 parts of surfactant, 10-20 parts of oil phase, 5-10 parts of SEBS and 1-5 parts of cross-linking agent.

As a further technical scheme, the cross-linking agent is one or more of dicumyl peroxide, di-tert-butylperoxydiisopropylbenzene and 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane.

As a further technical scheme, the oil phase is one or more of white oil, naphthenic oil and hydrogenated naphthenic oil.

As a further technical scheme, the surfactant is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, span, tween and octyl phenol polyoxyethylene ether.

As a further technical scheme, the particle size of the water plugging material is 100 nm-1 μm.

The invention provides a preparation method of a novel super-elastic nano-micron deep profile control water shutoff material, which comprises the following steps:

s1, adding an oil phase into SEBS, heating, stirring and dissolving to obtain an S1 oil phase, and keeping the temperature for later use;

s2, stirring and dissolving water and a surfactant to obtain a water phase;

s3, heating the water phase obtained in the step S2, preserving heat, adding the S1 oil phase into the water phase system in a dropwise adding mode, stirring at a high speed for emulsification, and stirring at a low speed;

and S4, dissolving a cross-linking agent in xylene, adding the solution into the emulsified system of S3, carrying out heat preservation reaction, then heating for reaction, and cooling to room temperature.

In a further technical scheme, in the step S1, the temperature is increased to 50-60 ℃.

As a further technical scheme, in the step S3, the temperature of the water phase is raised to 50-60 ℃, the high-speed stirring speed is controlled to be 2000-4000 r/min, the time is controlled to be 30-60 min, and the low-speed stirring speed is controlled to be 500-700 r/min.

As a further technical scheme, in the step S4, the heat preservation reaction is specifically to maintain the temperature at 50-60 ℃ and react for 2-5 h, and the temperature rise reaction is specifically to maintain the temperature at 80-90 ℃ and react for 5-10 h.

The invention has the beneficial effects that:

1. the invention aims to provide a novel super-elastic nano-micron deep profile control and water shutoff material, which has the advantages that the initial particle size is small, the profile control and water shutoff material can smoothly enter deep parts of an oil reservoir through a near wellbore zone, meanwhile, a main body thermoplastic elastomer has excellent elastic deformation capacity, can be deformed and passed without being broken through shearing at a stratum pore throat, the plugging strength is high, and effective water injection resistance can be generated on a water injection dominant channel of the deep parts of the oil reservoir, so that the effects of precipitation and oil increment are achieved.

2. The invention also aims to provide a method for preparing the super-elastic nano-micron deep profile control and water shutoff material with good elastic deformation plugging performance by adopting a thermoplastic elastomer (SEBS) with good elastic recovery capacity as a main material and utilizing a high-temperature emulsification crosslinking process. The method is simple, flexible and efficient, and can prepare the super-elastic profile control water plugging material with different particle sizes according to different oil reservoir geological conditions applied to oil fields on site.

3. The invention selects the thermoplastic elastomer (SEBS) as the main body of the profile control water shutoff material, the polystyrene-polyethylene-polybutylene-polystyrene (SEBS) is a novel elastomer which is prepared by the selective hydrogenation of polybutadiene unsaturated double bonds in rubber sections in thermoplastic block copolymer polystyrene-polybutylene-polystyrene (SBS) molecules, different from other thermoplastic elastomers, the SEBS can obtain the dispersion fluidity in inert solvents such as white oil and the like at lower temperature due to the polybutadiene block contained in a polymer chain, and the processing and forming temperature of the SEBS after oil filling is lower than that of other thermoplastic elastomers, thereby being more beneficial to the emulsion forming of the SEBS in water phase; in addition, the unsaturated double bonds on the polymer chain are subjected to selective hydrogenation, so that the content of the unsaturated double bonds is reduced, and the thermoplastic elastomer has more excellent aging resistance compared with other thermoplastic elastomers, and can still maintain the elastic plugging capability under the severe geological conditions of high temperature and high mineralization at the deep part of an oil reservoir; meanwhile, a small amount of double bonds remained by hydrogenation provide possibility for further micro-crosslinking, so that the pressure-resistant plugging performance of the composite material can be further improved, the high-elastic deformation recovery capability is kept at the deep part of an oil reservoir, the pore throat shearing of the stratum can be effectively overcome, and the composite material is not blocked, can be transported, can be plugged in multiple stages and is continuously effective; in addition, the biological safety is excellent, and the oil field application environmental protection requirement is completely met. Therefore, the SEBS is used for preparing the super-elastic spherical deep profile control and water shutoff material with the initial particle size of nanometer and micron level by dissolving and dispersing the SEBS in the inert oil phase and emulsifying and forming the SEBS in the high-temperature water phase with a certain crosslinking agent, and the problems that the existing rubber particles are too large and difficult to enter the deep part of an oil reservoir and the traditional polyacrylamide microspheres have poor pressure resistance and low plugging strength are effectively solved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any inventive step, are intended to be within the scope of the present invention.

Example 1

S1, adding 10 parts of white oil into 5 parts of SEBS, heating to 50 ℃, stirring and dissolving to obtain an S1 oil phase, and keeping the temperature for later use;

s2, stirring and dissolving 60 parts of water, 5 parts of span 80 and 15 parts of Tween 60 to obtain a water phase;

s3, heating the water phase obtained in the step S2 to 50 ℃, preserving heat, slowly adding the S1 oil phase at 50 ℃ into the water phase system in a dropwise adding mode, controlling the stirring speed at 2000 revolutions per minute, continuously emulsifying for 60 minutes, and reducing the stirring speed to 500 revolutions per minute;

s4, dissolving 5 parts of dicumyl peroxide in xylene, adding the xylene in an amount which is the minimum amount capable of dissolving the dicumyl peroxide into the emulsified system S3, continuously stirring for 2 hours, heating the system to 90 ℃, continuously keeping the temperature, stirring for reaction for 5 hours, and cooling with cold water to room temperature.

Example 2

S1, adding 20 parts of naphthenic oil into 10 parts of SEBS, heating to 60 ℃, stirring and dissolving to obtain an S1 oil phase, and keeping the temperature for later use;

s2, stirring and dissolving 50 parts of water and 19 parts of OP-13 to obtain a water phase;

s3, heating the water phase obtained in the step S2 to 60 ℃, preserving heat, slowly adding the S1 oil phase at the temperature of 60 ℃ into the water phase system in a dropwise adding mode, controlling the stirring speed at 4000 revolutions per minute, continuously emulsifying for 30 minutes, and then reducing the stirring speed to 700 revolutions per minute;

s4, dissolving 1 part of di-tert-butylperoxy diisopropylbenzene in xylene, adding the xylene in an amount which is the minimum amount capable of dissolving di-tert-butylperoxy diisopropylbenzene into the emulsified system of S3, continuously stirring for 2 hours, heating the system to 90 ℃, continuously preserving heat, stirring and reacting for 5 hours, and cooling with cold water to room temperature.

Example 3

S1, adding 20 parts of hydrogenated naphthenic oil into 10 parts of SEBS, heating to 55 ℃, stirring and dissolving to obtain an S1 oil phase, and keeping the temperature for later use;

s2, stirring and dissolving 60 parts of water and 5 parts of sodium dodecyl sulfate to obtain a water phase;

s3, heating the water phase obtained in the step S2 to 55 ℃, preserving heat, slowly adding the S1 oil phase with the temperature of 55 ℃ into the water phase system in a dropwise adding mode, controlling the stirring speed at 3000 r/min, continuously emulsifying for 50 min, and then reducing the stirring speed to 600 r/min;

s4, dissolving 5 parts of 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane in xylene, adding the xylene into the emulsified system of S3, continuously stirring for 3.5 hours, heating the system to 85 ℃, continuously keeping the temperature, stirring and reacting for 8 hours, and cooling to room temperature with cold water.

Example 4

S1, adding 17 parts of white oil into 8 parts of SEBS, heating to 60 ℃, stirring and dissolving to obtain an S1 oil phase, and keeping the temperature for later use;

s2, stirring and dissolving 55 parts of water and 17 parts of sodium dodecyl sulfate to obtain a water phase;

s3, heating the water phase obtained in the step S2 to 60 ℃, preserving heat, slowly adding the S1 oil phase at the temperature of 60 ℃ into the water phase system in a dropwise adding mode, controlling the stirring speed at 4000 revolutions per minute, continuously emulsifying for 50 minutes, and then reducing the stirring speed to 700 revolutions per minute;

and S4, dissolving 3 parts of dicumyl peroxide in xylene, adding the xylene in an amount which is the minimum amount capable of dissolving the dicumyl peroxide into the emulsified system S3, continuously stirring for 4 hours, heating the system to 90 ℃, continuously keeping the temperature, stirring for reaction for 7 hours, and cooling the mixture to room temperature by cold water.

The experimental parameters of the indoor sand pipe plugging simulation experiment are shown in table 1.

TABLE 1 Experimental parameters for indoor simulation of sand pipe plugging experiment

Length of sand pipe	Cross sectional area	Average permeability	Injection velocity	Concentration of implant material
					60cm	5.3cm2	2000mD	1ml/min	5000mg/L

Table 2 experimental data of indoor sand pipe plugging simulation experiment

The novel hyperelastic nano-micron deep profile control water shutoff material prepared by the embodiment of the invention has the advantages that the form of the water dispersion liquid is similar to spherical, the particle size is 100 nm-1 mu m, the appearance is a flowing emulsion, and the material can be rapidly dispersed in the water injected into an oil field.

The novel hyperelastic nano-micron deep profile control water shutoff material provided by the invention simulates the plugging of a sand pipe in a roomIn the test, the length of the sand pipe is 60cm, and the sectional area is 5.3cm²The average permeability is 2000mD, the injection speed is 1ml/min, the concentration of an injection material is 5000mg/L, the pressure of the head, the middle and the tail of the sand pipe is increased to different degrees, and the integral average plugging pressure is increased by more than 1 MPa. Although the pressure at each part of the polyacrylamide microsphere sand pipe with the same concentration and the same particle size as those in the embodiment of the invention is increased, the overall average plugging pressure is increased by far less than that in the embodiment of the invention, and the plugging strength is low. Compared with rubber profile control water shutoff particles injected with the same concentration, the pressure at the head of the sand pipe rises greatly due to the larger particle size, and the pressures at the middle part and the tail part of the sand pipe are not changed, so that the capability of entering the deep part of an oil reservoir is weak.

From the experimental data obtained in the embodiments 1 to 4 of the present invention, it can be found that different process parameters and raw materials all affect the plugging pressure of the obtained water plugging material, wherein, compared with other embodiments, the embodiment 3 has the advantages of optimal performance, maximum plugging strength and moderate particle size, and can affect the plugging strength by adjusting the reaction temperature at a proper stirring speed.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.