A preparation method of a high-efficiency environment-friendly water treatment agent for low-permeability oilfield development

Abstract

The application discloses a preparation method of a high-efficiency environment-friendly water treatment agent for low-permeability oilfield development, and steps of the preparation method comprise the following steps: 30ml of cyclohexanol is taken, added with a catalyst, and then placed in a 50ml beaker, a magnetic stirrer is used for heating and stirring to form a solution state, temperature control is performed at 30 DEG C, and standing is performed for 1h; 20ml of the mixed solution is taken; after 2.31g of epichlorohydrin and 12.5ml of a triethylamine solution are added, the mixed solution is placed in a 200ml closed container, the container bottle is provided with a temperature display device, and reaction is performed; when the digital display temperature does not change within 2h, the reaction is ended; the obtained solution gel block is granulated, cut into bean-size gel particles, placed in a 60 DEG C oven for drying for 5h, taken out, ground into powder, screened, and the particles in the middle layer of the screen are taken out and bagged, so as to obtain a product BW-1; the product BW-1 is compounded with screened carboxymethyl starch complex flocculants, so as to obtain a high-efficiency two-in-one BW series composite sewage treatment agent. The application improves the sewage treatment efficiency.

Description

Technical Field

[0001] This invention relates to the field of water treatment agent preparation technology, specifically a method for preparing a highly efficient and environmentally friendly water treatment agent for the development of low-permeability oilfields. Background Technology

[0002] my country's oilfields generate 20×10⁸ to 30×10⁸ tons of wastewater annually. From both economic and environmental perspectives, reinjecting or reusing oily wastewater is essential. Currently, most of my country's oilfields have entered the mid-to-late stages of oil production, with the water content of the extracted crude oil reaching approximately 80%, and in some cases even reaching 90%. The treatment of this wastewater is a major problem plaguing these oilfields. Oilfield wastewater is a multiphase system consisting of suspended solids, oil, and dissolved substances, formed after oil-water separation. It must be treated before being reinjected into the formation, especially in low-permeability and ultra-low-permeability oilfields. Due to the small pore radius and low permeability, the water quality requirements are stringent, and oilfield wastewater cannot meet the A1 standard for injection water quality in low-permeability oilfields as stipulated in the "Recommended Indicators and Analysis Methods for Water Quality in Clastic Rock Reservoirs".

[0003] Currently, the most widely used and lowest-cost wastewater treatment method in major oilfields is to add wastewater treatment agents to the wastewater, so that the wastewater can meet the reinjection standards or discharge requirements through the purification effect of the wastewater treatment agents.

[0004] Based on this, this application proposes a method for preparing a highly efficient and environmentally friendly water treatment agent for the development of low-permeability oilfields. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a highly efficient and environmentally friendly water treatment agent for the development of low-permeability oilfields. The preparation method includes the following steps:

[0006] Step 1: Weigh 30ml of cyclohexanol, add it to the catalyst, and place it in a 50ml beaker. Heat and stir with a magnetic stirrer until it becomes a solution. Control the temperature at 30℃, let it stand for 1 hour, and measure 20ml of the mixture.

[0007] Step 2: After adding 2.31g epichlorohydrin and 12.5ml triethylamine solution, place the mixed solution in a 200ml sealed container equipped with a temperature display device and carry out the reaction. When the temperature on the digital display does not change within 2 hours, the reaction is complete.

[0008] Step 3: Granulate the obtained solution gel block into granules the size of soybeans, place them in a 60℃ oven and dry for 5 hours. Grind the dried granules into powder, sieve them, and take the granules from the middle layer of the sieve and put them into bags. This is the product BW-1 obtained from the reaction.

[0009] Step 4: Combine the obtained product BW-1 with the screened carboxymethyl starch composite flocculant to obtain the high-efficiency two-in-one BW series composite wastewater treatment agent.

[0010] Furthermore, the catalyst includes tin tetrachloride and silicon dioxide.

[0011] Furthermore, the tin tetrachloride is 1.42g and the silicon dioxide is 2.5g.

[0012] Furthermore, in step two, the reaction temperature is controlled at 30-90℃, and the reaction time is 8-15h.

[0013] Furthermore, the sieve used in step three is a 100-mesh sieve.

[0014] Furthermore, the BW-1 obtained in step three is white granules with a pH value of 8-10.

[0015] Furthermore, the ratio of BW-1 to the screened carboxymethyl starch composite flocculant is 1:1.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) By combining the selected polymer flocculant with the self-made treatment agent, a high-efficiency two-in-one BW series composite sewage treatment agent with multiple functions is formed. This solves the compatibility problem between the composite agent and other agents contained in the sewage, reduces the types and amounts of agents and the treatment process, and lowers the cost. It has good economic benefits and application prospects.

[0018] (2) The selected polyaluminum chloride composite carboxymethyl starch flocculant is currently the water treatment agent with the largest industrial production volume, relatively low price, and widest application range at home and abroad. Through composite, it can overcome many shortcomings of single flocculants, improve flocculation performance, reduce flocculant dosage, and has a wider range of applications. It has good water purification effect on low or high concentration water quality, improves the removal rate of organic matter during flocculation, and can reduce the concentration of residual metal ions and reduce secondary pollution. Attached Figure Description

[0019] Figure 1 This is a comparison chart of the results of the present invention without flocculants;

[0020] Figure 2 This is a graph showing the oil-water separation data of the wastewater treatment agent under different mixing ratios of the present invention.

[0021] Figure 3 This is a graph showing crude oil emulsification data of the wastewater treatment agent under different mixing ratios according to the present invention;

[0022] Figure 4This is a graph showing the suspended solids data of the wastewater treatment agent under different mixing ratios according to the present invention;

[0023] Figure 5 This is a graph showing the bactericidal data of the wastewater treatment agent under different mixing ratios according to the present invention;

[0024] Figure 6 This is a water quality analysis diagram of a certain polymer injection station according to the present invention;

[0025] Figure 7 This is a schematic diagram illustrating the effect of different proportions of the present invention on the polymer. Detailed Implementation

[0026] (1) Raw material preparation and main instruments and equipment

[0027] Cyclohexanol: purity greater than 99.9%; tin tetrachloride: purity greater than 99.9%; silicon dioxide: purity greater than 99%; epichlorohydrin: purity greater than 99.8%; triethylamine: purity greater than 90%.

[0028] Aluminum chloride composite carboxymethyl starch flocculant: content greater than 90%;

[0029] Water: Wastewater from the polymer injection station

[0030] Main instruments and equipment: pH meter, constant temperature water bath, stepless speed stirrer, J6-1A six-beaker experimental apparatus, 722-line spectrophotometer, bacterial test bottles, constant temperature drying oven, small meat grinder, precision balance, grinder.

[0031] (2) Preparation method of high-efficiency two-in-one BW series composite sewage treatment agent

[0032] To achieve better results, flocculants should have strong adaptability to water quality, a wide pH range, large flocs, fast formation speed, rapid sedimentation, good purification, and minimal temperature influence. Commonly used flocculants include ferric chloride and aluminum chloride. A comparative experiment was conducted with polyaluminum chloride combined with carboxymethyl starch flocculant.

[0033] As attached Figure 1 As shown in the data, neither aluminum trichloride nor basic aluminum chloride can meet the actual needs on site. However, the composite flocculant can meet the flocculation conditions and has a certain settling ability. After adding the composite flocculant, the water quality is clear and the flocs are large, making it a more ideal flocculant. The results of the two samplings are consistent.

[0034] Weigh 30 ml of cyclohexanol, add 1.42 g of tin tetrachloride and 2.5 g of silicon dioxide to a 50 ml beaker, heat and stir with a magnetic stirrer until a solution is formed, control the temperature at 30℃, and let stand for 1 hour. Measure 20 ml of the mixture, add 2.31 g of epichlorohydrin and 12.5 ml of triethylamine solution, and place the mixture in a 200 ml sealed container with a temperature display device. React at a temperature of 30-90℃ for 8-15 hours. The reaction is complete when the digital temperature display remains unchanged for 2 hours. Granulate the resulting solution into pea-sized granules, dry them in a 60℃ oven for 5 hours, grind the dried granules into powder, pass them through a 100-mesh sieve, and bag the granules that pass through the middle sieve. This is the product BW-1. The technical specifications of BW-1 are: white granules, pH 8-10.

[0035] The obtained product BW-1 is compounded with the screened carboxymethyl starch composite flocculant to obtain the high-efficiency two-in-one BW series composite sewage treatment agent.

[0036] The experimentally obtained BW-1 was compounded with the screened carboxymethyl starch composite flocculant at ratios of 1:1, 1:2, and 2:1. The effects of different mixing ratios on oil-water separation, emulsification, suspended solids, sterilization, and polymer were tested.

[0037] As attached Figure 2-7 As shown, the wastewater quality improved significantly after the addition of the agent, and the viscosity of the polyacrylamide solution increased slightly. The interaction between the wastewater treatment agent and various components in the wastewater on site had no adverse effect on the viscosity of the polyacrylamide solution.

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A method for preparing a highly efficient and environmentally friendly water treatment agent for low-permeability oilfield development, characterized in that: The preparation method comprises the following steps: Step one: 30ml of cyclohexanol is weighed and added with a catalyst, and then placed in a 50ml beaker, heated and stirred into a solution state by a magnetic stirrer, the temperature is controlled at 30℃, and the solution is left for 1h, and 20ml of the mixed solution is measured; Step two: after adding 2.31g of epichlorohydrin and 12.5ml of triethylamine solution, the mixed solution is placed in a 200ml closed container, the container bottle is provided with a temperature display device, and the reaction is carried out, when the digital temperature does not change within 2h, the reaction is ended; Step three: the obtained solution gel block is granulated and cut into bean-sized gel particles, placed in a 60℃ oven for drying for 5h, taken out, and then the taken-out dried particles are ground into powder, sieved, and the particles in the middle layer of the sieve are taken out and bagged, which are the obtained product BW-1; Step four: the obtained product BW-1 is compounded with a polyaluminum chloride composite carboxymethyl starch flocculant to obtain a high-efficiency two-in-one BW series composite sewage treatment agent; The catalyst comprises tin tetrachloride and silicon dioxide; The tin tetrachloride is 1.42g, and the silicon dioxide is 2.5g; The ratio of the BW-1 to the polyaluminum chloride composite carboxymethyl starch flocculant for compounding is 1:

1.

2. The preparation method of a water treatment agent for low-permeability oilfield development according to claim 1, characterized in that: The reaction temperature in step two is controlled at 30-90℃, and the reaction time is 8-15h.

3. The preparation method of a water treatment agent for low-permeability oilfield development according to claim 1, characterized in that: The sieve in step three is a 100-mesh sieve.

4. The preparation method of a water treatment agent for low-permeability oilfield development according to claim 1, characterized in that: The appearance of the BW-1 prepared in step three is white particles, and the pH value is 8-10.

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