A foam net synergistic solid foam displacement agent and a preparation method thereof

Abstract

The present application relates to a kind of bubble net synergistic solid foam displacement agent and its preparation method.Mainly solve the gas well in the process of foam drainage gas recovery, solid foam displacement agent after adding cannot fully utilize bottom-hole energy to form disturbance, with bottom-hole effusion mixture is not uniform, resulting in serious slip loss, foaming effect is poor, liquid carrying effect is poor.Its characteristics are that bubble net structure made of soluble support material is introduced, and the bubble net structure is coated on the surface of solid foam displacement agent, which plays a synergistic effect.The present application includes the following components by mass fraction: (1) 1-10 parts of bubble net structure made of soluble support material with adjustable degradation time; (2) 50-70 parts of foaming agent; (3) 1-5 parts of foam stabilizer; (4) 1-10 parts of functional additives; (5) 10-20 parts of filler.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas field foam drainage gas recovery, and relates to a solid foam drainage agent for foam drainage gas recovery, in particular to a bubble net synergistic solid foam drainage agent and a preparation method thereof. BACKGROUND

[0002] With the development of gas reservoirs year by year, more than 70% of gas wells in China need to rely on artificial drainage to realize benefit development at present, and the foam drainage gas recovery technology has obvious advantages and is widely used in major gas fields. Compared with liquid foam drainage agents, solid foam drainage agents have the characteristics of good stability, convenient operation and low transportation cost, and can significantly reduce the work load of adding agents at the production site, especially for some remote wells.

[0003] The existing solid foam drainage agents are mainly improved in terms of agent formula, shape and applicable conditions, but the key to the effect of the foam drainage agent lies in the disturbance degree in the wellbore, therefore, it is of great significance to develop a solid foam drainage agent that can increase the disturbance intensity without causing adverse effects on the liquid carrying and subsequent liquid discharge treatment of the wellbore. SUMMARY

[0004] The application provides a bubble net synergistic solid foam drainage agent and a preparation method thereof to solve the above problems. The formula composition adopted by the application is all cheap and easily available materials on the market, and the bubble net structure provided can effectively enhance the disturbance intensity of the solid foam drainage agent after contacting with gas-liquid, improve the foaming effect and enhance the liquid carrying performance.

[0005] To achieve the above purpose, the application adopts the following technical solutions:

[0006] A bubble net synergistic solid foam drainage agent and a preparation method thereof, including the following components in mass fraction: 1-10 parts of a bubble net made of a soluble scaffold material with adjustable degradation time; 50-70 parts of a foaming agent; 1-5 parts of a foam stabilizer; 1-10 parts of a functional additive; and 10-20 parts of a filler.

[0007] The bubble net made of a soluble scaffold material with adjustable degradation time according to the application is a bubble net made of one or two of polylactic acid, gelatin, starch and carboxymethyl cellulose. The preparation method includes the following steps:

[0008] a. Material preparation: prepare the soluble scaffold material, water and other required additives, and the additives include a thickening agent, a substance capable of adjusting the dissolution speed and the like. The soluble scaffold material is polylactic acid, gelatin, starch and the like; the thickening agent is carboxymethyl cellulose, epoxidized starch and the like; and the substance capable of adjusting the dissolution speed is sodium carbonate, calcium carrageenan and the like. Each component includes the soluble scaffold material 50-100 parts, water 200-300 parts, the thickening agent 1-5 parts and the substance capable of adjusting the dissolution speed 1-5 parts in mass fraction;

[0009] b. Mixing materials: the soluble scaffold material, thickening agent, dissolution rate control substance are added into water in turn according to the amount, and stirred uniformly to form a uniform colloid;

[0010] c. Forming: the mixed colloid is poured into a mold with a mesh, and is pressed into a linear shape by external force, and a glue line is obtained after drying, and the glue line is woven into a glue net with a desired mesh size;

[0011] d. Testing and optimization: according to actual needs, the glue line is tested and evaluated for dissolution time, and the formula is further adjusted according to the test results to achieve the desired dissolution time range.

[0012] The foaming agent in the application is selected from one, two or three of sodium dodecyl benzene sulfonate, alpha-alkenyl sulfonic acid sodium, dodecyl sulfide propyl betaine, cetyl trimethyl ammonium chloride, one of cocamide propyl amine oxide, two or three. The compounding of the above-mentioned foaming agent can effectively realize the functions of temperature resistance, salt resistance, anti-condensate oil, sterilization and corrosion inhibition.

[0013] The foam stabilizer in the application is selected from one or two of diutan gum, xanthan gum, starch and polyacrylamide, and a small amount of the foam stabilizer can increase the viscoelasticity of the foam displacement agent system, thereby improving the foam stability of the foam displacement agent.

[0014] The functional additive in the application is selected from one or two of zinc nitrate, cetyl amine, amino tris methylene phosphonic acid and hydroxy ethylene diphosphonic acid, and the foam displacement agent has corrosion and scale inhibition performance.

[0015] The filler in the application is selected from one or two of urea, paraffin and sodium bicarbonate.

[0016] The application also provides a preparation method of the foam net synergistic solid foam displacement agent, which comprises the following steps:

[0017] e. After the foaming agent, foam stabilizer, functional additive and filler are stirred uniformly, they are pressed into a solid foam displacement agent in a mold, and the solid foam displacement agent is dried at low temperature to obtain the solid foam displacement agent;

[0018] f. The glue net is loosely and uniformly coated on the surface of the solid foam displacement agent, and the two ends are fixed with glue lines, so that the foam net synergistic solid foam displacement agent is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0020] Figure 1is the device diagram for testing the liquid carrying capacity of the solid foam cleanup agent described in Example 3. In the diagram: (1) liquid collecting pipe; (2) liquid collecting cylinder; (3) foaming pipe; (4) constant temperature water bath; (5) gas flow controller; (6) nitrogen gas cylinder.

[0021] Figure 2 is the comparison diagram of the liquid carrying volume of the five commercial solid foam cleanup agents with and without foam net described in Example 3. DETAILED DESCRIPTION

[0022] The technical solutions of the present application will be described in further detail below in combination with specific examples, but the protection scope of the present application is not limited to the following description.

[0023] Example 1: Preparation of solid foam cleanup agent.

[0024] 40 parts of sodium dodecyl benzene sulfonate, 30 parts of sodium α-alkenyl sulfonate, 15 parts of urea, 10 parts of sodium bicarbonate, and 5 parts of paraffin wax were poured into a stirrer, stirred uniformly, taken out, and placed in a mold brushed with polyethylene glycol 400, and then pressed and formed, and dried at low temperature for standby use.

[0025] Example 2: Preparation of foam net.

[0026] 4 parts of CMC and 2 parts of sodium carbonate were sequentially added to 300 parts of water, stirred uniformly, and then 100 parts of polylactic acid powder was slowly and uniformly added to the water, and stirred gently to prevent caking. After stirring uniformly, the polylactic acid powder was placed at room temperature to absorb moisture and swell for about 30 minutes to form a polylactic acid colloid. The polylactic acid colloid was poured into a mold, and then extruded into a linear shape by external force, and then dried and woven into a foam net.

[0027] Example 3: Comparison of liquid carrying capacity of solid foam cleanup agent with and without foam net.

[0028] Five commercial solid foam cleanup agents were taken, and two indoor test samples of 0.5 g were prepared for each. One of the samples was wrapped with a foam net prepared in Example 2, and then the liquid carrying volume of the samples with and without foam net was tested respectively. It should be noted that, in order to reduce the original disturbance in the foaming pipe and enhance the contrast between the samples, the sand core head was not used at the gas inlet, but the gas was directly introduced from the liquid outlet below the foaming pipe, and the amount of water pre-added in the foaming pipe was 500 mL. The test device is shown in Figure 1 , and the test data comparison is shown in Figure 2 .

Claims

1. A foam-in-place synergistic solid foam frac agent, characterized by: The solid foam agent adds a layer of foam net made of soluble support material on the surface of the solid agent, and includes the following components in mass fraction: 1-10 parts of foam net made of soluble support material with adjustable degradation time, 50-70 parts of foaming agent, 1-5 parts of foam stabilizer, 1-10 parts of functional additive, and 10-20 parts of filler.

2. The foam-in-place gelling solid foam frac agent of claim 1 wherein, The foam net preparation method comprises the following steps: a. Material preparation: prepare soluble support material, water and other required additives, including thickening agent, substance for adjusting dissolution rate; the soluble support material is one or two of polylactic acid, gelatin and starch; the thickening agent is one or two of carboxymethyl cellulose and epoxidized starch; the substance for adjusting dissolution rate is one or two of sodium carbonate and calcium carrageenan; each component includes soluble support material 50-100 parts, water 200-300 parts, thickening agent 1-5 parts, and substance for adjusting dissolution rate 1-5 parts in mass fraction; b. Mixing materials: sequentially add soluble support material, thickening agent and substance for adjusting dissolution rate into water according to the amount, stir uniformly to form a uniform colloid; c. Forming: pour the prepared colloid into a mold with mesh, extrude and press into a linear shape by external force, and obtain a glue line after drying; the glue line is woven into a foam net with a desired mesh size; d. Testing and optimization: according to actual needs, test and evaluate the dissolution time of the prepared glue line, and further adjust the formula according to the test results to achieve the desired dissolution time range.

3. The foam-in-place gelling solid foam frac agent of claim 1 wherein, The mesh size of the bubble net is 0.1mm 2 4mm 2 The dissolution time of the bubble net is 2-10 days.

4. The foaming agent for enhancing foam release as described in claim 1, characterized in that, The foaming agent is selected from one, two or three of sodium dodecyl benzene sulfonate, sodium alpha-alkenyl sulfonate, dodecyl sulfopropyl betaine, cetyltrimethylammonium chloride, cocamide propyl oxide amine.

5. The foam-in-place gelling solid foam frac agent of claim 1 wherein, The foam stabilizer is selected from one or two of diutan gum, xanthan gum, starch and polyacrylamide.

6. The cellulose web enhancing solid lift agent of claim 1, wherein, The functional additive is selected from one or two of zinc nitrate, cetylamine, aminotri-methylene phosphonic acid and hydroxy ethylene diphosphonic acid.

7. The foaming agent for enhancing foam release as described in claim 1, characterized in that, The filler is selected from one or two of urea, paraffin and sodium bicarbonate.

8. The preparation method of the foam net synergistic solid foam agent according to claim 1, comprising the following steps: e. After stirring the foaming agent, foam stabilizer, functional additive and filler uniformly, press and form in a mold, and dry at low temperature to obtain a solid foam agent; f. Loosely and uniformly coat the foam net on the surface of the solid foam agent, and fix the two ends with glue line to obtain a foam net synergistic solid foam agent.

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