阅读说明：本技术 疏水改性型吸水膨胀树脂及其制备方法 (Hydrophobic modified water-swellable resin and preparation method thereof ) 是由 曾志强 黄冬 袁俊秀 朱魁 靳志超 于 2018-06-06 设计创作，主要内容包括：一种用于油田钻井领域中的吸水膨胀树脂堵漏助剂及其制备方法：先将水放入自制反应罐中,搅拌中缓慢加入丙烯酰胺、丙烯酸、2-丙烯酰胺基-2-甲基丙磺酸；待完全溶解后,缓慢加入NaOH溶液,调pH值至9-10；加入增强剂,搅拌分散均匀；通氮气,再依次加入交联剂、引发剂,升温至40-70℃反应2-5h,取出切块、烘干、粉碎造粒过筛待用；加入疏水改性剂溶液中,缓慢升温,待反应结束后,取出样品烘干,得疏水改性型吸水膨胀树脂。本发明产品具有明显的延迟吸水膨胀特征,在井筒中膨胀缓慢,到达漏失称为后可继续膨胀,从而可有效地改善漏失地层,达到修复的效果。(A water-swelling resin plugging additive used in the field of oilfield drilling and a preparation method thereof are disclosed: firstly, putting water into a self-made reaction tank, and slowly adding acrylamide, acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid while stirring; after complete dissolution, slowly adding NaOH solution, and adjusting the pH value to 9-10; adding a reinforcing agent, and uniformly stirring and dispersing; introducing nitrogen, sequentially adding a cross-linking agent and an initiator, heating to 40-70 ℃, reacting for 2-5h, taking out, cutting into blocks, drying, crushing, granulating and sieving for later use; adding the mixture into a hydrophobic modifier solution, slowly heating, taking out a sample after the reaction is finished, and drying to obtain the hydrophobic modified water-swellable resin. The product of the invention has obvious characteristic of delaying water absorption expansion, slowly expands in a shaft, and can continue to expand after loss occurs, thereby effectively improving the lost stratum and achieving the effect of repairing.)

1. A hydrophobic modified water-swellable resin characterized by: the resin is prepared from the following components in percentage by mass: 60 to 80 percent of distilled water, 5 to 10 percent of Acrylamide (AM), 5 to 10 percent of Acrylic Acid (AA), 2 to 5 percent of 2-acrylamide-2-methyl propane sulfonic Acid (AMPS), 0.01 to 0.5 percent of cross-linking agent N, N-Methylene Bisacrylamide (MBA), 0.01 to 0.3 percent of initiating agent, 2 to 5 percent of reinforcing agent and 5 to 10 percent of hydrophobic modifying agent.

2. the hydrophobically modified water swellable resin of claim 1, wherein the hydrophobic modifier is any one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, hexadecylbenzyldimethylammonium chloride, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, hexadecylbenzyldimethylammonium chloride bromide or hexadecylpyridylchloride.

3. The method for producing a hydrophobically modified water-swellable resin according to claim 1, which comprises the steps of:

(1) Firstly, distilled water is put into a reaction tank, and acrylamide, acrylic acid and 2-acrylamide-2-methyl propanesulfonic acid are slowly added while stirring; after complete dissolution, slowly adding NaOH solution, and adjusting the pH value to 9-10; adding a reinforcing agent, and uniformly stirring and dispersing; introducing nitrogen, sequentially adding a cross-linking agent and an initiator, heating to 40-70 ℃, reacting for 2-5h, taking out, cutting into blocks, drying, crushing, granulating and sieving to obtain a 6-30-mesh intermediate product for later use;

(2) and adding the intermediate product into a hydrophobic modifier solution, slowly heating, taking out after the reaction is finished, and drying to obtain the hydrophobic modified water-swellable resin.

4. The method for producing the hydrophobically modified water-swellable resin, according to claim 3, wherein the NaOH solution has a concentration of 5 to 50%.

5. The method for preparing the hydrophobically modified water swellable resin as described in claim 3, wherein nitrogen is introduced for 0.5-3 hours and the nitrogen concentration is not less than 99%.

6. The method for producing the hydrophobically modified water-swellable resin as claimed in claim 3, wherein the reaction temperature for the hydrophobic modification is 30 to 70 ℃.

7. The method for producing the hydrophobically modified water-swellable resin as claimed in claim 3, wherein the reaction time for the hydrophobic modification is 1 to 4.5 hours.

8. The hydrophobic modified water swellable resin of claim 1, wherein the initiator is any two of ammonium persulfate, anhydrous sodium sulfite, potassium persulfate and sodium persulfate, and the mixing ratio is 1:9.5-5: 1.

9. The hydrophobically modified water-swellable resin according to claim 1, wherein the reinforcing agent is sodium bentonite, kaolin, lithium montmorillonite or alkali calcium montmorillonite, and the mesh number is 100-400 mesh.

Technical Field

The invention relates to a plugging additive used in the field of oilfield drilling.

Background

The well leakage is a complex problem existing in the process of well drilling, well cementing, well logging and well repairing, which causes the drilling fluid to leak into a leakage channel from a well bore, not only consumes a large amount of mud and leakage stoppage materials, but also can cause serious accidents such as well collapse, drill sticking, blowout and even well bore abandonment, and cause huge economic loss.

For a long time, engineering technicians select various plugging materials in practice aiming at lost circulation under different conditions, the current domestic research on the plugging agent and the plugging technology makes great progress, many practical problems are solved, but some defects still exist, and the common defects of the materials are as follows: firstly, the deformability of the particles is poor in the process of leaking stoppage, the particles which are slightly larger than or not matched with the shape of the pore cracks of the leaking layer are not easy to enter, and the particles are accumulated on the surface of the leaking layer and do not go deep into the leaking layer; secondly, most of the plugging materials have no expansibility or only slight expansion amount, and are not easy to stably stay in the leaking layer under the action of external force. Due to the reasons, when the materials are used for treating lost circulation, poor leaking stoppage effect and repeated leaking after leaking stoppage are easy to cause. Although the expandable plugging material has certain advantages in solving the two problems, the expansion speed of the conventional expandable plugging material is generally difficult to control, and the process from the ground to the leakage passage usually requires several hours, but the excellent water-absorbing expandable material absorbs water at a high speed in the period of time, so that the volume of the material greatly expands, and the actual plugging effect is influenced.

The method for controlling the water-absorbent resin not to expand in the pumping process and the water-absorbent resin to expand after reaching a leakage stratum is a difficult problem, and in order to enable the water-absorbent resin plugging material to better exert the expansion plugging effect, the water-absorbent resin plugging material is expanded in a delayed manner, and a wrapping method, a non-aqueous carrier fluid, a grafted hydrophobic monomer and the like are mainly adopted. Among them, the hydrophobic modification has the advantages that: the hydrophobic modifier is grafted on the surface of the water-absorbent resin by an ion exchange method, has an inhibiting effect on the entry of water molecules into the water-absorbent resin, and can slow down the water absorption expansion of the water-absorbent resin. From the viewpoint of production process and site construction, the method for achieving the delayed water absorption swelling of the water-absorbent resin by surface hydrophobic modification is the simplest and most effective method.

Disclosure of Invention

The invention aims to solve the technical problem that the conventional expansion material is rapidly expanded in a wellbore and the expansion performance is reduced after the conventional expansion material enters a loss zone. Hydrophobic chains are grafted on the surface of the water-swelling resin through an ion exchange method, so that water is not easy to enter the interior of resin particles at the initial stage of water swelling, the hydrophobic property of the resin is gradually reduced along with the influence of other conditions such as formation temperature and the like, and the water-swelling capacity of the resin is gradually enhanced, so that the water-swelling capacity of the resin is effectively delayed, the function of the plugging material in a leakage passage is furthest exerted, and the practical application effect of the plugging material is improved.

The hydrophobic modified water-swellable resin is prepared from the following components in percentage by mass: 60 to 80 percent of distilled water, 5 to 10 percent of Acrylamide (AM), 5 to 10 percent of Acrylic Acid (AA), 2 to 5 percent of 2-acrylamide-2-methyl propane sulfonic Acid (AMPS), 0.01 to 0.5 percent of cross-linking agent N, N-Methylene Bisacrylamide (MBA), 0.01 to 0.3 percent of initiating agent, 2 to 5 percent of reinforcing agent and 5 to 10 percent of hydrophobic modifying agent.

Typically, the hydrophobic modifier is any one of dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, hexadecylbenzyldimethylammonium chloride, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, hexadecylbenzyldimethylammonium chloride bromide, or hexadecylpyridylchloride.

The initiator is any two of ammonium persulfate, anhydrous sodium sulfite, potassium persulfate and sodium persulfate, and the mixing ratio is 1:9.5-5: 1.

The reinforcing agent is sodium bentonite, kaolin, lithium montmorillonite or alkaline calcium montmorillonite with the mesh number of 100-400 meshes.

The preparation method of the hydrophobic modified water-swellable resin comprises the following steps: firstly, putting water into a reaction tank, and slowly adding acrylamide, acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid while stirring; after complete dissolution, slowly adding NaOH solution, and adjusting the pH value to 9-10; adding a reinforcing agent, and uniformly stirring and dispersing; introducing nitrogen, sequentially adding a cross-linking agent and an initiator, heating to 40-70 ℃, reacting for 2-5h, taking out, cutting into blocks, drying, crushing, granulating and sieving, and reserving 6-30 meshes of intermediate products for later use; and adding the intermediate product into a hydrophobic modifier solution, slowly heating, taking out after the reaction is finished, and drying to obtain the hydrophobic modified water-swellable resin.

Typically, the NaOH solution is present in a concentration of 5 to 50%.

Introducing nitrogen for 0.5-3h, wherein the nitrogen concentration is more than or equal to 99%.

The reaction temperature of the hydrophobic modification is 30-70 ℃.

The reaction time of the hydrophobic modification is 1-4.5 h.

The invention has the beneficial effects that: (1) the hydrophobic modified water-swellable resin provided by the invention has good toughness and high extrusion strength, enhances the plugging strength, and improves the pressure-bearing capacity of the plugging layer; (2) the water-absorbing expansion rate is slow, the obvious delayed expansion characteristic is achieved, the expansion in a shaft is slow, and the expansion can be continued after the expansion reaches a leakage layer, so that the leakage stratum can be effectively improved, and the repairing effect is achieved.

Detailed Description

The invention is further illustrated by the following specific preparation examples.