阅读说明：本技术 油田用粘土缩膨剂及其制备方法 (Clay expansion and contraction agent for oil field and preparation method thereof ) 是由 李国旗 周嘉龙 冯康康 张鹏 郭娟娟 李金营 赵淑丹 孙建磊 白源松 余洋 于 2021-08-25 设计创作，主要内容包括：本发明公开油田用粘土缩膨剂及其制备方法,由如下组分组成：多乙烯多胺、氯化苄、氢氧化钠、正丁醇和有机金属催化剂。本申请合成粘土缩膨剂新材料中,胺基强力吸附粘土颗粒,带刚性基团的长链通过缠绕、包裹,固定粘土颗粒,强力压缩粘土颗粒的双电层使膨胀粘土脱水收缩。由于长链扭曲刚性结构,形成扭曲的梳状结构,在抵抗流体冲刷能力大大提高,同时本产品使用浓度有一定的降低。注入后可以快速与粘土颗粒电性吸附,强力压缩粘土双电层,使粘土颗粒收缩,增大油层孔隙度,恢复和扩大产油喉道,实现增产增注目的。防膨率可达90％、缩膨率可达35％；模拟岩心动态注水实验,持续时间150天有效；不发生颗粒运移。(The invention discloses a clay swelling and shrinking agent for oil fields and a preparation method thereof, wherein the clay swelling and shrinking agent comprises the following components: polyethylene polyamines, benzyl chloride, sodium hydroxide, n-butanol and organometallic catalysts. In the new material of the clay swelling and shrinking agent, the amino strongly adsorbs clay particles, the long chain with rigid groups fixes the clay particles by winding and wrapping, and the double electric layers of the clay particles are strongly compressed to dehydrate and shrink the swelling clay. Because the long-chain twisted rigid structure forms a twisted comb-shaped structure, the fluid scouring resistance is greatly improved, and the use concentration of the product is reduced to a certain extent. After injection, the oil can be quickly and electrically adsorbed with clay particles, the double electric layers of the clay are strongly compressed, the clay particles are shrunk, the porosity of an oil layer is increased, an oil production throat is restored and enlarged, and the purposes of increasing production and injection are achieved. The anti-swelling rate can reach 90 percent, and the shrinkage-swelling rate can reach 35 percent; simulating a dynamic water injection experiment of a rock core, wherein the duration is 150 days; no particle migration occurs.)

1. The clay swelling and shrinking agent for the oil field is characterized by comprising the following components: polyethylene polyamines, benzyl chloride, sodium hydroxide, n-butanol and organometallic catalysts.

2. The clay swelling and shrinking agent for the oil field according to claim 1, wherein the weight ratio of each component is as follows: 30-60 parts of polyethylene polyamine, 15-25 parts of benzyl chloride, 7-9 parts of sodium hydroxide, 15-35 parts of n-butanol and 0.3-3.0 parts of organic metal catalyst.

3. The oilfield clay swelling shrinking agent of claim 1, wherein the organometallic catalyst is potassium tert-butoxide.

4. The preparation method of the clay swelling shrinking agent for the oil field according to any one of the claims 1 to 3, characterized by comprising the following steps:

(1) adding polyethylene polyamine into a closed reaction kettle with a heat exchange condensation reflux tower and an interlayer heating and cooling facility, heating and maintaining, and sequentially adding sodium hydroxide, n-butanol, an organic metal catalyst and benzyl chloride under the stirring condition;

(2) after the temperature is raised, the reaction is continued for a period of time;

(3) when the pH value reaches 8-10, cooling, centrifugally filtering out solid particles, wherein the filtered liquid is the expansion agent stock solution;

(4) the solid particles filtered in the step (3) are sodium chloride, and the sodium chloride is washed and dried and then is used for ion exchange in an industrial softened water process;

(5) and (3) washing water for washing solid particle sodium chloride in the step (4) or washing softened water of the reaction kettle after the reaction in the step (3) is finished, and preparing a swelling shrinkage agent product which is a red brown transparent liquid.

5. The method for preparing the clay swelling-shrinking agent for oil field according to claim 4, wherein in the step (1), the temperature is kept constant when the temperature is raised to 50-80 ℃.

6. The preparation method of the clay swelling shrinking agent for the oil field according to the claim 4, characterized in that in the step (2), the temperature is raised to 90-120 ℃ for 5-8 h.

7. The method for preparing the clay swelling shrinking agent for the oil field according to the claim 4, wherein in the step (3), when the reaction pH is measured to be 8-10, the temperature is reduced to below 40 ℃ for filtration and discharging.

8. The method for preparing the clay swelling and shrinking agent for the oil field according to claim 4, wherein in the step (5), the swelling and shrinking agent product is prepared by using the swelling and shrinking agent stock solution as a solute and using water for washing sodium chloride or softened water in a reaction kettle after the washing reaction as a solvent, and the mass fraction of the swelling and shrinking agent product is 20%.

Technical Field

The invention relates to a special product in the technical field of water injection operation in the oil extraction process of an oil field. In particular to a clay swelling and shrinking agent for oil fields and a preparation method thereof.

Background

In the process of oil field exploration and development, clay in a shale water-sensitive stratum expands when meeting water, so that a low-permeability oil production throat is blocked, and the following problems are caused: because the oil production throat is blocked, the oil cannot be produced, the balanced formation pressure water injection cannot meet the injection allocation requirement or cannot be injected at all, and the oil production efficiency is greatly reduced.

The products on the market at present are non-rigid structure products of large cations formed by polymerizing organic small cations generated by substituting dimethylamine, trimethylamine, unsaturated epoxy groups and alkenyl groups or small cations with unsaturated bonds, and in order to reduce cost, the products are compounded with materials such as inorganic salt ammonium chloride and potassium chloride to different degrees, the shrinkage-expansion capacity of the products is low (70%), the duration is short, and the defects of secondary blockage caused by underground clay particle migration after long-time flushing of fluid (30 days or shorter time can lose effect) are overcome. Meanwhile, the small molecular amine has strong volatility and low flash point, so that the production is a serious challenge for safety and environmental protection.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide the clay swelling and shrinking agent for the oil field and the preparation method thereof, wherein the clay swelling and shrinking agent can shrink clay particles, increase the porosity of an oil layer, recover and expand an oil production throat, reduce injection allocation pressure and realize yield increase and injection increase.

In order to solve the technical problems, the invention provides the following technical scheme:

the clay swelling and shrinking agent for the oil field comprises the following components: polyethylene polyamines, benzyl chloride, sodium hydroxide, n-butanol and organometallic catalysts.

The clay swelling and shrinking agent for the oil field comprises the following components in parts by weight: 30-60 parts of polyethylene polyamine, 15-25 parts of benzyl chloride, 7-9 parts of sodium hydroxide, 15-35 parts of n-butanol and 0.3-3.0 parts of organic metal catalyst.

The organic metal catalyst of the clay swelling shrinking agent for the oil field is potassium tert-butoxide.

The preparation method of the clay swelling and shrinking agent for the oil field comprises the following steps:

(1) adding polyethylene polyamine into a closed reaction kettle with a heat exchange condensation reflux tower and an interlayer heating and cooling facility, heating and maintaining, and sequentially adding sodium hydroxide, n-butanol, an organic metal catalyst and benzyl chloride under the stirring condition;

(2) after the temperature is raised, the reaction is continued for a period of time;

(3) when the pH value reaches 8-10, cooling, centrifugally filtering out solid particles, wherein the filtered liquid is the expansion agent stock solution;

(4) the solid particles filtered in the step (3) are sodium chloride, and the sodium chloride is washed and dried and then is used for ion exchange in an industrial softened water process;

(5) and (3) washing water for washing solid particle sodium chloride in the step (4) or washing softened water of the reaction kettle after the reaction in the step (3) is finished, and preparing a swelling shrinkage agent product which is a red brown transparent liquid.

The preparation method of the clay swelling and shrinking agent for the oil field comprises the step (1) of heating to 50-80 ℃ and keeping the temperature constant.

The preparation method of the clay swelling and shrinking agent for the oil field comprises the step (2) of heating to 90-120 ℃ and reacting for 5-8 hours at constant temperature.

In the preparation method of the clay swelling and shrinking agent for the oil field, in the step (3), when the reaction pH is measured to be 8-10, the temperature is reduced to below 40 ℃, and then the filtration and the discharge are carried out.

In the step (5), the swelling and shrinking agent raw liquid is used as a solute, water for washing sodium chloride or softened water of a reaction kettle after washing reaction is used as a solvent, and a swelling and shrinking agent product is prepared, wherein the mass fraction of the swelling and shrinking agent product is 20%.

The technical scheme of the invention achieves the following beneficial technical effects:

1. the clay swelling shrinking agent adopts polyethylene polyamine with strong adsorbability, introduces phenyl derivatives of rigid hexacyclic groups with strong hydrophobicity as raw materials, uses n-butyl alcohol as a solvent and uses organic metal materials as a catalyst, and reacts at a certain temperature and within a certain time to synthesize a long-chain new material.

2. In the new material of the rigid comb-shaped clay swelling and shrinking agent synthesized by the method, the amino strongly adsorbs clay particles, the long chain with rigid groups fixes the clay particles by winding and wrapping, and the double electric layers of the clay particles are strongly compressed to dehydrate and shrink the swelling clay. Because the long-chain twisted rigid structure forms a twisted comb-shaped structure, the fluid scouring resistance is greatly improved, and the use concentration of the product is reduced to a certain extent. In addition, after the benzyl group is grafted, the rigidity and the organic polarity are stronger, the water repellency is stronger, and the comprehensive synergistic effect is better.

3. After being injected, the product can be quickly and electrically adsorbed with clay particles, and the double electric layers of the clay are strongly compressed, so that the clay particles shrink, the porosity of an oil layer is increased, an oil production throat is restored and enlarged, and the purposes of increasing yield and increasing injection are achieved.

4. The anti-swelling rate of the swelling shrinkage agent can reach 90 percent, and the swelling shrinkage rate can reach 35 percent; simulating a dynamic water injection experiment of a rock core, wherein the duration is 150 days; no particle migration occurs.

5. In the preparation process, sodium hydroxide and benzyl chloride are added into raw materials in a slightly excessive molar amount so as to neutralize generated acid as much as possible.

The water for washing sodium chloride or the softened water for washing the reaction kettle after the reaction is finished is used for preparing the expansion-contraction agent diluent, and three wastes are not generated.

Detailed Description

Examples

The mass fractions of the polyethylene polyamine, benzyl chloride, sodium hydroxide, n-butanol, and the organic metal catalyst (XOR) in the clay swelling and shrinking agent for oil field in this example were 51.70%, 25.00%, 8.00%, 15.00%, and 0.30%, respectively.

The organometallic catalyst (XOR) is potassium tert-butoxide, CAS865-47-4, Shanghai Demaol chemical Co., Ltd.

The preparation method comprises the following steps: the product is completed by a closed reaction under the catalysis of a special catalyst at a certain temperature and normal pressure.

(1) Adding polyethylene polyamine, heating to 50-80 deg.C, keeping the temperature, and sequentially adding quantitative sodium hydroxide, n-butanol as solvent, catalyst and benzyl chloride as rigid material under stirring;

(2) after the addition, the temperature is raised to 90-120 ℃ for constant temperature reaction for 5 hours, and then the pH is discontinuously detected;

(3) in the monitoring process, when the pH value is 8-10, the reaction is finished, the temperature is reduced, when the temperature is reduced to below 40 ℃, solid particles are filtered, and the filtered liquid is the original liquid of the swelling and shrinking agent.

(4) The filtered solid particles are sodium chloride, and sodium hydroxide is added into reaction raw materials, so that acid generated gradually in the reaction process can be neutralized, and sodium chloride is directly crystallized and separated out. Washing and drying the filtered sodium chloride solid, and then using the sodium chloride solid for ion exchange in an industrial softened water process;

(5) and (3) water for washing sodium chloride or softened water for washing the reaction kettle after the reaction is finished is used for preparing the swelling shrinking agent diluent, and the swelling shrinking agent diluent is a red brown transparent liquid.

It can be said that no three wastes are produced in the whole reaction process.

(6) Taking the expansion-shrinking agent stock solution as a solute, and taking water for washing sodium chloride or softened water of a reaction kettle after washing reaction as a solvent to prepare an expansion-shrinking agent product with the mass fraction of 20%, wherein the expansion-shrinking agent product is a red-brown transparent liquid.

When the performance of the swelling agent is measured by adopting the swelling agent prepared in the embodiment, the field application concentration is evaluated by preparing the swelling agent product with the mass fraction of 20%.

The test method comprises the following steps:

and (3) measuring the anti-swelling rate: respectively weighing 2.00g and 3.00g of the shrinkage-expansion agent product with the mass fraction of 20 percent into two 250ml beakers, respectively adding 98.00g and 97.00g of distilled water, and uniformly stirring to obtain 2 percent and 3 percent shrinkage-expansion agent solution for later use. The anti-swelling rate of a 2% solution of a swelling and shrinking agent for fracture acidizing was measured as specified in SY/T5971-1994, evaluation method of Properties of Clay stabilizer for Water flooding, clause 4.

And (3) measuring the shrinkage-expansion rate: respectively weighing 0.5g of bentonite, loading into 6 10mL centrifuge tubes, adding 10mL of distilled water into 2 tubes, adding 3% by mass of shrinking and swelling agent (20% by mass of shrinking and swelling agent product) water solution into the other two tubes, shaking thoroughly, adding 10mL of kerosene into the other 2 tubes, standing at room temperature for 2h, loading into a centrifuge, centrifuging at 1550r/min for 15min, reading out the volume V of bentonite in water₁、V₂And V₃。

Calculating the shrinkage-expansion rate formula:

x-epitome,%;

V₁-the sedimentation volume of bentonite in distilled water, mL:

V₂the settling volume of the bentonite after the swelling shrinkage agent for fracture acidification is added is mL;

V₃the settling volume of bentonite in kerosene, mL

And (3) continuous effective evaluation: the core flow tester simulates a formation fluid experiment and detects the change condition of the permeability of the core for 150 days;

and (3) test results: the anti-swelling rate can reach 90 percent, and the shrinkage-swelling rate can reach 35 percent; simulating a dynamic water injection experiment of a rock core, wherein the duration is 150 days; no particle migration occurs.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications are possible which remain within the scope of the appended claims.