阅读说明：本技术 一种泡沫稳定性的评价方法 (Foam stability evaluation method ) 是由 华朝 靖波 王姗姗 张健 王秀军 胡科 陈文娟 赵文森 王大威 张世仑 于 2019-10-18 设计创作，主要内容包括：本发明公开了一种泡沫稳定性的评价方法。该方法包括：1)在温度T下,取体积为V的起泡剂溶液进行搅拌,搅拌结束后立即启动秒表计时；2)将步骤1)产生的泡沫倒入量筒中,加入浮标,读取并记录起泡剂的发泡体积V<Sub>0</Sub>；3)在设定温度下,读取t时刻泡沫总体积V<Sub>1</Sub>及析出液体体积V<Sub>2</Sub>,按公式K<Sub>t</Sub>＝(V<Sub>1</Sub>-V<Sub>2</Sub>)/V<Sub>0</Sub>计算泡沫衰变率；令K<Sub>t</Sub>＝0时,t＝T<Sub>0</Sub>；若T<Sub>0</Sub><120min,则所述起泡剂溶液产生的泡沫强度为0级；所述K<Sub>t</Sub>越小,则所述起泡剂溶液产生的泡沫强度越低。该方法操作简单,规避“虚泡”影响,泡沫界面清晰,数据读取方便,同时对高强度泡沫实现分级评价,有效实现对泡沫强度快速评价。(The invention discloses an evaluation method of foam stability. The method comprises the following steps: 1) at the temperature T, stirring the foaming agent solution with the volume of V, and starting a stopwatch to time immediately after the stirring is finished; 2) pouring the foam produced in step 1) into a measuring cylinder, adding a buoy, reading and recording the foaming volume V of the foaming agent 0 (ii) a 3) At a set temperature, reading the total foam volume V at the time t 1 And volume V of precipitated liquid 2 According to formula K t ＝(V 1 ‑V 2 )/V 0 Calculating the foam decay rate; let K t When T is 0, T is T 0 (ii) a If T 0 <120min, the foam strength generated by the foaming agent solution is 0 grade; said K t The smaller the frother solution, the lower the froth strength produced. The method is simple to operate, avoids the influence of 'virtual bubbles', is clear in foam interface, is convenient to read data, and meanwhile, realizes grading evaluation on high-strength foam and effectively realizes quick evaluation on the foam strength.)

1. A method for evaluating foam stability, comprising:

1) at the temperature T, stirring the foaming agent solution with the volume of V, and starting a stopwatch to time immediately after the stirring is finished;

2) pouring the foam produced in step 1) into a measuring cylinder, adding a buoy, reading and recording the foaming volume V of the foaming agent₀；

3) At a set temperature, reading the total foam volume V at the time t₁And volume V of precipitated liquid₂According to formula K_t＝(V₁-V₂)/V₀Calculating the foam decay Rate K_t；

Let K_tWhen T is 0, T is T₀(ii) a If T₀The foam strength generated by the foaming agent solution is 0 grade when the time is less than or equal to 120 min;

said K_tThe smaller the frother solution, the lower the froth strength produced.

2. The method of claim 1, wherein: in the step 1), T is 0-100 ℃;

v is 50-200 mL;

in the stirring step, the speed is 200-20000 r/min; the time is 20 to 300 s.

3. The method according to claim 1 or 2, characterized in that: the step 1) of stirring is carried out in a Wuyi stirrer.

4. A method according to any one of claims 1-3, characterized in that: in the step 2), the measuring range of the measuring cylinder is 250-2000 mL; the inner diameter R satisfies the following condition: 40mm < R <90 mm.

5. The method according to any one of claims 1-4, wherein: in the step 2), the diameter D of the buoy, the depth H of the outer wall of the buoy, the depth H of the inner wall of the buoy and the wall thickness b of the buoy meet the following conditions:

1.5mm≤R-D≤2.5mm，

wherein R is the inner diameter of the measuring cylinder; d is the diameter of the buoy; h is the depth of the outer wall of the buoy; h is the depth of the inner wall of the buoy; b is the wall thickness of the float.

6. The method according to any one of claims 1-5, wherein: in the step 2), the buoy is made of polytetrafluoroethylene or plastic.

7. The method according to any one of claims 1-6, wherein: the step 2) further comprises the following steps: after the foam generated in the step 1) is poured into a measuring cylinder, and before the buoy is added, the foam remained in the foam container is transferred into the measuring cylinder by a scraper.

8. The method of claim 7, wherein: the scraper is a silica gel scraper, a silica gel brush, a hairbrush or a rubber scraper.

Technical Field

The invention belongs to the field of oilfield chemistry, and relates to a foam stability evaluation method.

Background

The foaming agent is a chemical agent widely applied in the petroleum industry, can be applied to drainage gas production, high-temperature steam foam flooding, drilling fluid and the like, and also has the related measures and applications of more foaming agents in offshore oil fields. The evaluation indexes of the foaming agent comprise foaming capacity of the foaming agent, stability of foam, thermal stability, compatibility and the like, and based on different purposes of the foaming agent, the experimental method of the same evaluation parameter is different, and the used experimental instruments are different and uniform.

At present, the evaluation methods aiming at the foaming agent mainly comprise a Roche bubble height method, a foam scanner and a Waring stirring method. Wherein: the Roche bubble height method is a large glass instrument, the assembly and the use are time-consuming and labor-consuming, and the preparation and the reading are not separated; the measurement data is single, and the half life of the analysis solution cannot be measured; the glass instrument has a plurality of nonstandard products. Foam scanners are expensive to equip with; the preparation measurement is not separated, and is not suitable for evaluating a large number of samples. The virtual foam influences interface reading when the foam stability is measured in the Waring stirring method, and meanwhile, the foam half-life period is long, so that the foam is difficult to read, and manpower is restrained; in examining the thermal stability of the foam, the foam half-life cannot be observed in real time.

Disclosure of Invention

The invention aims to provide a quick, simple and convenient evaluation method for foam stability, which is suitable for different application fields.

The invention claims a method for evaluating foam stability, which comprises the following steps:

1) at the temperature T, stirring the foaming agent solution with the volume of V, and starting a stopwatch to time immediately after the stirring is finished;

2) pouring the foam produced in step 1) into a measuring cylinder, adding a buoy, reading and recording the foaming volume V of the foaming agent₀；

3) At a set temperature, reading the total foam volume V at the time t₁And volume V of precipitated liquid₂According to formula K_t＝(V₁-V₂)/V₀Calculating the foam decay Rate K_t；

Let K_tWhen T is 0, T is T₀(ii) a If T₀The foam strength generated by the foaming agent solution is 0 grade when the time is less than or equal to 120 min;

said K_tThe smaller the frother solution, the lower the froth strength produced.

In the step 1) of the method, T is 0-100 ℃;

v is 50-200 mL;

in the stirring step, the speed is 200-20000 r/min; the time is 20-300 s;

the blowing agent solution can be a variety of single or composite systems capable of foaming, such as sodium lauryl sulfate or sodium lauryl sulfate-polymer composite systems; in the sodium dodecyl sulfate-polymer composite system, the polymer is specifically selected from at least one of partially hydrolyzed polyacrylamide, hydrophobic association polymer and amphiphilic polymer;

the step 1) stirring can be carried out in various stirrers; for example, it can be carried out in a Wu Yin stirrer.

In the step 2), the measuring range of the measuring cylinder is 250-2000 mL; the inner diameter R satisfies the following condition: 40mm < R <90 mm.

The diameter D of the buoy, the depth H of the outer wall of the buoy, the depth H of the inner wall of the buoy and the wall thickness b of the buoy meet the following conditions:

1.5mm≤R-D≤2.5mm，h≥1mm，1mm<b<4 mm; b is specifically 2 mm;

wherein R is the inner diameter of the measuring cylinder; d is the diameter of the buoy; h is the depth of the outer wall of the buoy; h is the depth of the inner wall of the buoy; b is the wall thickness of the float.

The buoy is made of polytetrafluoroethylene or plastic.

The step 2) further comprises the following steps: after the foam generated in the step 1) is poured into a measuring cylinder, and before the buoy is added, the foam remained in the foam container is transferred into the measuring cylinder by a scraper.

The scraper is a silica gel scraper, a silica gel brush, a hairbrush or a rubber scraper.

The foam evaluation method provided by the invention is simple to operate, avoids the influence of 'virtual foam', has clear foam interface and convenient data reading, and meanwhile, realizes grading evaluation on high-strength foam and effectively realizes quick evaluation on the foam strength.

Drawings

FIG. 1 is a photograph of foam in a measuring cylinder 30min after adding a buoy;

FIG. 2 is a photograph of the foam in the measuring cylinder after the buoy is added for 80 min;

FIG. 3 is a photograph of the foam in the measuring cylinder after the buoy is added for 80 min;

FIG. 4 is a photograph of the foam in the measuring cylinder at various times after the addition of the float: (a)30min, (b)60min, and (c)110 min.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified. In the following examples, the half-life of the eluent is defined as: reading the time when the liquid separated out from the foam reaches V/2 at the temperature T, namely the half-life period of the separated liquid; the longer the liquid half-life, the greater the foam stability of the frother solution to produce a foam.