CN-117288890-B - Method and device for measuring stability of oil-containing emulsified waste liquid

CN117288890BCN 117288890 BCN117288890 BCN 117288890BCN-117288890-B

Abstract

The invention provides a method and a device for measuring the stability of oil-containing emulsified waste liquid, wherein the method comprises the steps of diluting the oil-containing emulsified waste liquid into oil-containing emulsified waste liquid with different concentrations; obtaining Zeta potential of the oil-containing emulsified waste liquid with different concentrations, obtaining the surface tension and the first derivative of the concentration of the oil-containing emulsified waste liquid with different concentrations, and determining the stability of the oil-containing emulsified waste liquid according to the Zeta potential and the first derivative. The method for measuring the stability of the oil-containing emulsified waste liquid has the advantages of simplicity and easiness in operation, has good test and measurement effects when being applied to simulating the oil-containing waste liquid, can support the optimization and upgrading of the existing process and the development of the green technology, and has application prospects for guaranteeing the high-quality development of enterprises. The invention also provides a device for measuring the stability of the oil-containing emulsified waste liquid, which is used for executing the method for measuring the stability of the oil-containing emulsified waste liquid.

Inventors

ZHANG HUA
ZHANG XIAOFEI
XIE JIACAI
LI TING
SUN XIUMEI

Assignees

中国石油天然气集团有限公司
中国石油集团安全环保技术研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20220617

Claims (8)

1. A method for determining the stability of an oily emulsion waste liquid, the method comprising: diluting the oil-containing emulsified waste liquid into oil-containing emulsified waste liquid with different concentrations; acquiring Zeta potentials of oil-containing emulsified waste liquid with different concentrations; obtaining the surface tension and the first derivative of the concentration of the oil-containing emulsified waste liquid with different concentrations; determining the stability of the oil-containing emulsified waste liquid according to the Zeta potential and the first derivative, wherein the method specifically comprises the following steps: determining the concentration C1 when the absolute value of the Zeta potential is maximum; Determining the concentration C2 of the first derivative mutation point; determining the stability of the oil-containing emulsified waste liquid according to the concentration C1 and/or the concentration C2, wherein the method specifically comprises the following steps: determining the stability of the oil-containing emulsified waste liquid according to the ratio R of the concentration C1 to the concentration C2; Wherein r=c1/C2; When R is more than or equal to 3, the oil-containing emulsified waste liquid is very stable; R is more than or equal to 1.5 and less than or equal to 3, the oily emulsified waste liquid is stable; r is less than 1.5, and the oil-containing emulsified waste liquid is unstable; the determining of the concentration C2 specifically includes: According to the change relation of the surface tension of the oil-containing emulsified waste liquid with different concentrations along with the concentration, acquiring the first derivative of the surface tension and the concentration; When the first derivative has only one mutation point, the corresponding concentration of the mutation point is concentration C2; When there are multiple mutation points in the first derivative, the mutation point corresponds to the lowest concentration as concentration C2.
2. The method of claim 1, wherein the greater the concentration C1, the less stable the oily emulsion waste.
3. The method of claim 1, wherein the smaller the concentration C2, the higher the stability of the oily emulsion waste.
4. The method according to claim 1, wherein the dilution of the oily emulsion waste liquid into oily emulsion waste liquid with different concentrations comprises the following steps: The oil-containing emulsified waste liquid is prepared by mixing and diluting deionized water and the oil-containing emulsified waste liquid, and the volume concentration range of the oil-containing emulsified waste liquid with different concentrations is 1-100%.
5. A device for measuring the stability of oil-containing emulsified waste liquid is characterized by comprising an acquisition unit and a determination unit, The device comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring Zeta potentials of oil-containing emulsified waste liquid with different concentrations and first derivatives of surface tension and concentration of the oil-containing emulsified waste liquid with different concentrations, wherein the oil-containing emulsified waste liquid with different concentrations is formed by diluting the oil-containing emulsified waste liquid; The determining unit is used for determining the stability of the oil-containing emulsified waste liquid according to the Zeta potential and the first derivative acquired by the acquiring unit; the determining unit determines the stability of the oil-containing emulsified waste liquid specifically includes: determining the concentration C1 when the absolute value of the Zeta potential is maximum; Determining the concentration C2 at the first derivative mutation; Determining the stability of the oil-containing emulsified waste liquid according to the concentration C1 and/or the concentration C2; the determining unit determines the stability of the oil-containing emulsified waste liquid specifically includes: determining the stability of the oil-containing emulsified waste liquid according to the ratio R of the concentration C1 to the concentration C2; Wherein r=c1/C2; When R is more than or equal to 3, the oil-containing emulsified waste liquid is very stable; R is more than or equal to 1.5 and less than or equal to 3, the oily emulsified waste liquid is stable; r is less than 1.5, and the oil-containing emulsified waste liquid is unstable; the determining unit determining the concentration C2 specifically includes: According to the change relation of the surface tension of the oil-containing emulsified waste liquid with different concentrations along with the concentration, acquiring the first derivative of the surface tension and the concentration; When the first derivative has only one mutation point, the corresponding concentration of the mutation point is concentration C2; When there are multiple mutation points in the first derivative, the mutation point corresponds to the lowest concentration as concentration C2.
6. The apparatus according to claim 5, wherein the higher the concentration C1 determined by the determining unit, the lower the stability of the oily emulsion waste liquid.
7. The apparatus according to claim 5, wherein the smaller the concentration C2 determined by the determining unit is, the higher the stability of the oily emulsion waste liquid is.
8. The device of claim 5, wherein the volume concentration of the oil-containing emulsified waste liquid with different concentrations ranges from 1% to 100%.

Description

Method and device for measuring stability of oil-containing emulsified waste liquid Technical Field The invention relates to the technical field of emulsion analysis and detection, in particular to a method and a device for measuring stability of oil-containing emulsified waste liquid. Background In recent years, the waste liquid from the transformation of unconventional oil and gas development reservoirs has greatly progressed in the aspects of classification treatment technology and large-scale equipment, but under the targets of green, environment-friendly and low-carbon industrial production, the waste liquid treatment of oilfield operation still faces the requirements of continuous improvement and optimization. Particularly, with the improvement of the production mode of unconventional oil and gas fields, the application of the high polymer fracturing fluid is large-scale, and because the stabilization and separation mechanism of the oily emulsified waste liquid is unclear, the optimization and the efficiency improvement of the recycling treatment process lack the basis, the treatment difficulty of the flowback fluid is increased, and the knowledge limit of the stability and the separation mechanism of the flowback fluid needs to be broken through. Stability is a permanent manifestation of emulsification in the environment, stable emulsified forms requiring the presence of emulsifiers such as clay particles, chemicals, naphthenic acids, etc., forming a rigid layer around the dispersed droplets, preventing coalescence from occurring. The research on the oil-containing emulsion stabilizing system is started earlier abroad. In 1910, ostwald pointed out two emulsification types, O/W and W/O, and subsequently proposed a variety of emulsion stability mechanisms. Among these, the accepted stabilization theory is the charge balance theory. There are three possible sources of charge on the colloidal particles, namely ionization, adsorption, frictional contact between the oil droplets and the medium. It is considered that the emulsion is stable due to mutual repulsion of charges on the colloid, so that the liquid beads are not easy to aggregate, and the emulsion becomes stable, and three parameters, namely interfacial tension, interfacial film property and interfacial charge are involved. Under the condition that the oil-water interface area is unchanged, the influence of the reduction of the interfacial tension on the stability of the crude oil emulsion is two, namely, the interfacial free energy is reduced, the unstable trend of the emulsion is reduced, so that the emulsion becomes more stable, and the emulsification of the crude oil and water is easier, and the thermodynamic unstable trend is increased. The interfacial film strength is a main intrinsic factor affecting the stability of crude oil emulsion, especially when solid particles or polymers are adsorbed on the oil-water interface, so that the capability of preventing coalescence of liquid beads is enhanced, and the emulsion is more stable. Although the mechanism and the detection method of the liquid film interface in the demulsification process are more studied, the research on multiphase forms such as oil content, polymers, clay particles and the like of actual waste liquid is still lack of deep analysis. Therefore, aiming at the technical requirements of on-site waste liquid treatment, cost reduction and synergy, the research on the stability of the oil-containing emulsified waste liquid is urgently needed. It is desirable to provide a method for determining the stability of an oily emulsion waste. Disclosure of Invention The application provides a method and a device for measuring the stability of oil-containing emulsified waste liquid, which are used for solving the problems that the existing method can not quickly provide the stability information of the emulsified waste liquid and is difficult to support the efficient low-cost destabilizing process. In order to achieve the above object, the present invention provides the following technical solutions: a method for determining the stability of an oily emulsion waste, the method comprising: diluting the oil-containing emulsified waste liquid into oil-containing emulsified waste liquid with different concentrations; acquiring Zeta potentials of oil-containing emulsified waste liquid with different concentrations; obtaining the surface tension and the first derivative of the concentration of the oil-containing emulsified waste liquid with different concentrations; and determining the stability of the oil-containing emulsified waste liquid according to the Zeta potential and the first derivative. Further, the determining the stability of the oil-containing emulsified waste liquid specifically comprises: determining the concentration C1 when the absolute value of the Zeta potential is maximum; Determining the concentration C2 of the first derivative mutation point; and determining the stability of th