Evaluation device and evaluation method for dynamic demulsification and dehydration characteristics of crude oil emulsion

Abstract

The invention discloses a device and method for evaluating dynamic demulsification and dehydration characteristics of a crude oil emulsion. The device comprises an emulsion feeding tank, electric heating devices, a high-speed shearing dispersion machine, an emulsion metering pump, a thermometer, a demulsification box, an emulsion recovery tank, a demulsifier feeding tank, a medicament feeding pump, a high-voltage power supply and an oscilloscope, wherein the emulsion feeding tank and the emulsion recovery tank are connected with an inlet of the emulsion metering pump through a three-way valve; an outlet of the emulsion metering pump is connected with an inlet of the demulsification box; an outlet of the demulsification box is connected with the emulsion feeding tank and the emulsion recovery tank through a three-way valve; a front sampling port and a rear sampling port are formed in an inlet pipeline and an outlet pipeline of the demulsification box respectively; the high-voltage power supply and the oscilloscope are sequentially connected to apply a high-voltage electric field to the demulsification box, and the demulsifier feeding tank and the medicament feeding pump are arranged on the inlet pipeline, in front of the front sampling port, of the demulsification box. The structure is compact, few crude oil emulsions are consumed, continuous flowing is realized, observation is convenient due to the fact that a box body of the demulsification box is made of a transparent material, and the device and the method can be used for quickly evaluating the dynamic demulsification and dehydration characteristics of the crude oil emulsion in a laboratory or a project site.

Description

Technical field [0001] The invention relates to a technique for testing the dynamic demulsification and dehydration characteristics of crude oil emulsion, in particular to an evaluation device and an evaluation method for the dynamic demulsification and dehydration characteristics of crude oil emulsion. Background technique [0002] Water is almost "following" in the process of crude oil exploitation. As oil fields around the world gradually enter the middle and late stages of exploitation and the extensive use of enhanced oil recovery (EOR) technology, the water content in the produced fluid of oil wells has increased year by year, and the degree of emulsification has been increasing. Seriously, not only often the crude oil emulsion with water content higher than 15% enters the electric dehydrator, but also the increase of the thickness of the emulsified layer in the electric dehydrator and the enhanced stability of the emulsion make the original electric dehydrator difficult. T...

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Problems solved by technology

However, there are still many deficiencies in the device: ①The device is large in size and the structure of the high-voltage electric dehydrator is complex. Not only does it need to consume a large amount of crude oil emulsion during operation, but it is also difficult to effectively solve the problem of timely cleaning of the equipment after the experiment is over; ②The The electrode plate of the device is a bare metal material, and a "collapsed electric field" phenomenon will appear when the water content is too high, and it is difficult to make an effective evaluation of the demulsification and dehydration characteristics of different electric field parameters at high water content; In terms of method, the device only monitors the upper layer of crude oil and the lower layer of sewage by using the online water content monitor. When the water content of the crude oil layer is 99.5%, the oil and water are discharged respectively. Observing the oil layer through the window can only evaluate the electric dehydration performance from a macro perspective, and cannot accurately sample and characterize the influence of the electric field on the physical and chemical properties of the emulsion

In summary, it is difficult to use this equipment for applied basic research in the laboratories of non-factory and mining enterprises

[0007] Sinopec Refining and Chemical Engineering Co., Ltd. Cao Zhenxing and others proposed a visual dynamic electric dehydration simulation device in CN203768310U. The main part of the electric dehydration tank is made of glass, which can realize real-time observation of the crude oil emulsion in the tank, but there are the following problems: ① bare metal electrodes cannot implement electric field demulsification for high water content crude oil emulsion; ② Except for the observation of the electric field demulsification and dehydration of the crude oil emulsion in the tank, there are no other evaluation methods, and the conclusions obtained lack a theoretical basis; It can be applied in the laboratory of the enterprise

However, this experimental device also has many shortcomings: ①The electric dehydrator is made of stainless steel, and the flow state of the emulsion cannot be observed in real time during operation; ②The electrode plate is made of bare metal materials. When it is high, the phenomenon of "collapse electric field" will occur, and it is impossible to explore the dehydration characteristics of different electric field parameters under high water content; ③ a large amount of crude oil emulsion is consumed during operation, and it is difficult to carry out systematic and in-depth experiments when the crude oil samples in the laboratory are limited Research; ④The design of the device is complicated, and the pipeline is easily blocked when the viscosity of the crude oil emulsion is too high, and the problem of cleaning the equipment after the experiment is also difficult to solve

[0009] In summary, the experimental results of static demulsification and dehydration of crude oil emulsion in the prior art are quite different from those on the engineering site; the existing commercialized dynamic (electric field) demulsification and dehydration evaluation test device is relatively large in size, and consumes a lot of crude oil emulsion. Moreover, the cleaning and maintenance of the equipment is time-consuming and laborious; moreover, the plates of the existing commercialized dynamic (electric field) demulsification and dehydration evaluation experimental devices are bare metal, which cannot adapt to high-water emulsions

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