JPS6398545A - Apparatus for measuring precipitation temperature of wax - Google Patents

Abstract

PURPOSE:To accurately measure the precipitation temp. of wax in dark color crude oil having a high pour point, by holding a specimen between two transparent glass plates to form the same into a membrane having a thickness of about 0.1mm. CONSTITUTION:A heating medium flows in a cylindrical thermostatic tank 1 from the inlet 2 thereof and flows out from the outlet 3 thereof. A specimen support part on which a specimen 4 is placed is formed in the hollow part of the thermostatic tank 1. The specimen 4 is preliminarily held between transparent glass plates 5, 6 and both ends of said glass plates re fixed by spring type binders 7, 7 to pace the specimen on the specimen support part in a state of a membrane having a thickness of about 0.1mm. The thermocouple 8 mounted on the glass plate 5 is connected to a display device 9. By irradiating the specimen 4 with light from the outside to measure transmitted light, the precipitation of wax is detected and the temp. thereof at that time is read from the display device 9 to measure the precipitation temp. of wax.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for measuring the wax precipitation temperature of crude oil containing wax.

[Prior Art] In recent years, as energy resources have become increasingly popular, heavier crude oil has been increasingly used. Among these types of crude oil, high pour point crude oil containing many waxes is being developed on a large scale in the United States, China, Indonesia, and other countries.

By the way, since these high pour point crude oils exhibit special flow characteristics unlike conventional crude oils, various considerations are required when designing the installation of drilling, piping transportation, and storage. For example, steam heating, addition of pour point depressants, etc. are well known techniques.

Here, it will be explained that the special flow characteristics exhibited by high pour point crude oil are due to the behavior of the waxes contained therein.

First, wax is an organic precipitate composed of various components mainly including normal paraffin and isoparaffin. The structure varies depending on the properties of crude oil, thermal history, etc., and plate-like, needle-like, and irregular crystals called microcrystals are known. Since the wax melts at high temperatures, crude oil behaves like a Newtonian fluid. However, near the pour point or below the clouding temperature (lI point) at which wax begins to precipitate, it becomes a non-Newtonian fluid and behaves as a thixotropic fluid. In this way, high pour point crude oil has completely different rheological properties depending on the temperature. Furthermore, the melting point of wax ranges from several tens of degrees Celsius to nearly 100 degrees Celsius depending on the type of wax. For this reason, the type of wax,
It is no exaggeration to say that the fluidity of crude oil is controlled by its content.

As described above, the behavior of wax precipitation is an important factor that affects handling of high pour point crude oil.

Therefore, when designing equipment such as measures against reflow after shutdown, it is necessary to fully understand the wax precipitation temperature and flow temperature that affect the rheological properties of crude oil.

Conventionally, JIS K2269 has been used as a method for measuring the wax precipitation starting temperature (l point).

This is a method in which a sample is heated to a certain temperature, becomes liquid, then cooled, and the moment when wax begins to precipitate is visually observed.

In addition, the sample was placed in a glass capillary with an inner diameter of 1M,
Instead of visual observation, there is also a method of determining the temperature at which wax begins to precipitate by detecting changes in the intensity of light that passes through the sample.

[Problems to be solved by the invention] However, among the conventional methods described above, the method of visually observing the moment when wax precipitates cannot detect vA with black high pour point crude oil containing heavy components. Yes, it could not be applied. Furthermore, the method of placing a sample in a capillary and detecting changes in the intensity of transmitted light could not be applied to black, high-pour-point crude oil because light does not pass through it, making measurement impossible.

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide an apparatus that can accurately measure the wax precipitation temperature of dark-colored high pour point crude oil, which could not be measured using conventional methods. do.

[Means for Solving the Problems] The wax precipitation temperature measuring device of the present invention uses two transparent glass plates that sandwich a sample to form a thin film in order to transmit light and detect wax precipitation from the transmitted light. The apparatus is characterized by comprising: a constant temperature bath for controlling the temperature of the sample; and means for measuring the temperature of the sample.

According to this type of @ placement, the sample can be made into a thin film with a thickness of about 1 gm by sandwiching the sample between two transparent glass plates, and even if the sample is a highly colored high pour point crude oil, it can be made into a thin film. Since the transmittance of light passing through can be increased, wax precipitation can be detected either visually or with a detector. The temperature at that time, that is, the wax precipitation temperature, can be accurately measured by a temperature measuring means.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a wax precipitation temperature measuring device according to the present invention. In FIG. 1, a heat medium such as water or oil flows into a constant temperature bath 1 having a cylindrical appearance from a heat medium outlet 2 and flows out from a heat medium outlet 3. A step (sample support part) for setting a sample is formed in the hollow part of this constant temperature bath 1. The sample 4 is sandwiched between transparent glass plates 5.6 and fixed at both ends with a spring-type binder 7.7, and the sample 4 is placed in the thermostatic chamber 1 in a state where it is made into a thin film with a thickness of about 0.18 mm. Installed on the support.

As the transparent glass plate 5.6, quartz glass, potash glass, or the like is used. Further, a thermocouple 8 is attached to one transparent glass plate 5, and this thermocouple 8 is connected to a display 9.

Using such a device, the sample 4 is irradiated with light from the outside,
The light transmitted through sample 4 is not shown. l Detect wax deposition by observing it with the eye 7111 with a mirror or the like or by measuring the intensity of transmitted light with a phototube or the like (not shown), and read the temperature detected by the thermocouple 8 at that time with the display 9. Measure the wax precipitation temperature.

Actually, the wax precipitation temperature of high pour point crude oil was measured as follows. The high pour point crude oil used as a sample in these experiments had a specific gravity of <15/4°C.
> 0.8500, wax content 46.2%, residual carbon 4
．． Ivt%, moisture 1.2 vo1%, ask yp)L
/te'/min 0.15wt%, viscosity (70℃) 15cp
Met.

Experimental Example 1 First, as shown in FIG. 1, a sample was exposed to XQ and then subjected to an optical microscope (not shown). After heating the sample to 90°C in advance to make it completely fluid, the sample was heated at 2°C/mi.
The mixture was cooled at a rate of n and the state of wax precipitation was observed using an optical microscope.

As a result, wax began to precipitate at 70°C from a fluid state at 90°C, and then rapidly grew to 62°C.
It was found that the wax had completely precipitated.

Experimental Example 2 First, a sample was installed as shown in FIG. 1, and then a light source, a phototube, and a recorder (not shown) for recording changes in the current value of the phototube were installed. As in Experimental Example 1, the sample was heated to 90°C in advance to make it completely fluid, and then heated to 2°C.
It was cooled at a rate of /min. Figure 2 shows the relationship between temperature and current value.

From FIG. 2, the wax precipitation start temperature was 72° C., and the wax precipitation end temperature was 62° C., which almost coincided with the results of Experimental Example 1.

[Effects of the Invention] As detailed above, according to the wax precipitation temperature measurement device of the present invention, the wax precipitation temperature can be accurately measured even in dark-colored high pour point crude oil, and the wax growth status can also be observed. It has a remarkable effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a wax precipitation temperature measuring device according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the temperature measured using the device and the current value of a phototube. 1... Constant temperature chamber, 2... Heat medium inlet, 3... Heat medium outlet. 4... Sample, 5.6... Transparent glass plate, 7... Binder, 8... Thermocouple, 9... Display device. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] Two transparent glass plates sandwiching the sample to form a thin film to allow light to pass through and detect wax precipitation from the transmitted light, a thermostat to adjust the temperature of the sample, and a means to measure the temperature of the sample. A wax precipitation temperature measuring device characterized by comprising: