RU2379632C1 - Method for measurement of liquid medium characteristics, namely volumetrical flow and viscosity, and device for its realisation - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention is related to the field of measurement of physical-chemical characteristics of liquid mediums and may be used in various fields of industry. Device comprises flow cylindrical body with metering annular channel coaxial to body, unit of generation and picking of electric signal, ground unit for provision of power supply and indication of volumetrical flow, cable joint of ground unit with unit of generation and picking of information electric signal. At the inlet of metering annular channel there is flow rotator installed with circular shape, which is arranged with blades of curvilinear profile in section radial relative to metering channel. In external wall of metering channel of body there is groove arranged, being produced by two cone surfaces, where ball-like rolling body is arranged of magnetic material. At a certain distance from available channel there is the second channel arranged with ball-like rolling body and unit of generation and circuit of information electric signal, which are structurally arranged similarly to the first ones. Using frequency of rotation of the first ball-like rolling body F₁, volumetrical flow of flowing liquid is identified. Ratio of frequency F₁ to frequency of rotation of the second ball-like rolling body F₂ is used to identify viscosity of liquid.

EFFECT: expansion of functional resources.

3 cl, 2 dwg

Description

The invention relates to the field of measuring the physicochemical characteristics of liquid media and can be used in various industries, including automated process control systems in the oil, construction, chemical and food industries, as well as in oilfield geophysics during hydrodynamic studies of wells.

In oilfield geophysics, well research using integrated well equipment [1, 2], which implements a variety of methods for measuring the physicochemical characteristics of the studied fluids in a well, in oil reservoirs, is very relevant. Undoubtedly, the speed (volumetric flow rate) and viscosity, which are the main parameters that describe hydromechanical phenomena in moving fluids (including well conditions).

There are many known methods for measuring the viscosity of a liquid, as well as a number of devices that implement these methods [3-7].

The disadvantage of these methods and devices that implement them [3-7] is the fact that they can only be used in laboratory (stationary) conditions and cannot be applied, for example, downhole research, or other production areas.

Also known are tachometric flow meters [8], one of the disadvantages of which is the occurrence of an additional error in the measurement of flow due to the influence of the viscosity of the measured liquid. Special design decisions are made [9, 10], which make it possible to compensate to some extent the effect of viscosity, which manifests itself in the action of the boundary layer on the outer radial surface of the turbine, on the process of measuring fluid flow.

However, it is known that, despite the general industrial use of turbine flow meters (including in borehole conditions), they have significant drawbacks: difficulty in operation, susceptibility to clogging, unreliability, especially in the presence of hydraulic shocks in the line.

Also known are ball flow meters, including borehole flowmeters [8], which belong to the class of tachometric flowmeters, which in many respects surpass turbine flowmeters in their technical characteristics. In ball flow meters, the main unit for generating an information signal about the flow of fluid in closed channels, that is, in pipelines, is a spherical rolling body of one or another material located in the annular channel groove, moving along a circular path under the influence of a pre-swirling (rotating) fluid flow Wednesday. The frequency of rotation of the spherical body is functionally related to the velocity (flow rate) of the fluid, which is recorded using fairly simple technical solutions of the information signal pick-up unit.

However, in these flow meters, the viscosity of the medium being measured also influences the measurement error of the flow. Nevertheless, this manifestation of viscosity is indirect (as in turbine flow meters), and without special design studies, it is impossible to obtain the function of measuring viscosity in flow meters.

The closest technical solution (prototype) to the claimed method is a method [11] for measuring viscosity, the essence of which is that the liquid is imparted by a rotational motion, the magnetic field is applied to the jet along its axis, the emf is measured (E ₁ and E ₂ ) between radially spaced points in two sections spaced apart along the length of the jet, and the rotational motion is imparted to the entire fluid flow, both EMFs are measured in the decay zone of the rotational perturbation, and viscosity is judged by their ratio.

A device that implements the method [11] contains a cylindrical body-electrode, a fluid flow swirl (jets), coaxially arranged electrodes, an insulator, a magnetic system (solenoid) and a computer, the flow swirl located in the electrode body on the side of the incoming liquid flow, electrodes ( the first and second) are internal and spaced along the axis of the housing, and the first electrode is installed in the zone of the flow swirl.

The disadvantage of this method and its implementing device is the limited list of measurement objects, namely: the possibility of their use for measuring the viscosity of only electrically conductive liquids, which severely limits the scope of their application, including in the oil industry, not to mention their use in oilfield geophysics at conducting downhole research. In addition, it is a rather difficult task to isolate a useful information signal in electromagnetic devices (in particular, in electromagnetic flowmeters) against the background of a variety of interference (transformer, quadrature, electrochemical) [8].

The required technical result (otherwise, the purpose of the creation of the claimed objects) is to provide well-known technical solutions with higher consumer properties, taking into account the expansion of applications.

The required technical result in the claimed method for measuring the characteristics of liquid media, namely, volumetric flow rate and viscosity, in which a liquid stream is imparted to a rotary motion in a ring channel, two spherical rolling bodies rotate along circular paths of the annular grooves located in the decay zone of the rotational fluid perturbation formed inside the pipe and spaced along its length, the frequency F ₁ of the first rotation spherical rolling bodies judged flow flowing liquid and with respect to the frequency F _1, F ₂ frequency of rotation of the second ball-shaped rolling body is judged on the magnitude of the measured viscosity.

The required technical result in terms of a device for implementing the inventive method, as shown by bench and industrial tests of the inventive device and operating experience of the prototype device, is ensured by the fact that the known device comprising a flowing cylindrical body with a measuring, coaxial body, an annular channel at the input of which a ring-shaped flow rotator with radial, relative to the measuring channel, curved profile vanes in cross section, a spherical body of quality a magnetic material located in the measuring channel of the housing, a groove in the outer wall of the measuring channel of the housing to allow the spherical body placed in it along a regular annular path under the influence of a rotating flow of the medium to be measured, and the groove in the measuring channel of the housing is made with surface S, for rolling a spherical body formed by an arc of a circle with a diameter greater than the diameter of the spherical body, the site of formation and removal of the electrical signal, ground the first block for providing power supply and indication, volumetric flow rate, as well as cable connection of the ground block with the node for generating and removing the information electric signal, and at a certain distance, metrologically justified (from the point of view of maximum measurement sensitivity), from the existing groove with a spherical a second groove with a spherical rolling body and a node for generating and removing an information electric signal, structurally made similar to the first, are installed by the rolling body.

An additional difference of the claimed object is the presence in it of a second flow rotator, which allows the measurement of volumetric flow rate and viscosity in the reverse flow of the measured medium.

The required technical result is ensured by the presence of a combination of essential features (characterizing the proposed method and the device implementing it for measuring the characteristics of liquid media, namely, volumetric flow rate and viscosity) with undoubted applicability in industry, which suggests compliance of the claimed objects with the criteria of the invention.

The drawings (see Figs. 1 and 2) show a device for implementing a method for measuring the characteristics of liquid media, namely, volumetric flow rate and viscosity (in a borehole embodiment), which comprises: a flowing cylindrical body 1 with a measuring, coaxial body, annular channel 2 at the input of which a rotator 3 of a ring-shaped flow with radial, relative to the measuring channel, blades of curved profile in cross section is installed, a spherical rolling body 4 of magnetic material placed in the measuring chamber a housing aperture, a groove 5 in the outer wall of the measuring channel of the housing to allow the spherical body 4 located therein to move along a regular annular path under the influence of a rotating flow of the measured medium, and the groove 5 in the measuring channel of the housing is made with surface S, for rolling the spherical body 4, formed by an arc of a circle with a diameter larger than the diameter of the spherical body, the node 6 for the formation and removal of the electric signal, the ground block (not shown) to provide electric Tanya and the work and recording the volumetric flow rate and viscosity, the cable connection block land 7 to node 6 formation and removal information of the electric signal. At a certain distance, metrologically justified (from the point of view of maximum measurement sensitivity) from the existing groove 5 with a spherical rolling body 4 located in it, having a shape formed by two conical surfaces S ₁ and S ₂ , a second groove 8 with a spherical rolling body 9 is installed and node 10 of the formation and removal of the information electric signal, structurally made similar to the first. In the lower part of the downhole tool, an additional flow rotator 11 is installed (see Fig. 2).

A device for measuring volumetric flow rate and viscosity (for example, its use in the well) works as follows. When the device is installed in the well, its threaded ends (shown, but not shown in separate positions) are connected (screwed) with tubing or some other downhole equipment, while the communication cable 7 is between the ground unit and the nodes ( 6 and 10) the removal of the information electrical signal, is attached by well-known technical means to the tubing.

The operation of the device (as a downhole tool) can occur in the following modes:

1) the mode of measuring the volumetric flow rate of the liquid (with forward and reverse flow direction of the measured medium);

2) the mode of measuring the viscosity of the liquid (with forward and reverse flow direction of the measured medium);

3) a comprehensive mode of measuring the volumetric flow rate and fluid viscosity (with the forward and reverse flow direction of the measured medium).

Naturally, the most preferable is a comprehensive measurement mode, and the classification is given here for the convenience of considering the principle of operation of the device in a borehole design.

1. The measurement mode of the volumetric flow rate of the liquid medium

In this mode, measurements are made, for example, in tubing to measure the volumetric flow rate of a liquid (e.g. water) pumped into a well.

The principle of operation of the device is as follows. The measured medium enters the tubing and then part of the flow passes through the central cylindrical cavity of the housing 1, and the other part of the flow is twisted by the flow rotator 3, goes along the measuring annular channel 2, entraining the spherical rolling body (ball) 4 in a circular motion along the annular path of the groove 5, made in the outer wall of the measuring channel of the housing with a surface S and having a shape formed by two conical surfaces S ₁ and S ₂ . The angular velocity (speed) of the ball is a measure of the flow rate of the measured fluid. The rotation frequency of the ball F ₁ , which is directly proportional to the flow rate and, therefore, the volumetric flow rate of the passing fluid, is converted into an electric frequency signal either by an induction, or inductive, or magnetically controlled contact of the unit 6 for generating and removing an electric signal. Further, an electrical signal with a frequency of F _{1 is} converted by a microcontroller (not shown in FIG. 1), which is part of the unit 6 for forming and removing an electric channel, into a flow, and the flow information is transmitted via cable connection 7 to a ground unit (not shown) , which performs the functions of power supply and volume flow indication.

When the flow direction of the measured medium changes (see FIG. 2), the flow is twisted by the second flow rotator 11, respectively, the second spherical rolling body 9 comes into rotation, the rotation frequency of which is perceived by the second electric signal generation and acquisition unit 10, and then the flow rate information is transmitted via cable communication 7 to the ground unit.

2. The mode of measuring the viscosity of the liquid.

Let the flow of the medium to be measured flow (see FIG. 2) from top to bottom, while under the action of the rotating flow, spherical rolling bodies 4 and 9, respectively, having rotational speeds F ₁ and F ₂ , respectively, come into rotation through their grooves the inequality F ₁ > F ₂ must be observed. We substantiate this statement by the following reasoning.

In connection with the condition of continuity of flow (or continuity of flow) [12] for an incompressible fluid, we can write:

where Q is the flow rate of the fluid;

ϑ - average (linear) flow rate;

s is the cross-sectional area of the pipeline.

Based on this, for our case, the following equality will be true:

where Q ₁ and Q ₂ are the fluid flow rates respectively in sections S ₁ and S _{2 of the} location of the first 5 and second 8 grooves. Therefore, you can write:

but, since s ₁ = s ₂ , a Q ₁ = Q ₂ , we can write:

where K ₁ and K ₂ - respectively, the scaling factors.

We prove that in our case, when the ring-shaped grooves 5 and 8, along which the spherical bodies 4 and 9 move under the action of a rotating flow, are linearly, along the flow, spaced from each other at a certain distance, in the general case

and in a particular case

This inequality is true for both laminar and turbulent modes of fluid flow in closed pipelines.

When fluid moves through the pipeline, due to viscosity, forces of hydraulic resistance (friction) arise, as a result of which the fluid particles are inhibited, and the speed of the particles decreases as they move away from the pipe axis. To overcome the frictional resistance and maintain a uniform translational motion of the fluid, it is necessary to expend energy, called the lost energy or the lost pressure h _tp .

Losses of friction pressure in the laminar regime are proportional to the average flow velocity and viscosity of the moving fluid and do not depend on the state of the inner surface of the pipe walls. This is explained by the fact that the liquid adheres to the walls of the pipeline, as a result of which the friction of the liquid against the liquid, and not the liquid against the wall, occurs. The following formulas are given in [12, p. 160]:

where λ is the coefficient of hydraulic friction;

l is the linear flow length;

d is the diameter of the pipeline;

R _e is the Reynolds number;

υ is the kinematic viscosity of the liquid;

ϑ is the average linear fluid velocity.

q is the acceleration of gravity.

For turbulent fluid flow, the following functional relationship is valid:

where k / d is the ratio of the absolute roughness to the diameter of the pipeline (relative roughness).

Analyzing expressions (8, 9, and 10), we can draw the following conclusions. The hydraulic friction coefficient in pipelines is proportional to the viscosity of the moving fluid for the laminar flow regime (formula 9) at low Reynolds numbers (up to 2000), and for the turbulent flow regime it is proportional to viscosity and relative roughness (formula 10). Moreover, in the second case (turbulent mode), the influence of roughness on a change in the coefficient of hydraulic friction is the smaller, the smaller the ratio k / d, or the greater the ratio r / k, where r is the radius of the pipeline. It follows from [12, Fig. XII.4, p. 169] that for hydraulically smooth pipes with a relative roughness r / k> 500, the coefficient of hydraulic friction varies linearly in the range of Reynolds numbers from 2.6 to 5.3 (logarithmic scale ) and depends only on the viscosity of the liquid.

Thus, taking into account the above, we should expect a decrease in the frequency _of rotation F ₂ of the second spherical rolling body 9 due to the attenuation of the rotational motion due to the action of viscous friction, and in the general case we can write:

and finally we will have

where υ is the kinematic viscosity of the liquid;

K is the scaling factor;

L is the distance between the centers of the grooves 5 and 8.

The test results of the experimental sample showed that for reliable measurement of viscosity, the following conditions must be observed:

- the density of the spherical rolling body should be close to the density of the measured fluid. In this case [13, p.30, 31], the systematic error of the velocity measurement method disappears;

- the distance L between the centers of the grooves is found experimentally, taking into account the cleanliness of the surface treatment of the grooves, the measuring coaxial annular channel and the greatest sensitivity of the detected frequency gradient;

- to reduce the measurement error it is necessary to use not instantaneous measurements of the frequencies F ₁ and F ₂ , but their average estimates.

When the flow direction changes, the viscosity is measured in the same way as described above, and formula (13) is transformed to:

3. The complex mode of flow and viscosity measurement occurs in the sequence given in the description of modes 1 and 2, taking into account the conditions of measurement of mode 2.

Thus, in view of the foregoing, the claimed object is subject to protection as an industrial property object with the issuance of the relevant security document to the applicant.

Information sources

1. Gabdullin T.G. Development of integrated downhole equipment on a single-core cable, as applied to the station for the study of existing wells. Report on the topic No. 134-76. Funds VNIINPG. Ufa, 1977.

2. USSR, A.S. No. 1051247, M class ³ . ЕВВ 47/10, 1982.

3. USSR, A.S. No. 1746254, M. Cl ⁴ . G01N 11/10, 1992.

4. USSR, A.S. No. 1081473, M. Cl ³ . G01N 11/10, 1984.

5. USSR, A.S. No. 1837208, M. Cl ⁴ . G01N 11/10, 1993.

6. USSR, A.S. No. 1300333, M. Cl ⁴ . G01N 11/10, 9/10, 1987.

7. Tomus Yu.B. Development and research of IMS to determine the main rheological parameters of drilling fluids in drilling. Abstract of dissertation for the degree of candidate of sciences. Kuibyshev, 1976 .-- 14 p.

8. Abramov G.S., Barychev A.V., Zimin M.I. Practical flow measurement in industry. M., JSC "VNIIOENG", 2000. - p.104-109.

9. USSR, A.S. No. 322623, M.C. G01f 1/06, 1970.

10. USSR, A.S. No. 301540, IPC G01f 1/12, 1969.

11. USSR, A.S. No. 868473, M.cl ³ . G01N 11/16, 1980 (prototype).

12. Altshul A.D., Kiselev P.G. Hydraulics and aerodynamics (Fundamentals of fluid mechanics). Textbook for universities. Ed. 2nd, rev. and add. M., Stroyizdat, 1975.332 s. (P. 67).

13. Sheypak A.A. Hydraulics and hydropneumatic actuator: Textbook, Part 1. Fundamentals of fluid and gas mechanics. 4th ed., Stereotyped. - M.: MGIU, 2005 .-- 192 p.

Claims (3)

1. A method of measuring the characteristics of liquid media, namely, volumetric flow rate and viscosity, in which a stream of liquid in the annular channel is imparted rotational motion, characterized in that the rotating fluid is rotated by two spherical rolling bodies moving along the annular paths of annular grooves located in the attenuation zone rotational perturbations formed inside the pipeline and spaced along its length, according to the rotation frequency F ₁ of the first spherical rolling body, they judge the volumetric flow rate of the flowing fluid, and the ratio of the frequency F ₁ to the frequency F ₂ rotation of the second spherical rolling body is judged on the value of the measured viscosity. 2. A device for implementing a method for measuring the characteristics of liquid media, namely, volumetric flow rate and viscosity, according to claim 1, comprising a flowing cylindrical body with a measuring coaxial body with an annular channel, at the input of which there is a ring-shaped flow rotator with curved blades radial relative to the measuring channel in cross section, a spherical rolling body of magnetic material placed in the measuring channel of the housing, a groove in the outer wall of the measuring channel of the housing for sintering the possibility of movement of a spherical body placed in it along a standard annular path under the influence of a rotating flow of a measured medium, and the groove in the measuring channel of the housing is made with a surface S for rolling a spherical body formed by an arc of a circle with a diameter larger than the diameter of the spherical body, the formation and removal unit an electric signal, a ground unit for providing power and an indication of the volumetric flow rate, as well as cable communication between the ground unit and the formation and removal unit information electric signal, characterized in that at a certain distance, metrologically justified from the point of view of maximum measurement sensitivity, from the existing groove with a spherical rolling body located in it, having a shape formed by two conical surfaces S ₁ and S ₂ , a second groove with a spherical the rolling body and the node for the formation and removal of the information electric signal, structurally executed similarly to the first. 3. A device for implementing the method of measuring flow and viscosity according to claim 2, characterized in that it is equipped with an additional flow rotator, which allows the measurement of flow and viscosity in the reverse flow of the medium to be measured.

Images