FI110335B - Measuring flow directions and velocities - comprises sealing off volumetric section, dividing section into three sectors and using sensors placed in flow ducts - Google Patents

Abstract

Flow measuring procedure for measuring liquid flow in a hole bored in the ground comprises: (a) certain volumetric section being sealed off from hole in longitudinal direction; (b) volumetric section being divided into at least three sectors (1); (c) sectors being interconnected via flow ducts (2) permitting free flow between sectors; and (d) directions and velocities of currents between sectors being measured by sensors (4) placed in flow ducts.

Description

110335

FLOW MEASUREMENT METHOD AND FLOW METER

The invention relates to a measuring method as defined in the preamble of claim 1 and to a flow meter as defined in the preamble of claim 4.

Particularly when searching for nuclear waste disposal sites, it is necessary to know the types of currents present in the soil rock and its various fissures. In other words, where the currents are moving and at what speed.

Problems with such measurements are caused by the small volumes and low speeds of the flow rates. In the prior art, attempts have been made to determine the magnitudes of the flows by separating the known portion from the hole drilled in the rock and filling it with a suitable mixture or solution, thereby monitoring the flow changes in the concentration of this mixture or solution. However, this does not provide information on the direction of the flows.

20 There have been attempts to determine the directions of currents by using various markers, the flow of which may be • • • observed in rock formations.

The problem with all known flow measurement methods is their slowness. Because flow rates are about an order of magnitude per milliliter, one measurement usually takes months to obtain results over a wide range of drilled holes. is expensive and slow.

#. . The object of the invention is to eliminate the disadvantages mentioned above. In particular, it is an object of the invention to provide a novel method and flow measure; tari, which can be used to measure very small currents relatively quickly and to know both magnitude and direction of currents.

»Φ. 35 With respect to the features characterizing the invention, "*" refers to the preamble.

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In the method of the invention, a rock; the drilled test hole is separated longitudinally

In this case, a certain volume period over which the flows are studied. The volume period is subdivided into end-to-end sectors, such as four 90 ° sectors, in the longitudinal direction of the hole, such that the sectors form separate, separated volumes in the volume period. The sectors are then interconnected by flow channels that allow free flow between sectors 10. Then the sensors in the flow channels measure the intersectoral! J

water currents, ie their directions and velocities.

Thus, the method according to the invention is based on dividing a certain portion of the drilled hole into longitudinal portions, i.e., flows entering or exiting sectors and sectors, or concentrating them in a suitable flow channel system so that flows occurring in different sectors can be measured.

Advantageously, flow measurement in a flow channel is accomplished by providing an impulse suitable for the flow, the movement of which provides the direction and velocity of the flow to obtain flow rates through the flow channel cross section. Preferably, the impuls-25 you use an extremely small thermal pulse, for example 1/1000 °, whose movement is monitored. The heat pulse must be extremely small so that it does not cause turbulence at low currents and that heat is not conducive to counter current. In this way, measurements can be made at very low flows, of the order of one milliliter per hour.

The flow meter according to the invention consists of a cylindrical, long piece having two annular • · *; earth and internal pressure expandable members! · · · 35 protruding members in the longitudinal direction of the hole to be examined: ·. Similarly, the flowmeter includes a divider extending against the bore of the hole, allowing the volume period to be pressure-tightly divided into at least three, preferably four, sectors of the sealing member. sensors are placed so that when flows occur between sectors, the directions and velocities of flows can be measured.

Preferably, an impulse source is provided at the junction of the flow channels, wherein the sensors measure impulse movements in the flow channels.

Preferably, the sectors utilize manifolds through which flows to the sectors pass into the respective flow channels as the flow channels join outside the separated volume period symmetrically at the common center of the flow channels where the impulse source is located.

Preferably, a heating thermistor is used as the pulse source and measurement thermistors 20 are used as sensors to detect the thermal pulse transmitted by the heating thermostat.

Because the flow can vary widely across • parts of the hole, which can be up to • thousands of meters, large pressure fluctuations can occur across the flow meter. For this reason, preferably • · · * * ;; 'open pipe' or other flow channel that allows free flow through the 'flowmeter' · '· through the flowmeter between the portions of the hole on the opposite side of the flowmeter. * ": Or damage the meter.

. *. Preferably, the * * * • »· open tube passing through the flow meter is provided with flow sensors to measure the amount of fluid flowing through the '··' tube.

Advantageously, the measurement is performed with a suitable impulse source, with suitable transducers on both sides of the • • 4 110335, for measuring the direction and velocity of the impulse.

The measuring method and flow meter according to the invention have significant advantages over the prior art ankle. Significantly smaller currents can be measured with the invention than was previously possible. Likewise, the directions and magnitudes of the flows, both in the longitudinal direction of the hole and by region, can be measured. In addition, the measurement according to the invention is considerably faster than the corresponding prior art measurements which take about two months in one hole when the better and more versatile measurement results according to the invention are obtained in less than a week.

In the following, the invention will be described in detail with reference to the accompanying drawing, in which Figure 1 is a partially sectional view of a flowmeter according to the invention, Figure 2 is a cross-sectional view of Figure 1; : details and Figure 4 shows another one of the meter of Figure 1 - '* ·; further details.

The flowmeter according to the invention, shown in the drawing, comprises cylindrical tubular: '·· an annular * sealing members 5, i.e., elastic parts extending outwardly under the inner pressure. Between the sealing members 5 3 0 is a cross section according to Fig. 2

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···, four dividing members 6, i.e. a ridge or wall extending from one sealing member to another, dividing the space between the sealing members into four 90 ° sectors. The and • · * test members are sealing members, respectively, in the interior ....: 35, expandable and compressible under pressure.,,; outwards against the surfaces of the hole to be examined.

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110335 5

Each sector 1 has a flow channel 2 extending throughout its length, which through a plurality of openings 11 opens into the sector.

The flow channels 2 extend from the sectors past the upper sealing member 5 to the sensor section 12, where, as shown in Figure 3, the flow channels are symmetrically interconnected with respect to the center axis of the flow meter to provide free and substantially unobstructed flow links between the sectors.

As shown in Figure 3, a heating thermistor 3 is disposed at a junction of the flow channels 2, at their center of symmetry, and measuring thermistors 4 acting as sensors are located at each flow channel 2 at the same distance from the heating thermistor.

In addition, the flowmeter includes an end-to-end open tube 7 that allows free flow between the portions of the hole on each side of the flowmeter. In this open pipe is placed the heating thermistor 9 and on both sides 20, at a suitable distance in the flow direction, the sensors 8 with which the heat pulse 10 | travel speed and direction can be measured.

| Figure 3 shows the junction of the flow channels 2 | at the top there is a valve 25 closed by a valve and a hose 16 which can be opened. Hose 16 extends to the ground • · · ;; · 'In measurement and has three different applications * · • *'. At the highest point of the measuring arrangement, gas may be generated, which will obstruct the measurement and may be removed along the hose 16 by opening the vented brick therein. Secondly, water can be fed through the hose 16 at a suitable pressure and subjected to a • · · water conductivity test. Third, pressure measurement of the measuring interval can be carried out through the hose 16.

* ·

In addition, the upper end 13 of the apparatus includes a processor, amplifiers, filters, a magnetometer, an A / D converter, and valves for operating the flowmeter and measuring means.

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ί j 110335 f 6 The results are known per se. Thus, they are not described in further detail herein. The flowmeter is connected to the ground by a cable 14 and a pressure hose 15, the upper portion of the ground comprising a suitable winch or other hoisting means for raising and lowering the flowmeter to the hole to be examined and a suitable measuring computer or other similar data processing device.

The flowmeter shown in the drawing is operated as follows.

| The flowmeter is lowered by the cable 14 into the hole to be examined at the desired survey height, preferably at a height known to have some currents in the rock fractures. Once the flow meter 15 has been drilled into the hole drilled to the desired depth, the sealing member 5 as well as the manifolds 6 are bulged and pressed against the hole shell by a pressure hose 15 to form four sector-like sections spaced apart

Thereafter, flows between different sectors. : They are only possible through flow channels 2.

| In this case, by sending an impulse source 3, a thermal pulse! The flow sensors 4 can measure the direction of motion of the thermal pulse • · * 25 and the speed of movement and obtain accurate information on the flow rates of the · · · ·· · * sectors between different sectors. In a similar manner, by means of a heat pulse 10 in the open pipe 7, flow information »» · V · 'is obtained about the flows acting past the flowmeter.

30 Because the flows in such measurements are extremely small, even as little as a milliliter per hour, very small amounts of heat are also used as a heat pulse. Thus, the heating of the flow must be so small that it neither causes turbulence in the flow nor; ·; 35 heat may be due to upstream current, therefore, operating temperatures are in the order of 1 mK.

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The invention has been described above by way of example with reference to the accompanying drawings, in which various embodiments of the invention are possible within the scope of the claimed inventive concept.

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Claims (12)

1. Flow measurement method for measuring the fluid flow in one in the ground, such as in a rock, drilled heel, whereby the heel in the longitudinal direction is sealed separately a certain volume section, characterized in that - the volume section is divided into at least three sectors (1), - the sectors are joined to each other by flow channels (2) which allow a free flow between the sectors; - with the sensors (4) placed in the flow channels, the directions and velocities of the flow between the sectors are measured. 2. A method according to claim 1, characterized in that the directions and velocities of the flows are measured by arranging in the flow an impulse whose movement is observed. Method according to claim 2, characterized in that a pulse of heat is used as a pulse. . . 4. Flowmeter for measuring the fluid flow in a ground, such as in a rock, drilled heel, which flowmeter consists of a cylindrical, elongated piece, belonging to annular sealing means (5). * * In the longitudinal direction of the heel at a distance from each other for separating a certain volume section from the other heel, characterized in that the flow meter belongs: - dividing means (6) for dividing the volume section into at least three from one sealing means for another extending sectors (1), V / - flow channels (2) joining the sectors:: with each other, and '. - sensors (4) placed in the soldering channels for. , 35 measuring the flows between sectors sizes and speeds. 12 110335 A flow meter according to claim 4, characterized in that the contact point between the flow channels (2) hears an impulse source (3) while the transducer (4) follows the impulse as the impulse source transmits direction of movement and speed. Flow meter according to claim 4, characterized in that the sealing means (5) and the dividing means (6) are elastic means which are tightly pressed against the heel of the heel with an internal pressure. Flow meter according to any of claims 4 to 6, characterized in that the flow channels (2) project from the sectors (1) and connect symmetrically with each other relative to the center axis of the sectors. Flow meter according to any of claims 4 to 7, characterized in that the pulse source is a heat thermistor, with which a heat pulse is supplied to the flow. Flow meter according to any of claims 20 - 8, characterized in that the sensor (4) is a meter thermistor. * · .: 10. Flow meter according to any of the claims • · j * ·· 4-9, characterized in that, by means of the • • * * | liner-shaped elongated piece likes an open tube (7), which forms a free flow connection between pipes. * different sides of the flow meter being parts of the heel • past the separated volume section. Flow meter according to claim 10, characterized in that the open pipe is connected to the open pipe. * ·: 30 (7) includes sensors (8) and an impulse source (9) for determining * the liquid flowing through the direction and velocity by means of a heat pulse (10) which is supplied to the flow. A flow meter according to any of claims 1 to 4, characterized in that it is dependent on: *.! the point of contact between the flow ducts (2) is connected to a pipe (16) provided with a valve extending to the ground surface for removing air from the measuring system, for conducting the test of the conductivity of the water at the measuring distance and / or for carrying out the a pressure measurement of the measuring distance. »· * · Φ ·« * * · I · · f 1 9 * * · I I »I · t I I t» * t i f i I ·