JPS6148720A - Measuring instrument for physical quantity in geothermal well - Google Patents

Abstract

PURPOSE:To measure physical quantities if the chute continuously even during the digging of the well by providing a measurement cable which detects the temperature, pressure, etc., in the well between casing pipes, and connecting one terminal of the measurement cable to a measuring mechanism installed on the ground. CONSTITUTION:The measuring device has the casing pipes 3 and 6 and the measurement cable 6 which detects the temperature, pressure, etc., in the well is provided between the casing pipes. Further, one terminal of this measurement cable 6 is connected to the measuring mechanism 11 installed on the ground. When the pressure, temperature, etc., in the well are measured, a signal from a sensor is sent to the measuring mechanism 11 connected to one terminal of the cable 6 to perform signal control, display, and recording. This device eliminates the need to droop the measuring device in the chute every time a measurement is taken, and measures physical quantities in the well continuously even during the digging of the well.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a geothermal well in which physical quantities such as temperature and pressure inside a geothermal well are determined by δIII, in which geothermal fluid is ejected from underground and guided to the surface in geothermal power generation. It relates to a physical quantity measuring device.

[Background technology and its problems] Generally, geothermal power generation involves ejecting fluid containing steam and hot water with some salt through a geothermal well from a reservoir where underground water is heated by magma and stored. The fluid is sent to the momme water pumping device via an anti-Japanese equipment on the ground, where hot water and salt are removed, and the remaining high-temperature steam is guided to a turbine, which generates electricity by a generator driven by the turbine. It is.

Therefore, in order to generate geothermal power, it is necessary to drill a geothermal well and eject geothermal fluid from the reservoir. It is necessary to constantly measure and check physical quantities such as temperature and pressure inside the mine in order to investigate the presence of harmful substances such as hydrogen sulfide gas contained in the fluid, and to take measures to prevent blowouts.

However, in conventional measurements, it was necessary to suspend the measuring instrument into the pit from a tower built to resist the sun in a geothermal well, which not only required large-scale equipment and increased construction costs. There was a problem in that measurements could not be taken with a drilling device inserted into the mine to remove scale accumulated inside the mine.

In addition, conventional δIII determination of underground physical quantities in geothermal wells was a spot measurement in which measuring instruments such as temperature and pressure gauges were inserted when necessary, as described above. Continuous monitoring of flushing points that have a major impact, temperature recovery status inside the mine, and storage
It was not possible to continuously record the data necessary for evaluating the l accumulation layer, such as changes in gj layer pressure.

For this reason, there has been a demand for a measuring device that can measure physical quantities inside a mine even during excavation, and that can constantly monitor necessary data.

[Object of the Invention] The object of the present invention is to provide a physical quantity measuring device for a geothermal well that can continuously measure physical quantities inside the well even while the well is being excavated! i.

[Means for Solving the Problems] In order to prevent the inflow of groundwater near the earth's surface and the collapse of the strata, the present invention provides a geothermal well by inserting and arranging multiple casing pipes into the ground in substantially concentric circles. A measurement cable that can detect the temperature, pressure, etc. inside the well is installed between the casing pipes, and by connecting one end of the measurement cable to a measurement mechanism installed on the ground, the pressure and temperature inside the geothermal well can be measured. It enables continuous measurement of physical quantities such as
[Embodiments] Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of a geothermal well using the physical quantity measuring device of the present invention. In this figure, a geothermal well has a casing pipe section 1 located relatively close to the ground, and a It consists of an open pit section 2 below which leads to a geothermal fluid reservoir.

The bare pit section 2 is made of hard rock and the like, and since there is no risk of collapse of the strata, etc., the structure remains as it was excavated without inserting a casing pipe or the like.

The casing pipe section 1 is composed of a plurality of pipes having different diameters arranged approximately concentrically, and specifically includes a finished casing pipe 3 as an inner casing pipe that guides geothermal fluid from the fluid reservoir to the ground. , a protective casing pipe 4 that protects the upper part of the finished casing pipe 3 and is maintained at a predetermined distance from the finished casing pipe 3 by an appropriate centralizer, and a protective casing pipe 4 that is placed outside of this protective casing pipe 4 near the ground surface. A measuring cable 6 is provided between the finishing casing pipe 3 and the protective casing pipe 4, and a distance of 3.4 between each casing pipe, 4.
5 and between the casing pipes 3, 4.5 and the stratum 7, cement 8 is placed.

The finished casing pipe 3 has a diameter of, for example, 957 mm.
8 inches long and 1600m long.

(2) A wooden pipe may be used, but the illustrated example is a two-wood pipe, upper and lower, in which the lower end of the upper finished casing pipe 3A is constricted and fitted into the upper end of the lower finished casing pipe 3B. The protective casing pipe 4 has a diameter of, for example, 135/8 inches and a length of 900 m, and has a main valve 10 connected to the upper end projecting above the ground via a mouth pipe 9.
connected to. The surface casing pipe 5 has a diameter of, for example, 20 inches and a length of 70 m, and is used to prevent earth and sand from collapsing especially near the surface of the earth.

Said measurement case! Le 6 has a total of Δ11 with one end installed on the ground.
It is VC connected to the mechanism 11, and the other end accommodates a sensor for measuring physical quantities such as pressure and temperature, and is bent into an L shape, and the bent portion 6A is connected to the upper finishing casing pipe 3.
It passes through a small hole 12 formed in A and is exposed in the finished casing pipe 3A. At this time, the depth of the other end of the measurement cable 6 exposed inside the finished casing pipe 3A is set to be a depth sufficient to measure physical quantities in the mine, for example, about 700 m underground.

The iia recorder 11 mechanism 11 includes a converter that appropriately processes the signal from the sensor, a monitor that continuously displays the converted data, and an I! l! It consists of a recorder, etc. that continuously records data.

When forming a geothermal well having the above configuration, for example, the following excavation method is used.

A well suitable for inserting the surface casing pipe 5 is dug from the ground surface, the surface casing pipe 5 is inserted, and then a hole with a smaller diameter than that hole is further dug from the bottom of the excavated hole and the protective casing pipe 4 is inserted. do. Furthermore, a hole with a smaller diameter than this hole is dug from the bottom of the hole into which the protective casing pipe 4 was inserted, and the finished casing pipes 3A and 3B are inserted therein. Next, apply cement 8 to each casing pipe 3.
B, 4 spaces, 4.5 spaces and casing pipe 3B, 4.5
After the cement 8 is placed between the earth layer 7 and hardened, the open hole 2 below the casing vibe section 1 is excavated in this state. Here, pre-finished casing pipe 3
The measurement cable 6 is attached to the outside of A with a band or other fixing device (not shown) and is positioned inside the protective casing pipe 4. Thereafter, cement 8 is placed between the casing pipes 3A and 4, and after the cement 8 has hardened, one end of the measurement cable 6 is taken out from the sunscreen and connected to the recorder 11 on the ground.

Pressure inside the mine + li! When measuring degrees, etc., the 'A1
Since the sensor at the tip of the bent portion 6A of the 1 constant cable 6 is exposed to the casing pipe 3A, the signal from the sensor is transmitted to the measuring mechanism 11 connected to one end of the δ11 constant cable 6.
The signal is sent to , where it is processed, displayed, and recorded.

According to this embodiment as described above, the measurement cable 6 is integrally installed in the geothermal well, and one end of the measurement cable 6 is connected to the measurement mechanism 11 installed on the ground, so that the measurement device can be installed in the well every time a measurement is made. There is no need to hang it down, and fluctuations in temperature, pressure, etc. can be continuously recorded even when the drilling equipment is inserted into the mine. It also has the effect of continuously recording data necessary for geothermal reservoir evaluation, such as continuous monitoring of flushing points, underground recovery status, and reservoir pressure fluctuations. Furthermore,
Since it is not necessary to insert the measuring device into the mine, equipment for hanging the measuring device can be eliminated, and equipment costs can be reduced. Furthermore, since the work of inserting the measuring device into the mine can be completely eliminated, work efficiency can be improved and lining costs can also be reduced.

In addition, in carrying out the measurement, the tip of the measurement cable 6 may not necessarily be finished as shown in the illustrated example, depending on its material, thickness, or the nature of the physical quantity to be measured.
There is no need to expose it inside the casing pipes 3 and 4, and it is enough to insert it between the casing pipes 3 and 4.

[Effects of the Invention] The present invention has the effect of providing an apparatus for measuring physical quantities in a geothermal well that can continuously measure physical quantities in the pit even while the well is being excavated.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a geothermal well to which an embodiment of the present invention is applied, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1... Casing part, 2... Bare pit part, 3, 3A, 3
B... Finished casing pipe as inner casing, 4... Protective casing pipe as outer casing, 6... Measuring cable, 8... Cement, 11
...Measurement mechanism.

Claims (1)

[Claims] (1) An inner casing pipe inserted underground to guide geothermal fluid to the ground, an outer casing pipe arranged approximately concentrically outside the inner casing pipe, and an outer casing pipe provided between the two casing pipes with one end connected above the ground. a measurement cable that is placed at a predetermined depth position and the other end is placed at a predetermined depth;
A device for measuring physical quantities in a geothermal well, characterized in that it is connected to the measurement cable and includes a measurement mechanism for measuring physical quantities in the well.