JPH0465199B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to cleaning dirt from casing pipes, etc. of wells inserted underground, and dredging sand, etc. buried in these pipes. [Conventional technology] As a conventional well cleaning technology,
There are gas lift methods, brushing methods, acid treatment methods, and water jet cleaning methods. These conceptual diagrams are shown in FIGS. 4a to 4d, respectively. In the gas lift method, high pressure gas is blown into the straight pipe portion of the casing pipe 4 at an appropriate depth. In the brushing method, a metal tube 22 with a brush 23 attached thereto is lowered into the casing pipe and dirt is scrubbed away by the brush. In the acid treatment method, acid is poured into the casing pipe to perform acid cleaning. In the water jet cleaning method, a metal tube with a nozzle attached is lowered into the casing pipe, water is sent into the tube, and the water jetted from the nozzle performs cleaning. Conventional dredging techniques include gas lift dredging and pump dredging, as shown in FIGS. 5a and 5b, respectively. The gas lift method can be applied to casing pipes with a diameter of approximately 4.5 inches or more, and metal pipes 2
2 is lowered to the vicinity of the earth and sand layer 27, and gas is blown from the gas lift pipe 26 attached to the metal pipe 22 to blow up the earth and sand. In the pump method, water is ejected from the metal pipe 22,
blow up sand and dirt. Since this method does not require a gas lift pipe, it can also be applied to small diameter pipes of about 3 inches. In addition, for horizontal pipes, such as pipelines, instead of wells, the water jet method is applied, in which a high-pressure hose fitted with a nozzle is inserted into the pipe and water is jetted out from the nozzle for cleaning. [Problem to be solved by the invention] In wells, casing pipes reach hundreds of meters, sometimes more than a thousand meters underground, and the lower part becomes a perforated pipe 12 with many holes as shown in Figure 4. ing. If dirt, rust, etc. accumulate in the pipes, it becomes impossible to extract the desired gas or liquid through the holes, so not only cleaning but also dredging work is required periodically. However, there has been no simple and effective method for cleaning and dredging wells. That is,
The cleaning method described above does not have a dredging effect, and the gas lift method has a cleaning effect near the gas lift pipe 3, but the cleaning effect cannot be expected much further away from there. Also brushing, acid treatment,
In the water jet cleaning method, metal pipes 22 are connected for several hundred meters and lowered, so in order to perform this work, iron plates must be laid on the ground, a turret that reaches several tens of meters above the ground must be installed, and a hoisting machine, etc. must be attached. However, just cleaning it is a fairly large-scale task. Moreover, since the conventional dredging technique also uses the metal pipe 22 in the same way, the scale of the work is similar to that above. In addition, in lift dredging, gas lift pipes are lowered into the well in addition to metal pipes, so it cannot be applied to small-diameter wells. Pump dredging is applied to small-diameter wells, but this method causes a pressure drop when flowing through the hydraulic head and the gap between the metal pipe and casing to the wellhead, so the water jetting out from the metal pipe cannot escape from the hole. It can easily leak in large quantities to the outside, and the ability to send soil to the ground is extremely low.In general, the soil is simply pushed out of the casing pipe, and in reality, even after dredging, the soil is buried as it was before. Put it away. For this reason, it was often better to construct new wells than to dredge them, especially for small-diameter wells. In some cases, the metal tube 22 is made of a special metal to give it flexibility so that it can be rolled up, eliminating the need for a tower. This requires an engine, etc., and the work is extensive. Furthermore, the technology is basically the same as conventional cleaning and dredging technology, except that the metal pipe has more flexibility. In addition, the water jet cleaning method using a high-pressure hose used on pipelines, etc. uses a lightweight hose, so the work is relatively simple, but since this method is horizontal, it requires dredging by sending the earth and sand vertically several hundred meters. There is no need for this, and it is a completely different technology from that used in wells. The present invention aims to provide a simple and highly effective method for cleaning and dredging a well and an apparatus therefor. [Means for Solving the Problems] The present invention involves lowering a high-pressure hose whose inner pipe and outer sheath are made of resin and having a jet nozzle at the tip into a casing pipe through a reubricator disposed at a wellhead device, and injecting water into the high-pressure hose. water is introduced from the jet nozzle to clean and dredge the inside of the casing pipe and fluidize the object to be cleaned and the material to be dredged.At the same time, water is compressed from the gas lift pipe installed below the fluid level in the casing pipe. This method of cleaning and dredging a well is characterized by blowing out gas and discharging objects to be cleaned and dredged together with the ejected gas from the well. By using a high pressure hose like the one above,
Since the weight is reduced, the large-scale equipment such as a turret that was necessary in the past becomes unnecessary. Figure 2a shows a cross section of the high pressure hose. By making the inner pipe 203 of the high-pressure hose made of resin, deformation is reduced, so the tensile force generated when the high-pressure hose is hung vertically causes the hose to stretch, resulting in an extremely small inner diameter and a significant pressure loss. can be prevented. Furthermore, by making the outer sheath 201 of the high-pressure hose made of resin, the high-pressure hose will not become stuck due to friction with the packer (701 in FIG. 3) in the reubricator. Furthermore, by combining the water jet method and the gas lift method, cleaning and dredging can be carried out simultaneously and effectively. FIG. 1 shows a conceptual diagram of an apparatus for implementing the present invention. Figure 1a is an underground diagram, and Figure 1b is a ground diagram. A schematic diagram of the high pressure hose 2 is shown in FIG. 1a. The jet nozzle 1 has a direction that is more than 0 degrees and less than 90 degrees from the axial direction of the high pressure hose, that is, 0 degrees < θ < 90 degrees in the direction toward the well entrance, that is, toward the center of the high pressure hose. A small hole is made in the direction,
It would be good if the water was spouted in that direction. This is because the earth and sand above the jet nozzle can be blown up and fluidized by this diagonally upward water flow, and can be prevented from falling below the jet nozzle. In other words, the pumping effect of the jet water flow can be utilized. It is preferable that a straight pipe section 11 is provided between the jet nozzle 1 and the high pressure hose 2, and that the length of the straight pipe section is longer than the inner diameter of the casing pipe 4. The straight pipe part is a part that does not have flexibility like a high pressure hose, and may be made of a metal pipe or the like, or a metal plate or the like may be wrapped around the high pressure hose. If this straight pipe part is not present or the length is shorter than the above-mentioned length, it will be difficult to move the inside of the casing pipe up and down smoothly. Depending on the depth of the well, it may be necessary to connect several high-pressure hoses together. In this case, the high-pressure hoses are connected by a joint, but since the outside diameter of the joint is larger than the outside diameter of the high-pressure hose, conventional relubrators are unable to prevent the fluid being pumped up by the gas lift, and are usually A reubricator for different pipe diameters is required, which has a structure in which two reubricators are connected in the axial direction. This structure is shown in FIG. In this relubricator for different pipe diameters, a hollow cylindrical packer 701 having a conical surface on the outside and a hollow cylindrical packer pusher 702 having a conical surface on the inside that engages with the conical surface are meshed together to form a set, Two pairs of these sets are arranged in the body 705 at intervals 704 in the axial direction, each pusher is fixed to the body, and each pusher is independently moved in the axial direction to obtain the force of the pusher pushing the pusher. It is characterized by having two sets of means having means 703 for adjusting. Although this relubricator is operated by mechanical means using rotational force, a reubricator having a pressure type structure in which the packer is pushed out by the pressure of the fluid is recommended because it operates more quickly. When passing a high-pressure hose through a joint, first close the outlet reubricator, open the inlet reubricator, pass the joint between the inlet and outlet relubrators, and then After closing the relubricator, open the outlet-side relubricator and allow the joint to pass through to the outlet. Moreover, any reubricator may be used as long as it has the function of preventing blowout and allows passage of different pipe diameters. [Example] The procedure of the example will be explained according to FIG. The compressor for gas lift is operated, compressed gas is injected from the gas lift pipe 3 installed below the fluid level in the casing pipe, and the gas is extracted from the well.
Brine was produced (pre-washing). A tripod 8, sheaves 5 and 6, and a relubricator 7 for different pipe diameters were installed. Attach a short pipe 11 and a jet nozzle 1 to the tip of the high-pressure hose 2, and attach a reubricator 7 for different pipe diameters.
The high pressure hose 2 was lowered into the mine. (Washing,
(at the dredging depth) A high-pressure pump was operated to jet high-pressure water from jet nozzle 1 to perform cleaning dredging. When dredging sand, the high-pressure hose was raised and lowered frequently in order to effectively utilize the pumping effect of jet water flow. This also has the effect of preventing the high pressure hose from becoming trapped by sand. For dredging, once a certain section has been dredged, the high-pressure hose is hoisted up to the pre-dredging depth, the high-pressure pump is stopped, the injection from the jet nozzle is stopped, and the dredging is lowered to the dredging depth again to ensure that there is no re-burial. I did this while checking. During cleaning and dredging, pay attention to the water quality (dirt, water, etc.) of the brine being pumped up at the mine entrance, and complete cleaning and dredging when there is no dirt, etc., no matter how high or low the nozzle is moved up and down. Example 1 and Comparative Example 1 A well of 1000 m depth was cleaned and dredged according to the above procedure. The casing pipe is a 3 inch PVC pipe (inner diameter 73mm), and the high pressure hose has an outer diameter of 21mm and an inner diameter of 12.8mm.
mm, the inner tube and outer jacket are nylon 12, the reinforcing layer is high-tensile steel wire, and the normal pressure is 1000 kgf/cm ² , and the outer diameter is 20.4 mm, the inner diameter is 12.8 mm, the inner tube is nylon 12, and the outer jacket is polyurethane. The reinforcing layer was made of high-tensile wire with a normal pressure of 700 Kgf/cm ² . Any reinforcing layer may be used as long as it has a reinforcing effect. The shape of the jet nozzle is as shown in FIG. 2b, and in this example, the reverse injection nozzle 101 has an inclination θ of 30° from the axis of the high-pressure hose toward the center of the high-pressure hose. In addition to this, a rotating nozzle 102 is provided so that the jet nozzle rotates. In addition, the straight pipe section following the jet nozzle was 40 cm. The tripod 8 shown in FIG. 1 had a height of about 3 m and a distance between legs of about 2 m, which could be carried by two people. The results of implementing the present invention as described above are shown in Table 1 together with the results of performing similar work using the conventional method. The effect of discharging sand, etc. was determined using the conventional method. Example 2 and Comparative Example 2 The same tests as Example 1 and Comparative Example 1 were carried out.
The test was carried out on a 370m well. As for the high pressure hose, only the above-mentioned normal pressure hose of 700 Kgf/cm ² was used. The results obtained are shown in Table 2. Note that all costs are shown with the cost of Example 1 set at 100. As can be seen from the Examples and Comparative Examples, according to the present invention, the number of working days and costs can be significantly reduced, and the land required is much smaller, making it possible to dredge wells that were previously impossible to dredge due to nearby structures. Dredging is now possible.

【table】

〔Effect of the invention〕

The present invention has made it possible to easily clean and dredge wells extending from several hundred meters underground to more than a thousand meters underground. In particular, the present invention can be easily applied to small-diameter wells, for which cleaning dredging has been difficult in the past.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an apparatus for cleaning and dredging according to the present invention, Fig. 2 is a sectional view of a high-pressure hose used in the present invention, Fig. 3 is a reubricator for different pipe diameters of the present invention, and Fig. 4 is a FIG. 5 is a diagram illustrating a conventional well dredging technique. 1: Seat nozzle, 2: High pressure hose, 3: Gas lift pipe, 4: Casing pipe, 5: Upper sheave, 6: Lower sheave, 7: Reubricator for different pipe diameters, 8: Tripod, 9: Pressure feed pipe, 10: Wellhead device , 11: Straight pipe part (high pressure hose), 12: Perforated pipe, 13: Straight pipe part, 22: Metal pipe, 23: Brush, 24: Packer, 25: Nozzle, 26: Gas lift pipe, 27: Dredged object, 201: Outer cover, 20
2: Reinforcement layer, 203: Inner pipe, 204: High pressure hose joint, 701: Push car, 702: Push car, 703: Push car moving means, 70
4: Interval, 705: Body.

Claims (1)

[Scope of Claims] 1. A high-pressure hose whose inner tube and outer sheath are made of resin and has a jet nozzle at the tip is lowered into the casing pipe through a relubricator installed at the wellhead, and water is introduced into the high-pressure hose to Water is jetted out from the jet nozzle to clean and dredge the inside of the casing pipe, and fluidize the objects to be cleaned and dredged. At the same time, compressed gas is jetted out from the gas lift pipe installed below the fluid level in the casing pipe. A method for cleaning and dredging a well, which comprises discharging objects to be cleaned and dredged from the well along with ejected gas. 2 When spouting water from the jet nozzle,
2. The method according to claim 1, further comprising jetting water from the jet nozzle toward the well entrance in a direction greater than 0 degrees and less than 90 degrees from the axial direction of the high-pressure hose. 3. The method according to claim 1 or 2, wherein the high-pressure hose is provided with a straight pipe section following the jet nozzle, and the length of the straight pipe section is longer than the inner diameter of the casing pipe. 4. A high-pressure hose for cleaning and dredging wells, the inner pipe and the outer jacket are made of resin, and the jet nozzle has a jet nozzle at the tip, and a straight pipe part follows the jet nozzle, and the jet nozzle has a high-pressure hose in the center. 90 degrees beyond 0 degrees from the axis of the high pressure hose
1. A high-pressure hose, characterized in that it is provided with a small hole extending in a direction less than 10 degrees, and the length of the straight pipe section is longer than the inner diameter of a casing pipe of a well. 5 A hollow cylindrical packer having a conical surface on the outside and a hollow cylindrical packer pusher having a conical surface on the inside that engages with the conical surface are engaged with each other to form a set, and this set is separated by two sets in the axial direction. each pusher is fixed to the body, and has two sets of means having means for independently moving each pusher in the axial direction to adjust the force with which the pusher pushes the pusher. A reubricator for different pipe diameters. 6. The relubricator is a relubricator for different pipe diameters according to claim 5, and when passing the high pressure hose having a diameter larger than that of the high pressure hose through the joint part, first, the outlet side relubricator is closed and the inlet side relubricator is closed. High pressure hose 4. The method according to claim 1, 2 or 3, characterized in that the tube is passed through a relubricator for different pipe diameters installed in the wellbore.