RU2042777C1 - Device for opening water-bearing bed - Google Patents

Abstract

FIELD: mining. SUBSTANCE: device for opening water bearing bed includes rock cutting tool with water course, tubular, sub, filter and casing string. Filter has filtering tube with perforated middle part and end parts free of perforation, and filter element located inside filtering tube. Filter element is connected with end parts of filtering tube by means of front and rear circular connecting strips to form central, periphery, front and rear end hollows. Located inside the filter element is pressure pipe which is connected with tubular sub by its one end, and provided with packer on its other end. Check values are located in hollows of sub and packer. Filter periphery hollow and rear end hollow are additionally hydraulically communicated with each other by means of slot channels. Front circular connecting strip of filter has sealing member, and filter periphery is hydraulically communicated with its front circular hollow by means of slot channels for forced washing. Filter element may be corrugated, with tops and bottom located on the lines parallel to longitudinal axis of filter element. EFFECT: higher efficiency. 3 cl, 7 dwg

Description

 The invention relates to mining and can be used in the construction of uprising and directional-rising drainage wells in difficult hydrogeological conditions.

 Known drill (ed. St. USSR N 1234597, CL E 21 B 43/10, G 01 N 1/04), which is made in the form of a double column. The projectile includes a rock cutting tool, a sub valve with a check valve, a casing string of pipes, an inner string of filter pipes made of synthetic filter elements and a mechanism for fixing the inner string. The device provides for the penetration of a well to a certain depth, the extension of the inner column, its installation in an aquifer with subsequent fixing.

 A disadvantage of the known device is that the filter element under conditions of a high-pressure aquifer can be deformed, which leads to increased colmatization and reduces the duration of the filter, since the formation of a natural filter in the filter zone is not ensured.

 A device for opening an aquifer [1] is also known, which includes a rock cutting tool with a flushing channel, a filter, and a casing string. The filter contains an inner perforated pipe with a filter element made in the form of wire winding, while the pipe has annular non-perforated parts with threads, one of which is connected to the upper (front) jumper, and the second to the casing string. The filter is protected by an external perforated pipe connected to the front jumper to form an annular cavity between the external pipe and the filter element. And the lower (rear) jumper is made with one or more windows hydraulically connecting the formed cavity with the external space in the filter zone. Inside the filter there is a pipe (pressure pipe), which is connected with the upper end detachably to the front jumper, and on the other is equipped with a packer that interacts with the inner surface of the non-perforated part of the inner pipe. In the channels of the packer and the upper jumper placed check valves. The known device protects the filter element from drill cuttings. A disadvantage of the known device is that after sinking the clay layer underlying the aquifer, the cavity between the pipe and the filter element is clogged with a clay seal and the filter element is disabled. Natural washing of this cavity is difficult, since the openings of the outer perforated pipe and the channels of the lower bridge connecting the clogged cavity with the outer space are in the same pressure zone, which complicates the movement of the water of the high-pressure aquifer, in addition, the known device does not provide the formation of a natural filter, and suffusion stability of the rocks of the filter zone.

 Closest to the proposed device [2] includes rock cutting tool with a flushing channel, a tubular sub, a filter and a casing string. The filter contains a filter pipe with a middle perforated and end non-perforated parts and a filter element located inside the filter pipe. The filter is equipped with front and rear annular jumpers, as a result of which a closed cavity is formed between the filter tube and the filter element and a central cavity. A pressure pipe is placed inside the filter element, which is connected to a sub with a thread, and is equipped with a packer at the other end and has check valves located in the channels of the packer and sub.

 A disadvantage of the known device is that after the device passes the clay layer in the cavity between the filter pipe and the filter element, a dense clay seal is formed, which is held by the rear annular jumper, as a result of which the filter element is clogged, and the filter is not operational.

 The aim of the invention is to provide a device for opening the aquifer, providing the penetration of the clay layer underlying the aquifer, and the subsequent stable long-term operation of the filter with ensuring the suffusion stability of the rocks of the filter zone by reducing the hydraulic resistance of the filter during the development of the well.

 The device includes a rock-breaking tool with a washing channel connected in series with each other, a tubular sub, at least one filter and a casing string. The filter contains a filter pipe with a middle perforated and non-perforated end parts and a filter element located inside the filter pipe, which is connected to its end parts by means of the front and rear annular jumpers with the formation of a central, peripheral, front end and rear end cavities. A pressure pipe is placed inside the filter element, which is detachably connected at one end with a tubular sub and equipped at the other end with a packer interacting with the inner surface of the non-perforated part of the filter pipe or an adjacent casing pipe.

 A distinctive feature of the device is that the peripheral cavity of the filter and its rear end cavity are additionally hydraulically interconnected by means of slotted channels in the rear ring jumper.

 This reduces the hydraulic resistance of the filter at the time of well development due to the pressure differential between the aquifer and the casing cavity, as a result of which the peripheral cavity of the filter is flushed from clay compaction and the cavity is subsequently filled with sand and fine gravel particles to form an additional natural filter that works together with the filter element . In addition, the conditions for the formation of a natural filter in the filter zone are improved, which ensures the suffusion stability of the rocks of the filter zone and the durability of the filter.

 For forced washing of the peripheral cavity from the clay seal, the front annular filter jumper is equipped with a sealing element that can interact with the outer surface of the pressure pipe, and the filter peripheral cavity is hydraulically connected to its front end cavity by means of slotted channels made in the front ring jumper. This expands the scope: the device can work in case of insufficient natural differential pressure. In addition, the use of forced washing can speed up the process of cleaning the peripheral cavity from clay particles.

 To improve the washing and removal of the clay seal, the filter element can be pleated with the vertices and depressions on the lines parallel to the longitudinal axis of the filter element and oriented by depressions against the slits of the annular bridges.

 This achieves an additional technical result due to the possibility of enhancing the result of natural washing by loosening the clay seal in the area of the vertices of the filter element, and also due to the direction of the flow of pressure water along lines parallel to the longitudinal axis of the filter element.

 In FIG. 1 shows the proposed device, a vertical section, the phase of penetration of the clay layer; in FIG. 2, section AA in FIG. 1; in FIG. 3 the same, vertical section, the phase of forced washing of the clay seal; in FIG. 4 device with a corrugated filter element, part of a cross section; in FIG. 5 a section BB in FIG. 4; in FIG. 6 device, vertical section, the washing phase of the clay compaction under the natural pressure of the aquifer; in FIG. 7 node I in FIG. 6, the final phase of filling the filter peripheral cavity with sand and small gravel particles.

 The proposed device includes sequentially interconnected rock cutting tool 1 (Fig. 1), a tubular sub 2, at least one filter 3 and a casing string 4. The rock cutting tool 1 has a flushing channel 5. The tubular sub 2 also has a similar channel 6; equipped with a check valve 7 and connected to the rock cutting tool 1 by means of a threaded connection 8. The filter 3 contains a filter pipe 9 with a middle perforated part 10 with holes 11 and end non-perforated parts 12 and 13 and a filter element 14 located inside the filter pipe 9.

 The filter element 14 is made, for example, of fiberglass, is rigidly connected by means of the front 15 and rear 16 annular jumpers with the end non-perforated parts 12 and 13 of the filter pipe 9. In this case, the central 17 and peripheral 18 cavities and the end cavities front 19 and rear 20 are formed. Peripheral a cavity 18 is enclosed between the filter element 14 and the perforated part 10 of the filter pipe 9. Inside the filter element 14, a pressure pipe 21 is placed in the central cavity 17, which is detachable, for example by means of a threaded connection 22, connected at one end to a tubular sub 2, and at the other end has a packer 23 cooperating with the inner surface 24 of the non-perforated portion 13 of the filter pipe 9 or an adjacent casing string 4. The packer 23 is provided with an axial channel 25 and a check valve 26.

 To ensure the natural washing of the filter and the subsequent formation of the protective zone of the filter element in the rear annular jumper 16, slotted channels 27 are made (Fig. 2), hydraulically connecting the peripheral cavity 18 of the filter with its rear end cavity 20. The size of the slotted channels is selected taking into account the provision of suffusion stability filter zone.

 For forced washing of the filter 3 (Fig.3), the front annular jumper 15 can be made with slotted channels 28 and provided with a sealing element 29 that overlaps the gap between the front annular jumper 15 and the pressure pipe 21.

 To intensify the washing, the filter element 30 (Fig. 4) is made corrugated, in which the vertices 31 and depressions 32 are located on lines 33 and 34 (Fig. 5) parallel to the longitudinal geometric axis 35 of the corrugated filter element 30 and are oriented by depressions 32 against the slotted channels 27 and 28 of the front 15 and rear 16 ring jumpers.

 The filter element 30 may be made of fiberglass.

 The device operates as follows.

 The device using a drilling rig (not shown in the drawings) are drilling uprising or inclined-rising wells 36 (figure 1). Before opening the aquifer, drilling is carried out along the underlying water-resistant layer 37, represented by clays. When this layer passes, clay particles through the openings 1 of the filter pipe 9 fill the peripheral cavity 18, forming a tight impermeable clay seal, which turns the filter element 14 out of operation. After filter 3 is inserted into the aquifer 38 (Fig. 6), it is removed using an inventory column (on not shown) a packer 23 with pressure pipes 21. At this time, the filter element 14 does not work due to the presence of a clay seal in the peripheral annular cavity 18. However, in the presence of a pressure differential in a high-pressure aquifer 38 and those of the cavity 4 of casing string vacuum suction effect is created and the gradual leaching of the clay particles circumferential cavity 18 of the first zone adjoining the rear annular bridge 16, and then the whole of the peripheral zone 18, and their removal through the slit 27 channels.

 As a result of the movement of pressure water, sand and small gravel particles of the aquifer 38 (Fig. 7) fill the peripheral cavity 18, the openings 11 of the filter pipe 9 and the space of the filter zone, forming a natural filter 39, working in conjunction with the filter element 14.

 If it is necessary to use forced flushing (Fig. 3) after disconnecting the pressure pipes 21 from the sub 2, they are limitedly moved down so that the upper end is in the cavity 19, which is hydraulically connected through the slotted channels 28 to the peripheral cavity 18. After turning on the flushing pump (not shown) flushing fluid at a pressure higher than the pressure of the aquifer 38, from the pressure pipes 21 enters through the cavity 19 and slotted channels 28 into the peripheral cavity 18 and flushes clay parts through holes 11 of the filter pipe 9 into the annulus, starting from the front, and then washing out through slotted channels 27.

 In the case when the filter element 30 is corrugated (Fig. 4), the formed clay seal is weakened, and the washing of the peripheral cavity 18 is improved, in the presence of depressions 32, the erosion efficiency increases, since directed flows are formed, in addition, the thickness of the gland in the area of the peaks 31 is much smaller, there is a connection of vertical flows and a more effective fracture of the clay seal (Figures 4 and 5).

 During the operation of the filter, this embodiment of the filter element 30 will provide an additional drainage effect by increasing the filter surface.

Claims (3)

 1. DEVICE FOR OPENING THE AQUARIUM PLASTIC, comprising a rock cutting tool with a flushing channel connected in series, a tubular sub, at least one filter and a casing string, the filter comprising a filter pipe with a middle perforated and end non-perforated parts and a filter element housed in filter tube and connected to its end parts by means of the front and rear annular jumpers with the formation of a Central, peripheral, front end and rear end cavities, and inside the filter element there is a pressure pipe connected detachably at one end to a tubular sub and equipped at the other end with a packer interacting with the inner surface of the non-perforated part of the filter pipe or an adjacent casing pipe, characterized in that the peripheral and rear end cavities of the filter additionally hydraulically interconnected by means of slotted channels made in the rear annular bridge.  2. The device according to claim 1, characterized in that it is equipped with a sealing element that is installed between the inner surface of the front annular jumper of the filter and the outer surface of the pressure pipe, and the peripheral cavity of the filter is hydraulically connected to its front end cavity through slotted channels made in the front ring jumper.  3. The device according to paragraphs. 1 and 2, characterized in that the filter element is corrugated, and the generatrix of the vertices and troughs of the corrugations are parallel to the longitudinal axis of the device, and the troughs are oriented opposite the slits of the annular jumpers.

Images