SU1288285A1 - Deep-well filter - Google Patents

Abstract

The invention relates to the field of mining and is intended for the drainage of mineral deposits from underground mines. The purpose of the invention is to increase the efficiency of the filter (F) by increasing the duty cycle and reducing the contact resistances. For this, F contains a frame 1 with longitudinal ribs 2, having alternate, and a deep 3 and shallow 4 grooves. There is a wire winding (SW) 5 in them, which forms shells 7 and 6. Moreover, the width of the slit 6 vertically above the grooves 3 is larger than the width of the busbar 7 and under the grooves 3. The distance bi and bo between the grooves is determined by the dfip + (aid5o -f 2dnp-h -) - d., p; b2 a2d5o (a2d5o + 2dnp) - dnp, where bi is the greater distance between the slots, m; bo is the smaller distance between the slots, m; dnp - PO diameter 5, m; ai is an empirical coefficient equal to 4.2-4.5; ao-empirical coefficient equal to 3.0-3.5; dso — average particle diameter of the drained rock, m; h is the difference between the depths of the adjacent grooves 3 and 4, m. When F is working, the particles of rock at the contact with the turns of the software 5 form arched structures. Due to the uneven vertical positioning of the grooves 3 and 4 between the coils, there are defined passage openings of unequal magnitude, which creates optimal conditions for the formation of stable arched structures and eliminates blocking of the passage openings by rock particles. 3 il. 1 F (L to 00 00 ts3 oo ate

Description

The invention relates to the field of mining and can be applied in the drainage of mineral deposits from underground mines.

The purpose of the invention is to increase the efficiency of the filter by increasing the duty ratio and reducing the contact resistances.

FIG. 1 shows the filter, obsh, iy kind; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. 2

The downhole filter contains a frame 1 with longitudinal ribs 2. The ribs 2 have deep 3 and shallow 4 slots, the wire winding 5 located in them, the shells 6 and 7, formed by the wire winding 5, have an unequal width. Moreover, the width of the slit 6 vertically above the deep grooves 3 is larger than the width of the neck 7 located under the slots 3, and the distance bi and b2 between the grooves is determined by the formulas

B | Vd.p + aid5o (aid5o + 2d.p). dnp; b2 a2d5o (a2d5o + 2diip) dnp,

where bi is the greater distance between the slots, m;

b2 is the smaller distance between the slots, m;

dnp - diameter of the wire winding, m; di is an empirical coefficient of 4.2-4.5 (determined experimentally for high-flow wells);

A2 is an empirical coefficient of 3.0-3.5 (determined experimentally for high-production wells);

dso — average particle diameter of the drained rock, m;

h is the difference in depth of adjacent grooves, m. The difference in depth of adjacent grooves helps create optimal conditions for the formation of arch structures 8 and 9 in the near-contact zone and reduces the contact loss of groundwater pressure and thereby increases the filter performance and the degree of drainage of the aquifer.

The formation of a natural filter occurs as a result of the complex movement of rock particles in the filter zone, the filtration of the fluid into the filter cavity 10, the removal of fine fractions to the surface and the formation of arched structures 8 and 9 at the passage openings of large particles. Description of the mathematical equations of complex particle displacements is impossible, therefore, to take it into account, we introduce the coefficient determined on the basis of experiments and, by its value, allows us to create a highly permeable natural filter. With this factor

0

five

0

five

0

five

40

,,, 55

45

the size of the filter gap is determined by the expression adso (empirical coefficient). The coefficient depends on the design features of the water intake surface of the filter and takes on different values.

According to experimental data, it is known that the indicators that affect the quality of formation of arches on crossing gaps are also the distance between the axial lines of the winding turns equal to ad5o + dnp (where dnp is the diameter of the winding wire), the difference in depth between the adjacent grooves and the distance between the slots bi and b2.

The filter works as follows. When the aquifer is opened by the filter column, the upper end of the frame 1 of the filter is closed with valves (not shown) to avoid penetration of the fractured rock into the cavity 10. After the design depth of the well is reached, the filter is installed in the aquifer. After that, the flow of fluid passing through the wire winding 5 begins to carry out small fractions through the filter, while the large ones linger on contact with the turns of the wire winding 5. Particles of water-bearing rock under the influence of the flow of filtering fluid move in the contact area top down. Particles with a diameter less than and within the mean diameter d5o pass through the passage slits 6 and 7 and are carried along the wellbore, and coarse structures 8 and 9 are formed from larger particles.

Since the outer turn of the spiral winding 5, located in the shallow groove 4, is vertically closer to the turn located in the deep groove 3, and protrudes by the value of h, it is a reliable support for waterborne rock particles. The particles of the water-bearing rock, resting on the outer turns of the helix, form the arched structure 8 and do not block the passage opening between these turns. Due to the small size of the throughput slits 7 and as a result of the hydrodynamic forces of the fluid flow and the force of gravity, the arch structure 8 has a stable package, being at the same time a support for the formation of the arch structure 9. The stable support allows to form a larger stable size arch structure 9 of particles of rock of larger diameter. The dimensions of the arch structure 9 are larger than the dimensions of the arch structure 8, thereby increasing the filter duty cycle, ensuring free flow of water and reducing contact pressure losses. The stability of the roof structure 9 is ensured by the stable packaging of the roof structure 8. The reduction of contact

filter loss allows in all cases to increase the filter capacity, the degree of drainage of the aquifer.

Example. In the drainage rising well of an underground mine, the drained aquifer is represented by loose sandy rocks with an average particle size of d5o 1.0 mm. The filtration coefficient of the aquifer reaches 5–7 days, and the pressures are 10–15 m. The filter cage is made of annular sectors obtained from a pipe with a diameter of 89 mm. The annular sectors are interconnected by inwardly convex welding. Milling structures are made on the longitudinal ribs of the framework. Due to the uneven vertical positioning of the grooves 3 and 4 between the coils, there are defined passage openings of unequal magnitude, which creates optimal conditions for the formation of stable arched structures and eliminates blocking of the passage openings by rock particles.

Claims (2)

Invention Formula A downhole filter comprising a frame with longitudinal ribs that have alternating deep and shallow grooves, and a wire winding laid in them with the formation of a neck, implying that. the grooves with alternating depth - shallow, with the goal increased; - effectiveness cue and deep. The depth of the shallow grooves is 1.2, deep 5.0 mm. The diameter of the spiral winding wire laid in the grooves is 1.0 mm. For drainage filter operation by increasing the duty ratio and decreasing the contact resistance, the slots are made with different widths, and the width of the slots vertically over sands with d5o 1.0 mm empirical coefficients; jn deep groove has a larger size, ai 4.2 and a2 3, 2. More distance b | between the slots is the width of the slot below it, and the distance between the slots is determined by the formulas B, 4.2-1.0 (4.2-1.0 + 2.1) -3, - 1.0 2.5 mm The smaller distance between the slots is Ь2 V 1 + 3.2-1.0 (3.2-1.0 + 2-1) -3, - 1.0 0.8 mm. The wire winding in the grooves of the frame is laid in two bores. The total length of the filter is 2.0 m. A drill bit is installed at one (upper) end of the filter, blocking the access of the drilled rock into the space between the frame and the spiral wire winding. When the filter is in operation, the rock particles at the contact with the windings form arched structures. Due to the uneven vertical positioning of the grooves 3 and 4 between the coils, there are defined passage openings of unequal magnitude, which creates optimal conditions for the formation of stable arched structures and eliminates blocking of the passage openings by rock particles. Invention Formula A downhole filter comprising a frame with longitudinal ribs that have alternating deep and shallow grooves, and a wire winding laid in them with the formation of a neck, implying that.  that, with a view to elevated; - effectiveness filter operation by increasing the duty ratio and decreasing the contact resistance, the slots are made with different widths, and the width of the slots vertically over  deep groove has a larger size  deep groove has a larger size the width of the slot below it, and the distance between the slots is determined by the formulas 6, Vi / .tp-f (, (2rfnp) d bi - ldnf- - (2diip) - / iip, where Y is the greater distance between the slots, m; bi is the smaller distance between the slots, m; dnp - diameter of the wire winding, m; di is an empirical coefficient equal to 4.2-4.5; “2 is an empirical coefficient equal to o, io, b | dso is the average particle diameter of the drained rock, m; h - the difference of the depths of adjacent grooves, m Aa F1 / yr Editor N. Dumbass Order 7778/27 VNIIPI USSR State Committee for Inventions and Discoveries  113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, ul. Project, 4 ff- b (loG) H Jig Compiled by E. Molchanova Tehred I. VeresKorrektor O. Lugova Circulation 554Subscribe