SU983265A1 - Deep-well filter - Google Patents

Description

(54) WELL FILTER

one

The invention relates to the mining industry, and more specifically to the oil and gas industry, and can be used in oil wells for sand control.

In oil fields, various types of filters are used: gravel, sandstone, slotted, metal-ceramic, sand-plastic 1.

The disadvantages of these filters are: rapid blockage of their hydraulic channels, which leads to a decrease in the inflow of formation fluid into the well; the possibility of sticking filters on the bottom of the well; it is impossible to wash the filters and inject chemicals into the reservoir without lifting them from the well.

The closest technical solution is a downhole filter comprising a filter tube with a housing located concentrically in the perforated production string 2.

The disadvantage of the known filter is that possible sand deposition in the annular space between the filter and the production string is not excluded. which leads to the sticking of the filter in the well and probkoobrazovaniyu in the wellhead space, which ultimately reduces the reliability of work.

The aim of the invention is to increase the reliability of the filter by preventing sand from settling in the annular space.

The goal is achieved by the fact that

Claims (2)

10 downhole filter vklyuchayugtsy filter tube with casing raspolozhen1tuyu concentrically on the perforated production casing, is provided with a telescopically vydvigayuschims dopolnitely1ym outer casing formed of perforated, with emphasis and the check valve in the lower part and the annular cuffs, chant) gozhennymi on the outer surface of the casing and having apertures, communicating with the cover of the casing and the eksgo of the plowing column, and the lower part of the production casing and the back of the casing are made with interconnecting beveled limiting cams. The drawing shows a downhole filter for operation of wells, a longitudinal section. The downhole filter consists of filtering tube 1, gravel 2, casing 3. Between tube 1 and casing 3 is placed a ring-shaped piston 4, pushed by spring 5, to automatically press the gravel as it is worn. The casing 3 is telescopically inserted inside the secondary casing 6. The serial one has holes 7, an emphasis 8, bushings 9 and cuffs 10 alternating with each other and pressed by nut I. There are holes 12 in the cuffs 10 that coincide with holes 7. The filter is lowered into the wells. into which the production string 13 with pre-drilled holes 14 in the lower part, is lowered to allow formation fluid to enter the interior of the well. In this case, the inner diameter of the lower part of the production column, which overlaps the thickness of the formation, should be 4-6 mm smaller than the diameter of the upper part of the production column. However, the lower part of the production string can be perforated with a cumulative perforator even after lowering them into the well. In order to prevent the cuff filters 10 from rubbing against the walls of the well during the descent into the well, lamellar springs 15 are provided around the periphery of the additional narcotic casing 6, fastened with screws 16. The additional outer casing 6 is sealed with the cuff 17, and so that it does not completely come out of the leather case 3, A limiter 18 is provided. The bottom of the additional outer casing 6 has oblique restrictive cams 19. The response cams 20 are provided in the production string 13 for an oriented filter fit, “to open the holes th column 13 and the filter matched. In the anvil 8 of the additional outer casing, a check valve 6 times is placed, made in the form of a ball 21 placed together with the spring 22 in the housing 23. To avoid rotation of the cuff 10 through one of the holes, the hollow screw 24 is screwed into the additional outer casing 6. Downhole filter works as follows. A filter in an extended telescopic position is lowered into the well, where the production column has already been lowered with the drilled holes Tvra. Income to the lower part of the production string, the cuffs 10 of the filter are somewhat compressed and fit tightly into the shank. When this plate spring 15. the entrance is also in the lower part of the production string 13, provide the centering of the filter. After reaching the cams 20 of the production string 13, the filter with its cams 19 is turned so that the holes coincide. with holes in the shank. The movement of the additional outer casing 6 stops therewith. Then the filter parts 1, 2, 3, 4 and others, telescopically slid inside the additional outer casing 6, abut against the support of the latter. If necessary, rinse the filter, the inner part of it telescopically extend the stroke by raising the tubing string, and of which it is suspended. After direct or backwash, it is again lowered to the bottom. In the event of both parts sticking, the entire filter is removed to the surface, cleaned and then returned to the well. If necessary, injection into the reservoir of a chemical reagent, the filter is lifted by two turns so that the lower cuff is not removed from the shank. Re-delivery is done through the lower spring-loaded non-return valve. The filter can be lowered for slaughter on the tubing or on a sub with a lera thread, leaving it at the bottom. The invention has a downhole filter including a filter tube with a casing arranged concentrically in a perforated production string, characterized in that, in order to increase the reliability of the filter by preventing sand from settling in the annular space, it is equipped with a telescopically rotating additional outer casing made perforated with a stop and a check valve in the lower part and annular cuffs located on the outer surface of the casing and having openings communicating with openings of the casing and production casing, and the lower part of the production casing and the casing stop are made with interacting beveled restrictive cams. Sources of information taken into account in the examination 1. AM Yasashin. Liquidation of sand plugs in oil wells. M, Nedra, 1964, p. 6-19. 2. USSR author's certificate N ° 840307, cl. E 21 B 43/08; 1979 (prototype).