RU2180699C1 - Method of tapping of producing formation of fluid mineral - Google Patents

Abstract

FIELD: oil producing industry; applicable in mining of producing formations containing oil and/or gas. SUBSTANCE: method includes installation and cementing of casing string in drilled well; perforation of casing string; formation of process cavity in producing formation round well. This is done by cutting and carrying out of rocks of producing formation by high-pressure jet of fluid with abrasive supplied through jet-forming nozzles of well hydraulic giant. In so doing, abrasive is separated from pulp for its reuse in well. One part of cut rocks of producing formation is lifted to surface in pulp flow. Walls and roof of formed process cavity are maintained in stable state due to its filling with mixture of cut rocks of producing formation and abrasive. According to invention, prior to lowering of well hydraulic giant, its body and well bottom hole are filled with abrasive. Abrasive is supplied to jet forming nozzles in pulp flow ejected by high- pressure jet of fluid. Process cavity is formed by separate parts with pillars leaved between them successively from top down from roof of producing formation to its bottom. Abrasive is separated from pulp for its reuse above opened top body of well hydraulic giant in zone of reduction of pulp flow velocity. EFFECT: increased productivity of labor in tapping of producing formation of fluid mineral. 2 cl, 3 dwg

Description

 The invention relates to the field of oil and gas industry and can be used in the development of productive formations containing oil and / or gas. Another area of use may be the extraction of water from aquifers. It is fundamentally possible to use in the development of solid mineral deposits by underground leaching.

 There is a method of opening productive mineral strata in which a casing string is installed and cemented in a drilled well, perforated, and in the bottom-hole zone of the formation form a zone with increased permeability for fluid minerals, which is also a reservoir. The specified zone is created by the destruction of the rocks of the reservoir by high-pressure fluid flow with an abrasive (see ed. Certificate. SU 1629500 A1, IPC Cl. 6 E 21 B 43/114, publ. 23.02.1991).

 The disadvantage of this method is the low productivity of work on opening the reservoir and the inability to create a zone with increased permeability with the specified parameters.

 The closest in technical essence and the achieved result to the claimed one is a method of opening a productive formation of a flowing mineral, including installing and cementing a casing in a drilled well, perforating the casing, forming a technological cavity in the producing formation around the well by destroying and removing rocks of the productive formation with a high-pressure jet liquids with an abrasive supplied through the jet-forming nozzles of a downhole hydraulic monitor, separating the abrasive from the pulps s for its reuse in the well and lifting part of the destroyed rocks of the productive formation to the surface in the pulp stream, maintaining the walls and the roof of the formed technological cavity in a stable condition by filling it with a mixture of the destroyed rocks of the productive formation and abrasive (see patent RU 2123579 C1, IPC , CL 6 E 21 B 43/114, publ. 12/20/98, bull. 35).

 The disadvantage of this method is the need to install a separate pipeline for feeding the abrasive to the jet forming nozzles of the hydraulic monitor, which increases the time for tripping and reduces the productivity of opening the reservoir.

 The problem to which this invention is directed is to increase the efficiency of opening productive formations of fluid minerals.

 The technical result consists in increasing the productivity of work on opening a productive formation of a flowing mineral.

 The specified technical result is achieved by the fact that in the known method of opening a productive formation of a flowing mineral, including installing and cementing a casing in a drilled well, perforating the casing, forming a technological cavity in the producing formation around the well by destroying and removing the rocks of the producing formation with a high-pressure liquid stream with abrasive, supplied through the jet-forming nozzles of a borehole hydraulic monitor, separating the abrasive from the pulp for its repeated use crawling in the well and raising part of the destroyed rocks of the productive formation to the surface in the pulp stream, maintaining the walls and the roof of the formed technological cavity in a stable condition by filling it with the mixture of the destroyed rocks of the productive formation and abrasive, according to the invention, before housing the downhole monitor, its body and bottomhole zone of the well fill with abrasive, which is fed to the jet-forming nozzles in a pulp stream ejected by a high-pressure liquid stream, the technological cavity is formed t leaving portions therebetween pillars sequentially downward from the top of the producing formation to its soil, and separation of the abrasive slurry for reuse is carried out over the open top of the housing to a downhole jetting zone reducing the slurry flow rate.

 The indicated set includes all the signs, each of which is necessary, and all together are sufficient to achieve the specified technical result in all cases of using the invention for which the scope of legal protection is claimed.

 In particular cases of use, the invention is characterized by the following set of features.

 The loading of new portions of abrasive is carried out at the wellhead after stopping the process of destruction of the rocks of the reservoir.

 The method of opening a productive formation of a flowing mineral is illustrated by the drawing, where Fig. 1 shows a scheme of opening (vertical section), Fig. 2 is a section A-A of Fig. 1, Fig. 3 is a section B-B of Fig. 1.

 The method of opening the reservoir of fluid mineral is as follows.

 The bottomhole zone 1 drilled to the design level 2 and cased casing 3 of the well 4 is filled with abrasive. After that, the downhole hydraulic monitor 5 is lowered into the well 4, the casing of which is also filled with an abrasive. Structurally, the borehole hydraulic monitor 5 must be made with at least one lateral jet forming nozzle 6 for cutting through windows in the casing string 3 and rock formation 7 and one downhole jet forming nozzle 8 to create an upward flow of pulp with abrasive in the bottom hole zone 1 of well 4 below the level of the lateral jet forming nozzle 6. In addition, the lateral jet forming nozzles 6 must have a device 9 for ejection of the abrasive.

 Borehole hydraulic monitor 5 is the opening of the reservoir 7 and create a technological cavity 10, which is used as a receiving tank for coming from the reservoir 7 of a flowing mineral. To do this, a high-pressure fluid stream is fed through the bottomhole jet forming nozzle 8, which is used to wash and transfer to the pulp an abrasive located in the bottomhole zone 1 of the well 4. A high-pressure fluid stream is fed through the side jet forming nozzle 6.

 The fluid to the nozzles 6 and 8 is fed through a string of high-pressure pipes 11 from the surface. The high-pressure flow supplied through the lateral jet forming nozzle 6 ejects the abrasive located in the bottom-hole zone 1 of the well 4. The abrasive caught by the high-pressure fluid flow contacts the wall of the siege pipe, as a result of which, and then in the cement ring holding the casing string 3 , cuts a vertical gap 12 with a length equal to the height of the site. Initially, the gap 12 is cut in the area 13 of the formation of the technological cavity at the roof 14 of the productive formation 7. Then, at the site 13, hydraulic fracturing of the rocks of the productive formation 7 is performed.

 Hydrocracking in section 13 can be performed both from top to bottom and from bottom to top along the height of section 13. In the latter case, as the volume of the worked-out space increases due to a decrease in the pulp flow rate, its solid fraction is partially deposited in the worked-out space. The solid fraction of the pulp contains abrasive and particles of the destroyed rocks of the reservoir 7.

 The fine clay fraction of the destroyed rocks of the productive formation 7, the abrasive, as well as the sand fraction of the destroyed rocks that have not settled in the working space of the formed section 13 of the technological cavity, flow through the annular space 15 between the casing string 3 and the borehole hydraulic housing 5. At the junction the columns of high-pressure pipes 11 with the housing of the downhole monitor 5, the annular gap increases sharply and the flow rate decreases.

 Since the abrasive has a large hydraulic size in comparison with other fractions of the pulp, a reduced flow rate becomes insufficient for it to rise to the surface and, under the influence of its own weight, it is lowered into the downhole hydraulic monitor body 5 open from above, from where it is ejected by a high-pressure flow and reused in the process of hydraulic fracturing.

 After the part 12 of the section of the technological cavity is formed through the slot 12 cut in the casing and cement ring, the downhole hydraulic monitor 5 is rotated by a certain angle and the slot is cut through the same way and the next part of this section of the technological cavity is formed. In the future, operations for cutting the gap and hydraulic fracturing of the rocks of the reservoir are repeated until an upper section of the technological cavity is formed around the well. The specified cavity has a cross-sectional view of a multipath star.

 Then downhole hydraulic monitor 5 is lowered to form the next section of the technological cavity. At the same time, the pillar 16 of the rocks of the productive formation 7 is left between the indicated areas. In this sequence, the cycle is repeated until the technological cavity of the given volume is formed.

 As the abrasive is consumed due to its deposition in the formed technological cavity for loading new portions, the process of rock destruction of the productive formation 7 is stopped and the next portion of the abrasive is poured into the wellhead. The abrasive under its own weight falls to the bottom of the borehole 4, filling the bottom-hole zone 1 and partially the body 6 of the borehole hydraulic monitor 5. After supplying the pressure fluid to the bottom-hole 8 and side 6 jet-forming nozzles, the abrasive is ejected by a high-pressure fluid stream through the side stream-forming nozzles 6 and the rock formation process reservoir resumes.

 The advantage of this scheme is that there is no need to extract production equipment from the well, which is especially important when opening productive formations at great depths.

 In the case when the hydraulic fracturing of the rocks of the productive formation 7 on the site is performed in the direction from top to bottom, the deposition of the abrasive and the sand fraction of the destroyed rocks does not occur. In this case, the filling of the formed technological cavity to maintain its roof and walls in a stable state is carried out after the formation of the section of the technological cavity by supplying a high-pressure jet with an abrasive to the upper part of the formed section of the technological cavity. The consumption of abrasive with this seme will be slightly higher than with hydraulic fracturing in the direction from the bottom up. According to this scheme, replenishment of the worked out space formed and filled during hydraulic fracturing in the direction from bottom to top can be carried out.

Claims (2)

 1. A method of opening a productive formation of a flowing mineral, including installing and cementing a casing in a drilled well, perforating a casing, forming a technological cavity in a producing formation around a well by destroying and removing rocks of the producing formation with a high-pressure jet of liquid with an abrasive supplied through the jet-forming nozzles of the well a hydraulic monitor, separating the abrasive from the pulp for reuse in the well and raising part of the destroyed rocks is productive of the formation to the surface in the flow of pulp, maintaining the walls and the roof of the formed technological cavity in a stable condition by filling it with a mixture of destroyed rocks of the productive formation and abrasive, characterized in that before the descent of the borehole hydraulic monitor, its body and bottomhole zone of the well is filled with abrasive, which is to the jet -forming nozzles are fed in a pulp stream ejected by a high-pressure liquid stream, the technological cavity is formed by sections, leaving pillars between them in series with upward from the roof of the reservoir to its soil, and the separation of the abrasive from the pulp for its reuse is carried out over the open top of the borehole hydraulic monitor body in the zone of decrease in pulp flow rate.  2. The method according to p. 1, characterized in that the loading of new portions of the abrasive is carried out at the wellhead after stopping the process of destruction of the rocks of the reservoir.

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