Differential filters to arrest water in oil production

FIELD: process engineering.

SUBSTANCE: invention relates to operation of oil production wells. Differential filter comprises swelling polymer applied on matrix particles to swell after contact with water to decrease filter permeability. Polymer is selected from polyacrylic acid or polymethacrylic acid, polymaleic anhydride, acrylamide polymer, polyamide, polyester, latex, and polyvinyl alcohol. Method of adjusting water ingress into well comprises incorporating claimed differential filter into wall bottom for operation therein. Note here that differential filter permeability decreases after contact with water.

EFFECT: controlled water ingress.

18 cl, 2 dwg, 1 ex

 

The technical field to which the invention relates

The present invention relates to a method of reducing the flow of water to hydrocarbon wells drilled through the subsurface. More specifically, it relates to such methods for selectively reducing the flow of underground water fluids in the borehole while maintaining its hydrocarbon production.

The level of technology

The allegations in this section provide only information about the prior art relating to the present invention, and may not constitute prior art.

During the period of operation of the well for production of hydrocarbons (oil and gas), water is often produced along with the hydrocarbons. The amount of water extracted from a well, usually increases over time with accompanied by a reduction in hydrocarbon production. Often the supply of water becomes so excessive that require remedial measures to reduce the ratio of water/hydrocarbons. The result of the uncontrolled flow of water may be the abandonment of the well.

Before hydrocarbons can be extracted from underground reservoirs, the area of production must be completed so that the borehole was reported with uglevodorodnaya area (zones). In the ideal case, the area of hydrocarbon production does not need to be reported in Nessim plot (plots). However, some areas of hydrocarbon production may unintentionally communicate with wednesaday area. For example, water breakthrough can occur when the crack goes out and creates a crack in the water zone. Even if there is no actual original unstable messages between the zone of hydrocarbon production and Voronezhsky zones of the reservoir, such a message may develop during the production of hydrocarbons. For example, the water can rise up from vodonasosa plot method, known as the cone watering.

The supply of water in hydrocarbon wells is a significant problem. It is especially difficult to deal with the inflow of water into the open trunk, horizontal wells, where there is no easy way to isolate and stop the flow of water, at the same time allowing other parts of the well to produce hydrocarbons. This problem is of special concern when the water passes through the upper part of the borehole and prevents oil from more remote places in the wellbore.

Another difficulty with the water flow into the well refers to the uncertainty in what areas and zones of the borehole to obtain water. The necessary technology to determine vododobyvayuschih zones, in order to take appropriate action.

Sometimes the supply of water cannot be isolated or stopped without significant vmeshatelst is for injection of cement into the perforations or uploading relevant gels in the matrix. This requires the placement of packers and/or location using coiled tubing. These procedures are lengthy and expensive.

In U.S. patent 3,719,228 described method of treatment of a subterranean reservoir containing hydrocarbons or brine to stimulate production of hydrocarbons, to eliminate the flow of water and/or education of a water cone. In accordance with this method, the composition for pre-rinse containing aqueous solution of the resin Soaps and Soaps of fatty acids, is injected into the reservoir. The pre-rinse composition reacts with residual salt solution, forming a precipitate, which blocks the path, carrying the salt solution. The composition of the preliminary washing must not react with the hydrocarbons, thus allowing uglevodorodnym ways to stay open.

Another method is described in U.S. patent 4,617,132. In accordance with the specified method, Sandstone initially brought into contact with an aqueous solution containing water-soluble anionic polymer having a molecular weight of more than 100,000. Then, the anionic polymer is brought into contact with a liquid containing water-soluble cationic polymer having a molecular weight of more than 1,000. As a result of interaction with anionic, cationic polymer, the formation of complex donor-acceptor type between the two polymers to the th reduces the amount of anionic polymer, flushed out of the reservoir fluids, quarried from there. The presence of stable polymer in the reservoir reduces the ratio of water/oil reduction of formation permeability to water in the wellbore.

In U.S. patent 5,146,986 described another way selective reduction of the permeability of the underground formation. The layer is brought into contact with uglevodorodnaya liquid containing a surfactant. Suppose that the surfactant is adsorbed on the walls of the interstitial passages in the reservoir, resulting in the flow of water through the passages is reduced.

In U.S. patent 5,150,754 describes how selective introduction in uglevodorodnaya the area of oil, can form a solid gel, which degrades for the indicated period of time. Then, water glioblastoma mixture is introduced into the area water supply reservoir. After degradation of the initial gel hydrocarbon production can continue.

Another method, described in U.S. patent 5,203,834, includes the steps of introducing into the well gas, polymer composition, capable of forming a foamed gel with gas, and a gel that slows the degradation agent is able to open the passages in the gel.

In addition, K. E. Thomson (K. E. Thomson and H. C. Vogler (H. S. Folger) published in SPE Production and Facilities, May 1995, pages 130-137, the proposed method, which uses the introduction is ratiwatana and the procedure stops, as well as diverting agent on the basis of slowly reacting silicic anhydride. Stage countercurrent described as expandable displacement agent before beginning or end of the pattern formation.

In U.S. patent 6,803,348 issued by Jones and others, and the U.S. patent 6,920,928 issued by Davies and others, described hydrophobic modified polymers for water regulation and use of these polymers for water regulation. The polymers described in these patents, based on polymers having side chains which can be crosslinked with chromium(III), zirconium(IV), or organic bridges (for example, geksanalem) in aqueous media, but not in hydrocarbon environments.

Although these methods of the prior art have been successfully used to regulate the flow of water, there remains a need for simpler and more convenient ways to regulate the flow of water into the well.

The invention

In one aspect the present invention relates to a differential filter. The differential filter in accordance with one embodiment of the invention contains a swellable polymer that swells after contact with water so that the differential permeability of the filter is reduced.

In another aspect, the present invention relates to a method for controlling admission to the water in the well. The method in accordance with one embodiment of the invention includes deploying a differential filter in the bottom hole and work in the bottom hole, while the differential filter contains a swellable polymer that swells after contact with water so that the differential permeability of the filter is reduced.

Other objects and advantages of the invention will become apparent from the following description and appended claims.

Brief description of drawings

1 shows a diagram of the production well, with three zones and fluid, in accordance with one embodiment of the invention, which is pumped into the hole to block the flow of water.

Figure 2 shows a block diagram illustrating the method in accordance with one embodiment of the invention to prevent the entry of water into the well.

Detailed description of the invention

Embodiments of the invention relates to a differential filters, which have different permeability to water unlike hydrocarbons. These filters can be porous filters to trap particles. In accordance with a variant embodiment of the invention the permeability of the filters are changed after contact with water. More specifically, these filters to trap ASTIC become less permeable after contact with water, reducing or preventing the passage of water. On the other hand, the permeability of these filters is practically not reduced when they are faced with hydrocarbons (oil or gas). Consequently, these filters to trap particles will not interfere with the passage of hydrocarbons. These filters, which can provide selective passage of hydrocarbons and to retard the passage of water, can relate to so-called "differential filters.

Below will be described embodiments of the invention with several detailed description, which is intended for illustration only and is not intended to limit the scope of the invention. In addition, it should be understood that in this description, if the number of concentrations or quantities described as used, or suitable, or the like, it is understood that any or each concentration or value within the range, including the end points, should be considered as mentioned. Moreover, each numeric value should be read once as modified by the term "about" (unless already specially not been so modified), and then read again without using such modifications, if within the context States otherwise. For example, "a number from 1 to 10" should be read as indicating any or every possible Chi is lo in the range between about 1 and about 10. In other words, when presented with a certain number, even if only a few specific points of the parameter defined or referred within the series, or even when the point of the parameter is not assigned within the series, it is necessary to understand that the authors of the invention take into account and assume that any or all points of the parameter within the series shall be considered as included in the description, and that the inventor is entitled to the full range and all points within the series.

In accordance with certain variants of the invention, the differential filters may contain a mixture of solid particles "matrix" type, mixed with particles of swellable polymer. Swellable particles can uniformly be mixed in the mass (mixture). Because the oil is extracted through the filler filter, as a rule, there is no reduction in the permeability of the filter. When the water will be extracted through the filter, bulbs, razbujeny in the water will expand, reducing the permeability of the filter. Thus, the filters may function by blocking or restricting the flow of water in the bottom of a well.

In accordance with a variant embodiment of the invention the particles of the matrix is inert to oil, gas or water. Any inert particles known from the prior art, can be used. For example, particles of a matrix can be normal is if lightweight gravel, glass beads, ceramics, walnut shells or the like. The particles of the matrix can also be any type covered by the resin gravel or proppant, or polymer balls (no swelling). Examples of materials of the polymer matrix, for example, may include semi-crystalline polymers, such as polyethylene, polypropylene, crosslinked termotorgmash polymers or thermoplastic polymers.

In accordance with certain variants of the invention, the inert particles of the matrix may contain polymer particles, which can be "welded" together, subjecting them to the action of another reagent. Examples of such polymer particles can include poly(L-lactide)(PLA) and the beads or particles of polystyrene. These polymer beads can be welded together (or to form agglomerates) effect of organic solvent. The agglomerates of these polymer particles may provide some strength filter structure according to the invention. In operation, a mixture containing such a polymer matrix, may be pumped into the well, forming the mixture into the bottom of a well or borehole, or perforations. This will be accompanied by a sharp stream of solvent. The rapid influx chemically "point will sew" the mass of particles in a uniform porous filter. This is described below in the examples.

In accordance with some options ASU is estline invention of differential filters may contain particles of matrix type, covered swellable polymer. The floor of the swellable polymer will expand and reduce the permeability of the filter, resulting in reduced water flow (as a consequence, reduced water inflow). On the other hand, hydrocarbons are not able to significantly expand the coverage of the swellable polymer. As a result, the hydrocarbons may pass through the filter and hydrocarbon production does not significantly change. Consequently, these filters can serve well bottom to block or stop the flow of water.

In accordance with certain variants of the invention, the differential filters may contain swellable polymers in water. These swellable in water, the polymers can be used in pure form or in combination with other agents commonly used in the bottom hole. For example, these swellable in water, the polymers can be mixed with the proppant in the fluid for fracturing or gravel for gravel-filled.

Swellable in water balls in accordance with a variant embodiment of the invention, for example, can include polyacrylic acid (PAA), polymethacrylic acid (PMA), polimolekuly anhydride, polyvinyl alcohol (PVOH), latex with a low viscosity or a polymer, similar to the types used in swellable towels. Also Chari and may include polyethylene oxide, polypropylene oxide, Polyoxymethylene, polyvinyl methyl ether, polyethylene imide, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene Imin, polyethylene acid, polysilicon acid, polyphosphoric acid, polystyrene acid, polyvinylene, natural water-soluble polymers, derivatives of guar, cellulose derivatives, xanthan gum, chitosan, daiten and any suitable copolymers or mixtures thereof. These types of balls contain polymers that are sewn together to prevent them from dissolving in the water. These polymers are a class of polymers known as polyelectrolytes. Polimernye swellable beads can also be used in accordance with some variations of the invention, for example, but not limited to, such inorganic materials as sodium salt of bentonite or even silica gel. In addition, the swellable particles may also be made of inert particles (ceramic, metal or polymer) with a covering layer of swellable crosslinked polymer material (for example, PAA, PMA, and the like). From the mechanical point of view, swellable beads, usually swell and block the pores of the filter, when they brought forth water.

In some embodiments, the implementation of the swellable beads can contain polymers that include functional groups that can hydrolize Atsa water and the hydrolysis product may swell in the water. Examples of such polymers may include cross-linked polyvinyl acetate or other polymers having a functional group capable of hydrolysis (such as lactones, lactams, imides, anhydrides, thiolactone, dianhydride, etc). In the presence of water is essential functional groups of polyvinyl acetate, as a rule, hydrolyzed, forming a polyvinyl alcohol (PVOH), which usually swells in water. Another modified PVOH may include PVOH copolymers and another ester such as methyl methacrylate. Examples of such modified PVOH polymers described in U.S. patent 5,137,969 issued by Marten and others (Col, lines 1-11). Some of these modified PVOH sold Celanese Chemicals, Dallas, Texas, USA) under the trademark VytekTM.

In addition to the PVOH swellable beads-based polymers having capable of hydrolysis of functional groups can be based on other polymers, such as polyamides, polyesters, latex or similar. Latexes suitable for such purposes (for example, latexes with low viscosity), are produced by Hexion Specialty Chemicals (Columbus, Ohio, USA). Latex can be obtained synthetically by polymerization of the monomer, which emulsify with surface-active substances. For example, in U.S. patent 5,175,205 describes the obtaining of latex with a low viscosity. The latex described in this patent, synthesized from able to copolym the polarization of the monomer, having at least one terminal alanovoy (CH2=C<) group. Such monomers are preferably alkyl esters of acrylic or methacrylic acid, and latex can be synthesized from a single monomer or combination of monomers. After polymerization, the polymer can be used as is, or ester group in the polymer can be partially hydrolyzed, giving karboksilirovanie polymers, which are latex with a low viscosity. Hydrolysis of the ester can be controlled at any desired level (e.g. 10% or 20%) so that the latex will still contain capable of hydrolysis of the ester group, which will be either hydrolyzed by water. After hydrolysis, the latex will have polycarboxylate side chains that can function like polyelectrolytes.

The particle sizes of the balls of the matrix and swellable beads may have any dimensions suitable for its intended use. For example, if these balls are designed for placement in cracks, smaller particle sizes are preferred. On the other hand, if these balls are used to form filters in the wellbore, can be used particles of large sizes. In most cases, balls and particle filter according to the invention can have dimensions (also known as the average diameter is ture) in the range from about 10 mesh (average size of about 2 mm or less) to about 1000 mesh (average size of 10 microns or less), for example, about 20 mesh (average size of about 940 microns or less), about 40 mesh (average size of about 350 microns or less), about 60 mesh (average size of about 250 microns or less), about 80 mesh (average size of about 160 microns or less), about 100 mesh (average size of about 1200 microns or less), about 200 mesh (average size of about 60 microns or less) and the like. However, particles outside this range may also be used. Any average person in the art knows, what sizes are better suited for the work required. For example, a filter for bookmarks balls for use with gravel backfill preferably has dimensions similar to the dimensions of the materials gravel backfill, which can be 24, 40 or 60 mesh, for example. The use of particles of a larger size can reduce the capillary forces that arise in mixed water-oil flow or when the water flows back into the reservoir, which produces oil. On the other hand, the smaller mesh sizes may be used in tools downhole, such as MDT®.

In accordance with some variations of the invention filters to trap particles may include other features to provide information about the admission of water into the wellbore. For example, swellable beads can be loaded before use is using chemical indicator, which will diffuse out of the ball and pushed the collision of the balls with water. Marbles can fit various indicators, which are distributed in prepacked screens. The indicators in the balls will indicate what areas of the wellbore overcome the ingress of water. Samples of water or oil selected from the wellbore may then be analyzed to determine the source of water without the use of the tool in the bottom hole.

As described above, there are several mechanisms that can cause the ingress of water into the well. Embodiments of the invention can be used to reduce or limit the flow of water regardless of the mechanisms that cause the ingress of water. Figure 1 shows one of such situations. As shown in figure 1, the well 10 for extraction includes the mouth 11 of the bore and the barrel 12 bore. The barrel 12 bore passes through three permeable layer 13, 14, 15 in the reservoir. Of these layers, the layers 13, 15 is extracted hydrocarbons, and the layer 14 produces water.

In accordance with a variant embodiment of the invention, the liquid 16 for processing may be pumped from the surface with mechanical isolation (packers) or without it. The liquid 16 for processing may not be aqueous fluid that includes one or more filters to trap particles according to the invention. In is the quality alternative the liquid 16 for processing may be aqueous liquid in which the particles according to the invention can be suspended as of the encapsulated particles. Encapsulation can dissolve or decompose under the conditions of the borehole bottom (for example, high temperature or high pressure). Once injected into the bottom of the borehole fluid 16 for processing can come in all open areas (e.g., layers 13, 14, 15). Filters to trap particles in the liquid 16 for processing will be in contact with oil or water in various zones. When these filters to trap particles in contact with water (e.g., layer 14), a swellable polymer in the filters will be expanded, leading to reduced permeability of the filters. As a result, the supply of water from the layer 14 will be reduced or avoided.

On the other hand, these filters to trap particles entering into the layers 13 and 15, will be in contact with hydrocarbons. Swellable in water, the polymer is not significantly expand (or not will be expanded) when it encounters hydrocarbons. Thus, filters to trap particles in the layers 13 and 15 mainly will retain its original permeability. As a consequence, the production of hydrocarbons will not be difficult.

As described previously, the filters for particulate according to the invention Zack who receive the bottom of a well in fluid 16. Alternative ways to deploy filters to trap particles of the invention may include lowering filters to trap particles as tablets, bars or other solid forms. These balls filter to trap particles can be encapsulated by a material, such as polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid or even wax with a low melting point, such as paraffin, Montan, camphor or polyethylene waxes; as waxes melt at temperatures well, releasing swellable particles, or other suitable mixture of the above materials, these materials can degrade under conditions of downhole (e.g., high temperature) or can easily be destroyed with the addition of another reagent. Many of these encapsulating materials, such as in the case of camphor, not necessarily water soluble, but more soluble in oil. Using particles in combination with soluble oil materials, encapsulated particles can be injected into the wellbore through the carrier fluid is water based as oil, particles become active when removing soluble in oil sealant.

The techniques described above, illustrate one application among many possible applications is of embodiments of the invention. Other applications, for example, may include the following.

Filters for particulate of the invention, for example, can be used with mixtures of gravel backfill. A mixture of gravel backfill may be used in wells with open hole. In this application, swellable polymer beads or particles) can be injected with gravel or with a lightweight gravel, as during normal operation with gravel backfill. Balls swellable polymer may be provided as an encapsulated particles. Encapsulation will dissolve or degrade in the bottom hole. In this application, the swellable polymer should not be mixed with particles of the matrix before using, as the gravel can function like particles of the matrix. However, swellable polymers, pre-mixed with other particles of the matrix, may also be used.

When using gravel backfill, if the well begins to produce water in one place, such as the wellhead, swellable beads will swell and stop the flow of water. Other parts of the wells along the wellbore will continue to produce oil or gas through the gravel backfill. This usually prevents costly measures to stop the flow of water.

Similarly, filters for particulate according to the invention can the e be used with screens from pre gasket (for example, screens to combat the flow of sand into the well)containing a mixture of normal gravel or coated with resin gravel and swellable polymer beads. The advantages of using these filters in such applications is similar to operation of gravel backfill.

In another application, a mixture of normal and swellable in water balls can be injected into the bottom hole in the perforation. Then these balls are the flow of solvent in place for "spot welding" conventional polymer beads in the reservoir. In this application the balls such that can be made solvent, such as PLA and the above-described polystyrene.

Filters for particulate according to the invention can also be used with mixtures for hydraulic fracturing, which include proppants. In this application swellable beads that can be encapsulated, can be cracked with proppants. Swellable beads in the cracks will prevent the ingress of water through the zones that intersect the crack. Water zone, crossing the area of production, can occur when there are no cracks in the zone of production or when the area of production is filled with water. Other zones crossing the crack and producing gas or oil, as a rule, normally extracted.

Filters for particulate according to the invention can also use the change as a temporary filter in the bottom hole, which allow you to continue the production of gas and oil. At this time, the filters will prevent the entry of water into the production line, when water passes through them. Temporary filters can be obtained from a mixture of swellable beads and balls PLA. Balls PLA can be welded or specalise together, forming the agglomerate, the supporting structure. Agglomerates PLA can degrade over time in the bottom hole. Conversely, a suitable reagent such as calcium carbonate, magnesium oxide, sodium hydroxide and the like, as a non-limiting example) can be added to increase the degradation of sinter PLA when it is no longer necessary in the temporary filter.

Filters for particulate according to the invention can also be used as permanent filters in wells that allow you to continue the production of gas and oil, but do not allow water to flow through them. These filters may contain inert beads (coated with resin proppants or other materials, powder ceramic or plastic balls), mixed with beads that swell in water. These filters in the bottom of a well, whether temporary or permanent, can be installed in the tools downhole (such as the multi-tool test fluid (MDT®) from Schlumberger), mud motors, pumps or even elements of the packer

Below is a description of several examples to illustrate embodiments of the invention. These examples are intended for illustration only. Any average person skilled in the art generally understands that these examples are not exhaustive and do not imply a restriction of the scope of the invention.

Examples

Differential transmission of hydrocarbons and blocking the passage of water differential filter according to the invention is illustrated in the following examples. In the first example, beads of poly(L-lactide)(PLA) size of about 20 mesh was mixed with particles of overabsorbed (such as particles Terra-sorb approximately 40 mesh) in the ratio 5:1 by weight. Terra-sorb is a crosslinked potash polyacrylamidegel copolymer, commonly used in horticulture for soil enrichment, and available from many vendors. The resulting mixture balls was merged into the trunk of a glass pipe and hardened (i.e., balls PLA point race) using a stream of acetone, which was formed agglomerates balls PLA. This process was performed separately for two different pipes. In the third trumpet the process was repeated except that the mass of balls contained only balls PLA, i.e. without any particles overabsorbed.

In the third pipe when the water is conducted is camping along the pipe through the agglomerated mass of balls PLA observed unimpeded flow of water through the mass, indicating that the mass of permeable and open to the flow of water. The second pipe oil lightweight composition with a viscosity of about 5 MPa was passed through the mass of balls. This oil was also demonstrated through the mass of balls, indicating that the mass is permeable to oil, even through the material of overabsorbed included in the packing. The first water pipe was carried out through a stuffing balls containing balls PLA and particles overabsorbed. There have been no water leakage through the stuffing balls, even after more than 24 hours. Material overabsorbed in the stuffing balls swell after contact with water and plugged capable of permeability stuffing.

A similar experiment was conducted using a spray instead of pipes. A similar mixture of stuffing balls were prepared in three sprayers. It was found that stuffing balls of material overabsorbed did not pass water, even under some slight pressure (about 10 psi), created by the plunger. These experiments clearly show that the filters are made of materials overabsorbed, stuffing balls were selective filters, which allow oil and not water.

The above examples demonstrate that differential is iltr according to the invention may create a selective permeability gaskets, which regulates water flow, at least a substantial cessation of flow of liquid when the level of water supply becomes undesirable. Since these differential filters practical in many different applications, clear the way in which they should be used, as a rule, definitely depends on the specific applications. Figure 2 shows a block diagram illustrating the basic method of how the filters according to the invention can be used.

As shown in figure 2, in a typical application, differential filters according to the invention are unfolding in the bottom hole (step 21). Depending on the type of work that you must perform in the bottom of the well, the filters may be unfolding with the help of liquid, which, for example, fetch. Other deployment methods may include the use of filters in the tool for deployment downhole. It should be noted that differential filters according to the invention may contain a water soluble polymer in the ratio, up from about 1% to about 100% relative to the total weight of the particles (i.e., the sum of the particle matrix and swellable particles). Then perhaps an optional wait for a certain period of time for response filters with water (step 22). This waiting may be the necessary or not, depending on the work in the bottom hole, and the types of swellable materials. For example, in the case of swellable material which swells upon contact with water, this is not required. On the other hand, if the swelling depends on the hydrolysis of certain functional groups (i.e., anhydrides, esters, etc), it may be necessary for some time to perform hydrolysis. After hitting filters into the reservoir operation in the well bottom can be made or continued (step 23).

Embodiments of the invention can contain one or more of the following advantages. Differential filters according to the invention are effective to prevent flow of water, not hydrocarbons. As a result, they can be used in the well to reduce or prevent the flow of water. Prior knowledge about where you can do water are not necessary. These filters can be easily deployed without the need for special equipment. These filters can be deployed without interrupting normal operations in the well, additional time and costs. These filters can include indicators (markers) to identify areas in which the water passes in the well.

Although the invention has been described in relation to a limited number of options to implement the ia of the invention, specialists in the art will understand that can be developed other embodiments of the invention, is not beyond the scope of the invention described here. Therefore, the scope of the invention should be limited only by the attached claims.

1. Differential filter containing particles of a matrix and a swellable polymer that swells after contact with water so that the differential permeability of the filter is reduced, while the swellable polymer is insoluble in water, contains at least one material selected from the group consisting of polyacrylic acid, polymethacrylic acid, polymolecular anhydride, polyacrylamide, polyvinyl alcohol, latex, polyamide, polyester, and their copolymers, and deposited on the particles of the matrix.

2. The filter according to claim 1, in which the swellable polymer contains a polymer having a functional group, which can be either hydrolyzed by water.

3. The filter according to claim 1, in which the particles of the matrix contain at least one type of particles selected from the group consisting of: gravel, glass beads, ceramics, shell walnuts, covered with tar gravel, covered with resin sand and polymer beads.

4. The filter according to claim 1, in which the particles of the matrix contain at least one type of particles selected from the group consisting of: poly(L-lactide), is ostirala, stitched termotorgmash polymers and thermoplastic polymers.

5. The filter according to claim 1, additionally containing a token that is displaced from the differential filter in the collision with the water.

6. The filter according to claim 1, in which it is mixed in the liquid for use in the bottom of a well.

7. The filter according to claim 6, in which the liquid for use in downhole selected from the group consisting of: fluid for gravel backfill and liquids for hydraulic fracturing.

8. The filter according to claim 1, in which the differential filter is located on the device for deployment in a borehole bottom.

9. The filter of claim 8, in which the device for deployment downhole selected from the screen to combat the flow of sand into the well, the packer, the pillar of completion and tools for maintenance.

10. The method of regulating the flow of water into the well, comprising: deploying a differential filter in the bottom of the borehole; and at the bottom hole, while the differential filter contains particles of a matrix, and a swellable polymer that swells after contact with water so that the differential permeability of the filter is reduced, while the swellable polymer is insoluble in water, contains at least one material selected from the group consisting of polyacrylic acid, polymethacrylic acid, the floor is maleic anhydride, polyacrylamide, polyvinyl alcohol, latex, polyamide, polyester, and their copolymers, and deposited on the particles of the matrix.

11. The method according to claim 10, in which the particles of the matrix contain at least one type of particles selected from the group consisting of: gravel, glass beads, ceramics, shell walnuts, covered with tar gravel, covered with resin sand and polymer beads.

12. The method according to claim 10, in which the particles of the matrix contain at least one type of particles selected from the group consisting of: poly(L-lactide), polystyrene, crosslinked termotorgmash polymers and thermoplastic polymers.

13. The method according to item 12, further comprising passing the solvent through the particle matrix for agglomeration of the particles of the matrix.

14. The method according to claim 10, in which the differential filter further comprises a token that is displaced from the differential filter in the collision with the water.

15. The method according to claim 10, in which the deployment of the differential filter in the bottom of a well carried out by injecting a differential filter in the bottom of a well with liquid.

16. The method according to claim 10, in which the work in the bottom hole selected from the group consisting of: gravel backfill, hydraulic fracturing, well completion and production.

17. The method according to claim 10, in which the deployment of the differential filter in the second well provide the location of the differential filter device for deployment in a borehole bottom.

18. The method according to 17, in which the device for deployment downhole choose from screen to combat the flow of sand into the well, the packer, the pillar of completion and tools for maintenance.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: method includes production from a bed with a water-oil mixture in a forced mode, separation of the product into oil and water, and pumping of the released water into the bed for water intake. According to the invention, an overlying bed is opened in the well for water intake, a device is lowered into the well in the form of a lower pump and an upper pump, the inlet device of which is made as a pipe between a casing pipe and a pipe string, providing for total speed of flow during water and oil offtake that is lower than the speed of oil floating in water to separate the product in the well into oil and water. At the same time the released water is pumped with the lower pump into the bed for water intake. Pumps are selected with efficiency corresponding to watering of the bed produce, and total efficiency providing for forced offtake of the product with water and oil mixture. The device comprises pumps with drives made as capable of their serial arrangement on the pipe string in the well and having inlet and outlet devices, and a packer capable of arrangement between beds in the well, one of which is with a water-oil mixture, and the other one is intended for water intake. The inlet device of the upper pump is made as a cylindrical reservoir with an inlet side hole communicated with a bed holding a water-oil mixture, and the outlet device of this pump is made as a valve unit that lets oil through into a pipe string. The outlet device of the lower pump is made in the form of a channel with an injection valve to inject water into a bed intended for water intake, and the inlet device - in the form of a channel with a suction valve for pumping of settled water into the pump. According to the invention, the reservoir is made in the form of a pipe arranged between a casing pipe and a pipe string with the area of the inner circular section that provides for total speed of flow during water offtake with a lower pump and oil with an upper pump, which is lower than the speed of oil floating in water during intensive offtake in the reservoir. The side hole of the reservoir is arranged below the foot of the bed with water-oil mixture and the inlet of the upper pump by at least 1 m. At the same time above the upper bed designed to intake water, between the casing string and the reservoir, which is made as open at the bottom, there is an additional packet installed, and a channel of the outlet device of the lower pump is communicated with an internal packer space of the well, besides, the side hole of the reservoir is arranged above the inlet device of the lower pump at least by 1 m and below the dynamic level of the water and oil contact.

EFFECT: higher oil recovery of producing formations due to lower watering of the products, limitation of water offtake, higher gradient of pressure in borehole environment of the bed.

2 cl

FIELD: oil and gas industry.

SUBSTANCE: method involves extraction of product from formation with water-oil mixture in forced mode, separation of product into oil and water and pumping of separated water to water receiving formation. According to the invention, drilling of lower water receiving formation is performed; device in the form of lower pump and upper pump is lowered into the well; inlet system of the above device is made in the form of a pipe between casing pipe and pipe string, which provides total flow velocity at water and oil extraction, which is less than floating-up velocity of oil in water for separation of product in well into water and oil. Separated water is pumped with lower pump to water receiving formation; at that, pumps are chosen with the capacity corresponding to formation product water content and total capacity providing the forced product extraction from the formation with water-oil mixture. Device includes pumps with drives, which have the possibility of being located in series on pipe string in the well and have inlet and outlet devices, and packer having the possibility of being located between formations in the well, the upper one of which has water-oil mixture, and lower one is intended to receive water. Inlet device of upper pump is made in the form of cylindrical capacity with side inlet hole interconnected with formation containing water-oil mixture, and outlet device of this pump is made in the form of valve unit passing the oil to pipe string. Outlet device of lower pump is made in the form of channel with water delivery valve to the formation intended to receive water, and inlet device is made in the form of channel with suction valve for pumping of settled water to the pump. At that, annular section area outside the capacity is chosen so that maximum flow velocity of water-oil mixture downstream of this section exceeds floating-up velocity of oil in water. At that, capacity is made in the form of a pipe located between casing pipe and pipe string with inner annular section area providing the total flow velocity at water extraction with lower pump and oil extraction with upper pump, which is lower than floating-up velocity of oil in water at intense extraction in the capacity. Side hole of the capacity is located at least 1 m below bottom of formation containing water-oil mixture and inlet of upper pump. At that, inlet device of lower pump is interconnected with the capacity at least 1 m below side hole. Capacity is closed from below with a plug with a connection pipe interconnected with outlet device of lower pump and with borehole space.

EFFECT: increasing oil recovery owing to increasing reservoir coverage coefficient at water flooding at advanced stage of development, and reducing material costs.

3 cl, 1 dwg

FIELD: electric engineering.

SUBSTANCE: the invention relates to submersible electric motors used in pumps. The electric motor comprises a frame, numerous stator laminations inside the frame, several rotors. Each stator lamination has a central window and several slots. The rotors are positioned inside the space formed by the central windows of stator laminations. The coil wires pass through each slot of each stator laminations. The heat shrink tube wraps the coil wires and tightens them into cords. Furthermore, the space between the heat shrink tube around the coil wires and the inner space of stator laminations allows the fluid flow through stator lamination slots. The heat shrink tube is installed into the stator lamination slots to improve the heat transfer in the electric motor. Numerous wires are inserted into the slots in stator laminations. The coil wires are heated, shrinking the heat shrink tube around the coil wires and tightening them into cords, in such a way so the gap between the heat shrink tube and inner surface of the stator laminations allows the fluid flow through wire cords inside the stator laminations.

EFFECT: improved heat transfer during cooling of submersible electric motors used in pumps, improved coil wires protection from wearing.

11 cl, 3 dwg

FIELD: oil producing industry.

SUBSTANCE: invention belongs to the oil producing industry, more specifically, to killing of gas and gas-condensate wells within the framework of well-workover, primarily carried out in productive formations with abnormal low pressure and within the severe environment. Essence of the invention: the production string is filled with sealing composite in the volume equal to the total volume of the production string and the volume of the annular sub-packer space of a well. The sealing composite is pushed into a sub-packer space of a well, gradually pumping the production string with displacement and killing fluid, whereupon the well is left off for return-to-thermal-equilibrium time. After that the completion fluid is pumped into the annular space of a well, pushing out the gas, accumulated in the annular space, and into the completion string leak interval and the upper part of the annular space of a well, where it is gathered in a gas cap and blown off. Subsequently the annular space of a well is filled with a plugging composite with its driving into the completion string leak interval, whereupon the well is left off for about 12 hours. After that the production string upper than the packer and lower than the completion string leak interval is located, through holes are made. Beneath the through holes, from within the production string, a blind plug is placed. He production string is filled with killing fluid, which, while going through holes in the production string, rinses the rests of the plugging composite, displacement and completion fluid from the annular space of a well. The killing fluid supply is ceased, when its density in the annular space equals an initial density.

EFFECT: enhancement of packer well killing security within the conditions of abnormal low pressure and severe environment, more specifically, unpressurized completion string or faulty circulation valve.

1 dwg

FIELD: oil-and-gas production.

SUBSTANCE: proposed method comprises selecting initial fluid-salt solution of natural origin and/or its semi-finished product with content of dissolved salts providing for initial density in preset limits. Prepared solution is cleaned of gaseous, and/or mechanical, and/or mineral, and/or biological admixtures. Solution, thus produced, is concentrated in preset number of stages. Solution density and concentration is increased in every said stage to preselected intermediate value. Concentrated solution is forced by high-pressure pumps through integrated units of reversed osmosis. Said units are made up of concentrate and permeate tanks are separated by reversed osmosis membranes. Said reversed osmosis is used at every stage to increase salt solution concentration. Pressure of 30-190 atm is used in every concentrate tank in time interval wherein intermediate density is increased to final magnitude.

EFFECT: reduced power consumption, higher efficiency, possibility of process automation.

4 cl, 2 tbl, 2 ex

FIELD: oil-and-gas production.

SUBSTANCE: proposed device comprises parker. Said parker comprises casing with lock, top coupling, elastic gland and adjusting assembly made up of hollow casing locked in coupling, seat, radial channels, shut-off element and compression spring. Locking element is made up of slips moving apart in fitting in place. Hollow casing inner space is provided with changeable jet. Hollow casing is provided with annular contraction with top and bottom chamfers arranged above radial channels. Top chamber angle is smaller than that of bottom chamber. Seat is fitted into hollow chamber to move up and down therein as-sealed. Shut-off element is provided with shaft with grooved surface to receive spring ring to interact with said annular contraction. Note here that spring stiffness, angles of chamfers and rigidity of spring ring are selected to allow spring contraction by pressure differential and spring ring displacement below said hollow casing annular contraction. Thereafter, shut-off element moves up while spring ring displaces into its initial position, that is, above hollow casing annular contraction.

EFFECT: simplified design, decreased consumption of metal.

1 dwg

FIELD: gas and oil production.

SUBSTANCE: method involves perforation interval locking by locking composition and a portion of choking fluid feed. Additional portion of choking fluid is injected through pump compressor pipe string to wellhead before feeding locking composition. Perforation interval zone overlapping is implemented at wellhead height of minimum 110% of perforation interval length. Volume of choking fluid portions are calculated so as the height of choking fluid portion column against surface of locking composition in pump compressor pipe string is equal to the height of additional choking fluid portion column against surface of locking composition in annular space. When pressures in pump compressor pipe string and in annular space are equal, gas is extracted from annular space together with gas extracted by displacement in pump compressor pipe string.

EFFECT: extended functional possibilities of the method, reliable locking insulation screen in perforation interval zone in a well with abnormally low bed pressure.

2 dwg

FIELD: gas and oil production.

SUBSTANCE: pressure of extracted fluid in pump zone is monitored, pump performance is controlled by control station located on the surface. Pressure gauge is placed into extracted fluid collection chamber located between suction valve and plunger. Reciprocal plunger movement rate is regulated from the station by the gauge readings so that pressure in collection chamber does not fall below specified value.

EFFECT: increased performance of bottomhole plunger pump due to more compact filling of the chamber between plunger and suction valve at each plunger stroke.

1 dwg

FIELD: gas and oil production.

SUBSTANCE: device consists of perforated casing and of chamber-divider with channels for supply of mixture of water and oil and for water removal. Also, the chamber-divider is made in form of a case containing upper and lower chambers divided with a bridge equipped with an axial channel and a shank end wherein there is installed a back spring valve. At least two spring loaded back valves are installed in the said bridge. The lower chamber of the case is equipped with pressure tight secured bush forming a cavity between a low end of the said bridge and an upper end of the said bush. The said cavity is communicated with a lower section of circular space by means of channels made in a lower section of the case. Circular space is formed with internal surface of the casing and external surface of the case. Upper and lower sections of the case have circular cylinder lugs. Also, the upper part of the case is pressure tight connected with a hollow cover in axial channel of which there is installed the back unidirectional spring loaded valve. Back unidirectional spring loaded valves are installed in a side wall of the upper section of the upper chamber of the case. A hollow tube is set inside the upper chamber resting on the bridge of the case and a lower end of its cover. The hollow tube has a row of through orifices. A float equipped with lock valves on ends is positioned inside the tube.

EFFECT: raised efficiency of operation due to self-regulation of water evacuation into water bearing reservoir and discharge of hydrocarbons - into production string.

1 dwg

FIELD: gas and oil production.

SUBSTANCE: device for selective completion of wells is equipped with electric control valve, case of control component of which is secured on flow string. A gate is connected with an electric actuating mechanism connected with an electric power source via a control unit by means of wiring laid on a shuttle device. The shuttle device is equipped with a tubular case with a telescopic elastic component concentrically arranged outside. The elastic component is connected with the case by means of thermo-sensitive element of alloy with shape memory effect and by means of a reverse element. Additionally the device is equipped with a split electro-contact element. One of split sections of the electro-contact element has a form of electric contacts electrically insulated one from another and connected with corresponding electric wires with an electric actuating mechanism. Another part has a form of electric contacts insulated from each other, arranged on a spacing element of the shuttle device and connected with corresponding electric wires secured on it. The reverse element has a form of a thermo-sensitive element of alloy with shape memory effect. Ends of both thermo-sensitive elements of the shuttle device are connected with electric wires secured on it.

EFFECT: expanded functionality of device.

3 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, namely, to methods for suppression of spills from emergency oil and gas wells and may be used to eliminate accidents with the help of shut-off plugs during field development, arranged at water reservoir bottoms, on the day surface, in underground mines, and also in continental shelves. During realisation of the method, using a cut casing pipe, a discrete material that is easily deformed under its own weight, having size and specific weight that ensure material falling in an ascending flow of oil and gas, is supplied in a quantity sufficient to form a shut-off plug in the well, which makes it possible to suppress the reservoir fluid of oil or gas. The shut-off plug may be formed in intervals, where first the discrete material of larger fraction is filled, then fractions with reducing size of solids are serially filled. The discrete material may be used in the form of solids of revolution. The material may be supplied via a hopper, which is installed above the cut casing pipe. After formation of a shut-off plug, the hopper is filled with a hardening mud. Discrete particles are made either from a homogeneous material or from composite materials.

EFFECT: invention provides for safety of a technological process and reduced impact at environment.

6 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: well construction method includes borehole sinking, lowering and attachment of casing and production strings. During drilling of the direction, cyclic controlled-angle drilling of the direction and bore hole under grief stem is performed using screw, with periodic lifting of drilling tool and discharge of drilled out slurry. Screw and drilling tool with diameter of 500 mm or 630 mm are used for drilling. Pipes with diameter of 377 mm or 426 mm are used as conductor pipes. In its upper part casing conductor pipe is plugged and provided with connection pipe, in its lower part it is provided with circulating openings for cement solution to pass. Casing pipe is arranged in well shaft so that upper part of the pipe is above ground level.

EFFECT: reducing of construction time and cost during well construction.

1 dwg, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: group of inventions refers to oil and gas production industry and can be used for emergency killing of wells. The method of well emergency killing with submarine location of mouth consists in pumping of cementing compound. Note that the cementing depth of the well area is determined in advance taking into account the well condition and pressure in the well. Injector attached to the tank with cementing compound and located inside the bag from flexible material is put on the bottom and inside the mouth of emergency well to the specified depth. The bag is filled with cementing compound; the compound is pumped from the tank through injector providing close contact of the bag outer surface with inner surface of the well. Note that injector is kept at the specified depth due to the weight of the whole structure filled with cementing compound, after pumping the pressure is maintained in the bag till the cementing compound is hardened. After cementing compound is hardened the fluid is pumped off or the well is killed.

EFFECT: method allows performing emergency killing of the well.

26 cl, 4 dwg

FIELD: gas and oil production.

SUBSTANCE: well construction involves drilling and fixation of direction, conductor and intermediate or operation column. Process water is used as drilling mud in drilling of intermediate or operation column. Rock caving zone is reamed, lower zone of non-caving rock is drilled. Drilling set is lifted from the well, drilling pipe string with open end is lowered into the well. Clay drilling mud is pumped through the well and displaced to the surface by process water, drilling pipe string is rotated, cement slurry is injected into drilling pipe string. When cement slurry enters annular space, rotation is stopped, and drilling pipe string is reciprocated to 10-14 m length. Cement slurry is pushed out to annular space by process water of the same density as in the well till drilling pipe strin and annular space have the same level. Drilling pipe string is lifted from the well, process maturing is performed till cement solidification, cement bridge is reamed by the same drilling set used earlier, and well construction is continued to the project level.

EFFECT: prevented cavern formation an drilling tool seizing during drilling.

FIELD: gas and oil production.

SUBSTANCE: device for shutoff of emergency hole of pipeline corresponds to plug including rod made of rigid solid or flexible material at one end of which there is located cylinder brush. Bristle or nap of the cylinder brush are made of flexible elastic material, for example, sections of metal wire secured radially around surface of the rod. Also, the rod of the plug can be solid or hollow in form of a pipe with a through orifice. On opposite from the cylinder brush side the through orifice of the rod is equipped with a shut-off device functioning as a gate of slide.

EFFECT: simple design of device, increased reliability of emergency pipeline shutoff facilitating collection of flowing out fluid; reduced time for assembly of device both on earth surface and in deep water regions difficult to access.

3 cl, 8 dwg

FIELD: gas and oil production.

SUBSTANCE: unstable interval of reservoir in hole is opened by means of drilling equipment with inhibited polymer drilling mud on water base. Further, there is pumped water-repellent composition with the following component contents, wt %: hydrocarbon product 10.0-60.0; tall oil or a product of its processing 1.0-3.0, amine-containing emulsifier of reverse emulsions 1.0-3.0, the said inhibited polymer drilling mud - the rest. A bath out of composition is set in an interval of the unstable reservoir for a period of not less, than 0.5 hour. Further, during drilling water-repellent composition having been used in form of the bath is transited into drilling agent by circulation.

EFFECT: raised degree of strengthening unstable rock due to its maximal hydrophobisation and mudding by forming water repellent barrier in kind of layer of reverse emulsion in near-borehole zone of well upon reservoir opening; water-repellent barrier further prevents rock contact with disperse water medium of drill agent thus facilitating complex of structure-mechanical properties of said layer at following drilling.

6 cl, 1 tbl

FIELD: gas and oil production.

SUBSTANCE: device for selective completion of wells is equipped with electric control valve, case of control component of which is secured on flow string. A gate is connected with an electric actuating mechanism connected with an electric power source via a control unit by means of wiring laid on a shuttle device. The shuttle device is equipped with a tubular case with a telescopic elastic component concentrically arranged outside. The elastic component is connected with the case by means of thermo-sensitive element of alloy with shape memory effect and by means of a reverse element. Additionally the device is equipped with a split electro-contact element. One of split sections of the electro-contact element has a form of electric contacts electrically insulated one from another and connected with corresponding electric wires with an electric actuating mechanism. Another part has a form of electric contacts insulated from each other, arranged on a spacing element of the shuttle device and connected with corresponding electric wires secured on it. The reverse element has a form of a thermo-sensitive element of alloy with shape memory effect. Ends of both thermo-sensitive elements of the shuttle device are connected with electric wires secured on it.

EFFECT: expanded functionality of device.

3 cl, 3 dwg

FIELD: construction.

SUBSTANCE: method to restore tightness of borehole annulus in a well of a gas field or a field that contains natural gas in its produce, relates to oil and gas producing industry and may be used in reconstruction, repair, preservation and liquidation of wells with gas-untight borehole annulus at fields and underground gas depots (UGD). The method includes formation of a ring channel in a well to connect borehole annulus and tubing of the well. On completion of the ring channel formation, production tubing is lowered into the well, equipped with a packer and a circulation valve. The ring channel and the joined borehole annulus are filled with liquid via the circulation valve of the production tubing. Variation or maintenance of density and/or height of the pumped liquid column above the formed ring channel are used to provide for permanent exceeding of hydrostatic pressure of the liquid column over the layer pressure of gas.

EFFECT: simplified and more efficient method to restore tightness of borehole annulus.

1 dwg

FIELD: oil and gas production.

SUBSTANCE: procedure consists in evacuation of fluid - water, condensate and mechanic impurities from bottomhole zone of well, in pumping reagents into oil-well tubing at closed annular space, in delivery of reagents to bottomhole of well with power of compressed air of annular space, in forcing reagents through into reservoir upon stabilisation of pressure in pipe and annular space, in evacuation of reaction products from reservoir, and in lowering and setting instrument - density metre - for record of changes of fluid density at bottomhole of well upon well shutdown. Reagents are driven into the reservoir and the bottomhole zone through orifices cut in a production string in gas medium in an interval of planned water-isolating operations, simultaneously there is supplied compressed nitrogen into annular and tube space and pressure of performed operation is controlled. The density metre is first arranged 10-15 m above lower orifices of the perforation interval, but upon pumping water-isolating reagents and upon forming a water-isolating screen a blocking solution is pumped and the density metre is positioned 100-150 m above a roof of the perforation interval to fix a level of the blocking solution. After process sedimentation calculated volume of killing fluid is refilled; its level is also measured with the density metre.

EFFECT: maintaining permeability of reservoir during repair operations.

6 dwg

FIELD: oil and gas production.

SUBSTANCE: invention refers to oil and gas producing industry, particularly to facilities for well completion and can be implemented at installing shank ends-filters in directional and horizontal boreholes of wells. The facility consists of a hollow case, of a sealing unit in form of sections of collars and of a centraliser positioned above the sections of the collars. Also the centraliser located above the shank end from inside is equipped with left hand thread for positioning equipment with an over located cone guide, from outside it is equipped with lengthwise grooves. The sections of the collars are set with tightness on the case. They correspond to composed packing washers, where in between there are installed spring washers. Also diametres of washers in the sections exceed diametre of a column with arranged sections of the collars. The sections of the collars are positioned between rigid circular insertions; in insertions there are made openings for tightening rods.

EFFECT: minimal metal input and simple design reduce expenditures for fabrication of shank end and for its installation in well; packing unit of shank end compensates heat expansion of shank end and ensures reliable packing and centring in well due to axial mobility and to alternating packing heat resistant washers and steel spring washers.

2 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to filtration materials for exhaust gases. Invention covers the substrate for ICE black filter provided, at least, partially with "washcoat" coating that includes material of relatively high density equal to, at least 3.50 g/cm3. Said substrate may contain catalytically active metal compound.

EFFECT: selective increase in substrate weight without increase in counter pressure.

12 cl, 3 dwg

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