Hydro-jet-mechanical procedure for decreasing permeability of well walls

FIELD: oil and gas production.

SUBSTANCE: procedure consists in simultaneous effecting permeable walls of well borehole with scrapers for removal of filtration crust and with high-pressure jets generated from hydro-monitored heads of mud injector during well bottom hole deepening with drilling. Also, hydro-jets are directed at angle towards each other, they converge at one point on the wall of the well and destroy their nuclei, thus preventing destruction of walls of the well and formation of cavities. Well walls are subjected to the similar effect when the well is treated before lowering a producer for cementing. Drill agent containing dispersed solid particles is used as fluid for high-pressure hydraulic jets.

EFFECT: raised efficiency of mud fill, reduced expenditures for emergency-recovery operations and time for construction of well.

2 cl, 2 dwg

 

The invention relates to the oil and gas industry, in particular to the construction of oil and gas wells, namely the technology of preparation of the wellbore to the descent of the production casing cementing.

Known methods and devices for reducing the permeability of the reservoir of high-pressure jets and mechanically (see "Oil industry", 1973, 3 6, S.11-14, article Kurochkin BM and other "Intensification of the process of clogging porous rocks by mechanical means, and A.S. No. 819306, 3 EV 33/138, BI No. 13, 07.04.81 "Method of reducing the permeability reservoirs", A.S. No. 1051236, EV 37/00, BI No. 40, 30.10.83).

It is also known technical solution (see A.S. 1627672, IPC EV 37/00, 33/138, publ. in BI No. 6, 1991) under the name of the device for processing the borehole walls, fully described Gidrostroy-mechanical method of reducing the permeability of the walls of the borehole, including simultaneous impact on the permeable wall of the wellbore scrapers to remove mud cake and high-pressure Gidrostroy to clogged pores and cracks coming from the jetting nozzles of collocator in the process of deepening of the bottom-hole drilling.

A common disadvantage of the known technical solutions, including the prototype, is that high-pressure stream of fluid flowing from us jetting the dock under high pressure and speed, perpendicular to the walls of the well, not only collateral pores and cracks of the reservoir, but also leads to the destruction of the wall of the wellbore and the formation of cavities, which creates additional difficulties in the removal of mud cake.

The technical task of the present invention is to increase the efficiency of the clogging of pores and cracks of the walls of the borehole permeable layer by preventing the destruction of the walls of the borehole and the formation of cavities.

The problem is solved by the described method involving the simultaneous impact on the permeable wall of the wellbore scrapers to remove mud cake and high-pressure Gidrostroy to clogged pores and cracks coming from the jetting nozzles of collocator in the process of deepening of the bottom-hole drilling,

What's new is that the impact of the aforementioned high-pressure Gidrostroy conduct directed at an angle to each other to meet at a single point in the borehole wall and the destruction of their cores to prevent the destruction of the walls of the borehole and the formation of cavities, and a similar effect on the wall of the wellbore carry out and in process of elaboration of the well prior to running production casing cementing. At the same time as liquids for high-pressure Gidrostroy use drilling fluid containing dispersed solid particles.

Presents graphic materials explain the essence of the invention, in which figure 1 shows schematically a General view of one embodiment of a design for implementing the method in partial section, where visible scrapers to remove mud cake and at an angle to each other mounted jetting nozzle to create a high-pressure jets, which seal the pores and cracks permeable layer.

Figure 2 - cross section a-a of figure 1.

Collocator for implementing the method includes a cylindrical housing 1 with internal mounting threads on the ends (threads on the figures not shown) to the pipe 2 of the drill string and the casing 3 bit 4. Through one of the openings 5 in the housing 1 is made side channels 6 and 7 are directed at an acute angle to each other, communicating with the Central channel 8, is equipped with jetting nozzles 9 and 10, the outlet of which is directed outwards. Axis side channels intersect at point B, lying in the immediate vicinity of the circumference of the wellbore 12. As can be seen from figures 1 and 2 point B does not lie on the borehole wall 12. The housing 1 is made from a segment of heavy-weight drill pipe (UBT) or round the same grade of steel that UBT.

In the other two openings are mounted scrapers 13 and 14 of the same size, made of lengths of rope 15 by melting one end is in prior to the formation of bundles of many wires.

The implementation of the method is given in the work of collocator.

He works as follows.

Before the descent of collocator in the hole first, workers geological survey drilling company according to GIW specify the intervals of occurrence of permeable sediments rocks, the actual thickness of mud cake, you want to remove, and are subject to clogging pores and cracks permeable layer, the intervals of the section with cavities, as well as the distance between the productive strata design depth slaughter, and other parameters.

Further collocator lowered into the well in the layout with the bottom of the drill string, placing it directly above the bit. Then collocator result in rotational movement of the rotary or turbine way, while the circulation of the drilling fluid containing dispersed solid particles. As a solution you can use clay or pinamalayan etc. solutions. During the rotation of collocator in the work connected wire scrapers 13, 14 and others, removing the top layer of loose mud cake, which is swept up by the flow of drilling fluid to the wellhead. At the same time from the jetting nozzles 9 and 10 of the high-pressure jets 16 and 17 of the drilling fluid is directed toward the borehole wall and, reaching then the key "B", lying in close proximity to the circumference of the wellbore, meet, making the hammer, in which there is a mutual destruction of jet engines. High-pressure water-blast, devoid of nuclei, has no destructive effect on the walls of the wellbore and prevents the formation of cavities in the clay-argelith rocks. Under the action of non-nuclear hammer thickened structured drilling mud on the walls of the borehole is broken. While using pigs removed from the walls of the wells of the filtration cork, at the same time ensures that the clogging of pores and cracks permeable layer in the near-wellbore zone and thereby prevents re-formation of mud cake.

As can be seen from the above, along with the deepening of the well is at the same time and the training of its trunk to mount. However, it is established that under the action of alternating loads during tripping of the tool partially reverses the output into the well to seal fine solid particles and re-education in such areas of mud cake that may adversely affect the quality of attachment. Therefore, according to the present method similarly as described above, considering the wellbore and before the descent of the column casing cementing After the end of the study the wellbore washed.

Technical and economic advantage of the invention is as follows.

The method prevents the formation of mud cake through reliable clogging of pores and cracks permeable formations, leading simultaneously to decrease the depth of penetration of polluting the reservoir of the leachate - liquid phase process fluids (drilling mud, cement and buffer liquids), which reduces the Skin effect caused by gidratatsiei clay material contained in the reservoir, and to prevent the formation of a mud cake, eliminating the migration of water within casing cement mortar in the waiting period of hardening cement (RFQ). All this will ultimately allow you to save filtration-capacitive properties of the productive strata, trouble-free run a string into the borehole, to reduce the costs of salvage and restoration work and reduce the time spent on the construction of the well.

1. Gidrostroy-mechanical method of reducing the permeability of the walls of the borehole, including simultaneous impact on the permeable wall of the wellbore scrapers to remove mud cake and high-pressure Gidrostroy emerging from the jetting nozzles of collimator in the process of deepening of the bottom-hole drilling, characterized in that near is due to the aforementioned high-pressure Gidrostroy do sending them at an angle to each other to meet at a single point in the borehole wall and the destruction of their cores to prevent the destruction of the walls of the borehole and the formation of cavities, and a similar effect on the wall of the wellbore carry out and in process of elaboration of the well prior to running production casing cementing.

2. The method according to claim 1, characterized in that as the fluid for high pressure Gidrostroy use drilling fluid containing dispersed solid particles.



 

Same patents:

FIELD: oil and gas production.

SUBSTANCE: procedure for performing operations of cleaning borehole of well consists in preparation and introduction of water fluid containing sphinganic hetero-poly-saccharide into well borehole, in carry-over of material filling well borehole in water fluid, in extraction of at least part of fluid and carried over material filling borehole on surface for in essence separation of material filling borehole from fluid and in introduction of given part of fluid into borehole for second cycle not requiring considerable replenishment with sphinganic hetero-poly-saccharide. The procedure can be used at drilling, exposing, substitution, repair, well completion, maintenance, testing, well killing, hydraulic break and in filling with packer liquid.

EFFECT: raised resistance to shear destruction.

19 cl, 5 ex, 7 tbl

FIELD: oil and gas production.

SUBSTANCE: device consists of case with connecting threads, central channel and retractable cutting elements. On external surface the case is equipped with upper and lower stops. Cylinder axles are installed between the stops symmetrically relative to axis of the case. Cutting elements are made in form of loads with cutters on external surface. The cutting elements have holes for corresponding cylinder axles; the loads are spring loaded to inside and rotate; their rotation under centrifugal force is restricted with the regulated stop. The upper and lower stops are equipped with through washing holes.

EFFECT: expanded process functionality and increased service life of device.

2 cl, 3 dwg

FIELD: oil and gas production.

SUBSTANCE: device consists of nozzle located in upper section of pipe. The nozzle receives liquid supplied from surface and is installed into a plug with radial packing. Also, the device consists of a receiving chamber. The upper section is equipped with an upper sub, while a section of the pipe for arrangement of a filter is connected to it from beneath. A section collecting slime with an internal pipe in it is connected in its turn to the above said section of the pipe. The nozzle is oriented from a bottomhole to a wellhead. The plug is equipped with a gland seal including a stuffing box and a press-on bush pressed with the sub by means of which the upper section of the pipe is connected with the section of the pipe encasing the filter. The receiving chamber is connected with a mixing chamber and a diffuser. The latter and an upper part of the plug of a relative upper section are arranged coaxially; a cavity for flow of liquid from surface is positioned in a gap between them. The cavity is communicated with the nozzle by means of radial holes in the upper part of the plug. With axial holes in the plug the receiving chamber is connected to an internal cavity of the filter. The upper section and the diffuser are connected with a triple sub having holes for output of mixture of liquid from surface and liquid coming from annular space and through holes connecting the cavity for flow of liquid from surface with the internal cavity of the upper sub.

EFFECT: raised efficiency and improved operation characteristics of device; reduced cost of cleaning operations.

2 cl, 3 dwg

FIELD: oil and gas production.

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EFFECT: raised efficiency of cleaning, expanded process functionality.

20 cl, 11 dwg

FIELD: oil and gas production.

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EFFECT: maintaining permeability of reservoir during repair operations.

6 dwg

FIELD: oil and gas production.

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EFFECT: increased service life and oil output of wells.

13 cl, 19 dwg

FIELD: construction.

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EFFECT: improved binding of cement with a casing string and a well wall.

15 cl, 3 ex, 1 dwg

FIELD: gas-and-oil producing industry.

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FIELD: gas-and-oil producing industry.

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EFFECT: raised efficiency and functionality of cleaning device.

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FIELD: gas-and-oil producing industry.

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EFFECT: raised efficiency of cleaning and reliability of device operation.

2 cl, 5 dwg

FIELD: oil and gas production.

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2 cl, 1 tbl, 20 ex

FIELD: oil and gas production.

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2 cl, 3 tbl, 11 ex

FIELD: oil and gas industry.

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EFFECT: increasing efficiency of isolation works.

3 ex

FIELD: oil and gas production.

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17 cl, 7 dwg

FIELD: oil and gas production.

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2 tbl, 1 ex

FIELD: oil and gas industry.

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EFFECT: increasing efficiency of insulating works, duration of effect, increasing overhaul period of operation, excluding metal corrosion of tubing string and production casing.

2 tbl, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: servicing method of the well shaft involves recovery of sealing composition containing cross-linkable material, cross-linking agent, addition preventing water absorption, water and formiate compound to shorten the time of gel formation of cross-linkable material or retarder of gel formation, which includes chemical compound which is capable of acetylating, hydrolysing, thermal decomposition of organic amine, separately or in combination, so that one or several acids are obtained in the above composition, supply of sealing composition to the permeable zone of the well shaft and exposure of sealing composition for curing. As per the second version, the method involves recovery of sealing composition by means of combination of cross-linkable material, cross-linking agent, addition which prevents water absorption, water and formiate compound to shorten the time of gel formation of cross-linkable material or retarder of gel formation, which includes chemical compound which is capable of acetylating, hydrolysing, thermal decomposition of organic amine, separately or in combination, so that one or several acids are obtained in the above composition, and cement in which the quantity of cement is decreased to effective quantity to increase the time for gel formation of sealing composition approximately to 4 hours or more at the impact of environment in the well shaft on the sealing composition. Then, sealing composition is supplied to permeable zone of the well shaft and exposure of sealing composition is performed till gel is obtained.

EFFECT: improving well sealing efficiency.

20 cl, 2 dwg, 1 tbl, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: borehole sinking, lowering and attachment of casing and production strings is performed. The first part of the well bore - direction is drilled with diametre of not more than 300 mm by using clay drilling solution with density of 1.12-1.20 kg/m3, the second part - conductor is drilled with diametre of not more than 220 mm, and the third main part is drilled with diametre of not more than 160 mm. As drilling solution, when drilling the conductor and the third part, there used is service water with density of 1.00-1.09 kg/m3. Flow rate of service water is determined with lost circulation zones exceeding the service water absorption. After the caving zone is opened and the bottomhole is deepened below the caving zone by 10-15 m, the well bore is washed with service water in the volume of 1-2 of the well volume, layout with the bit is lifted, layout with open end is lowered below caving zone, washing is performed for 1.5-2.5 hours with water for caverns to be formed in he caving zone, layout is lifted above the caving zone by 10-30 m, process exposure is performed during 0.5-1 hour for the soil to fall from caverns, layout is lowered and the caving value is determined as per the varying depth of the bottom-hole. In case of caving the end of pipes reaches the bottom-hole with washing. Layout is lowered and the caving interval is filled in the following way: clay solution is pumped with density of 1.12-1.25 kg/m3 in volume of 1 to 5 m3, fresh flush fluid to cut the clay solution from cement solution in volume of 0.5-1 m3, cement solution with addition of 1 - 3% setting calcium chloride agent in the volume equal to 1.1-1.3 of the design one to shutoff the caving zone. Flushing with service water is performed. Layout is lifted from the well, process exposure is performed for waiting on cement during 4-6 hours, drilling assembly by means of which the well bore has been drilled is lowered, cement bridge is drilled within the interval of the caving zone and the well drilling is continued to the design depth. When cement solution is being pumped, tubes are rotated with rotation frequency of 10 to 60 rpm, and when cement solution is flushed with water, reciprocation of pipe string is performed by the value of 8-12 m with frequency of 1 to 4 lifts per minute.

EFFECT: reducing the costs for well construction and well flushing in cavern formation and caving conditions.

FIELD: construction.

SUBSTANCE: invention proposes compositions, capable of setting and including water and cement furnace dust. Compositions, capable of setting, may optionally include an additive, which contains at least one component of the group below: ash dust, slate, slag cement, zeolite, metakaolin and their combinations. Compositions, capable of setting, may be optionally foamed with gas. Also methods of cementing are proposed, which include the following operations: preparation of composition capable of setting; introduction of composition, capable of setting, into a section to be cemented; and making it possible to set and form a hardened mass in this area. Section to be cemented may be located over earth surface or in subsurface bed.

EFFECT: improved operational characteristics.

35 cl, 25 tbl, 25 ex

FIELD: construction.

SUBSTANCE: method of borehole cementation includes the following: production of composition capable of setting, which includes water, cement kiln dust and additive selected from the following group: slate, zeolite, slag cement, metakaolin; adding composition, capable of setting, into borehole to be cemented and provision of possibility to set with formation of hardened mass inside of it.

EFFECT: increased efficiency of borehole cementation.

17 cl, 25 tbl

FIELD: oil and gas production.

SUBSTANCE: invention relates to grouting mortars used for cementing casing pipes of gas, gas-condensate, and oil wells complicated by presence of formations with low hydraulic rupture pressure as well as presence of permafrost rocks. Light-weight grouting mortar contains 47.0-60.0% special-type cement, 6.6-11.8% clinoptilite as light-weight additive, and water. As a result, casing-pipe annulus incidents during boring and running wells are avoided owing to improved parameters of grouting cement, in particular increased sedimentation stability of mortar, dimensional stability and needed strength of cement stone at low positive and negative temperature in early hardening stages are achieved at simultaneous lowering of grouting mortar density.

EFFECT: improved performance characteristics of grouting mortar.

1 tbl

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