Method for reservoir exposing and isolation in well with oil-water zone

FIELD: oil production industry, particularly methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells.

SUBSTANCE: method involves lowering casing pipe string in well, wherein the casing pipe string is provided with channels located in water-bearing productive reservoir section; cementing hole annuity; isolating water-bearing section of productive reservoir by injecting water-proofing composition via casing pipe string channels; closing the channels with gate and exposing oil-bearing productive reservoir section for the second time. Before casing pipe string lowering in well hollow rigid centrators are formed in the channels. The centrators and the channels are filled with bitumen and closed with gate. Before water-proofing composition injection in water-bearing productive reservoir section the gate is opened. The water-proofing composition is non-hardening water-proofing composition. Then hollow rigid centrators and channels are freed of bitumen and cement stone is broken within the interval of water-bearing productive reservoir section by implosion action application thereto.

EFFECT: increased efficiency and decreased labor inputs.

2 cl, 1 dwg

 

The invention relates to the oil industry and can be used for cementing casing for opening and zonal isolation in wells, built on oil-water deposits.

There is a method of zonal isolation (patent RU №2098602, IPC 7 EV 43/32, publ. 10.12.1997, including the descent into the well casing, equipped with a device for isolation of the productive interval of the formation and the cementing of the wellbore isolation of the productive interval of the formation from cement mortar.

The disadvantages of this method are:

firstly, in case of carrying out insulation works by pumping in water-bearing part of the reservoir cement compositions is insufficient insulation layer and reduced productivity due to clogging of oil-bearing portion of the insulating layer compositions, and may also be in violation of the tightness of the column;

secondly, after separation of the layers with water area and in the further development of the well creates a depression on the layer, leading to rapid flooding of the products due to the formation of a water cone.

Closest to the present invention is a method for zonal isolation in a well (patent RU No. 2183265, IPC 7 EV 43/32, 33/12 publ. in bull. No. 16 from 10.06.2002, with oil-water area, including the descent into the well casing pipes, equipped us what device isolation layer, to isolate the annulus of the well, by means of this device, and further cementing the annulus, having first carried out to isolate the annulus of the well corresponding to the aquifer portion of the reservoir, from the annulus to the rest of the well above and below the aquifer portion of the reservoir, then cement the annulus above and below the reservoir, and then cement the annulus of the reservoir, the corresponding part of the aquifer formation by filing a cement slurry through the channels of the specified device isolation layer, followed by an overlap of channels dampers.

The disadvantages of this method are:

- first, for opening and subsequent isolation of the aquifer is part of the productive formation requires at least twice to pull the tool in the casing column with different equipment: the first time for discovery channel; the second for downloading through these channels insulating cement composition;

- secondly, if the offence is repeated isolation in the same interval, it is necessary to re-implement the whole complex of works described above, that is certainly time-consuming and entail significant financial costs.

Object of the invention t is aetsa creation method, allowing for a single run of the tool to open and separate water-bearing part of the reservoir, while making it repeatedly during operation of the reservoir in this interval depending on the occurrence of insulation and education of the cone watering, not collatera oil-bearing part of the reservoir.

The problem is solved by the proposed method of opening and zonal isolation in a well with oil-water area, including the descent into the well casing pipes with the channels have opposite aquifer part of the reservoir, cementing the annulus, isolation of water-bearing part of the productive formation by injection through the channels in the column casing waterproofing composition, overlapping channels flap and secondary opening the oil-bearing part of the reservoir.

What is new is that the front casing in its channels fixed hollow rigid centralizers, which, together with the channels filled with bitumen and block valve, before being pumped into the water-bearing part of the productive formation waterproofing composition, which is used natureday waterproofing product, open the valve, release the hollow rigid centralizers and channels from bitumen and destroy the cement stone in the interval aquifer part about aktivnogo reservoir by creating an implosion effect.

New is also that subsequent violations isolation aquifer cycle by opening a valve, implosion cleaning of the reservoir and the injection poterjannogo waterproofing composition and the closure flap is repeated several times.

The drawing shows a device for the performance of the proposed method, where: 1 - column casing; 2 - producing formation; 3 - water-bearing portion of the formation; 4 - channels casing pipes, disposable opposite the aquifer portion of the formation; 5 - rigid centralizers, fixed in the channels of the casing pipe; 6 - bitumen, which is filled channels and a rigid hollow casing centralizers pipe; 7 - valve mounted inside the casing pipe in front of the TV with the possibility of opening and closing; 8 - cement stone, located in the aquifer portion of the formation; 9 - column pipes, spuskaemsya inside casing pipe; 10 - lower and 11 the upper part of the locking mechanism descent at the end of the column pipe; 12 - pokerwise device spuskaemogo in the column pipe located above the locking mechanism and creating implosive effect; 13 - annulus casing pipes.

The method consists in the following.

Column casing 1 with a rigid hollow units, zafa kiravannie in channels 4, descend into the well, while channels 4 and rigid centralizers 5 casing pipe 1, initially filled with bitumen 6 have opposite aquifer part 3 of the productive layer 2. In addition, initially the channels inside the casing pipe 1 is blocked by the valve 7. Next, the annulus 13 of the casing pipe 1 cement by any known method. After waiting for the solidification of the cement in the annulus 13 of the casing pipe 1 is formed of a cement stone.

Opening aquifer part 3 of the productive layer 2 is carried out as follows.

In the column casing down the string of pipe 9 with a locking mechanism at the end, consisting of the bottom 10 and top 11 parts and located above the locking mechanism patrolsim device 12. Reaching the interval where the channels 4 of the casing pipe 1 located opposite the aquifer part 3 of the productive layer 2, the lower part 10 of the lock mechanism comes into contact with the flap 7 and shifts it down, this opens up the channels 4.

After unloading the tubing 9 to the column casing 1 are spacerowa pokerwise device 12, resulting implosion effect inside the channels 4 and rigid centralizers 5, which is located inside the bitumen 6, and cement stone 8 in the interval of vodonos the second part 3 of the productive layer 2 in the casing 1. As a result, the bitumen 6 of the channel 4 and the cement stone 8 get inside the casing pipe 1, purifying water-bearing part 3 of the productive layer 2 opposite the casing pipe 1 and hydraulically communicating its with casing pipe 1.

After that make raspaculo pokerwise device 12 and the direct or reverse flushing wash products dissection (asphalt 6, cement stone 8, located outside the casing 1 aquifer in part 3 of the productive layer 2) of the casing pipe 1. Opening aquifer part 3 of the productive layer 2 is completed.

Separation (isolation) of the aquifer is part 3 of the productive layer 2 is as follows.

From the wellhead (not shown) in the column casing 1 is injected estimated number waterproofing composition, which is used natureday waterproofing composition, which is then forced through the channels 4 and the hollow rigid centralizers 5 casing pipe 1 aquifer in part 3 of the productive formation 2.

Waterproofing composition penetrates deep inside, securely isolates only water-bearing part 3 of the productive layer 2, because in the process of opening when creating implosive effects was destroyed only cement stone 8, located in the zone of the aquifer, part 3 of the productive layer 2, and cement stone, whic is its above and below the above-mentioned zone creates resistance to movement waterproofing composition, which moves in the radial direction, penetrating deep aquifer in part 3 of the productive formation 2.

Then from the column casing 1 forward and reverse flushing wash away the remnants of the waterproofing composition.

After washing the column casing 1 from the remnants of the waterproofing composition to pull the string of pipe 9 upward, while the upper part 11 of the locking mechanism acts on the valve 7, moving it from the bottom up, while the valve 7 is closed, tightly overlapping channels 4 of the casing pipe 1. The column pipe 9 continue to pull up, first the upper part 11, and then the lower part 10 of the lock mechanism is released from the valve 7, bypassing it.

Next, the string of pipe 9 which at its end a locking mechanism and patrolsim device 12 is removed from the casing pipe 1, and the channels 4 of the casing pipe 1 remain tightly overlapped by the flap 7, excluding the depression in the aquifer part 3 of the productive layer 2 during the subsequent development wells, which can lead to flooding of the products due to the formation of a water cone. The process of uncoupling aquifer productive part of the reservoir 2 is completed.

Perform secondary opening the oil-bearing part of the productive formation and run it in operation.

During operation the product is effective layer 2 possible subsequent insulation aquifer part 3 of the productive layer 2, leading to the flooding of products produced due to the formation of a water cone. In this case, you can eliminate the pop insulation faults in this interval by re-running of tools and creating implosive effects and additional injection waterproofing composition, repeating all of the above operations dissection and dissociation of aquifer part 3 of the productive formation 2.

The proposed method allows for a single run of the tool as to open and isolate the water-bearing part of the reservoir, while making it necessary number of times in the lifetime of the well, depending on insulation and education of the cone watering, not collatera oil-bearing part of the reservoir, which is a multiple saves material and financial costs.

1. The method of opening and zonal isolation in a well with oil-water area, including the descent into the well casing pipes with the channels have opposite aquifer part of the reservoir, cementing the annulus, isolation of water-bearing part of the productive formation by injection through the channels in the column casing waterproofing composition, overlapping channels flap and secondary opening the oil-bearing part of the reservoir, characterized in that lane is on the casing in its channels fixed hollow rigid centralizers, which, together with the channels filled with bitumen and block valve, before being pumped into the water-bearing part of the productive formation waterproofing composition, which is used natureday waterproofing product, open the valve, release the hollow rigid centralizers and channels from bitumen and destroy the cement stone in the interval of the aquifer is part of the productive formation by creating implosive effect.

2. The method of opening and zonal isolation in a well with oil-water area according to claim 1, characterized in that subsequent violations isolation of the aquifer is part of the productive formation cycle by opening a valve, eplosions cleaning of the reservoir and the injection poterjannogo waterproofing composition and the closure flap is repeated several times.



 

Same patents:

FIELD: petroleum industry; natural gas industry; methods of isolation of the productive strata overlapped by the casing strings and the grouting mortar for its realization at the productive strata overhaul repair.

SUBSTANCE: the invention is pertaining to petroleum industry and natural gas industry, in particular, to the productive strata overhaul repair conducted in the process of the fields operation and at elimination of the development wells, which have fulfilled their assignment. The method may find the greatest application at operation of the multi-layer oil-fields and at elimination of the wells of the complex construction, specially on the final stage of the realized works - in the direct proximity to the earth surface for protection, for example, of the potable water, brackish waters and of the permafrost area, where their boreholes are socket by 3-4 and more casing strings. The technical result of the invention is extension of the technological possibilities of the method at the increased efficiency of the isolationof the productive strata. The grouting mortar for isolation of the productive strata overlapped by the casing strings, including Microdur-261R-X and the water, additionally contains calcium chloride, aluminum sulfate, nitriletrimethylenephosphonic acid NTF at the following ratio of the components (in mass %): Microdur-261R-X - 10-30, calcium chloride - 20-50, aluminum sulfate - 0.5-3.0, NTF - 0.0-0.2, water - the rest. The method of isolation of the productive strata overlapped by the casing strings including installation of the isolation cement bridges provides, that one of the isolation cement bridges is installed in the production string by 10-30 m below the interval of works, then using the hydroabrasive perforator cut slits in the casing strings - in the operational string and the intermediate strings - the vertical slits (3-5 slits per one meter), by means of the hydroabrasive cutter below and above the interval of the vertical slots cut all the casing strings forming the horizontal slits and the local cavities, in the formed vertical and horizontal slits and in the local cavities press through the above-mentioned grouting mortar with location of the roofing of the isolation bridge by 10-20 m above the interval of the works, then install the control isolation cement bridge, the base of which is placed on the roofing of the isolation bridge.

EFFECT: the invention ensures extension of the technological possibilities of the method at the increased efficiency of the isolationof the productive strata.

2 cl, 2 dwg, 1 tbl

FIELD: oil extractive industry, in particular, methods for extracting oil deposit with gas cap, preferably at beginning stage of extraction of oil deposit.

SUBSTANCE: method includes drilling directional force wells, product and gas wells, forcing water into oil bed through force wells, extracting oil through extractive wells and forcing incidental oil gas into gas cap through gas wells. In accordance to invention, in case of vertical penetrability of oil bed constituting 0,5-0,8 of its horizontal penetrability, at beginning development stage at least one more product well is drilled with at least one horizontal borehole. In directional product wells lower part of gas cap of bottomhole zone in contact with oil bed is isolated for thickness and depth not less than falling radius of bed pressure in bottomhole formation zone during oil extraction. That is a radius of bottomhole formation zone, in which depression on bed is at least 50% lower than difference of bed and bottomhole pressures in well. Isolation is performed first of all in wells with maximal depression on bottomhole formation zone. Through force wells fed in turns into oil bed are sub-product or senoman water and incidental oil gas.

EFFECT: decreased danger of entry of incidental oil gas from gas cap into extracting wells.

2 dwg

FIELD: oil industry, particularly to prevent gas- or water-coning phenomena, for instance the formation of a conical column of gas or water around wells.

SUBSTANCE: method involves injecting acetone, to which separol in amount of 0.2% is added, in pool and then injecting silicone compositions in the pool.

EFFECT: increased product output due to improved well waterproofing.

1 tbl

FIELD: treatment of well drilled in productive reservoir, which is at later operation stage.

SUBSTANCE: method involves injecting polymeric compositions in reservoir; lowering hydroacoustic generator in well; applying hydroacoustic waves to polymeric compositions and to flushed reservoir interval; preparing inflow stimulation and stimulating well inflow. Polymeric compositions or solid dispersed filler in hydrocarbon liquid are injected in productive formation. Hydroacoustic generator is connected to flow string to be lowered in perforation zone. Polymeric composition or dispersed filler mixed with hydrocarbon liquid treatment is carried out when above materials are delivered to perforation interval and during injection thereof in reservoir. Before inflow stimulation hydroacoustic generator is installed in productive non-worked out reservoir interval and the interval is cleaned by applying hydroacoustic action to it. To apply above hydroacoustic action spectrum of acoustic wave with 0.2-16 kHz frequency and 1.5-6.0 MPa amplitude is generated. Then one spectrum frequency resonance is provided, wherein frequency is equal to that of self-oscillation of particles, which clog productive reservoir cracks and pores during primary opening thereof. Pressure drawdown is simultaneously created in well. Inflow stimulation and well development is carried out with the use of downhole vortex pump.

EFFECT: increased production well output along with water influx restriction, improved isolation quality and reduced repair costs.

FIELD: oil production, particularly to isolate casing annulus and tubing-casing annulus with the use of plugging polymer-based compositions curable in reservoir conditions.

SUBSTANCE: method involves injecting isolation material in injection or production well, wherein the isolation material includes polymer curable in reservoir conditions; forcing thereof through well and holding the composition inside well for time enough to cure and strength development. The composition is water-soluble polymeric composition including acetone-formaldehyde resin in amount of 80.0% by weight, sodium carbonate or potassium carbonate in amount of 4.0-7.0% by weight, chemical reagent Okzil-SM in amount of 0.5 % by weight, remainder is water or 30% NaCl solution. If reservoir temperature is 50°C or less alkali, namely sodium hydroxide NaOH, in amount of 0.1-2.5% by weight is additionally mixed with above composition. In the case of plugging operation performing in high-pressure wells fine inert filler, namely industrial talc, is added in amount of 30-100% of composition volume to be injected.

EFFECT: possibility of casing annulus and tubing-casing annulus plugging in temperature range of 20-90°C.

3 cl, 3 tbl, 3 dwg

FIELD: oil industry, particularly preventing gas- or water-coning phenomena, for instance the formation of a conical column of gas or water around wells.

SUBSTANCE: method involves supplying gel-forming material in isolation zone in one step up to full isolation zone saturation; injecting 27% hydrochloric acid at rate of 2-6 l/sec. The gel-forming material is pulp of syenite alkali-aluminum concentrate in calcium chloride solution having specific weight of not more than 1.2 g/cm3 and taken with volumetric ratio of 1:1. The gel-forming material is supplied at rate of not less than 3 l/sec. The gel-forming material and hydrochloric acid mass ratio is 1:1.

EFFECT: increased technological effectiveness and improved efficiency due to full isolation zone saturation with gel-forming material.

2 ex

FIELD: oil production industry, particularly to isolate water-permeable formation intervals during well repair and plugging operations.

SUBSTANCE: method involves injecting aqueous solution of high-modulus sodium silicate and acid gel-generation agent; leaving thereof in well for time enough for gel forming and creating isolation screen having thickness determined as L=(Pd·K)/grad(Ps), where L is isolation screen thickness, m; Pd is rate of differential pressure drawdown in flooded productive reservoir area, MPa; K is load factor of isolation screen, K=1.2; grad(Ps) is gradient of initial pressure of reservoir water filtration through screen, wherein grad(Ps) is equal to 7.7-40.0 on experimental investigation data, MPa/m. The high-modulus sodium silicate is colloid sodium silicate, the acid gel-generation agent is liquid waste obtained during electrochemical metal coating application. Above components are mixed to form solution having pH value of 3-9.

EFFECT: increased efficiency due to increased strength of obtained isolation screen due to usage of solution having optimal gel forming time and determining of optimal isolation screen thickness, reduced time of isolation screen forming, extended range of gel forming materials along with improved ecology and possibility to utilize industrial waste.

1 ex, 2 tbl, 4 dwg

FIELD: oil industry, particularly to isolate bottom water in producing well.

SUBSTANCE: method involves arranging bottom of production string in center of interval to be treated; injecting thickened water and oil in hole annuity of the well by circulating thereof; forcing cement grout in production string until bottom thereof; injecting oil into formation through hole annuity and simultaneously injecting cement grout into formation through production string. Rate of above injection operations are equal and set so that liquids are injected at laminar flow regime.

EFFECT: increased reliability of bottom water isolation.

2 cl, 1 ex

FIELD: oil production industry, particularly to restrict water influx into oil and gas wells and to level off injectivity profile in injection wells.

SUBSTANCE: method involves injecting dividing plug, working agent, and then dividing plug again in formation through injection or production well; forcing the injected reagents into well. Working agent is liquid zeolite production residue, namely mother zeolite solution and aqueous strong acid solution. Mother zeolite solution is fed as separate plug or mother zeolite solution and aqueous strong acid solution are injected simultaneously or serially. Sweet water is used as the dividing plug. Waste water is utilized for injected reagents forcing.

EFFECT: increased efficiency of permeability reduction in watered highly porous reservoir.

3 ex, 1 tbl

FIELD: oil production industry, particularly for cementing casings into boreholes.

SUBSTANCE: method involves performing geophysical investigations; perforating well; injecting sealing composition to create gas-tight screen in gas-bearing bed. In accordance with the invention gas-tight screen is multilayered and has radius of 15 m or more. To create the screen water, aqueous solution of water-shutoff agent and cement grout are alternately injected in gas-bearing bed. Water is fed under pressure of more than 7 MPa and less than hydraulic fracture pressure in amount of more or equal to 100 m3 per 1m thickness of the bed. Aqueous solution of water-shutoff agent is heated up to 30-50°C and is injected in amount equal or more than 3 m3. Cement grout is supplied in amount of not less than 0.5 m3.

EFFECT: increased isolation of gas-bearing bed and gas flow liquidation in behind-the-casing zone.

4 ex

FIELD: methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells, particularly for pressure regulation during perforation operation execution.

SUBSTANCE: method in accordance with the first embodiment involves determining characteristics of reservoir to be perforated; selecting dynamic pressure change profile on the base of reservoir characteristics; selecting perforation tool; choosing well fluid from reservoir characteristics and selected perforation tool to obtain chosen dynamic pressure change profile with taking into consideration explosive force of charges and perforator volume. Method in accordance with the second embodiment involves filling well with well fluid selected to regulate dynamic pressure change during perforation tool explosion and after perforation tool explosion with taking into consideration explosive force of charges and perforator volume. Well is perforated by perforation tool explosion.

EFFECT: improved fluid communication between well and reservoir.

14 cl, 5 dwg

FIELD: methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells, particularly perforators and permeators.

SUBSTANCE: method in accordance with the first embodiment involves lowering tool string in well; activating gun perforator, overburden condition providing device, processing liquid supply device and device, which creates local transition overburden condition. Method in accordance with the second embodiment involves taking information concerning fluid outburst characteristics for different well bore types; determining well bore type and processing liquid type for perforation tunnel treatment; selecting flow outburst characteristics; selecting time delay between perforation operation and flow outburst operation and selecting volume of low-pressure chamber for fluid borehole medium. Method in accordance with the third embodiment involves lowering tool string in well; activating tool string section including body with explosive charge arranged in the body; creating orifices in the body to open chamber for borehole media and activating tool string section to provide transition overburden condition. Tool string in accordance with the first embodiment comprises processing liquid supply device, which delivers processing liquid into tunnels, device to provide overburden condition and device to create local transition overburden condition. Tool string in accordance with the second embodiment comprises section with low pressure chamber and explosion means, section to create transition overburden condition and section to supply processing fluid medium in reservoir tunnels.

EFFECT: increased efficiency of reservoir fluid communication with well bore.

36 cl, 15 dwg

FIELD: methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells.

SUBSTANCE: device in accordance to the first embodiment comprises perforator with at least one explosive charge and pressure reduction means including heat absorbing means for quick explosive gas temperature reduction. In accordance to the second embodiment device has perforator with at least one explosive charge, explosive gas temperature reduction means and molar explosive gas density reduction means. Method involves utilizing perforator including explosive charges, blasting explosive charges and reducing explosive gas pressure near perforator by molar explosive gas density reduction.

EFFECT: improved hydrodynamic communication between reservoir and well bore and increased efficiency of pressure reduction in perforator after explosion.

42 cl, 1 tbl, 11 dwg

FIELD: oil and gas production industry, particularly equipment to create long perforation channels extending, for instance, outwards mudding zone.

SUBSTANCE: method involves lowering device connected to logging cable in well within predetermined perforation interval; fixing device on well wall with the use of corresponding module; moving device drive module to fixing module; extending revolving flexible shaft provided with cutting tool from guiding channel along with providing stored potential energy return in the device; delivering well liquid with the use of flushing pump through hollow rod to cutting tool; perforating the well by axial flexible shaft movement with advance force; returning flexible shaft with cutting tool in initial position at the end of well perforation operation; releasing the device in predetermined well perforation point and relocating the device to another well point for new perforation channel drilling. Device comprises drive module, fixing module, connection rods, flexible shaft, flushing pump, cutting tool and device motion converter. Drive module is moved towards fixing module secured in well bore by means of tightening unit. Connection rods transmit tightening force to return means to accumulate potential energy. The stored potential energy provides pulling apart of both modules and flexible shaft return in initial position. The flexible shaft is hollow.

EFFECT: increased method efficiency and device reliability due to controllable advance force and twisting moment acting on hollow flexible shaft.

23 cl, 4 dwg

FIELD: oil and gas industry, particularly operation of horizontal and gently sloping oil and gas wells, namely methods or apparatus for cleaning boreholes or wells.

SUBSTANCE: method involves increasing fluid velocity at the end of horizontal bore by arranging perforation intervals or filters to provide fluid velocity in last perforation section or in filter enough for effective impurity and water carryover from well bottom. Distance between perforation sections or between filters at the beginning of horizontal bore is to be greater than that between perforation sections or between filters at the end of horizontal bore. Perforation density at the beginning of horizontal bore is to be less than that at the bore end.

EFFECT: increased output from horizontal bore end, which accelerates fluid velocity and facilitates mechanical impurity and water carryover from the whole well bore.

1 ex, 3 dwg

Shaped charge // 2298762

FIELD: shooting-blasting operation by jet perforators in oil and gas wells.

SUBSTANCE: the shaped charge has a body accommodating a profiled blasting cartridge having a taper-shaped recess with a metal facing. For forming the profiled blasting cartridge use is made of a salvaged explosive based on octogen with granules measuring from 1 to 5 mm and with the following granulometric relation of particles, mass percent: granules from 1 to 3 mm - 30...40; granules from 3 to 5 mm - 60...70, the explosive together with the facing is pressed in the body.

EFFECT: enhanced depth of duct punching, formation of a stable shaped jet.

1 dwg, 1 tbl

FIELD: oil and gas production, particularly perforators and permeators.

SUBSTANCE: method involves lowering perforation device provided with flexible shaft and cutting tool into predetermined well interval; pressing the device to well wall and fixing thereof; transmitting rotation to flexible shaft and slowing flexible shaft movement during limited axial movement thereof; increasing longitudinal rigidity of flexible shaft; increasing radius of flexible shaft curvature; performing perforation in working regimes of axial advance and stable rotation of slowed shaft. Device comprises body with shaped longitudinal slot and radial channel having turning. Telescopic flexible diverter is located in the shaped slot. Flexible shaft with cutting tool is arranged in radial channel. Stepped conductor is fixed in device body. Device also has pressing and fixing unit, which pressed device to well wall and retains the device inside well. Flexible shaft slowing unit has brake blocks including one sliding one and comprises drive, which presses brake blocks to outer surface of flexible shaft.

EFFECT: increased efficiency.

13 cl, 2 dwg

FIELD: enhanced recovery methods for obtaining hydrocarbons by repressuring or vacuum methods.

SUBSTANCE: method involves performing cumulative well perforation and applying implosion action at the end of well perforation within perforation interval with the use of two implosion chambers located from perforator body top and bottom; performing local formation fracturing along with implosion action. To carry out above method perforator body is made of high-strength steel. Additional implosion chamber is arranged under lower implosion chamber. Additional and lower implosion chamber interiors are communicated through channel having diameter less than implosion chamber diameter. Pipe is installed in the channel so that the pipe is directed inside additional implosion chamber. When perforator is brought into operation and implosion chambers are filled with well and formation fluids air present in lower and additional implosion chambers and compressed under the action of inflowing liquid is located between body of additional chamber and pipe so that air dome is created. Compressed air in upper implosion chamber is located in upper part of upper implosion chamber having diameter less than that of implosion chambers so that air dome is created. Diameter and length of upper part in upper implosion chamber and pipe diameter and length are calculated to provide pressure of air compression in upper and lower air domes greater than hydrostatic well pressure, as well as air volume increase to displace liquid columns from interiors of lower and upper implosion chambers one towards another. Pressure pulses created in implosion chambers directed one towards another impinge one upon another inside perforator and create summary pressure pulse directed through perforation orifices in the body to bottomhole formation zone. Implosion chamber volumes are calculated so that time of summary pressure pulse creation concurs with time of liquid column drop in well over vacuum area, which results in summing of pulses from upper and lower implosion chambers with hydraulic impact pulse, and the summary pulse is to be greater than formation pressure. Pulses from upper and lower implosion chambers simultaneously act through perforation channels to create fissured zoned in well bore zone.

EFFECT: provision of local formation fracturing along with perforation operation and implosion action on formation in single trip.

6 cl, 1 dwg

Flexible shaft // 2297558

FIELD: the invention refers to machine building and is designed for using primarily in arrangements for perforation of cased borehole.

SUBSTANCE: the flexible shaft consists out of links connected with each other with the end parts. Each link is fulfilled in the shape of a cylindrical bushing with a central opening. On one of the end parts of the bushing there is a connective element in the shape of two lugs, each of them is of T- profile located in a diametrical plane in opposition to each other. At that the exterior surfaces of the walls are fulfilled together with the exterior ring surface of the cylindrical bushing. The distance between the inner surfaces of the walls is approximately equal to the diameter of the central opening. On the other end part transversely to the diametrical plane of the location of the plug a socket is fulfilled in the shape of a transversal through groove of T- profile oriented with the cut in the shelf into the cylindrical bushing. and with the cut in the wall - to the end face of the bushing. At that the dimensions parameters and also the profile of the groove are fulfilled on condition of placing the lugs in the mentioned groove for securing swing joint of one link with the other. Inside the central opening a core is placed. In quality of a core may be used a hollow tube over which a protective layer in the shape of a spiral is installed. Besides, for securing integrity of the covering and exclusion of a radial displacement of the links relatively to each other, a winding is made over it in the shape of a spiral metallic tape or a counter winding of the mentioned tape in two layers. The invention increases reliability of the work due to provision of reliable connection of the links with each other and excluding damage during the work of the core at simultaneous expansion of operational possibilities due to provision of transfer of significant rotary and longitudinal effort. Provision of various including small radiuses of the bends with creation at perforation of linear perforating channels.

EFFECT: increases reliability of work.

7 cl, 5 dwg

FIELD: well operation, particularly to stimulate marginal and temporary shut-in oil and gas wells.

SUBSTANCE: downhole instrument comprises measuring head 2, decision device 3, executive device 4, recorder 5 and AND circuit 6. All above components are located in common case 1. Measuring head 2 comprises sensor unit 7 and analog-digital converter unit 8. Decision device 3 includes time sensor 11, comparator unit to compare current parameter values with threshold values 9 thereof and AND circuit unit 10. Time sensor may comprise clock-pulse generator 12 provided with electromechanical switch 13 and pulse counter 14. Recorder 5 may be made as removable memory card. Executive device 4 may comprise capacitive storage 15 and electronic commutator. Capacitive storage 15 may include accumulator, multivibrator, high-voltage transformer, rectifier and high-voltage condenser.

EFFECT: extended range of functional capabilities of downhole instrument.

5 cl, 2 dwg

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes drilling perforation channels in wall of casing string and behind-pipe space, by drill. Drill is extended after each deepening for a length of its rod. Assembly for feeding drill is detached from received combined rod, left in drilled channel. Drill is provided with guiding elements, placed at distance from each other for keeping drilling direction. Firstly, wall of casing pipe is drilled by cutting portion of guiding element when it is in conductor of feeding assembly. With displacement into wall of casing string, another guiding element is inserted into conductor. With drilling of casing string, concurrent presence of guiding elements in feeding assembly conductor and in formed channel is provided for, said channel being used as conductor for drill after exit of guiding elements from feeding assembly conductor. Device has drilling perforator, containing electronic block, electric drive, fixing assembly, assembly for feeding drill with conductor, and case block with inbuilt cases containing drilling rods and drill. Drill is provided with guiding elements, having elliptic shape, placed at distance from each other along drill axis and turned relatively to each other for 90°.

EFFECT: higher reliability.

2 cl, 6 dwg

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