RU2376453C2 - Method of chemical reagent impulsive implosion bottom hole treatment, equipment for its execution - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: invention related to oil-and-gas production, can be used for bottom hole zone - BHZ cleaning out of calmative materials, including deposits of asphalts, resins, and paraffins - DARP, also for repairing BHZ collector properties during wells development, recovery efficiency increase, including production wells in complicated geophysical conditions. Method of chemical reagent impulsive implosion bottom hole zone - BHZ treatment, includes pumping into BHZ active reagent fluid media through hole clearance - hydrocarbon dissolver with adding of 0.05-0.1 wt % SAS, overflushing the media with killing fluid in tubing string during depressive-repressive treatment, after mentioned above active media riches reservoir top - pumping it into BHZ with alternated depressive-repressive treatment, then multiply repeated implosion treatment with created passive media withdrawal out of BHZ, which consists of asphalts, resins, and paraffins alteration products and other calmative materials, till previously pumped in active media volume disposed and the following depressive-repressive-impulse BHZ treatment with pumping into hole clearance killing fluid as a active media with adding 0.1 -2.0 wt % of water-repellent SAS for production well and hydrophilic SAS for injection well.

EFFECT: oil and gas condensate bottom hole zone recovery and productivity factor and initial permeability increase, well injection capacity increase for injection wells due to water-oil emulsion breaking down, noncoherent water withdrawal, dissolving and peptisation of deposits of asphalts, resins, and paraffins - DARP, water-repelling and hydrophing of the first space simultaneously decreasing contaminating particles excess into reservoir with gradual chemical treatment and vibration - wave treatment which provides optimal figures of reservoir depression and repression.

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Description

The invention relates to the oil industry and can be used to clean the bottom-hole zone of a formation — the bottomhole formation zone of production and injection wells from clogging materials, including the removal of asphalt-resin-paraffin deposits — paraffin deposits, as well as the restoration of the reservoir properties of the bottomhole formation zone during development, resuscitation and increase of well productivity, in including operated in complicated geological and physical conditions.

A known method of developing and cleaning the bottom-hole zone of wells by pulse drainage, including treating the well for 15-45 cycles of pressure increase-decrease, each of which produces 6-30 depression-repression drainage pulses that create when the overpressure exceeds the reservoir pressure in the well, by injecting fluid into the annulus, at the same time, at the beginning, the well is sharply opened and the fluid is poured through tubing into the surface collection tank, when the highest speed is reached and spout sharply close the well and create a damped standing wave, which reaches from 1-1.5 sump wells and returns to the mouth, while making pulsed blows to the PPP. The emerging vibrations are monitored by the wellhead pressure gauge and interrupted during the beginning of the wave return to the wellhead, increasing the depressive removal of contaminants from the BCP by the in-phase spout of the liquid through the pump-compressor tubes - tubing to the collection tank. The spout is produced for 2-4 s, then a standing wave is formed again, and so the operation is repeated until the overpressure in the well decreases. The fluid is injected at a constant rate to control the time it takes to reach a specific overpressure in the well. If time increases, processing continues. If it does not increase, then stop (RF Patent No. 2159326, Publ. 2000. Bull. No. 32).

The disadvantage of this method is its low efficiency due to the possible re-entry of colmatants, paraffin deposits and products of their dissolution or despergation in the PPP when the flow line is closed or the tubing is lifted to the surface. In addition, torn deposits and contamination of the pore channels due to the decaying nature of the oscillation amplitude will be forced to move into the reservoir, polluting the part of the bottom-hole zone more distant from the wellbore. This will be facilitated by the creation of increased pressure in the annulus, as well as an improvement in the injectivity of the wells after the initial cycles of pulsed drainage.

There is a method of creating multiple depression in the interval of the reservoir, which consists in lowering onto the tubing a device for processing PZP wells, consisting of a depression chamber with receiving holes in its upper part and installed in it with the possibility of reciprocating movement of the plunger with a valve. The implosion device is installed so that the windows of the depression chamber are opposite the interval of the treated formation. Then the well is packaged and then using the lifting unit lower the plunger all the way into the lower valve seat. After that, the plunger is raised to a level above the chamber windows, while the valve on the plunger closes and a vacuum is created in the chamber. From the moment the lower end of the plunger reaches the area above the windows, the borehole fluid from the sub-packer zone rushes to the lower part of the chamber, creating an instant depression in the bottomhole formation zone. In this case, the pressure in the PPP can decrease to atmospheric, the column of fluid in the annulus of the well is separated by a packer, and the fluid in the tubing is blocked by a plunger. Thus, the fluid from the reservoir under pressure of depression enters the sub-packer zone of the well and into the depression chamber. The specified cycle is repeated as many times as necessary until the completion of the process of cleaning the bottom-hole zone from the products of clogging and plugging agents.

The proposed method provides the ability to create instantaneous and repeatedly repeated depressions on the reservoir for a single descent of deep equipment without the use of special equipment. In addition, it allows immediately after the cleaning of the bottomhole formation zone to inject hydrocarbon solvents or other chemical reagents into the formation and thereby continue the process of processing the well to increase its production rate or injectivity (Popov A.A. Impact impact on the bottom hole zone of wells. - M., Nedra 1990, pp. 108-109).

However, this method does not allow the impact on the PPP using the energy of water hammer, because during its implementation, it is only possible to create depression on the formation. In addition, the procedure for carrying out technological operations when the first stage is used to clean the bottom-hole zone from clogging agents and plugging agents, and the second stage is used to treat the bottom-hole zone of the well with chemical reagents, is not optimal to achieve the desired end result. Moreover, the implementation of this method is generally impossible for oil wells producing paraffinic oils with a high gas factor, due to the precipitation of paraffins in the bottomhole formation zone.

A known method of cleaning the well from deposits during its operation, including the periodic creation of waves at the wellhead — negative pressure by blocking the flow line, keeping this line in the closed position and then opening it, while closing the flow line is carried out for 2-3 minutes, maintain this the line in the closed position for 5-10 minutes, and the subsequent opening is carried out for 0.1-2.0 s, and the shorter the opening time, the greater the value of the resulting vacuum. A distinctive feature of this method is the possibility of its implementation in wells operated by the fountain method, without structural changes of ground and underground equipment. According to this method, a negative pressure wave forms in the tubing during rapid pressure relief, a significant overheating of the liquid — shock boiling and spontaneous vaporization, gas evolution, intensive growth of cavitation bubbles, which leads to the formation of effective shock depression and cavitation destruction of colmatants (USSR Author's Certificate No. 1700207, Publ. 1991, Bull. No. 47).

However, this method can be used to create shock depressions exclusively in fountain wells. But even among fountain wells, wells producing paraffinic oils with a large gas factor are unacceptable for the indicated cleaning.

There is also known a method of reagent-pulsed impact on the well and the reservoir, including the supply through the pressure multiplier of the active liquid medium — AJS to the sub-packer zone of the well and then into the formation system, followed by a pulsed effect on the liquid medium, the supply of AJS to the nozzle of the jet apparatus and pumping from the formation zones of a passive liquid medium - PZhS, a mixture of aliphatic and aromatic hydrocarbon solvents with the addition of a treated demulsifier is used as AHS, the AHS is crushed into the reservoir under pressure and 10-20 MPa, hold for 12-24 hours, remove the PZhS with wave unloading of the well by a pulse-wave depressive action in two modes, then use a pressure multiplier with a flat-bladed head to carry out hydroimpulse time-dependent processing of the bottom-hole zone with a process fluid - TJ with flat fan jets with a pulse frequency of 50-300 per min and a pressure value of 1.5-2.5, the value of the static pressure in the well at the reservoir level, after which the final removal from the formation zone of the PZhS is carried out, as TJ and polzujut multifunctional surfactant solution (RF Patent №2275495, Cl. ЕВВ 37/06, Publ. 2006, Bull. No. 12).

The known method for the reagent-pulse impact on the productive formation of oil wells can increase the injectivity of injection wells, restore the initial injectivity of the bottomhole formation zone and increase the productivity of production wells. At the same time, loading ATZH through the tubing in dynamic mode requires a very high-quality packer fit, which is not always possible due to the casing string deformation and its ASPO walls overgrowing. In addition, for wells with high injectivity and low reservoir pressure, the operation of wave unloading and removal of the products of the destruction of paraffin deposits through the annulus is problematic. Also, it does not allow such an important final operation, such as the injection of hydrophilizing or hydrophobizing surfactant solutions into the PZP, without additional ups and downs.

The objective of the invention is to restore and increase the coefficient of productivity and initial permeability of the bottom-hole zone of the formation — the bottomhole formation zone of oil and gas condensate wells, increasing the injectivity of injection wells due to the destruction of water-oil emulsions, removing loosely bound water, dissolving and peptizing sediments of asphalt-resin-water-paraffin sedimentation or hydrophobic hydrophobization or hydrophobic hydrophobization at the same time reducing the entrainment of particles contaminating fluids deeper into the reservoir during the phased application of x chemical reagents and vibration exposure to provide optimal indicators of depression and repression on the reservoir.

The problem is solved by the method of repression-depression-pulse-implosion treatment of the bottom-hole formation zone — PZP, which includes injecting an active reagent liquid medium — a hydrocarbon solvent with the addition of 0.05-0.1 wt.% Surfactant — through the annulus with the replacement of the kill fluid in the tubing string during repression-depression-pulse treatment, after bringing the specified active medium to the roof of the reservoir, pumping it into the PPP with alternating rep essence-depressive effect, then repeatedly repeated implosive effect with removal of the formed passive medium from the PZP containing products of destruction of asphalt-resin-paraffin deposits and other clogging formations, until the injected volume of the indicated active medium is removed and the subsequent injection with the repression-depression-pulse effect of the kill fluid with addition of 0 , 1-2 wt.% Hydrophobizing surfactant for the production well or hydrophilizing surfactant for the injection well.

The essential features are:

- replacement of the kill fluid with an active reagent liquid medium - ARZhS with simultaneous repression, depression and impulse effects on the PPP;

- injection of ARZHS in the bottomhole formation zone for the destruction of paraffin deposits and dispersion of inorganic colmatants in the dynamic mode of translational-reciprocal movement due to the repression and depression of the pump unit and the ground pressure interrupter;

- removal of fracture products of paraffin and sedimentation particles by repeatedly repeated implosive unloading of the well in the amount of not earlier pumped ARS, taking into account dissolution of paraffin and dispersed inorganic colmatants;

- repression-depression-pulsed effect on PZP with hydrophobizing or hydrophilizing surfactant solutions after removal of paraffin and other contaminants from the pore space using an impulse-pulse device

The drawing shows a repression and depression installation with an implosion device, designed to implement the described method and consisting of a depression pulse generator installed on tubing 1 — DGI 2, located before the implementation of the method at or slightly below the perforation of the PPP.

A packer 3 is installed above the DGI, above the perforation zone. A hydraulic unit - pump 4 is installed on the surface for pumping ARGS, and the unit is equipped with a swab 5 for replacing the jamming fluid, removal of paraffin deposits and colmatants. A pulse-wave depressor - IVD 6 is installed on the surface.

A method using the specified installation implements the following technological operations.

1. Replacing the LH with ARG in the annulus with the removal of the LH through the DGI and tubing to the surface and the simultaneous repression, depression and impulse action on the PZP.

2. The injection of ARZHS into the reservoir with the periodic inclusion of the IVD for the destruction of paraffin and dispersion of inorganic colmatants.

3. Removing the products of the destruction of paraffin and colmatants by implosion-wave swabbing.

4. Hydrophobization or hydrophilization of the pore space of the PPP in the mode

repression-depression-pulse exposure.

In this case, solvents — Nefras A-150/200, Nefras AK, a mixture of aromatic and aliphatic solvents of the FLEK brand and others with the addition of surfactants — demulsifiers — Penta 491-M, Synterol, diproxamine 157-65M, Reopon IR, etc., are used as ARHS. , the following can be used as a silencing fluid: anhydrous oil from UPN units - oil treatment units - with the addition of demulsifiers, such as Penta 491-M, TN-10, SNPCH-4480, etc. at a concentration of 0.01-0.1 wt .%, mineral formation water, aqueous solutions of salts, with additives of complex surfactants, including Neftenol K, Sofek ol IFC QAM Synod other with a concentration of 0.3-4 wt.%. At the stage of hydrophobization of the pore space of the PZP, cationic oil-soluble surfactants - Don-52, Penta -804 and others in a concentration of 0.1-1.0 wt.% Or water-soluble surfactants - Neftenol K, Neftenol GF, IVV- are added to the oil-based killing fluid 1, Catamine AB and others in a concentration of 0.5-1.5 wt.%. For hydrophilization of the pore space of the PZP, killing fluids with the addition of anionic surfactants such as Neftenol NZ, Sulfonol, Oksifos B and others in a concentration of 0.3-2.0 wt.% Are used.

An example implementation of the method

At the initial stage of the treatment cycle, the ZhG well is muffled with anhydrous oil with the addition of 0.2 wt.% Penta491-M, downhole equipment is removed and the packer and DGI are lowered to the tubing to the bottom. Immediately prior to installation, the DGI is adjusted to a specific response pressure, which should not be higher than the possible pressure drop in the tubing and annulus during the implementation of implosion-wave swabbing. On the surface, a hydraulic unit is connected to the annulus, on the one hand, and on the other hand, an IED. The tubing at the mouth is connected to the flow line. When the wellhead valve is open on the tubing, they are pumped through the annulus of the gas-liquid filling unit - a Penta-491 hydrocarbon solution of the demulsifier at a concentration of 0.1% wt. In the hydrocarbon solvent SNPCH-7r-14 or Nefras AK with the addition of 0.02 wt.% Penta 491-M . When the pressure differential (2.5 MPa) between the annulus and the tubing is reached, the DGI is triggered and the GG rushes into the tubing due to the created implosion effect. To increase the repressive and depressive effects on the formation, an IED installed on the surface is periodically included. When it is turned on, primary loosening of the ARPD and colmatants occurs, and due to the generation of high pressure pulses with higher frequency, the DGI is triggered. After bringing the AGS to the roof of the formation, the wellhead valve on the tubing is closed and the AGS is pumped into the BFZ with periodic activation of the IED to create an implosion-wave effect of the reagents with the implementation of the “wash” effect of the pore space.

After pumping the AHF into the formation in a dynamic mode, the packer is planted and lowered to the swab, during operation of which a value depression is created in the tubing string when the DGI is turned on, which consists of a check valve system that operates when the pressure difference in the under-packer zone and the tubing is reached. Using swab and DGI in the well’s bottomhole formation zone, a repeatedly repeated implosion effect is created, in which the most favorable conditions are realized for the removal of paraffin deposits and the separation of the clogging particles from the surface of the perforation channels, as well as their removal from the most contaminated area directly adjacent to the well.

The process of removal of the resulting passive liquid medium from the bottomhole formation zone is completed when the previously pumped volume of AGS is removed from the well, taking into account dissolved and dispersed contaminants.

Then, the swab is disconnected from the tubing, the packer is torn off, the wellhead valve is closed and the pore space of the PPP for the producing well is hydrophobized by injecting a kill fluid - anhydrous oil with the addition of 0.5 wt.% Don-52 through the annulus with periodic activation of the IED to ensure the exposure of the reagents to dynamic mode.

The process of processing PZP wells is completed after the calculated amount of surfactant solutions is pushed into the formation, then the tubing with technological equipment is removed and the well is put into operation.

The proposed method allows 3-5 times to increase the productivity of wells.

Claims (1)

The method of repressive-depressive-impulse-implosion treatment of the bottom-hole formation zone — PZP, comprising injecting an active reagent liquid medium — a hydrocarbon solvent with the addition of 0.05-0.1 wt.% Surfactant — through the annular space, replacing the kill fluid in the tubing string during repression-depression-pulse exposure, after bringing the specified active medium to the roof of the reservoir - pumping it into the PPP with alternating repression-depression, s then - repeated implosion exposure with removal of the formed passive medium from the PZP containing the destruction products of asphalt-resin-paraffin deposits and other clogging formations, until the injected volume of the specified active medium is removed and the subsequent injection during repression-depression-pulse action of the suppression fluid with the addition of 0.1-2 wt.% hydrophobic surfactant for the production well or hydrophilizing surfactant for the injection well.

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