Bottomhole formation zone consolidation method

FIELD: oil and gas production industry, particularly to treat bottomhole formation zone during oil and gas production.

SUBSTANCE: method involves inserting material for further exothermal reaction performing in well; forcing hydrochloric acid through the material and executing time delay. The material used for exothermal reaction performing is in the form of aluminum cuttings. First of all aqueous carboxymethylcellulose solution is formed. Then calculated amount of aluminum cuttings and grinded raw rubber are added to the solution. Above components are taken in the following amounts (% by weight): carboxymethylcellulose - 1.5, aluminum cuttings - 14.5, raw rubber - 11.6, water - 72.4. After that the ready solution is forced in reservoir and 20% hydrochloric acid is injected in well. Ratio between aluminum and hydrochloric acid is 25.0 parts by weight of aluminum per 75.0 parts by weight of hydrochloric acid.

EFFECT: increased bottomhole formation zone treatment reliability.

1 tbl

 

The invention relates to the oil and gas industry and can be used in the processing of bottom-hole formation zone in the extraction of oil and gas.

One of the main development objects by gas production are Cenomanian sediments composed laborzentrifugen collectors. One of the main reasons that prevent successful development of deposits opened in weakly cemented reservoirs, is the removal of sand from the rock collector, which formed the sandy tube, reducing the flow rate, and increases the wear of the equipment.

The known method of fastening the bottom-hole zone, based on the injection into the perforation interval of aqueous solutions of calcium chloride from 2 to 3% (wt.) density of 1150 to 1200 kg/m3and holding it under pressure for 12 to 16 hours (Akihabara, Rimmerman, See. Intensification of oil production rates from wells in West Siberia. Tyumen. Publishing house "the Word", 2000, s-203).

The disadvantage of this method is that the efficiency of its application is very short, can be used in wells where there is a slight sand.

Closest to the proposed method is a method of fixing the bottom-hole formation zone in which the seam is pressed carrier fluid with magnesium. Then squag the well pump a solution of hydrochloric acid. Hydrochloric acid comes in an exothermic reaction with magnesium and formed a salt of magnesium chloride with the release of a large amount of heat. Depending on the filtration rate of the acid and the discharge pressure, the temperature on the treated surface reaches 800°and above, provided that the magnesium melts at a temperature of 651°C. the Flow rate of the injected acid and magnesium are carried on the surface of rocks, forming a film products from thermochemical reactions and magnesium, which forms a metal frame (A.S. USSR 960421. Published 23.09.82. Bull. No. 35).

The disadvantage of this method is the low reliability of fastening of the bottom zone due to the lack of reliable coupling a metal frame, which creates magnesium, with the breed of the reservoir, as in the process of cooling the metal frame is its shrinkage and cracking.

The problem to which the invention is directed, the reduction of sand in the operation of wells.

The technical result is increased reliability of fastening of the bottom zone.

This technical result is achieved by the fact that in the known method of attachment of the bottomhole zone of the formation, comprising introducing into the well of material for carrying out exothermic reactions with subsequent pumping through him hydrochloric acid and exposure time, unlike the prototype is, as a material for carrying out exothermic reactions using sawdust aluminum, in this case, initially prepared aqueous solution of carboxymethylcellulose, introducing him to the estimated amount of sawdust aluminum and chopped raw rubber in the ratio, wt.%:

carboxymethylcellulose1,5
aluminum14,5
crude rubberthe 11.6
water72,4

then push the resulting solution into the reservoir, then pump 20%hydrochloric acid, the ratio of aluminum and hydrochloric acid, wesc:

Aluminum25,0
Hydrochloric acid75,0

The method is as follows. Descend into the well tubing, a Shoe which is mounted near the upper perforations. Using cementing unit prepare an aqueous solution of carboxymethylcellulose and enter him in the estimated amount of sawdust aluminum and chopped raw rubber. Then the solution is forced into the reservoir, and the annular space of the pump 20%hydrochloric acid. The reaction is accompanied by evolution of heat (4,7 Kj/kg), and the rate the temperature in the wellbore area increases up to 150° C. the Amount of aluminum participating in the reaction with hydrochloric acid, is determined from the stoichiometric ratio of 25% aluminum and 75% of hydrochloric acid.

By physico-chemical processes accompanying the injection of hydrochloric acid into the formation, the interaction of hydrochloric acid with aluminum, is allocated hydrogen, growth temperature and begins the process of vulcanization of rubber.

When interacting particles of raw rubber with hydrocarbons - gas, gas condensate, oil, saturating productive formations, it is a partial dissolution and adhesion to the surface of the reservoir rocks.

Occurring chemical reaction between aluminum and hydrochloric acid generates heat, which contributes to the vulcanization of rubber and its adhesion to the surface of the rocks, and released when the hydrogen creates additional channels in the total mass of rubber that ensures the fastening of the bottom zone and reduces the sand.

Experimental validation of the method is carried out with the use of quartz sand, which consist of sandstones Cenomanian deposits of gas fields in the North of Western Siberia.

Selected a sample of sand is poured into the cylindrical container, squeeze the effective pressure from 9.6 to 11 MPa and simulate the initial neftegazonosnosti. Set C is indecency container in kindergaten, simulate reservoir conditions. Determine the permeability of the sample on kerosene. In an aqueous solution of carboxymethyl cellulose (CMC-a 1.5%water 72,4%) - 73,9 g add to 14.5% sawdust aluminum and 11.6% crude rubber is mixed in a mixer for 10 minutes for the best distribution in the solution components solution. Download the prepared solution in the sample by filtration hydrochloric acid. The next step is injected into a sample of hydrochloric acid in amount calculated to react all aluminum, injected into the sample, based on the stoichiometric ratio: 25% aluminum and 75% of hydrochloric acid.

Leave to react for 2 hours At the end of the experiment simulate the conditions of development wells. The sample from the opposite side of the injection of hydrochloric acid, washed with kerosene at a pressure equal to the depression during the development of well - 5 MPa in an amount of from 3 to 4 volumes of pores and determine its permeability.

In the result, the permeability of the resulting zone of stable species after treatment decreased slightly from 1.6 to 3.3% of the initial permeability values of the sample (table).

Table
The results of laboratory experiments to determine the permeability of samples resistant to the removal of the sand.
The number of experienceSolutionsThe injection pressure acid, MPaDepression, MPaThe permeability of weakly cemented samples, K-10′′3 μm2The permeability of the samples after processing, K-10′′3 μm2The decrease in permeability after treatment, %.
1.20% HCl0,025,0216,6213,11,6
2.20%0,045,0USD 192.1185,73,3
HCl
3.20%0,15,0the 122.7120,02,2
HCl

The method of attachment of the bottomhole zone of the formation, comprising introducing into the well of material for carrying out exothermic reactions with subsequent pumping through him hydrochloric acid and exposure time, wherein as a material for carrying out exothermic reactions using sawdust brand is Oia, in this case, initially prepared aqueous solution of carboxymethylcellulose, introducing him to the estimated amount of sawdust aluminum and chopped raw rubber in the ratio, wt.%:

Carboxymethylcellulose1,5
Aluminum14,5
Crude rubberthe 11.6
Water72,4,

then push the resulting solution into the reservoir, then pump 20%hydrochloric acid, the ratio of aluminum and hydrochloric acid, wesc:

Aluminum25,0
Hydrochloric acid75,0



 

Same patents:

FIELD: oil and gas production.

SUBSTANCE: whole process comprises primarily exposing well on polymer-chalk mortar, perforating bottom zone of formation under polymer-chalk mortar layer, creating acid-degradable protective shield in bottom zone by forcing polymer-chalk mortar under pressure exceeding specified cementation pressure by 10-15%. Thereafter, casing string is descended, annular space is cemented, and bottom zone of formation is re-perforated through casing string and protective layer is destroyed with acid. Polymer-chalk mortar has following composition, wt %: soda ash 1-6, carboxymethylcellulose 1-6, polyacrylamide 2-3, clay 48-52, chalk 46-50, water - the balance.

EFFECT: increased productivity of formation due to prevented negative action of drilling fluids and appearance of softened bottom 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

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.

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EFFECT: increased reliability of bottom water isolation.

2 cl, 1 ex

FIELD: oil and gas production industry, particularly methods or devices for cementing, for plugging holes, crevices, or the like, for instance abandonment of well drilled in permafrost zones.

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1 dwg

FIELD: oil and gas production industry, particularly methods or devices for cementing, for plugging holes, crevices, or the like, for instance abandonment of well drilled in permafrost zones.

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EFFECT: increased efficiency.

1 dwg

FIELD: oil and gas production.

SUBSTANCE: invention provides composition for treatment of carbonate formations in order to intensify production of oil and gas from the wells in question, which composition is constituted by 20-22% hydrochloric acid aqueous solution, 42-48%, polyglycol, 4-16%, and alumina-chloride solution obtained from chemical process waste, which contains 200-300 g/L of main material in solution having pH 0.6-2.0, 42-46%. Treatment with this composition leads to reduced permeability of washed zones of formation and reduced degree of nonuniformity thereof in direction of replacement.

EFFECT: reduced reaction rate and dissolution capacity of solution in water-saturated portion of formation accompanied by increase in dissolution capacity of solution in oil-saturated portion of formation.

2 tbl

FIELD: oil and gas production.

SUBSTANCE: invention provides grouting composition for use, in particular, in drilling of wells and during performing repairing and insulation operations but also in production of concretes and preparation of mortars. Water based grouting composition containing cement (52.46-76.92%) and plasticizer (0.066-0.41% on conversion to sodium adipates constituting plasticizer) is supplemented by 0.05-1% of water-soluble polymer as stabilizer.

EFFECT: improved rheological characteristics of grouting mortars and mechanical properties of stone, enhanced efficiency of performing repairing and insulation operations, improved lining of well and prolonged operating period in corrosive media.

3 tbl

FIELD: oil production industry, particularly development of drilled wells and to stimulate oil production from existent cased or uncased walls due to inorganic and organic deposit dissolving in well bore and in bottomhole reservoir zone.

SUBSTANCE: method involves killing well with liquid, namely with mineralized water; removing bottomhole equipment from well; installing electrodes electrically linked to power source in well; switching-on constant current source and treating productive reservoir with electric field by passing electric current through the reservoir. Electrodes linked with power source are installed in well below liquid level in well. Graphite anode and cathode provided with non-conductive centrators are used as the electrodes. The anode and cathode are spaced apart along well height. Anode is arranged within productive reservoir zone. Cathode is installed 10-100 m below anode. Mineralized water with alkaline surfactant taken in amount of 0.25-1.0% by weight is used for well killing. The invention is disclosed in dependent claims.

EFFECT: increased efficiency of productive reservoir zone cleaning of drill products, including polymer-based ones, and possibility to remove inorganic deposits accumulated in well and bottomhole reservoir zone during well operation due to creation of stable acid medium with low pH values within productive reservoir interval and prevention of acid medium neutralizing during well treatment, as well as sulfate-reducing bacterium growth suppression.

4 cl, 4 tbl, 5 dwg

FIELD: oil and gas production.

SUBSTANCE: invention relates to composition and process for improving production of oil from oil formation and cleaning oil-polluted land and surfaces. Composition contains at least 85% of fatty acid alkyl ester, surfactant, and acid. According to a process for producing crude oil, effective amount of production formulation based on the indicated composition is injected to oil formation before production of crude oil from that formation. Described are also oil-water emulsion demulsification process and oil-polluted land and surfaces cleaning. Invention is further developed in dependent claims.

EFFECT: reduced amount of residual oil in formation and improved quality of cleaning with nontoxic composition.

13 cl, 20 dwg, 1 tbl, 3 ex

FIELD: oil and gas production.

SUBSTANCE: invention relates to composition and process for improving production of oil from oil formation and cleaning oil-polluted land and surfaces. Composition contains at least 85% of fatty acid alkyl ester, surfactant, and acid. According to a process for producing crude oil, effective amount of production formulation based on the indicated composition is injected to oil formation before production of crude oil from that formation. Described are also oil-water emulsion demulsification process and oil-polluted land and surfaces cleaning. Invention is further developed in dependent claims.

EFFECT: reduced amount of residual oil in formation and improved quality of cleaning with nontoxic composition.

13 cl, 20 dwg, 1 tbl, 3 ex

FIELD: oil and gas production.

SUBSTANCE: method comprises mixing distillate-type solvent for petroleum wax, emulsifier "YALAN-E-1", and 22-24% aqueous solution of inhibited hydrochloric acid, which are charged to a vessel. Thereafter, hydrochloric acid solution is pumped out of the vessel from below while distillate is pumped out from above. Hydrochloric acid solution and distillate are then directed by different pumps to disperser and therefrom to the top of the vessel. Acid discharge pump is 2-3 times less efficient than distillate discharge pump. Mixing is effected at temperature from -15°C to +30°C in emulsion.

EFFECT: improved ability of oil-acid emulsion of washing out muding compounds from bottom zone.

1 dwg

Grouting mix // 2304606

FIELD: oil and gas production.

SUBSTANCE: invention relates to building wells and major repairs thereof, namely involving supporting casing strings and creating fluid-proofing isolation covers within chemical deposit interval as well as to exploitation of deposits and well abandonment. Grouting mix contains 50.00-53.95% calcium sulfate (gypsum semihydrate), 2.00-8.50% hardening additive constituted by fine mineral substance "Mikrodur-26RX", 0.05-0.08% nitrilotrimethylphosphoric acid, 41.42-44.00% sodium chloride solution having density 1.18 g/cc.

EFFECT: expanded technological possibilities of grouting mix due to proper pumpability and setting times, enhanced fluid-proofness and durability of grouting stone under complicated water-exchange conditions.

2 tbl

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling mud used for opening productive bed-collector. By the first variant drilling mud contains the following components, wt.-%: biopolymer xanthane "Saraksan-T" or "Saraksan", 0.2-0.6; chemically modified starch, 0.2-0.8; calcium nitrate, 14-50; ammonium nitrate, 2-7; froth breaker "Sofeksil 9056-20", 0.01-0.15, and water, the balance. By the second variant drilling mud contains the following components, wt.-%: biopolymer xanthane "Saraksan-T" or "Saraksan", 0.2-0.3; chemically modified starch, 0.1-0.3; calcium nitrate, 14-50; ammonium nitrate, 2-7; calcium chloride, 15-20; froth breaker "Sofeksil 9056-20", 0.01-0.15, and water, the balance. The density value of drilling mud is 1100-1600 kg/m3. Invention provides the creature of solid phase-free drilling mud and with retaining its rheological and filtrating indices for a long time and independently of the drilling mud density value.

EFFECT: improved and valuable properties of drilling mud.

2 cl, 2 tbl, 2 ex

FIELD: production and exploratory well drilling, particularly foaming drilling fluids used during penetration through incompetent rock intervals and during primary productive oil and gas deposit opening in the case of abnormally low formation pressure.

SUBSTANCE: foam composition comprises surfactant, foam stabilizer, water, water hardness control additive and lubricant. The water hardness control additive is sodium silicate. The lubricant is VNIINP-117 emulsion. The foam stabilizer is polyacrylamide, the surfactant is sulphonole. All above components are taken in the following amounts (% by weight): sulphonole - 0.8-1.5, sodium silicate - 0.2-0.5, polyacrylamide - 0.1-0.5, VNIINP-117 - 0.5-2, remainder is water.

EFFECT: reduced power inputs for well drilling, as well as reduced coefficient of friction between drilling tool and well wall.

1 tbl

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