Method of efficiency and control estimation for carbonate formation acid treatment. RU patent 2498060.
 Device for treatment of bottom-hole formation zone of oil well / 2496975Device for treatment of a bottom-hole formation zone of an oil well includes an air chamber with atmospheric pressure and a receiving chamber made from light-weight elasto-plastic material. In the receiving chamber a provision is made for composite materials of cylindrical shape: slightly gassy material and material that generates gas at combustion, and in addition, the receiving chamber of the device includes composite material that generates gas and acid at combustion between slightly gassy and gas-generating composite materials. Slightly gassy composite material at combustion, which faces the air chamber and is fixed with radially located metal pins relative to the receiving chamber housing, is made of composition containing the following, wt %: agranulated ammonium nitrate grade B 45-46, potassium bichromate 1-2, epoxy resin grade ED-20 40-42, plasticising agent grade EDOS 2-3, hardening agent Agidol grade AF-2M 9-10. Gas- and acid-generating composite material at combustion is made of composition containing the following, wt %: ammonium nitrate 40-50, powder-like fluorine rubber grade SKF-32 with dispersity of 0.5-1.5 mm 10, chlorinated paraffin wax grade KhP-1100 10-30, and fluoroplastic grade F-32L 10-40. Composite material that generates gad at combustion is made of composition containing the following, wt %: ammonia nitrate 78-85, powder-like nitryl butadiene rubber with dispersity of 0.5-1.5 mm 12, and potassium bichromate 3-10. |
| Treatment method of bore-hole zone / 2494246 Treatment method of a bore-hole zone involves the first stage, at which solution of surface-active substance (SAS) 0.5-1.5% in formation water in the volume of 100-200 m3 is pumped to the well; the second stage, at which there pumped is water solution of hydrochloric acid (10-15%) in the volume based on 0.25-0.5 m3 per running metre of perforated depth of the formation at initial pressure equal to final pressure at the previous stage; the third stage. At which there pumped is water solution of hydrochloric acid (10-15%) with a retarder of the reaction of acid with rock in the volume of 2-5% of volume of the acid solution in the pumping volume of 1-1.5 m3 per running metre of the perforated formation depth at initial pressure equal to final pressure at the previous stage; formation water forcing-through in the volume of 100-200 m3 at initial pressure equal to final pressure of pumping at the previous stage; process exposure during 16-48 hours and bringing the well into operation. Formation water can be pumped in advance to the well till pumping pressure rise at the well head to 1-2 MPa. |
 Treatment method of bottom-hole formation zone / 2494245Acid treatment method of a bottom-hole formation zone involves pumping to the formation of emulsion and water solution of an acid; at that, first, water solution of acid is pumped, and pumping of water solution of acid and emulsion is performed in a series-and-alternating mode, and emulsion containing the following components, wt %, is used as emulsion: acid 5.0-40.0; emulsifier - anionic or nonionic, or cationic surface-active substance, or their mixture 1.0-10.0; hydrocarbon solvent 5.0-40.0; decomposer - primary or secondary alcohol or their mixture 0.1-5.0; corrosion inhibitor 0.01-0.05 and water is the rest. Emulsion can contain viscosity regulator in the quantity of 0.01-6.0 wt %. Water solution of acid with concentration of 3.0-24.0% is used. |
 Treatment method of bottom-hole formation zone / 2494244In a treatment method of a bottom-hole formation zone, which involves pumping to the formation of acid-oil emulsion of reverse type and acid, as acid-oil emulsion of reverse type there used is emulsion containing the following components, wt %: dispersion medium - hydrocarbon liquid 31-38, emulsifier - reaction products of aliphatic amines of fat acids of hydrated tall oil with hydrochloric acid in terms of amines 0.02-0.08, dispersion medium - synthetic, inhibited hydrochloric acid (10-18%) is the rest. |
| Method for near well-bore treatment with acid / 2490444 Method for near well-bore treatment with acid involves at the first stage pumping into the well of 10-15% aqueous solution of hydrogen chloride in a volume calculated on the basis of 0.25-0.5 m3 per 1 running metre of penetrated stratum depth; at the second stage - pumping of 10-15% aqueous solution of hydrogen chloride with a retarder of the acid reaction with rock in the volume of 2-5% of acid solution volume in total volume of pumping calculated on the basis of 1-1.5 m3 per 1 running metre of penetrated stratum depth at initial pressure equal to the final pressure value during pumping at the previous stage; overflushing by oil in volume of 5-15 m3 at initial pressure equal to the final pressure value during pumping at the previous stage; soaking during 16-48 hours and input of the well into operation. |
 Procedure for treatment of bottomhole zone of producer with two wellheads / 2490443In procedure for treatment of bottomhole zone with two wellheads in case of failure of an electric-centrifugal pump (ECP) with no apparent deviation in its operating parameters and in case of alkalinity growth for extracted product up to pH>7 the required volume of hydrogen chloride solution is calculated on the basis of a length and diameter of the well filtering part; the required volume of hydrogen chloride solution is selected to treat the whole volume of the strainer; the required volume of flush fluid is calculated for delivery of compounds into a slope wellhead. ECP is shutdown at the vertical wellhead before pumping of hydrogen chloride solution is started. The required volume of hydrogen chloride solution is carried out into tubular annulus from the side of the vertical wellhead. When pumping of hydrogen chloride solution is over extraction from the slope wellhead is increased and ECP is started from the vertical wellhead. ECP is stopped at the vertical wellhead and hydrogen chloride solution is overflushed by the flush fluid into filtering part of the well. After ECP startup in enlarged extraction rate from the slope wellhead samples are taken periodically in order to check pH value, monitor dynamics in changes of fluid supply from the slope wellhead. When pH value id recovered up to the normal value ECP is started into operation from the vertical wellhead and supply from the slope wellhead is returned back to normal operation mode. |
| Method for well completion / 2490442 In method for well completion including pumping of acid solution into open horizontal hole in the mode of jet impact such impact is attained due to a jet delivery by a jet nozzle at the end of a flexible flush-joint pipe. The nozzle is placed at the borehole bottom. The acid solution is pumped with circulation through the well mouth; while acid solution is circulating the flexible flush-joint pipe is lifted simultaneously from the well with the speed not exceeding speed of the borehole filling by the acid solution. When horizontal hole is filled with the acid solution, the solution is overflushed into the stratum with staged pressure build-up and exposure at each stage. The flexible flush-joint pipe with a nozzle is placed again at the borehole bottom and the operation of borehole filling and overflushing is repeated again. Soaking takes place so that acid solution could react with the rock. The flexible flush-joint pipe is lifted to the interval of inert gas pumping, an inert gas is pumped and a build-up curve is recorded. Cyclic well killing is carried out in the mode of water pumping - soaking - oil draining till complete oil drain; thereafter a submerged pump is run-in and the well is input into operation. |
 Device for treatment of bottomhole formation zone of a well and method for treatment of bottomhole formation zone of well / 2487237Device for treatment of bottomwhole formation zone contains an air chamber with atmosphere pressure and length of 20-50 m connected to the first additional perforated chamber with seal layer, solid heat generating compound A with flame igniter, combustible high-strength compound B and breakable calibrated membrane located inside; the first added perforated chamber by means of a coupling with holes is connected to the second added inlet chamber with combustible high-strength compound C, igniter and breakable calibrated membrane located inside; the second additional perforated chamber by means of a coupling with added air chamber with length of 1.5-3 m connected by means of a coupling and metal adapter with to inlet chamber that is made of elastic plastic material with seal layer, solid acid generating compound D with igniter located inside; in the metal adapter there are drilled holes; compound A generated heat and gas of the following components by wt %: ammonium nitrate 35; sodium bichromate 2; barium nitrate 15; aluminium ASD-1 1.5; iron-aluminium thermite 31; epoxide compound (mixture of ED-20 tar, EDOS plasticiser and AF-2M hardener) 15.5; compound B is made of the following components by wt %: ammonium nitrate 30-40, calcium carbonate 5-10, the above epoxide compound 50-65; inside the added inlet chamber there is a layer of glass sealant and solid gas generating compound E made of the following compounds by wt %: ammonium nitrate 70, sodium bichromate 1, the above epoxide compound 29; compound C is made of the same composition as compound B; compound D is made as thermal-gas-chemical solid fuel with a layer of glass sealant and a layer of epoxide compound on top of it; the above fuel consists of the following components by wt %: ammonium nitrate 12-16, lithium fluoride 1-3, barium nitrate 5-8, aluminium ASD-1 0.7-0.8, iron-aluminium thermite 14-16, hexachlorane 20-30, polytetrafluoroethylene 20-30, the above epoxide compound 5-10. The method for treatment of bottomhole zone (BHZ) includes delivery of the above device by a wireline, combustion of compound D and formation of maximum quantity of chemical agents, holding for the purpose of reaction of acids produced during combustion with BHZ formation, running with installation of the coupling with holes at the level of treated stratum, opening of the chamber with length of 20-50 m, actuation of breakable calibrated membrane in result of layer-by-layer combustion of compounds A and B with implosion treatment of BHZ, removal of impurities from bottomhole stratum; during holding thermal-gas-chemical impact acts on the stratum for 30 minutes ad pressure can be corrected due to availability of holes in the metal adapter at fixed position of the above fuel inside the inlet chamber due to the above layers of sealant and compound with formation of gases heated up to high temperatures at high pressure within treatment range; opening of the chamber with length of 1.5-3 m is carried out by sequential actuation of the igniter, compounds E and C and breakable calibrated membrane located in the second added inlet chamber; after hydraulic shock there's another holding of the process for 30 minutes; when the chamber with length of 20-50 m is opened combustion of compound A takes place with formation of gases heated up to high temperature at high pressure within treatment range. |
 Stimulation method of formation fluid influx from well / 2485305Stimulation method of formation fluid influx from the well consists in lowering to the well of a tubing string. Counter pressure on the productive formation is decreased owing to replacing the liquid column with liquid-gas mixture (LGM) at observance of the required value of depression on the productive formation. Before the tubing string is lowered, its lower end is equipped with a remote subsurface pressure gauge and a filter. The tubing string is lowered to the well so that the filter is located opposite the formation perforation interval; after that, treatment of the bottom-hole zone of the formation is performed using a chemical method with process exposure for reaction. Then, the tubing string is lowered further so that the filter is located below the formation bottom, and into the inter-string space there lowered is a string of flexible tubes (FT) 100 m below the liquid level in the well. The liquid column is replaced in the inter-string space of the well with LGW and lowering of the FT string is continued. When lower end of the filter of the tubing string is reached, lowering of the FT string is stopped; then, stimulation of the formation fluid influx is started by gradual reduction of density of pumped LGM till the required depression on the productive formation, which is controlled as per readings of the remote subsurface pressure gauge, is achieved. After completion of stimulation of the influx from the well there removed is FT string from the inter-string space of the well, and operating equipment is lowered to the well and the well is put into operation. |
| Method for reagent clay cake removal from well / 2484244 Method for reagent clay cake removal from a well involves preliminary lowering of the tubing to lower perforation holes, formation in the zone of perforation holes of the first bath by pumping to the well via the tubing of a clay cake removing solution, its exposure, removal, further formation in the same zone of the second bath of water solution of acid with its being forced through the perforation zone to the formation and removal of the second bath by flushing; development of the well. As the clay cake removing solution, water solution of caustic soda with addition of surface active substance (SAS) is used. When the tubing is being lowered to the ell, it is equipped with a packer. Then, at open casing valve there performed is formation of the first bath by pumping of the above water solution of caustic soda via the tubing string, and the specified water solution of caustic soda is delivered to the formation by its being forced with process liquid via the tubing. Them the packer is set at the depth of not less than 50 metres above the treated formation, and forcing of water solution of caustic soda is performed with process liquid to the formation without exceeding allowable pressure on the formation; then, the well is kept for 10 hours for reaction under pressure not exceeding allowable pressure on the formation. Then, the packer is unpacked, and the working face is flushed by reverse flushing with process water by additional lowering of the tubing to the distance of 1-1.5 metres till the working face. Then, the packer is lifted so that it can be located at the depth of not less than 50 metres above the formation. Then, in the same zone there formed is the second bath by pumping of clay-acid solution with addition of Katapin KI-1 reagent on the basis of the fact that volume of clay-acid solution shall be 0.5-1 m3 per metre of the formation. The above clay-acid solution is forced with process fluid via the tubing to the formation; then, the packer is set and forcing of clay-acid solution is performed with process fluid to the formation without exceeding allowable pressure on the formation. Reaction exposure is performed during 1-2 hours. Then, well swabbing is performed via the tubing in the volume of 1.5-2 of the well volume. Then, the well injection capacity is determined at the pressure not exceeding maximum allowable pressure on the formation. When the required well injection capacity is not achieved, the above operations are repeated maximum for three times till the required well injection capacity is achieved. |
| Method of treating bottom zone of low-permeable oil reservoirs / 2244111 Invention aims at increasing productivity of oil- and gas-producing and injecting wells exposing high-temperature low-permeable oil reservoirs. In the treatment method according to invention including forcing enzyme substrate and separate enzyme into formation and creating conditions to enzymatically convert substrate into acid, geologic and productive characteristics for each interval of bottom zone are determined in order to pick out low-permeable intervals of oil reservoir for treatment, whereupon properties of enzyme substrate and separate enzyme as well as conditions for their pumping are chosen. Substrate utilized in the method is head fraction of methyl- and/or ethyl-, and/or butyl acetate production, to which aliphatic alcohols are added, and enzyme is an acid solution. Substrate is pumped simultaneously and/or before, and/or after pumping of enzyme, after which well is closed for some time and then opened and placed under predetermined operational conditions. |
 Device for treating well walls within range of productive bed / 2244112Device has pipe-like body with detachable upper and lower sleeves. Concentrically to body, with possible rotation relatively to it, a cover is mounted with blades with scrapers placed spirally on its surface. To lower sleeve a reactive end piece is connected with slit apertures. End piece hollow is filled with granulated material engaging in exothermal reaction with acid. Lower portion of end piece is provided with check valve. Upper sleeve is provided with check valve having locking element in form of sphere with shelf and centering elements, to be dropped from well mouth. Base of saddle of check valve is made in form of disc having diameter equal to diameter of body. Pass aperture of saddle in lower portion is overlapped with easily destructible and easily removed element. Length of sphere shelf is greater than height of pass aperture of saddle of check valve of upper sleeve. |
 Composition for treating bottom zones of wells / 2244114Invention relates to compositions used for intensifying wells owing to increasing permeability of rocks forming well bottom zones. Composition of invention contains 7.0 to 30.0% ethanol, 0.1 to 0.3% cupric chloride, 0.1 to 0.5% alkylbenzenesulfonate, and trichloroacetic acid (to 100%). |
 Acid composition for treating terrigenous oil reservoirs and a method for acid treatment of bottom area of formation / 2244816Invention provides composition that can be used to intensify oil inflow and to develop well by means of acid treatment of terrigenous oil reservoir as well as to intensify oil inflow and to increase oil recovery of formations with the aid of hydraulic rupture of formation assisted by acid solutions. Composition contains borohydrofluoric acid needed to create borosilicate films prohibiting migration of particles during acid treatment. In addition, composition is characterized by lowered rate of reaction with rock at formation temperature in order to extend coverage of formation by treatment and to diminish deposit formation risk, low surface tension, low corrosion rate, and compatibility with inhibitors added to commercial acid, which will enhance efficiency of acid treatment using composition of invention. Composition is made up of, wt %: inhibited hydrochloric acid 8.0-15.0, fluorine-containing reagent (hydrofluoric acid, ammonium bifluoride, or ammonium fluoride) 1.5-10.0, boric acid 1.0-3.0, additionally isopropyl alcohol 5.0-10.0, and "Alkylfosfat-Khimeko" or "Efiroks-7", or "Fosfol-10" 0.5-2.0, and fresh water to 100%. In a method of acid treatment of the bottom area of terrigenous formation comprising consecutively pumping flushing fluid and acid composition into borehole, forcing the latter into formation by the aid of flushing fluid, giving time (up to 8 h) for reaction and subsequent removal of reaction products. Acid composition is used as it is or in the form of aqueous solution obtained by diluting composition with fresh water at water-to-composition ratio (1-5):1 in amount corresponding to 0.5-2.0 m3 per 1 m of perforated thickness of the formation. As flushing fluid, 1.5-3.0% ammonium chloride solution is used in amount 0.5-1.5 m3/m before pumping of acid composition or in amount 1.0-5.0 m3/m when used to force acid composition. |
| Composition for declaying of bottom-hole formation zone / 2246612 Declaying composition contains clay dispersing reagent, peroxide compound and water, wherein as peroxide compound potassium fluoride peroxysolvate in activated form, comprising 1-3 mass % of oxalic or salicylic acid; and includes two sequential technological solutions. More specifically claimed composition contains (mass %): technological solutions 1: potassium fluoride peroxysolvate 1-2.5; hydrochloric acid as clay dispersing reagent 3-8.0; and balance: water; technological solutions 2: potassium fluoride peroxysolvate 1-2.5; sodium hydroxide as clay dispersing reagent 4-6.0; and balance: water. In addition said solution contain 0.1-1.0 mass % of water soluble surfactant. After treatment with disclosed solutions and well exposure dispersed reaction products are removed from bottom-hole formation zone. |
 Method for increasing productiveness of oil and gas wells / 2247234Method includes acidic treatment of bed, calculation of hardness decrease and pressure of rocks tearing and pressure for pressing working solution into bed, completion of well and the actual hydraulic tear. Pressure for pressing is determined from formula Pht=(2μ·Pm/(1-μ)+(1-3μ)·Pb/(1-μ), where Pht - rocks tear pressure, Pm - mountain pressure, Pb - bed pressure, μ - Poisson coefficient. |
 Oil extraction methods / 2247235Method includes treatment of face area of oil bed by hydrophobic powder in organic and pushing oil away from collector with following delivery of oil from face-adjacent area of extraction well for processing of oil-containing terrigenic bed into organic solvent additionally inserted is copolymer of ethylene with vinylacetate, well treatment is performed with relation of components in percents of mass: said powder 0.05-2, said copolymer 0,05-2, organic solvent - the rest. |
 Method for range-wise treatment of productive layer through open horizontal well shaft and device for realization of said method / 2247832Method includes determining porosity, penetrability and oil saturation level of shaft-adjacent area along whole length of deflected shaft. On basis of these ranges with low penetrability are detected, caverns presence level and diameters of shaft on ends thereof are determined. With consideration of characteristics of detected ranges at surface a pipe assembly is assembled, at end of which a ring saddle is mounted for locking ball, on both ends - hydraulic packers. Between these in assembly pipe a radial through calibrated channel is made. Pipe assembly is fixed at end of pipes column and these are lowered into chamber to level of deflected shaft mouth. With unpacked packers straight and backward washing of shaft is performed. After that acid is pumped into well in amount, equal to amount of first treatment range. Locking ball is dropped, first from the face shaft range with low penetrability is packed and concurrently acid is pressed therein, after that well is left for reaction. Then both packers are unpacked, backward washing of shaft is performed. By raising pipe column, pipe assembly with packers is transferred in backward, from face, direction into area of second, from face, range with low penetrability and above-mentioned operations are repeated. In turns, operations with each treatment range are performed. |
 Method for acidic treatment of productive bed / 2247833Method includes serial pumping of film-forming hydrocarbon liquid and hydrochloric acid with adding of salt-acidic corrosion inhibitor to these, as said inhibitor a special paraffin deposits inhibitor is used, in form of composition of surfactants and aromatic solvents, while hydrochloric acid with addition of inhibitor before pumping is dispersed with gas to receive foam. |
 Method for processing underground productive beds / 2249097Method includes injection of processing liquid into bed, which liquid contains solved or dispersed in water complicated ether and polymer destructor, selected from oxidizing destructor and ferment destructor in such a way, that complicated ether is hydrolyzed with production of organic acid for solution of material soluble in acid, present in filtering layer or adjacent to it or in other damage in productive bed, and polymer destructor destroys polymer material, present in filtering layer or bio-film in productive bed. |
FIELD: oil and gas industry.
SUBSTANCE: method of efficiency and control estimation for carbonate formation acid treatment involves core sampling and preparation of core samples. Chemical agent is pumped through core samples. Polished specimens are taken from the side of chemical agent input and output. At that before chemical agent pumping through prepared core samples the samples are surveyed at scanning electron microscope. After chemical agent pumping core samples are tested by CT-scanner. Images are compared and the most effective forms of solution channels are detected. Thereafter efficiency of acid treatment is estimated by calculating impact factor by computer processing of images; at minimum impact coefficient summary is made about the biggest efficiency of acid treatment.
EFFECT: improving efficiency of influence on bottom-hole zone of productive stratum.
15 dwg, 3 ex
The invention relates to the development of oil and gas fields with the use of acid methods of influence on the bottomhole formation zone and can be used to assess the effectiveness of the acid treatment, and improving the performance impact of bottom-hole zone the reservoir.
There is a method of allocation in terms of wells intervals for processing, including the selection of core samples, manufacturing, extraction mixture acid processing, wash with distilled water, with the subsequent calculation of the quantity dissolved in acid components of the reservoir rock, using data from magnetic logging (EN 2205951, IPC E21B 43/27, G01V 3/08, publ. 2003). However, the known method allows you to get complete information on the distribution of unreacted acid composition in the space of the reservoir rock, form and nature of the formed channels dissolution, as well as a detailed numerical calculation of area and depth of penetration acid composition. In addition, the magnetic susceptibility dissolved in acid components of rocks associated with the presence in the composition of the rocks ferrous and chlorite, which substantially limits the application of the method.
Closest to the proposed method is a way to control acid treatment of the reservoir, including the selection of core manufacturing of core samples for filtration studies, pumping through the core samples of chemical reagents of various concentrations with different time horizons, manufacturing of thin sections of core samples, selection of sections with a saved breed structure, defining the relationships number of pores in thin sections from the input of chemicals to the number of pores on the sections on the output side, chemical reagents, determination of optimal concentration of chemicals for the processing of the productive formation on the maximum ratio of a number of pores on the ground. (EN 2057918, IPC E21B 43/27, publ. 1996). The known method is not efficient enough because of the low visual information on the effectiveness of the acid composition and duration of counting, big error of calculation of the ratio of the number of pores on the ground from the entrance of chemical reagents to the number of pores on the sections on the output side of chemical reagents.
The present invention solves the problem of increasing the accuracy of determining the solvent properties of acid composition, visual informative way and evaluate the effectiveness of acid formation.
Task is solved as a method for the assessment and control of acid carbonate reservoir, including the selection of core manufacturing of core samples, pumping through the core samples a chemical production of thin sections entrance and exit of the chemical, before pumping chemical manufactured through the core samples previously conducted research on the scanning electron microscope, and the core samples after pumping chemical examine the x-ray tomography, conduct comparison of images emit the most effective channel of dissolution, followed by an assessment of the effectiveness of the acid processing, calculating the coefficient by means of computer processing of images, and the minimum value of the coefficient conclude the greatest efficiency acid treatment.
The method is as follows.
Produce coring and manufacturing of core samples. Next, perform a study these samples scanning electron microscope. Exercise pumping through chemical samples. Then the core samples after pumping chemical examine the x-ray tomograph by comparing the images, and emit the most effective channel of dissolution. To assess the effectiveness of the acid treatment, conduct determination of the coefficient of (impact) the method of computer processing of images. The effective result of the use of acid reagents education is dominant wormholes. Calculate the size distribution of wormholes (S k ). Figure 4 shows the image area of the wormhole. On the Fig.5 an area of influence of acid composition (S v ).
Determine the depth of penetration of the composition (g) by measuring its on the image (figure 9). Then estimated K s - ratio of the area of distribution of wormholes (S k ) to the area of influence of acid composition (S v ). K l - ratio of the depth of penetration acid composition (g) to the length of the sample (1). Using these data, calculate the coefficient K x - ratio values K s K K l for each structural-genetic type of carbonate rock. After that, analyze the results and the minimum value of the coefficient , conclude the greatest efficiency acid treatment.
Studies carried out on samples of a core fields of the Republic of Tatarstan. For sample processing carbonate strata of the middle Carboniferous use acid compositions:
1. Hydrochloric acid (12%, GOST 3118-77);
2. Hydrochloric acid + inhibitor SNPH-8903A (10% by weight, TU 2458-314-05765670-2006 with A1);
3. Acetic acid (10%, GOST 19814-74).
Pumping acidic compounds produced on an installation for the filtration of a fluid (-1M) through a sample of the breed.
Here is an example of a specific implementation.
Example 1. Select Kern, of it make five core samples. Using a diamond circle cut out the patterns on both end faces of the cores of which is made transparent sections. Next, perform a visual inspection of the scanning electron microscope for determining the specifics of hollow-pore space, define the belonging to a certain structural and genetic type of carbonate rock. Photos (Fig.1a, Б-1 - limestone -zoogenic the first type; b, Б-2 - limestone -zoogenic of the second type; and IP - ; d, IP - , e, IL - ) can be traced to differences in the structural-genetic types of carbonate rock, which is necessary for further studies at the MRI scanner.
Then spend pumping 12% hydrochloric acid through selected examples of core installation -1M, with working pressure P servant =4-6 ATM, crimping pressure P OBZH =8 ATM. Next Kern research in x-ray tomography, studying the received images (tomograms) of channels of dissolution (Fig.2). Repeat the same operations with other samples.
Spend comparison of tomograms of each sample, emit the most effective channel of dissolution. To assess the effectiveness of the acid treatment, evaluate the effectiveness of the acid exposure method of computer processing of images.
Calculation carried out as follows: the obtained using x-ray scanner, the image is placed in the graphic editor CorelDRAW (Fig.3), lead round a circuit wormhole so that the start and end points form a closed line - this will be the area of distribution wormholes, S k (Fig.4). Further held a closed line of extreme points of the channel dissolution is the area of influence of acid composition, S v (Fig.5). Then perform the following steps in the menu is selected, the Tools panel icon and Run the» versus «Macros» panel SanM_CurveInfo (Fig.6). Following the action of the computer calculates the area of distribution wormholes, S k =17,01222 cm 2 (7), the area of influence of acid composition, S v =21,427057 cm 2 (Fig.8), also determine the length of the sample, l=3 cm and depth of penetration of the acid solution, g, in this case l=g=3 cm (Fig.9). The calculation is given for limestone - of the first type. Thus,
area of distribution wormhole - S k =17,01222 cm 2 (Fig.7),
the area of influence of acid composition - S v =21,427057 cm 2 (Fig.8),
the depth of penetration of acid composition - g=3.0 cm (Fig.9),
the sample length is l=3.0 cm,
Ratio of area of distribution wormhole to the area of influence acid composition -
, K s =0,7976,
The attitude of the depth of penetration acid composition of the length of the sample -
K l =0,8313,
Coefficient -
.Similarly, all indicators are calculated for the other four structural-genetic types of limestone after exposure to hydrochloric acid.
Example 2-3 perform similarly to example 1, changing the type of acid reagent. Composition №2 - HCl + inhibitor SNPH-8903A, composition №3 - acetic acid).
After pumping acid composition №2 through the core samples examine them at the x-ray tomography, compare images and evaluate the effectiveness of the acid treatment using calculations by the method of computer processing of images.
The calculation for composition №2 (10):
Area of distribution wormholes - S k =14,003984 cm 2 ,
The area of influence of acid composition - S v =32,720104 cm 2 ,
The depth of penetration of acid composition - g=3.0 cm,
The sample length is l=3.0 cm,
Ratio of area of distribution wormhole to the area of influence of acid composition -
, K s =0,42799,
The ratio of depth penetration acid composition of the length of the sample -
K l =0,8738,
Coefficient -
.The calculation for composition №3 (11):
Area of distribution wormhole - S k =15,33754 cm 2 ,
The area of influence of acid composition - S v =26,83441 cm 2 ,
The depth of penetration of acid composition - g=3.0 cm,
Length sample - l=3.0 cm,
Ratio of area of distribution wormhole to the area of influence of acid composition -
, K s =0,4993,
The attitude of the depth of penetration acid composition of the length of the sample -
K, l =1,Coefficient -
.Acid composition of findings believe that the best, with a minimum the ratio K x .
Calculations factor K x for all structural-genetic types of limestone showed that the most effective acid structure was HCl+SNPH-8903 (composition №2).
Thus, the invention allows to define and visualize the degree of change ground-breaking space reservoir rocks composing the productive part of the section in the area of acid impact to improve the productivity of wells. When comparing all of the results of studies, ranking of filtration channels, receive objective, visual and numerical characteristic of the distribution of acid composition in zone taking into account the structural-genetic characteristics of the productive reservoir.
The invention solves the problem of increasing the accuracy of determining the solvent properties of acid composition, visual informative way and evaluate the effectiveness of acid formation.
Method of evaluating the efficiency and control of acid carbonate reservoir, including the selection of core manufacturing of core samples, pumping through the core samples a chemical production of thin sections entrance and exit of the chemical, characterized in that before leveling chemical made through the core samples previously conducted research on the scanning electron microscope, and the core samples after pumping chemical examine the x-ray tomography, conduct comparison of images emit the most effective channel of dissolution, after what evaluate the effectiveness of acid processing, calculating the coefficient by computer image processing and the minimum value of the coefficient conclude the greatest efficiency acid treatment.