Stimulation method of formation fluid influx from well
FIELD: oil and gas industry.
SUBSTANCE: stimulation 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.
EFFECT: improving efficiency and quality of stimulation of formation fluid influx from productive formation.
The invention relates to the oil industry and can be used for development wells.
There is a method of well completion by creating a depression on the layer (patent RU №2272897, IPC EV 43/18; 43/27, publ. 27.03.2006, bull. No. 9), which includes the replacement of the liquid filling hole on the solution of surface-active substances (surfactants) with its subsequent aeration by filing in the well of the gasifier in the form of ammonium carbonate, while before serving gas-forming substances bottom zone is subjected to acid treatment with displacement of the acid into the formation, as reagents of gas developing agents optionally used aqueous solutions of sodium nitrate NaNO2and hydrochloric acid HCl; the aqueous solutions of the reagents of the gas developing agents injected in portions of 0.5-2.0 m3in the following sequence: ammonium carbonate, hydrochloric acid, sodium nitrite, with each successive solution has a density greater than the previous volume of the injected reagent is from 0.3 to 1.0 volume of the well, but at least 1.1 times the internal volume of the pressure column, and due to the useful volume of the well, and a solution of surfactant further comprises hollow glass microspheres.
The disadvantage of this method is that the aeration of the surfactant solution is directly in the hole p is the supply of gas-forming substances in the bottom zone of the well, it is possible to change the sequence of the course of chemical reactions and temperature, which can lead to changes in physical and chemical properties of the replacement fluid, including the decomposition of carbonated liquid to gas and water, which generally reduces the quality of development wells.
Also there is a method call flow of formation fluids from the well (Naidanow. The drilling and operation of oil and gas wells. - M.: Nedra, 1982, SCR-271), including reduction of pressure on the producing formation by filing it with the surface of the gas or gas-liquid mixture and replace the liquid column in the well gas-liquid mixture, and the gas is fed by the compressor.
The disadvantages of this method are:
- firstly, the need for compressor - neutral source of fire and explosion at down hole conditions of high pressure gas;
- secondly, the compressor may not push all of the liquid column in the well, therefore, have to learn step by step that delays the process of the call flow of formation fluids from the well.
The closest in technical essence is a method call flow of formation fluids from the well (patent RU №2263206, IPC EV 43/25, publ. 27.10.2005 St, bull. No. 30), including reduction of pressure on the reservoir by replacement of the liquid column in the well gas-liquid mixture put the m feed mixture booster unit with the selection of the components of the mixture of working well or collector collection products thus the desired ratio of components of the mixture to achieve a given value of the pressure in the reservoir provides a selection of components of the mixture through the separator, the outputs of which communicates with the manifold collection of products.
The disadvantages of this method are:
first, the low quality of the call flow from the reservoir well, due to the unstable condition of the gas-liquid mixture due to its premature destruction;
- secondly, the absorption of gas-liquid mixture or its components in a given reservoir in the process of replacing the fluid in the well to a gas-liquid mixture and, consequently, reducing the natural permeability of the reservoir properties) of the reservoir;
- thirdly, it is almost impossible to find the desired ratio of components of the gas-liquid mixture to achieve the desired depression in the reservoir, without the testimony of the changing values of downhole pressure during the call flow of fluid from the reservoir;
- fourthly, the low efficiency of the call flow, due to the rapid decrease of the flow rate or the failure to achieve the specified flow rate when the call flow of formation fluids from the well.
Objectives of the invention are to increase the efficiency and quality of the call flow of formation fluid from the reservoir, and also excluded the e premature destruction of the gas-liquid mixture in the process and reducing the intensity of absorption of the gas-liquid mixture reservoir to control downhole pressure during the call flow of formation fluid from the well.
The problem is solved by a method call flow of formation fluids from the well, including the descent into the well of the column tubing - tubing, reducing the back pressure on the producing formation due to the replacement of the liquid column in the well gas-liquid mixture while respecting the desired magnitude of depression in the reservoir.
What's new is that before the descent of the casing the lower end equipped with remote depth gauge and filter, the tubing string lowered into the well so that the filter was located opposite the perforated interval of the reservoir, and then make processing of bottom-hole formation zone of a chemical method with technological exposure on reaction, then dopuskayut the tubing so that the filter was below the soles of the reservoir, and in the annular space of the well down the column flexible tubes - GT - 100 m below the liquid level in the well, install the spare column of fluid in the annular space of wells on gas-liquid mixture, continue the descent of the column of GT upon reaching the lower end of the filter columns tubing run a string GT stop, and then start the call flow of formation fluids gradual decrease in the density of the injected gas-liquid mixture to achieve a desired depression in the reservoir, which is controlled according to the testimony remote the traditional depth gauge, at the end of the call flow from the well to retrieve the column of GT from the annular space of the well, down into the well production equipment and run well.
In figures 1 and 2 consistently depicts the schema of the method call flow of formation fluids from the well.
The proposed method is as follows.
It is known that during operation of the well is reduced inflow of formation fluid downhole production well due to the deterioration of the permeability zone of the formation (PPP), and therefore there arises a need to restore the flow of formation fluids to the bottom of the production well. To do this, stop the production well 1 (see figure 1), remove operational equipment (e.g., a string of pipe with electrical submersible pump) (figure 1 and 2 is not shown). Before the descent of the casing 2 at its lower end sequentially from the bottom up remote set depth gauge 3, for example, plugged in the container to avoid damage in the process (figure 1 not shown), and then filter 4 (see figure 1). Then lowered into the borehole 1 column tubing (tubing) 2, the descent of the casing 2 is carried out so that the filter 4 was in the interval between the roof 5' and sole 5", i.e. was located opposite the interval perfor the tion layer 6. For example, if the perforation interval of the reservoir 6 is 3 m and the height of the filter 4 must not be less than 3 meters
Then chemical method produces the treatment of bottom-hole zone 7 layer 6. Filter 4 allows the injection of a chemical agent (e.g., acids, hydrocarbon solvent) in the treatment of bottom-hole zone 7 layer 6 by a chemical method. In addition, the presence of the filter 4 can be placed on the lower end of the casing 2 remote depth gauge 3, which control the pressure in the call flow of formation fluids from the well.
To do this, at the wellhead 1 (see figure 1) discharge line 8 pump unit 9 (for example, CA-320) tied with the internal space 10 of the casing 2. Further, with the pump unit 9 through the inner space 10 of the casing 2 and the filter 4 have pumped in the bottom zone 7 layer 6, for example a hydrocarbon solvent (i.e. install a bath of hydrocarbon solvent). As the hydrocarbon solvent used, for example, Nefras-150/200 on THE 38.40125-82 or Nefras-Ar 120/200 on THE 38.101809-80. The estimated amount of the hydrocarbon solvent is determined empirically individually for each well, depending on permeability, porosity, degree of pollution, but not less than the volume of the borehole from the bottom to the top ' of the reservoir 6 and is calculated by the formula:
Vp- the estimated amount of the hydrocarbon solvent, m3;
D - inner diameter of the casing wells, m;
h is the distance from the bottom to the top 5' of the reservoir 6, m
For example, when the distance h=50 m and the internal diameter of the casing string D=168 mm(9 mm·2)=150 mm=0.15 m define the required amount of hydrocarbon solvent (Vpfor bath installation:
Vp=3,14·(0.15 m)2/4·50 m=0.9 m3
Produce technological exposure for, for example, 12 h at the reaction of the hydrocarbon solvent for dissolving paraffin-resinous deposits in the critical zone 7 layer 6, thus removing the pressure line 8 and the pump unit 9.
Make the harness ground equipment as shown in figure 2. Then dopuskayut the tubing 2 (see figure 2) so that the filter 4 was below the soles of the reservoir 6, after which the inner space 10 of the casing 2 tied with gutter capacity 11 at the wellhead 1 through the annular valve 12 and the discharge line 13, with indications of distance depth gauge 3 are, for example, 9 MPa.
At the end technological shutter speed (reaction time, for example, 12 h) in the annular space 14 well 1 down a column of flexible tubes (GT) 15, for example, 38 mm diameter, placed on the drum (n is shown) coiled tubing installation 15' (see 2). Column GT down to 100 m below the liquid level (static level) in the well 1. Static level depends on the bottomhole pressure of the well and is individual to each well and is determined by geophysical research (space level) and provided in advance of the proposed method for the planning process parameters.
Next on the wellhead 1 column GT 15 through the discharge valve 16 tie with the pressure line 17 of the booster unit 18, which is used, for example, gas booster installation brand UNG 8/15. Additionally, the internal space 10 of the casing 2 tie with a Central valve 19 with a discharge line 20 into the chute container 11.
At the wellhead 1 prepare a gas-liquid mixture, which is an aqueous solution with a surface-active agent (surfactant), which is used as a foaming agent.
The necessary amount of an aqueous surfactant solution for call flow of formation fluid from the well is determined from the ratio of gas-liquid mixture, which is 3.5-5 in the call flow of formation fluids from the well, as well as the desired volume of gas-liquid mixture Vgconsisting of volume V1annular space 14 wells 1 to replace the fluid in the borehole on gazozhidkostnoi the second mixture before the beginning of the call flow and volume V 2annular space 14 well 1 for circulating the gas-liquid mixture in the call flow of formation fluids from the well. These volumes are equal, i.e. two equal volumes of one well, namely: V1=V2then Vg=2·V1will take a foam ratio equal to 4, then the volume of the aqueous surfactant solution is determined by the formula:
where Vin- the volume of the aqueous surfactant solution, m3;
V1- the volume of the annular space of the borehole, m3.
For example, if the height of a column of liquid from the reservoir to the mouth N=1600 m and the diameter of the casing 168×9 mm the volume of the gas-liquid mixture for the entire process of stimulation is determined by the formula:
V1- the volume of the annular space of the borehole, m3;
D - inner diameter of the casing bore, m:
D=168 mm(9 mm·2)=150 mm=0,15 m
d - outer diameter of the tubing string, for example, 73 mm=0,073 m;
H - the height of a column of liquid from the mouth to the bottom hole, m, for example, N=1600 m
Then, substituting in the formula (3): V1=(3,14·(0.15 m)2-(0,073)2/4)·1600 m=21,6 m3and the required volume of gas-liquid mixtures: Vg=2V1=2·21,6 m3=43,2 m3.
Then the required amount of an aqueous solution of a surfactant is determined by the formula (2):
Substituting numerical values, we get: Vin=Vg/4=43, m 3/4=10,8 m3will take the volume of the aqueous surfactant solution is equal to 10.8 m3.
To increase the stability of the gas-liquid mixture in an aqueous surfactant solution add stabilizer - 1%solution of CMC-700 with the addition of 2%KS1 according to GOST 4234-77.
CMC-700 - sodium salt of simple cellulose ether and glycolic acid polymer by MI Drilling Fluids (USA). Practical experiments have shown that the stability of the gas-liquid mixture with the addition of the stabilizer increases 5-9 times. The stabilizer is prepared as follows.
In fresh water ρ=1000 kg/m3(heated to 40-45°C) is added with constant stirring CMC-700, the process is complete dissolution of 2.0-2.5 h, then in the prepared solution add 2%KCl dry, mix until dissolved. In the calculated volume of the aqueous surfactant solution add the resulting stabilizer, stirred for another 20-30 minutes
As the surfactant used, for example, sulfinol (on THE 6-01-862-73) at a concentration of 0.1-0.3% of the volume of fresh water or other surfactants, such as OP-7; OP-10 (on THE 8433-81) at a concentration of 0.3-0.6% of the volume of fresh water.
Fill the tank 21 of the booster unit 18 in an aqueous solution of surfactant (see figure 2).
An aqueous surfactant solution eliminates premature destruction of the gas-liquid mixture in the process before reaching the surface of the well 1, i.e. becomes more stable. As a gas safe n the conditions of ignition of hydrocarbon environment, use generated by the gas generator 22 of the booster unit 18 gas (e.g. nitrogen), as a result of combustion of fuel (gasoline, diesel fuel in the compressed air, i.e. the depletion of oxygen.
Gas from the gas generator 22 is supplied to the booster (mixing) device 23, where there is continuous mixing of the gas with the process fluid in the form of an aqueous surfactant solution (with the formation of the gas-liquid mixture), with an aqueous surfactant solution is supplied with a constant flow of 3 l/s, the pump 24 from the tank 21 of the booster unit 18. Open annulus 12, the discharge 16 and the Central valve 19 and through the discharge line 17 of the booster unit 18 serves gas-liquid mixture (higher density) in the column GT 9, the density of which is, for example, 850 to 900 kg/m3.
The column GT 15 in the annular space 14 wells 1 to replace the liquid column in the well pump gas-liquid mixture density 850-900 kg/m3which is provided with a minimum degree of aeration of the aqueous surfactant solution, for example, 5-10 m3/m3. Continue the descent of the column of GT 15, the lower end of which is submerged beneath the liquid level in the well 1 to 100 m at a rate of 0.5-1 m/s (figures 1 and 2 not shown), while not exceeding the maximum pressure developed in the booster unit 18 (see figure 2), e.g. the 15 MPa. When displaced gas-liquid mixture fluid in the well reaches the wellhead 1, of the annular space 14 through the annular valve 12 and the discharge line 13 in the chute container 11 starts pouring out of the well fluid that is displaced by gas-liquid mixture.
As you descend the column GT 15 in the borehole 1 and injection of gas-liquid mixture in the annular space 14 is replaced fluid in the annular space 14 and the inner space 10 of the casing 2 wells 1, i.e. the gas-liquid mixture of higher density in the well volume 1 (V1=21,6 m3), keep track of readings remote depth gauge 3, the value of which gradually decreases. When the lower end of the column GT 15 reaches the lower end of the filter 4 of the casing 2, the descent of the column of GT 15 stop. Because the filter 4 of the casing 2 is below the bottom of the reservoir 6, under such conditions, in the bottomhole formation zone penetrates the minimum number of gas-liquid mixture and its composition can reduce the absorption intensity gas-liquid mixture reservoir or entirely prevent its absorption reservoir, resulting in the preservation of its natural permeability of the reservoir properties).
Thus, through the use of columns flexible pipes to call PR the current formation fluid from the well decreases the intensity of the absorption of the foam reservoir or prevents the absorption of the foam reservoir, which results in the preservation of its natural permeability of the reservoir properties) of the layer.
Then call the inflow of formation fluid from a well by gas-liquid mixture flow in the annular space 14 wells 1, gradually reducing the density of the gas mixture with 850-900 kg/m3to, for example, 150-250 kg/m3by gradually increasing the degree of aeration from 5-10 m3/m3to 120-160 m3/m3i.e. increase the flow of gas generated by the gas generator 22, the booster device 23 of the booster unit 18, at a constant flow rate of an aqueous surfactant solution, such as 3 l/s, supplied by the pump 24 from the tank 21 of the booster unit 18. The circulation of the gas-liquid mixture continues booster injection unit 18 through the discharge line 17, column GT 15, the annular space 14 and its exit therefrom through the discharge line 13 (if open gate valves 12 and 16 and 19) in the chute container 11 to achieve the desired magnitude of depression (reduction of pressure in the reservoir 6) by increasing the degree of aeration and, accordingly, reduce the density of the gas-liquid mixture. Thus, produce a circulation of the gas-liquid mixture to the consumption of volume V2while track changes the depth of the remote pressure gauge 3.
For example, initially, the downhole pressure is tion was 9 MPa, as described above, and the value of the required depression (reduced pressure) in the reservoir is P=4 MPa (a specified amount of pressure determines geological survey oil and gas companies individually for each well based on the strength of cement rings for casing and other factors (see Bulatov A.I. Development wells [Text]: Ref. manual / Aijalon, Udelar, Cat: under the editorship of Arenicola R.S. - M.:OOO "Nedra-Business", 1999. - S. 473).
Then the reading distance of the depth gauge 3 should not be less than 9 MPa-4 MPa=5 MPa. Thus, gradually increasing the degree of aeration of the aqueous surfactant solution (increase of volume of gas produced by the gas generator 22 of the booster unit 18), depending on changes in reservoir pressure to achieve a valid depression on the layer 6. The presence of the inflow from the reservoir 6 is determined visually on the volume yield of formation fluids from the well into the chute container 11 together with the gas-liquid mixture. When a sufficient amount of flow of formation fluids from the well (defines geological survey oil and gas companies individually for each well depending on the previous flow rate during this drilling operation) call flow of formation fluids cease.
Production is W ill result lifting columns GT 15 of the annular space 14 of the borehole 1. Descend into the well 1 operational equipment and run it in operation.
In the call flow of formation fluids from the well monitor the change in bottom hole pressure in the well by installing at the end of the casing 2 downhole depth gauge 3.
The proposed method can improve the efficiency of the call flow of formation fluid from the reservoir. Also, the proposed method can improve the quality of the call flow of formation fluid from the reservoir by adding gas-liquid mixture of a stable condition during its circulation in the borehole, to reduce the intensity of her absorption in a given reservoir, which results in the preservation of its natural permeability of the reservoir properties) of the layer.
The way the call flow of formation fluids from the well, including the descent into the well of the column tubing - tubing, reducing the back pressure on the producing formation due to the replacement of the liquid column in the well gas-liquid mixture, subject to the required size of the depression in the reservoir, characterized in that before the descent of the casing the lower end equipped with remote depth gauge and filter, the tubing string lowered into the well so that the filter was located opposite the perforated interval of the layer, n is the following which make processing of bottom-hole formation zone of a chemical method with technological extract to the reaction, then dopuskayut the tubing so that the filter was below the soles of the reservoir, and in the annular space of the well down the column flexible tubes - GT 100 m below the liquid level in the well, install the spare column of fluid in the annular space of wells on gas-liquid mixture, continue the descent of the column of GT, upon reaching the lower end of the filter casing descent columns GT stop, and then start the call flow of formation fluids gradual decrease in the density of the injected gas-liquid mixture to achieve a desired depression in the reservoir, controlled by remote indications of the depth gauge, at the end of the call flow from the well to retrieve the column GT of the annular space well, down into the well production equipment and run well.
FIELD: oil and gas industry.
SUBSTANCE: method for increasing the extraction in the reservoir bed involves the swabbing tests in the pipe at some depth. The pipe is arranged in the well shaft. Some part of the well shaft is locate inside the reservoir bed. From time to time, pressure is measured in lower part of the pipe using a pressure gauge in order to obtain a variety of pressure measurements during the swabbing test. Pressure gauge is attached to inner wall of lower pipe part. Variety of velocities of the fluid flowing from reservoir bed is determined through perforations made in the well shaft to the pipe using the flow velocity equation and variety of pressure measurements.
EFFECT: improving the information acquisition efficiency.
20 cl, 8 dwg
FIELD: oil and gas industry.
SUBSTANCE: according to the proposed method, using geophysical equipment in several steady-state operating modes of gas well with exposure of the well in each of the modes at least for 1-3 months simultaneously with measurement of pressure and flow rate profiles in the influx zone, temperature profile is additionally measured; after that, temperature of the gas supplied to the well shaft from each operating gas formation is determined, and bottomhole pressure is fixed in the middle of depth of each operating gas formation. Besides, after the well is changed over to the next steady-state mode after the specified parameters are measured, value of effective Joule-Thomson coefficient is determined for the previous steady-state mode as per the formula. Later, considering the obtained value of effective Joule-Thomson coefficient, formation pressure, temperature and filtration coefficients are determined as per formulae.
EFFECT: improving determination accuracy of formation pressure and filtration coefficients of simultaneously operating gas formations at reduction of the number of investigations in the wells; providing the determination of formation temperature of each operating gas formation.
SUBSTANCE: device comprises a tight body suspended on a geophysical cable, where a motor is installed, as well as an electromechanical packer connected to it by means of a screw gear and a controlled valve device. At the same time the device is additionally equipped with a switching unit, installed above the electric motor, an anchor installed above the electromechanical packer, two pressure compensators, one of which is installed above the anchor, and the second one is installed below a balancing valve, a tip of a cable head installed in the lower part of the device, and a remote well tool fixed to the tip of the cable head. Besides, the switching unit and the electric motor are arranged in a tight body.
EFFECT: higher reliability of tight closure of tubing string cavity and provision for possibility to efficiently monitor pressure change when operating in wells in a depression mode.
SUBSTANCE: device comprises a body, units of driving and picking oscillations, a membrane, a line of bottomhole linkage with a wellhead, a pressure converter in the form of a multi-turn tubular spring with pins fixed on its free end, in the gap between which there is a spiral inserted from a mechanical oscillating system of balance-spiral. The free end of the spring may move along the spiral circumference, varying its operating length.
EFFECT: enhanced reliability.
FIELD: oil and gas industry.
SUBSTANCE: invention may be used in development of wells with bed pressure of 0.8-1.0 of water column hydrostatic pressure in well. Proposed method comprises running-in of tubing into well, decreasing pressure on productive bed by replacing water column with gas-fluid mix by forcing it with the help of booster unit, and providing required ratio of mix components to reach required pressure on productive bed. Note here that at bed pressure of 0.8-1.0 of water column hydrostatic pressure in well, remote-control depth gage is fitted on tubing bottom end prior to running in. Tubing run-in in well, water column is replaced with gas-fluid mix be injecting it by booster unit, said mix representing higher-density foam including surfactant with minor aeration of 5 to 7 m3/m3. Then, fluid intrusion is initiated by injecting gas-fluid mix in well annular space while higher-density foam is replaced with lower-density foam. Aeration is gradually increased control pressure on production bed to preset magnitude to be controlled by said depth gage. Reached pressure is maintained by varying injection pressure of booster unit to circular foam in volume equal to that of the well. If fluid intrusion occurs, foam in well is replaced by process fluid with density that allows maintaining bed collecting properties. Note here that in case fluid intrusion does occur, foam circulation is terminated to define acidity of well fluid by sampling bed fluid for pH-factor. Thereafter, acid composition is injected and forced into bed via tubing. Then, pause is made for 2-3 h to open tubing gate valve to repeat abode described jobs.
EFFECT: higher quality and efficiency.
FIELD: oil-and gas industry.
SUBSTANCE: set of inventions relates to development of wells. Proposed system comprises set of perforators and transducers unit. Proposed method comprises the following jobs. Lowering the system in borehole on well-logging cable, locating said system nearby processing area; perforating processing zone; injecting propping agent-bearing fluid into said area; measuring, at least, one parameter in borehole with perforator system in said fluid; transmitting said parameter via well-logging cable to monitoring system and adjustments; adjusting at least one parameter in response to said transmitted measurement for increasing efficiency and optimising collector. Note here that, at least, one parameter of perforator system is selected from the set of processing fluid components, fluid pressure, fluid properties and their combination, and displacement of perforator system.
EFFECT: accurate monitoring.
17 cl, 7 dwg
FIELD: oil and gas production.
SUBSTANCE: method to call inflow of a formation fluid from a well includes lowering of a tubing string into a well, reduction of pressure to a payout bed of liquid displacement column into a well with a gas-liquid mixture by means of its supply into an annular space with a booster device, provision of the required ratio of mixture components to achieve the specified value of pressure reduction at the payout bed. Prior to lowering into the well, a remote depth pressure gauge is installed on the lower end of the tubing string. Replacement of the entire liquid column in the well is carried out with pumping of a gas-liquid mixture (foam), including a surfactant, into the annular space with a booster device, at a low extent of aeration - 10-20 m3/m3. After appearance of foam circulation the extent of aeration is gradually increased to 150-160 m3/m3, and the average density of foam is brought to 100-120 kg/m3. Foam circulation is continued to achieve the specified value of reduced pressure at the payout bed, which is determined by readings of the remote depth pressure gauge. Afterwards foam circulation is stopped for 2-3 hours. The possible inflow of the formation fluid is determined from the well. If there is no inflow of the formation fluid, foam circulation is stopped, an annular valve is closed, and foam is pushed along the tubing string into the bed in the amount of 5-10 m3 with soaking in the bed for 3-4 hours. Afterwards the annular valve is opened, and foam circulation is restored at maximum extents of aeration to produce inflow of the formation fluid from the well.
EFFECT: increased quality and efficiency of calling for inflow of a formation fluid.
FIELD: oil and gas production.
SUBSTANCE: proposed method comprises lowing, at least, one variable-diameter pipe string into well, said pipes being provided with one or several bed-separating parkers. Pressure in every bed is defined by exposing one bed and isolating other beds from annulus of pipe string. Note here that well is encased by telescopic casing string wherein every next operating string features smaller diameter than that of previous one. Casing hangers are lowered into well depending upon the number or exposed productive beds, concentrically one into another. Note here that diameters decrease from top bed to bottom bed. Static bed pressure is measured separately for every bed at one wellhead equipped with string and tubing head with pressure measurement devices.
EFFECT: higher efficiency of measurements, reduced capital and operating costs.
FIELD: oil and gas production.
SUBSTANCE: proposed method comprises measuring gravitational field at well locations and bed pressure at well bottom, revealing dependence between said magnitudes, measuring gravitational field at earth surface in interwell space zone and defining bed pressure in said zone from derived dependencies. In the case of gas deposits, bed pressure at external boundary of reservoir in interwell space zone is defined by special equation. Note here that factors in said equation are defined from dependencies obtained experimentally for well locations between gravitational field variation during deposit development monitoring, bed pressure variation and difference between gravity difference between adjacent sets of measurements. In the case of oil deposits, bed pressure at external boundary of reservoir is defined from another special equation. Note here that factors in this equation are defined from dependencies obtained at well locations on total volume of hydrocarbons extracted from well for time t at total yield q.
EFFECT: higher accuracy and reliability.
FIELD: oil and gas industry.
SUBSTANCE: well flow rate is changed in compliance with the method for determining the profile of fluid influx and parameters of borehole environment after continuous operation of the well with constant well flow rate during the time which is sufficient to provide minimum influence of production duration on speed of the next temperature change of the fluids supplied from productive formations to the well. Pressure on working face of the well is measured before and after the flow rate is measured. Temperature of influx of fluids supplied to the well is measured for each formation. Time versus fluid influx temperature graph and derivative versus influx temperature graph is built according to the logarithm of the time that passed after the flow rate change. As per the above derivative versus temperature graphs as per time logarithm there determined are the times when temperature derivative reaches constant value, and relative flow rates of formations are calculated as per mathematical expression. As per time versus fluid influx temperature graph there determined is fluid temperature change by this time, and skin factors of formations are calculated as per mathematical expression.
EFFECT: higher determination accuracy.
FIELD: oil and gas industry.
SUBSTANCE: 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.
EFFECT: simplifying the method and reducing costs for its implementation without loss of well clay cake removal efficiency, protection of the production string against action of high pressures occurring at forcing-through of the reagent to the formation considering maximum allowable pressure on the formation during implementation of process operations, and by development of the well via the tubing with a packer.
FIELD: oil and gas industry.
SUBSTANCE: method for increasing oil recovery of the deposit in carbonate reservoirs of fracture-pore type involves formation of a group of production wells with an injection well in the centre so that the injection well can be located in the lower part of the deposit structure in relation to production wells, oil recovery from the group of wells watered out with bottom water, forced extraction of fluid from the injection well till the response of the neighbouring wells to that action and reduction of formation pressure in the area of responding production wells. After steady reduction of formation pressure in the area of responding production wells by more than 10 %, each of them is pumped with waterproof compound that is strengthened under action of chlorhydric acid in the volume of 15-20 m3. After waterproof compound is cured, forced extraction of the fluid is stopped and acid bearing compound in the volume of 0.4-1.0 m3 per metre of oil saturated part of the formation is pumped to each well treated with waterproof compound. Responding production wells are brought into operation.
EFFECT: increasing the effective operating period of wells by 18-24 months with reduction of water cutting of well production, increasing oil recovery in the deposit area.
FIELD: oil and gas industry.
SUBSTANCE: method for formation bottom-hole area treatment includes mounting of oil-well tubing in the well below perforation holes, determination of technical condition of production string and character of production formation saturation in perforation zone on the base of geological-geophysical researches data, pumping and squeezing down to the formation water solution of alkali metal supersalt with holding for reaction for 10-12 h, extraction of reaction products from bottom-hole area by well blowing by inert gas or gas from well-donor through casing annulus, pumping and squeezing down to the formation hydrogen chloride, holding for reaction for 6-8 h, well development by gas from well-donor or inert gas.
EFFECT: increase of efficiency of formation bottom-hole area treatment at stimulation of hydrocarbons influx to the well.
SUBSTANCE: invention relates to an acidic aqueous solution containing a chelating agent and an acid, wherein the chelating agent is glutamic N,N-diacetic acid (GLDA) or a salt thereof and wherein the amount of GLDA or the salt thereof is 20-60 wt %, based on the weight of the aqueous solution, and wherein the acid is selected from hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, sulphuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, tartaric acid, maleic acid, boric acid, hydrogen sulphide or a mixture of two or more of these acids, and use of said solution in cleaning processes, precipitation processes or processes of removing salt deposits, at oil fields in completion and stimulation by acid treatment, fracturing and/or deposit removal. The acidic aqueous solution has pH below 3.
EFFECT: obtaining a solution with a higher acidic pH and higher content of biodegradable highly soluble chelating agent.
4 cl, 2 dwg
FIELD: oil and gas industry.
SUBSTANCE: according to the method of development of bottom-hole zone of terrigenous oil formation, before pumping of acid solution well is killed by solution of alkali metal hydroxide adding potassium and/or natrium chloride in quantity 0-35 wt % to obtain optimum density of composition, then well is pumped with aqueous solution containing 4-8 wt % of chlorhydric acid and 0.5-1.5 wt % of fluorhydric acid adding versene (trilon "B") in quantity 0.01-0.5 wt %, sodium dodecylsulfate in quantity 0.01-0.1 wt %, then aqueous solution of oil wetting agent NG-1 with concentration 0.01-2 wt % is pumped into formation.
EFFECT: improving efficiency of development of bottom-hole formation zone due to prevention of sedimentation of reaction products of solution chlorhydric and fluorhydric acid with rock of bottom-hole formation zone, reducing water content of well products due to modification of reservoir rock wetting, hardening of porous medium due to use of hydrophobisated reagents.
FIELD: oil and gas industry.
SUBSTANCE: method of well bore zone treatment of production well involves determination of material composition of formation rock in the treated zone by means of carbon-oxygen logging (COL) immediately after the well drilling, at the following formation rock component ratio: quartz - not more than 50 wt %, clay - more than 10 wt %, and content of a layer of bitumen-resin-paraffin substances in oil of more than 30 wt %, and temperature in the well bore zone of 80-100°C; as treatment agent, Khimeko TK-3 acid composition diluted with hydrochloric acid (3%) is used in the ratio with the latter of 1:(2÷4) by weight respectively.
EFFECT: improving the efficiency of the method due to possible quick acquisition of information on the state of well bore zone, up to its composition, and directed action on the treated medium of production well.
5 cl, 1 ex
FIELD: oil and gas industry.
SUBSTANCE: treatment method of bottom-hole zone of horizontal or inclined well involves well treatment with the liquid providing the absence of absorption; viscous oil or fuel oil is used as the above liquid; then, the well is flushed with gas condensate; solution of acid is pumped to productive formation; technological exposure is performed for reaction of the acid solution; hydrocarbon solvent is pumped to perform the well flushing from residues of viscous oil or fuel oil and reaction products; well is developed by means of inert gas or gas from donor well.
EFFECT: increasing treatment efficiency of bottom-hole zone of formation of horizontal and inclined wells at intensification of hydrocarbon inflow.
FIELD: oil and gas industry.
SUBSTANCE: well bore zone treatment method involves determination of formation rock composition in the treated zone by means of carbon-oxygen logging (COL) immediately after well drilling and at content of carbonates in the formation rock of more than 5 wt %, irrespective of clay and quartz content, brine water mineralisation of 200-250 g/l, iron content of 2000-5000 ppm, content of layer of bitumen-resin-paraffin substances in oil, which is equal to 30-40 wt %, and well bore zone temperature of 60-160°C; treatment agent there used is the solution of "Khimeko TK-2K" Intensifying Compound in the ratio of the latter and the solvent equalling to 1:(1-5) by weight respectively.
EFFECT: improving the efficiency of the method due to possible quick acquisition of information on the state of well bore zone, up to its composition, and directed action on the treated medium.
7 cl, 1 ex
FIELD: oil and gas industry.
SUBSTANCE: bottom-hole zone treatment method involves the transportation to the working face of the device by means of a wireline, which consists of an air chamber ending with a receiving chamber with the composition located in it and generating the gas during combustion, which releases the mixture of chlorhydric and hydrofluoric acids at thermal destruction, combustion of gas-generating composition and formation of heated gaseous products at increased pressure at treatment interval, process exposure for deeper reaction of chlorhydric acid with the rock, opening of the air chamber at the specified time period due to operation of the combustible diaphragm with igniter, which is installed at its bottom, and export of contaminants from the bottom-hole zone; as the above gas-generating composition there used is the mixture containing the following, wt %: ammonium nitrite grade B 32-33, hexachloroethane 51-53, plastic fluor FP-4 15-16.
EFFECT: increasing the treatment efficiency of bottom-hole zone composed both of terrigenous rocks, and carbonate rocks contaminated with silicate deposits.
FIELD: oil-and-gas industry.
SUBSTANCE: invention relates to oil industry. Proposed method comprises injection and driving acid agent into productive bed, process holding and extracting the products by depression effects. Note here that said acid agent comprises the following components in wt%: halogen acid - 0.5-5.0, acetic, or citric, or boric, or formic, or chloroacetic, or alkyl benzene sulfonic acid - 8.0-85.0, surfactant - 0.2-5.0, complexing agent - 0.1-1.0, water making the rest. In compliance with second version, prior to injecting said acid agent, bed is subjected to implosion effects.
EFFECT: higher yield and injectivity, intensified fluid influx from productive bed.
2 cl, 2 tbl, 9 ex
FIELD: oil and gas industry.
SUBSTANCE: stimulation method of formation fluid influx from a well involves lowering to the well of a tubing string, reduction of counter pressure on a productive formation due to replacement of a fluid column in the well with liquid-gas mixture (LGM) at observance of the required value of depression on the productive formation. Prior to lowering to the well of the tubing string, the latter is equipped in an upward direction with a remote subsurface pressure gauge installed in a plugged container, a filter and a packer. The tubing string is lowered to the well so that the filter can be arranged opposite the formation bottom. The packer is put 5-10 m above the formation roof. Treatment of the bottom-hole zone of the formation is performed by pumping via the tubing string of a hydrocarbon solvent and by its forcing into the formation with process liquid. Process exposure for reaction is performed. At that, during process exposure for 1.5-2 hours, there unpacked is the packer, and in 3-4 cycles in every 0.5 hour, process liquid in the volume of 0.5-0.8 m3 is pumped in turn to the tubing string and to the inter-string space of the well. The packer is put again upon completion of process exposure. Into inner space of the tubing string there lowered is a string of flexible tubes (FT) so that its lower end is on the liquid level in the well. After that, the space on the wellhead is sealed between the tubing string and the string of flexible tubes. Then, with stops in every 200-300 m there lowered is a string of flexible tubes into the tubing string until lower end of the string of flexible tubes reaches the filter. Replacement of well fluid with LGM is performed in inner space of the tubing string during stops and during lowering process of FT in equal LGM volumes.
EFFECT: increasing efficiency and quality of simulation of formation fluid influx from productive formation, reducing LGM pumping volumes and intensity of LGM absorption with the productive formation.