Stimulation method of formation fluid influx from well. RU patent 2485305.
 Method and system for interpretation of swabbing tests using non-linear regression / 2474682Method 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. |
 Method for determining main parameters of simultaneously operating gas formations / 2473803According 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. |
 Device for hydrodynamic monitoring of wells / 2471984Device 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. |
 Device to measure pressure of drilling mud in well / 2471983Device 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. |
 Method of causing fluid intrusion from well / 2470150Invention 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. |
 Methods of controlling operation of perforators system in borehole, underground bed fissuring and processing / 2467160Set 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. |
 Method to call inflow of formation fluid from well / 2466272Method 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. |
 Method of defining bed pressure in development of multiple-bed gas and gas condensate deposits / 2465454Proposed 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. |
 Method of defining pressure in interwell space / 2465453Proposed 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. |
 Method for determining profile of fluid influx and parameters of borehole environment / 2460878Well 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. |
| 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 for increasing oil recovery of deposit in carbonate reservoirs of fracture-pore type / 2482269 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. |
| Method for bottom-hole zone treatment / 2477787 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. |
 Acidic aqueous solution containing chelating agent and use thereof / 2476475Invention 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. |
 Development method of bottom-hole zone of terrigenous oil formation / 2475638According 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. |
| Method of well bore zone treatment of production well / 2473800 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. |
 Treatment method of bottom-hole zone of horizontal or inclined well / 2471978Treatment 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. |
| Well bore zone treatment method / 2469190 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. |
| Development method of bottom-hole zone / 2469189 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. |
 Method of bottom hole formation zone processing / 2467164Invention 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. |
 Stimulation method of formation fluid influx from well / 2485302Stimulation 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. |
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.
2 dwg
Field : oil producing industry; applicable when the producing wells.
There is a method of development wells creation of depression on a layer (patent RU №2272897, IPC 21 43/18; In 43/27, publ. 27.03.2006, bul. №9), which includes replacement downhole fluid on a solution of a surface-active substance (SAS) with its subsequent by filing into the well of blowing agent in the form of ammonium carbonate, before submission of blowing agents bottomhole zone is subjected to acid treatment with a squeeze of reagent slug acid into the reservoir as reagents- the additional use of water solutions of sodium nitrate NaNO 2 and hydrochloric acid HCl; aqueous solutions of reagents- upload portions of 0.5-2.0 m 3 in the following sequence: ammonium carbonate hydrochloric acid, sodium nitrite, each subsequent solution has a density greater than the previous one, the volume of injected of the reactants is 0.3 to 1.0 volume of the well, but at least 1.1 times the internal volume of the discharge column, and due to the useful volume of the well, and the solution of surface-active substances additionally contains a hollow glass microspheres.
The disadvantage of this method is that flash surfactant solution takes place directly in the well by the filing of blowing agents in the bottom-hole zone, change the sequence of the flow of chemical reactions and temperature mode may lead to a change in the physical and chemical properties of the replacement fluids, including decomposition of carbonated liquid gas and water, and generally reduces the quality of development wells.
Also known method of stimulation of formation fluids from the well (... Drilling and operation of oil and gas wells. - M: Nedra, 1982, .270-271), including the reduction of pressure on the reservoir by filing it with the surface of a gas or gas mixture and replacement of the liquid column in the borehole liquid-gas mixture, the gas is fed by the compressor.
Disadvantages of this method are:
- first, the need for a compressor - neutral source of fire and explosion in the conditions of high-pressure gas wells;
- secondly, the compressor can't push all column of liquid in a well, so mastered falls in stages, that delays the process of stimulation of formation fluids from the well.
The closest is essentially a technical method stimulation of formation fluids from the well (patent RU №2263206, IPC 21 43/25, publ. 27.10.2005, in Bulletin. №30), including the reduction of pressure on productive formation replacement column of fluid in the borehole liquid-gas mixture by filing a mixture Assembly with the selection of the components of the mixture of operating well or a reservoir collection of products, with the required ratio of the mix to achieve a given value of the pressure reduction in the reservoir provide a selection of the components of the mixture through a separator, the outputs of which communicated with the collector collection of products.
Disadvantages of this method are:
- firstly, the low quality of the influx from the reservoir well, due to the unstable state of the gas-liquid mixture due to premature destruction;
- secondly, the absorption of the liquid-gas mixture and its components reservoir in the process of replacement of fluids in the well of the gas-liquid mixture and, as consequence, decrease in natural permeability of reservoir properties) formation;
- third, almost impossible to find the desired ratio of components of liquid-gas mixture to achieve the desired depression on a layer, not owning the indications of changing the values of hydrostatic pressure in the process of stimulation of fluid from the reservoir;
- fourth, the low efficiency of stimulation due to rapid the reduction in flow rate or given the debit of the well when calling inflow of formation fluid from the borehole.
The objectives of the invention are to increase the efficiency and quality of stimulation of formation fluid from the reservoir, as well as the exclusion of premature destruction of liquid-gas mix in the process of work and reduce the intensity of absorption of the liquid-gas mixture reservoir controlled hydrostatic pressure in the process of stimulation of formation fluids from the well.
The problem is solved by way of stimulation of formation fluid out of the well, including descent in well tubing pipes, tubing, reducing the pressure on the reservoir due to the replacement of the liquid column in the borehole liquid-gas mixture at observance of the required value depression for the reservoir.
What is new is that before the descent of the casing the lower end of its equip remote depth gauge and a filter, the drill pipe descend into the well so that the filter was opposite the perforation interval reservoir, then make processing of bottom-hole formation zone chemical method technological exposure on the reaction, then the tubing string so that the filter was below the base of the reservoir and in the annulus of the well being pushed convoy flexible pipes - GT - 100 m below the level of the fluid in the borehole, produce the replacement of the liquid column in space wells at gas-liquid mixture, continue the descent of the column GT, when you reach the lower end of the filter casing tubing descent columns GT stop, then start to call flow formation fluid gradual decrease in the density of pumped liquid-gas mixture to achieve the desired depression for the reservoir, controlled by indications remote depth gauge, at the end of the influx of well retrieve column GT of inter-casing space wells, descend into the well production equipment and run well at work.
In the figures 1 and 2 in series diagrams are ways to call the inflow of formation fluid from the borehole.
The proposed method is as follows.
It is known that during well operation there is a decrease in the inflow of formation fluid to the face of the production well, owing to the deterioration of the permeability of the bottomhole formation zone (PPP), in this connection there arises the need to restore the inflow of formation fluid to the face of the production well. To do this, stop the production well 1 (see figure 1), remove the operational equipment (for example, a column of pipes with pump) (figures 1 and 2 is not shown). Before descending the tubing 2 on the lower end of its consistently upward establish remote depth gauge 3, for example, in the damped container to avoid damage during operation (not shown in figure 1), and then filter 4 (see figure 1). After that, down in the hole 1 column of pump-compressor pipes (NKT) 2, descent tubing exercise 2 so that the filter 4 was in the range between the roof of the 5' and 5 soles", i.e. was placed opposite the perforation interval reservoir 6. For example, if the perforation interval layer 6 is 3 m and the height of the filter 4 shall not be less than 3 m
Then chemically make processing of bottom-hole zone 7 layer 6. Filter 4 allows the injection of a chemical agent (e.g. acid, hydrocarbon solvent) on treatment of bottomhole zone 7 layer 6 chemical method. In addition, the presence of a filter 4 allows to place the lower end of the tubing 2 remote depth gauge 3, by which control the pressure in the process of stimulation of formation fluids from the well.
For this wellhead 1 (see figure 1) the discharge line 8 pump unit 9 (for example, CA-320) tied with the internal space of 10 tubing 2. Next, using a pump unit 9 through inner space of 10 tubing 2 and filter 4 have pumped bottomhole zone 7 layer 6, for example, hydrocarbon solvent (ie establish a bath of hydrocarbon solvent). As a hydrocarbon solvent used, for example, Nefras-With 150/200 TU 38.40125-82 or Nefras-Ar 120/200 TU 38.101809-80. The estimated number of hydrocarbon solvent determine empirically individually for each well depending on the permeability, porosity, degree contamination, but not less than the volume of the well from the face to the roof, 5' reservoir 6 and is calculated by the formula:
where P=3,14;
V p - estimated amount of hydrocarbon solvent, m 3 ;
D - internal diameter of the casing string wells, m;
h is the distance from the face to the roof, 5' reservoir 6, m
For example, when distance h=50 m and the inner diameter of the casing string D=168 mm(9 mm·2)=150 mm=0,15 m define necessary volume of hydrocarbon solvent (V p ) for bath:
V p =3,14·(0.15 m) 2 /4·50 m=0.9 m 3
Produce the technological holding due, for example, 12 hours on the reaction hydrocarbon solvent to dissolve wax-gummy deposits in the bottom hole zone 7 layer 6, dismantle the discharge line 8 and pump unit 9.
Produce obvjazku ground equipment as shown in figure 2. Then the drill pipe 2 (see figure 2) to filter 4 was below the base of the reservoir 6, then the inner space of 10 tubing 2 tie with flowline capacity of 11 wellhead 1 through 12 valve and flow line 13, the indications remote depth gauge 3) are, for example, 9 MPa.
Wellhead 1 prepared a gas-liquid mixture, which is an aqueous solution of surface-active agent (surfactant), which is used as a foaming agent.
The required volume of the aqueous solution surfactants for stimulation of formation fluid from the borehole determined by the multiplicity of the gas-liquid mixture, which is 3.5-5 in the process of stimulation of formation fluid out of the well, as well as of the required volume of the liquid-gas mixture V g , resulting from volume V 1 inter-casing space of 14 wells 1 to replace the fluid in the borehole at gas-liquid mixture before the call flow and volume V 2 inter-casing space of 14 wells 1 for circulation of liquid-gas mixture in the process of stimulation of formation fluids from the well. These volumes are equal, i.e. two equal volumes of one well, namely: V 1 =V 2 , V =2·V 1 , take foam multiplicity equal to 4, then the volume of water solution of surfactants is determined by the formula:
where V - volume of water solution of surfactants, m 3 ;
V 1 - volume of inter-casing wells, m 3 .
For example, if the height of the column of fluid from the reservoir to the mouth N=1600 m and the diameter of the casing string 168 x 9 mm volume liquid-gas mixture for the entire process of stimulation is determined by the formula:
where P=3,14;
V 1 - volume of inter-casing space wells, m 3 ;
D - internal diameter of the casing string wells, m:
D=168 mm(9 mm·2)=150 mm=0,15 m
d - outer diameter of the tubing, for example, 73 mm=0,073 m;
H - height of the column of liquid from the mouth to the slaughter, m, for example, N=1600 m
Then, substituting in the formula (3): V 1 =(3,14·(0.15 m) 2 -(0,073) 2 /4)·1600 m=21.6 m 3 , and the required volume of the liquid-gas mixture: a V g =2V 1 =2·21.6 m 3 =43,2 m 3 .
Then the required amount of water solution of surfactants is determined by the formula (2):
Substituting numeric values, we get: V =V g /4=43,2 m 3 /4=10,8 m 3 , take the volume of water solution of surfactants equal 10,8 m 3 .
To increase stability of the liquid-gas mixture in the water solution of PEAHENS add stabilizer - 1%solution of CMC-700 with the addition of 2%COP1 GOST 4234-77.
CMC-700 - sodium salt of a simple ether of cellulose and glycolic acid-polymer company MI Drilling Fluids (the USA). Practical experience has shown that the stability of the liquid-gas mixture with the addition of a stabilizer increases in 5-9 times. Stabilizer is prepared as follows.
Freshwater p=1000 kg/m 3 (heated to 40-45 degrees) With added with constant stirring CMC-700, the process of its complete dissolution of 2.0-2.5 h, the next in the prepared solution add 2%KCl in a dry kind, mix until dissolved. The calculated volume of water solution of PEAHENS add obtained stabilizer, stirred for another 20-30 minutes
In quality of PEAHENS are used, for example, (TU 6-01-862-73) in a concentration of 0,1-0,3% of the volume of fresh water or other drugs, such as OP-7; OP-10 (according to the TU 8433-81) at a concentration of 0.3-0.6% of the volume of fresh water.
Fill capacity 21 booster unit 18 aqueous solution surfactants (see figure 2).
Water solution of PEAHENS preclude the premature destruction of the liquid-gas mixture in the process of work to the surface wells 1, i.e. becomes more stable. As a gas, secure under the terms of the ignition hydrocarbon medium is used generated by core 22 booster unit 18 gas (e.g. nitrogen), as a result of the combustion of fuel (gasoline, diesel fuel) in compressed air, i.e. burnout oxygen.
Gas from core 22 served in (mixing) device 23, where there is a continuous mixing gas with the process fluid in the form of water solution of surfactants (with the formation of the liquid-gas mixture), the water solution of PEAHENS served with a constant flow rate, such as 3 l/s pump 24 of capacity 21 booster unit 18. Open 12, injection 16 and 19 Central valves and through the discharge line 17 unit 18 serves gas-liquid mixture (higher density) in column 9 GT, the density of which is, for example, 850-900 kg/m 3 .
The convoy GT 15 in the annulus 14 wells 1 to replace the liquid column in the borehole pump gas-liquid mixture density of 850-900 kg/m 3 , which is provided with a minimum degree of aeration of water solution of surfactants, for example, 5-10 m 3 /m 3 . Continue the descent of the column GT 15, the lower end of which is submerged under the level of the fluid in the borehole 1 100 m at a rate of 0.5-1 m/s (figures 1 and 2 is not shown), but do not exceed the maximum permissible pressure of ventilator unit 18 (see figure 2), for example 15 MPa. At the moment when the displaced liquid-gas mixture fluid in the borehole will reach the mouth of the well 1, of the inter-casing space 14 through valve 12 and the surface line 13 in capacity of 11 begins spout borehole fluid displaced liquid-gas mixture.
As you descend columns GT 15 in the well 1 and injection of the liquid-gas mixture in the annulus 14 replace the fluids in column spacing 14 and in the inner space of 10 tubing 2 wells 1, i.e. the gas-liquid mixture greater density in the volume of well 1 (V 1 =21.6 m 3 ), the monitor readings remote depth gauge 3, the value of which is gradually decreasing. When the lower end of the column GT 15 reaches the lower end of the filter 4 tubing 2, descent columns GT 15 ceased. Since the filter 4 tubing 2 is below sole reservoir 6, under such conditions, in the bottomhole formation zone penetrates the minimum number of gas-liquid mixture, and its component composition allows to reduce the intensity of the absorption of the liquid-gas mixture reservoir or completely prevent its absorption reservoir for resulting in the preservation of its natural permeability of reservoir properties).
Thus, through the use of flexible pipe string for stimulation of formation fluids from the well decreases the intensity of absorption of foam reservoir or prevents the absorption of foam reservoir as a result of the preservation of its natural permeability of reservoir properties) formation.
Then call the inflow of formation fluid from the borehole submission of gas-liquid mixture into the annulus 14 wells 1, gradually reducing the density of the liquid-gas mixture 850-900 kg/m 3 to, for example, 150-250 kg/m 3 by a gradual increase in the degree of aeration from 5-10 m 3 /m 3 to 120-160 m 3 /m 3 , i.e. increase the flow of gas produced by 22, device 23 booster unit 18, on constant flow of water solution of surfactants, such as 3 l/C, pumped 24 from capacity 21 booster unit 18. The circulation of liquid-gas mixture continue pumping unit 18 on the discharge line 17, column 15 GT, space of 14 and access it from there through the surface line 13 (open gate valves 12 and 16 and 19) in capacity of 11 until you reach the desired value depression (pressure reduction in the reservoir 6) by increasing the degree of aeration and, accordingly, reduce the density of the liquid-gas mixture. Thus, produce circulation of liquid-gas mixture until exhausted, volume V 2 , track changes indications of the deep remote gauge 3.
For example, initially the bottom hole pressure was 9 MPa as specified above, and the value of the required depression (pressure reduction) the reservoir is P=4 MPa (specified amount of pressure reduction determines the geological survey of oil and gas producing enterprise individually for each well, depending on the strength of the cement ring for casing and other factors (see A. I. Bulatov Well development [Text]: Ref. manual / ..Б, .., ..: Ed. R.S. - M OOO «Nedra-Business», 1999. - 473 C.).
Then testimony remote depth gauge 3 should not be lower than 9 MPa-4 MPa=5 MPa. Thus, gradually increasing the degree of aeration of water solution of surfactants (increase of the volume of gas produced 22 booster unit 18), depending on changes in the reservoir pressure achieve permitted depression on the layer 6. The presence of the inflow from the reservoir 6 is determined visually on the volume yield formation fluid from the borehole in capacity of 11 together with the gas-liquid mixture. When sufficient largest inflow of formation fluid from the borehole (defines the geological survey of oil and gas producing enterprise individually for each well, depending on the previous output during operation of the wells) call flow formation fluid cease.
Produce lift columns GT 15 of the inter-casing space of 14 wells 1. Down in the hole 1 operational equipment and launch her in the work.
In the process of stimulation of formation fluid from the borehole exercise control over the change of the downhole pressure in the well, thanks to the installation of the end of the tubing 2 hydrostatic depth gauge 3.
The proposed method allows to increase efficiency of stimulation of formation fluid from the reservoir. Also the proposed method allows to improve the quality stimulation of formation fluid from the reservoir by a gas-liquid mixture of stable condition in the process of its circulation in the hole, the lower the intensity of its absorption reservoir as a result of the preservation of its natural permeability of reservoir properties) formation.
The method of stimulation of formation fluid out of the well, including the descent into the well tubing pipes, tubing, reducing the pressure on the reservoir due to the replacement of the liquid column in the borehole liquid-gas mixture is subject to the required size depression on productive formation, characterized in that before the descent of the casing the lower end of its equip remote depth gauge and a filter, the drill pipe descend into the well so that the filter was opposite the perforation interval reservoir, then make processing of bottom-hole zone reservoir chemical method technological exposure on the reaction, then the tubing string so that the filter was below the base of the reservoir and in the annulus of the well being pushed convoy flexible pipes - GT 100 m below the level of the fluid in the borehole, produce the replacement of the liquid column in column spacing of wells at gas-liquid mixture, continue the descent of the column GT, when you reach the lower end of the filter tubing descent columns GT stop, then start to call flow formation fluid gradual decrease in the density of pumped liquid-gas mixture to achieve required depression for the reservoir, controlled by indications remote depth gauge, at the end of the influx of well retrieve column GT of inter-casing space wells, descend into the well production equipment and run well at work.