Well operation stimulation

FIELD: oil and gas industry.

SUBSTANCE: method comprises test forcing of fracturing fluid and pile of fracturing fluid with proppant, correcting the fracturing project and performing of the main fracturing process. In highly permeable reservoirs with absolute permeability not less than 100 mD the main fracturing process is carried out with usage of proppant fractions, which include initial fraction with mesh size from 30/40 up to 20/40 and the main coarse fraction with mesh size of 12/18 and more in the volume not less than 70% of the total proppant quantity with final proppant concentration not less than 750 kg/m3. While injecting fraction with mesh size of 12/18 and more through perforated openings fluid consumption is set so that it does not exceed 3 m3/min and wellhead pressure is maintained at the level less than 35 MPa.

EFFECT: improving the efficiency of hydraulic fracturing for highly permeable strata.

1 tbl

 

The invention relates to the oil industry and can be used with the intensification of the work of the well uncovered reservoir with high permeability header.

There is a method of hydraulic fracturing, in which pre-produce technical analysis water testing gelling on the solubility and structure formation, when a satisfactory result is dissolved gelling in water and re-test structure, with satisfactory results in the solution of gelling in water add stabilizer clays, the demulsifier and the control of destruction, pumped into the well the resulting solution and in the process of injection solution is injected, the destructor and the stapler, thereby forming the liquid gap filling replace the volume of the well to the fluid gap, stop the injection and record the decrease of pressure, resume pumping of fracturing fluid with a work flow on hydraulic fracturing, download "cushion" of fracturing fluid in an amount of from 3 to 6 m3then perform the download trial pack of fracturing fluid with proppant weight up to 1 ton with a concentration of from 30 to 200 kg/m3, bring it to the perforated interval, mark the initial wellhead pressure and then register the nature of its changes in the process of passing the bundle through the perforation interval and motion e is on crack the stack push fluid gap without proppant in the amount of 1.5-1.8 m3produce a displacement of fracturing fluid in an amount equal to the volume of the column tubing, podvecerni zone up to the roof of the perforation interval and another 2-4 m3, stop the displacement and write recession pressure, write and treatment intensity reduction wellhead pressure, the obtained data is processed, receive data about the effectiveness of fracturing fluid, the pressure value, the voltage gradient in the reservoir, the time and pressure of clamping cracks, pore pressure in the reservoir, the hydraulic pressure losses in the perforated interval and the bottom of the reservoir, on the basis of the received data to produce the adaptation of the design data, process of hydraulic fracturing to the received data processing the test injection, the correction data is used to re-calculate the three-dimensional models of fracture and conduct an updated version of the frac change the original plan for the main process of hydraulic fracturing by replacing the original data mining and geological factors on the program after the process of the test injection, spend the amended basic process of hydraulic fracturing, when conducting the modified main process of hydraulic fracturing on the basis of the produced p the accounts produce a set of necessary volume of process water and cooking gel testing, upon satisfactory test results, the process of hydraulic fracturing is carried out in accordance with the modified plan, where the amount of the final produce defined as the sum of the volume of the column tubing and podvecerni zone to the top of the perforated interval, the detection of growth wellhead pressure during injection trial packs of fracturing fluid with proppant in size from 1 to 2.5 MPa increase the volume of the injected proppant small and medium fraction 20/40, 16/30 and 16/20 mesh at minimum concentrations of from 30 to 120 kg/m3up to 800-1000 kg on stage, the efficiency of this measure assess to reduce wellhead pressure by passing this pack of proppant through the perforations and by reducing the pressure to 1 MPa conclude that hydraulic communication with the reservoir and improved the process of hydraulic fracturing should be performed according to the planned parameters according to the revised plan, in the absence of signs of recovery in connection with the formation of the concentration of proppant in the following stages lower, limited to maximum values of up to 350-400 kg/m3injection propane-gel mixture execute two portions, the first portion of the dosage destructor carried out according to the concentration, which provides a complete decomposition of the gel, and the time of closing cracks of not less than 12 hours, the second portion of the dosage des is rector carried out according to the concentration ensuring the process is complete decomposition of the gel, and the time of closing cracks not more than 4 hours after injection propane-gel mixture pumps stop and record the decrease of pressure for more information about the quality of the process of hydraulic fracturing, the intensity of the decrease of pressure, the presence of residual communication with the reservoir, the absence of the effect of preproduce, after which the wellhead is closed, the hole is left for the expectations of decrease of pressure, after the necessary time for the destruction of the gel to produce the etching residual wellhead pressure to atmospheric, the beginning of the bleed excess pressure is produced after 4 hours, at pressures above 4 MPa wellhead gauge drain produced with a flow rate of 30 l/min to atmospheric, and at a pressure of less than 4 MPa wellhead gauge drain produce a full opening of the wellhead valves, wellhead lasermedizin produce failure of the packer and the rise of underground equipment (RF patent No. 2453694, publ. 20.06.2012).

The closest to the proposed invention the technical essence is a method of hydraulic fracturing, according to which pre-produce technical analysis water testing gelling on the solubility and structure formation, when a satisfactory cut is ltate dissolve the gel in water and re-test structure, if satisfactory results in the solution of gelling in water add stabilizer clays, the demulsifier and the control of destruction, pumped into the well the resulting solution and in the process of injection solution is injected, the destructor and the stapler, thereby forming the liquid gap filling replace the volume of the well to the fluid gap, stop the injection and record the pressure decline, resume the injection of fracturing fluid with a work flow on hydraulic fracturing, download "cushion" of fracturing fluid in an amount of from 3 to 6 m3then perform the download trial pack of fracturing fluid with proppant weight up to 1 ton with a concentration of from 30 to 200 kg/m3, bring it to the perforated interval, mark the initial wellhead pressure and then register the nature of its changes in the process of passing the bundle through the perforation interval and the movement of her crack, the stack pushes the fluid gap without proppant in the amount of 1.5-1.8 m3produce a displacement of fracturing fluid in an amount equal to the volume of the column tubing, podvecerni zone up to the roof of the perforation interval and another 2-4 m3, stop the displacement and write recession pressure, write and treatment intensity reduction wellhead pressure, the obtained data is processed, receive data on the effectiveness of the work is s frac fluid, the pressure value, the voltage gradient in the reservoir, the time and pressure of clamping cracks, pore pressure in the reservoir, the hydraulic pressure losses in the perforated interval and the bottom of the reservoir, on the basis of the received data to produce the adaptation of the design data, process of hydraulic fracturing to the received data processing the test injection, the correction data is used to re-calculate the three-dimensional models of fracture and conduct an updated version of the fracturing change the original plan for the main process of hydraulic fracturing by replacing the original data mining and geological factors on the program after the process of the test injection, spend the amended basic process of hydraulic fracturing, when conducting the modified main process of hydraulic fracturing on the basis of calculations produce a set of necessary volume of process water and cooking gel testing, satisfactory test results, the process of hydraulic fracturing is carried out in accordance with the modified plan, where the amount of the final produce defined as the sum of the volume of the column tubing and podvecerni zone to the top of the perforated interval, the injection propane-gel mixture execute two portions, the first portion sets the end is the acidity of proppant to 300 kg/m 3the dosage destructor carried out according to the concentration, which provides a complete decomposition of the gel and the time of closing cracks of not less than 12 hours, a second portion set the proppant concentration in excess of 300 kg/m3the dosage destructor carried out according to the concentration, which provides a complete decomposition of the gel and the time of closing cracks not more than 4 hours, at the end of produce proppant-gel mixture pumps stop and record the decrease of pressure for more information about the quality of the process of hydraulic fracturing, the intensity of the decrease of pressure, the presence of residual communication with the reservoir, the absence of the effect of preproduce, after which the wellhead is closed, the equipment is removed and the well is left for expectations of decrease of pressure, after the necessary time for the destruction of the gel to produce the etching residual wellhead pressure to atmospheric, start bleed excess pressure is produced after 4 hours, at a pressure of more than 4 MPa wellhead gauge drain produced with a flow rate of 30 l/min to atmospheric, and at a pressure of less than 4 MPa wellhead gauge drain is a full opening of the wellhead valves, wellhead lasermedizin produce failure of the packer and the rise of underground equipment is based (RF patent №2453695, publ. 20.06.2012 - prototype).

A disadvantage of known methods is that the methods are successfully and effectively applicable at break permeable and sredneprotsentnyh layers, while in high-permeability reservoirs for the hydraulic fracturing does not provide adequate conductivity cracks. This may be a limiting factor for increasing the productivity of wells, so that the efficiency of hydraulic fracturing becomes low.

In the proposed invention solves the problem of intensification of wells that discover high-permeability layer.

The task is solved in that in the method of intensifying the work of wells, including test pumping of fracturing fluid and a pack of fracturing fluid with proppant, the adjustment of the draft gap and carrying out the basic process of the gap, according to the invention, in high-permeability reservoirs, with an absolute permeability of not less than 100 MD, conduct basic process of hydraulic fracturing using fractions of proppant, which includes the initial fraction dimension from 30/40 to 20/40 mesh and the main large fraction dimension 12/18 mesh and more in the amount of not less than 70% of the total proppant with the ultimate proppant concentration not less than 750 kg/m3the fluid flow when pumping faction 12/18 mesh and more through the perforations established which indicate no more than 3 m 3/min, and wellhead pressure support is not more than 35 MPa.

The invention

According to the proposed method candidates for hydraulic fracturing are high-permeability reservoirs, represented by sandstones, seal off sandstones and siltstones. The effective power of such layers is not less than 3 m, the absolute permeability is not less than 100 MD. When conducting a standard EMG data collectors increment of the crack gap happens all the time, the result is a long and narrow channel low conductivity. The contrast in permeability between the reservoir and separated by a crack is the determining factor. In weakly and sredneprotsentnyh reservoirs development of cracks in length without creating a high final concentration of proppant packs can increase the productivity of the well. However, in highly permeable formations lack the final concentration of proppant conductivity and cracks are a limiting factor for increasing the productivity of wells, thereby not produced the full potential of high-permeability layer. In the proposed invention solves the problem of intensification of wells that discover high-permeability layer.

The problem is solved as follows.

Typically, the fracturing is performed with the use of proppant three coat is s: 20/40 mesh 10-20%, 16/20 mesh 60-80%, 12/18 mesh - 10-20%. Fraction of proppant 16/20 mesh is primary in relation to the entire volume of proppant, larger (12/18 mesh and larger) and, accordingly, more conducted at the final stage is smaller, the result is fixing the cracks of a large fraction only in the vicinity of the part and unevenly along the length of the created cracks.

For the more effective carrying out of hydraulic fracturing with a permeability of more than 100 MD are encouraged to apply early in the fraction of proppant dimension from 30/60 to 20/40 mesh in the amount of from 10 to 30% of the total proppant, and the primary type to apply the proppant faction 12/18 mesh and above in the amount of from 70 to 90% of the total volume of proppant. Conducting hydraulic fracturing should be done with the proppant concentration is not less than 750 kg/m3. The use of high concentrations of proppant (more than 750 kg/m3) is connected with the necessity of creating a conductive cracks and vast development of its width, to increase the productivity of wells, in contrast to the standard fracturing.

For exceptions process "stop" and obtaining complications when pumping through the perforations of proppant dimension 12/18 mesh or more, the fluid flow may not support more than 3 m3/min, and wellhead pressure limit value not exceeding 35 MPa.

P is redlagaemyi method allows to increase the width and conductivity of fixed cracks in the bottom of the reservoir. Created and fixed the crack of the proposed method can significantly increase the productivity of high-permeability layers, to create a super-conducting channels, fixed throughout the thickness of the reservoir, to maximize the potential of the well.

Specific example

Example 1. Spend intensification of work of the oil wells.

Objects intensification: layers TV and DG at intervals 1634-1636 m, 1638-1642,6 m, the layers are separated between a clay jumper thickness of 2 m, the distance to the water-saturated layer of 16.2 m

Lithology of interest: the top layer of siltstone (absolute permeability, MD 23, porosity of 12.9%, clay content of 18.4%); the lower (main) formation - siltstone (absolute permeability 227,6 MD, porosity of 18.4%, clay content of 7.4%).

Well design and deflated equipment: production column with a diameter of 146 mm sealed.

Down the tubing, hold the landfilling of bottom sandy bridge to a depth of 1647 m

Lower packer on the tubing pipes with a diameter of 89 mm depth 1615 m and produce planting packer.

Conduct a test injection. The initial acceleration of the object frac Q-360 m3/day, initial pressure Rnac=9 MPa, the ultimate pressure Rcon=9 MPa. Perform the determination of the quality of communication with the reservoir by injection of 5 m3technical eskay fluid density of 1.15 g/cm 3without pre-saturation of the bottomhole zone.

Fracturing produce sampling industrial water and their analysis on the content of mechanical impurities, the content of free hydrogen ions and temperature, produce test preparation frac fluid, run the test on budbreak and the stitching. The results are satisfactory. Prepare the gel volume 27 m3on the basis of gel-WG 46 "Economic". Rheology - the temperature is 27°C, viscosity 21 JV, time knitting 4 C. Produce adding to the gel demulsifier, activator destruction and clay stabilizer, the mixture is brought to a homogeneous state with stirring, to produce the starting and warming-up injection pumps.

Produce a test injection with a record recession, pressure and processing of data obtained from the decay of the pressure - volume 27 m3frac fluid with the addition of 1000 kg of fraction 20/40 proppant. Trial pack passed the perforation interval with a small increase in the pressure of - 0.1 MPa. The obtained data is processed, receive data about the effectiveness of fracturing fluid, the net value of the pressure, the voltage gradient in the reservoir, the time and pressure of clamping cracks, pore pressure in the reservoir, the hydraulic pressure losses in the perforated interval and the bottom of the reservoir. Based on these results, adjust projectindiana process of hydraulic fracturing to the received data processing test injection.

Carry out the basic process of hydraulic fracturing.

The correction data is used to re-calculate the three-dimensional models of fracture and refinement of the plan to hydrofracturing. On the basis of calculations produce a set of necessary amount of the process liquid and the cooking liquid bursting with testing. The test results are satisfactory.

Carry out the basic process of hydraulic fracturing using fractions of proppant, which includes the initial fraction of the dimension of 30/40 mesh in the amount of 30% and the main large fraction dimension 10/14 mesh in the amount of 70% of the total proppant with a final concentration of proppant 750 kg/m3. The total amount of proppant is 11.7 T. the Flow of liquid when pumping faction 30/40 mesh is 3.5 m3/min when the pressure at the wellhead 45 MPa, when pumping faction 10/14 mesh through the perforations, the fluid flow is 3 m3/min at a wellhead pressure of 35 MPa.

The amount of the final produce defined as the sum of the volume of the column tubing and podvecerni zone to the top of the perforated interval minus the amount calculated nedopodacha. Work flow in the main process less than 3 m3/min reduces the risk of technological "stop" when the main process due to the large amount of PR is panta large fraction. At the end of produce proppant-gel mixture pumps stop and write recession pressure, after which the wellhead is closed, the equipment is removed and the well is left for expectations of decrease of pressure. After the necessary time for the destruction of the gel to produce the etching residual wellhead pressure to atmospheric. Start bleed excess pressure is produced after 12 hours. The wellhead lasermedizin produce breakdown and the rise of packer equipment.

Example 2. Perform as example 1. Apply at the initial stage of the fraction of proppant dimension 30/60 in the amount of 10% of the total proppant, and as the main fraction is used proppant faction 12/18 mesh in the amount of 90% of the total proppant.

Example 3. Perform as example 1.

Carry out the basic process of hydraulic fracturing using fractions of proppant, which includes the initial fraction of the dimension of 20/40 mesh (27% and the main large fraction dimension 12/18 mesh in the amount of 73% of the total proppant with a final concentration of proppant 800 kg/m3. The total amount of proppant is 12 so the Flow of liquid when pumping fraction 20/40 mesh is 3.4 m3/min when the pressure at the wellhead 44 MPa, when pumping faction 12/18 mesh through the perforations, the fluid flow is STI is 2.8 m 3/min at wellhead flowing pressure of 33 MPa. After passing proppant perforations pressure produce increased to 44 MPa.

According to the results of processing the recording results of the estuarine pressures done process, the following data: the length of the crack created (one wing) - 69,34 m; fixed - 69,19 m; the height of the crack created - 16.6 m; fixed - 9,5 m crack Width after removal of the pressure reservoir 2,22 mm, the maximum width of the crack at the perforation intervals 17.6 mm; conductivity cracks 622,8 MJ/m the Mass of proppant pumped 12000 kg (20/40 - 3000 kg, 12/18 - 9000 kg).

The well is put into operation through 9 days after completion of the hydraulic fracturing ratio increased productivity by more than 2.8 times without increasing watercut.

Comparative analysis of the proposed method and the prototype are presented in table 1.

From the values in table 1 shows that the wells have a comparable filtration-capacitive properties of the layers. However, the distinguishing feature of the proposed method is the use of a large fraction constituting 73% of the total volume used proppant. The process of hydraulic fracturing was carried out with limiting the development of cracks in length with the aim of dominant development in width with a final concentration of proppant 800 kg/m3. The process Provo is ILSA with a low flow rate of 2.8 m 3/min to prevent the growth of wellhead pressure during the passage of sand through the perforations in the injection of a larger volume of the coarse fraction and, consequently, the exceptions process "stop". Thus obtained, the crack length is shorter in contrast to the standard hydraulic fracturing, however, has a larger width, fixed height throughout the effective thickness of the layer has a high conductivity for maximum performance well. Thus, the proposed method can effectively carry out hydraulic fracturing in wells with high permeability reservoirs.

Table 1
Comparative parametersThe proposed method according to example 3The placeholder
The purpose wellsMiningMining
The total thickness of the perforated part of the reservoir, m6,46,4
Permeability, MD120120
Lithology collectorChevrolet Siltstone
Fractional composition of proppant20/40-3 tn20/40-1 tn
16/30-7 tn
12/18-9 tn12/18-2 HS
10/14-2 HS
The total amount of proppant, t1212
The volume of a large fraction of proppant, %7333
The flow rate during injection, m3/min2,83,5
The average working wellhead pressure, MPa3345
Maximum proppant concentration, kg/m3800720
The length of the crack created/fixed (one wing), m69,34/69,19105,88/105,78
The height of the crack created/fixed m16,6/9,512,25/5,79
Width Tr is women after clamping the maximum/average mm17,6/2,2212,8/a 1.88
Conductivity cracks, MJ/m622,8478,3

Intensification method works well, including test pumping of fracturing fluid and a pack of fracturing fluid with proppant, the adjustment of the draft gap and carrying out the basic process gap, characterized in that in high-permeability reservoirs, with an absolute permeability of not less than 100 MD, conduct basic process of hydraulic fracturing using fractions of proppant, which includes the initial fraction dimension from 30/40 to 20/40 mesh and the main large fraction dimension 12/18 mesh and more in the amount of not less than 70% of the total proppant with the ultimate proppant concentration not less than 750 kg/m3the fluid flow when pumping faction 12/18 mesh and more through the perforations establish not more than 3 m3/min, and wellhead pressure support is not more than 35 MPa.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to a propping agent and use thereof in hydraulic fracturing for oil and gas extraction. The ultralight propping agent is prepared from a mixture of raw materials comprising porcelain clay, pottery clay and kaolin and/or siliceous clay, in the following content, wt %: porcelain clay 5-85, kaolin and/or siliceous clay5-85, pottery clay 5-30. The ultralight propping agent with apparent specific gravity of 2.10 g/cm3 to 2.55 g/cm3 and volume density of 1.30 g/cm3 to 1.50 g/cm3 is prepared from a mixture of natural clays comprising porcelain clay, pottery clay and at least kaolin or siliceous clay, where alumina content is 5.5-35%. In the method of preparing said filler, high strength of the propping agent is achieved by controlling firing time in the range of 75-90 minutes and firing temperature of 1150°C to 1380°C. Sintered spherical granules prepared from a mixture of raw materials comprising porcelain clay, pottery clay and at least kaolin or siliceous clay, having a substantially circular or spherical shape, are characterised by a Krumbein coefficient of at least 0.8 with alumina content of 5.5-35%. The hydraulic fracturing method includes pumping into an underground formation a hydraulic fluid with flow rate and pressure sufficient for opening a fracture in the formation, and the fluid containing said filler is pumped into the fracture.

EFFECT: high strength of the propping agent and conductivity thereof.

29 cl, 13 tbl, 5 ex

FIELD: mining.

SUBSTANCE: method involves drilling of a horizontal well shaft, lowering and fixation of a shank with filters, lowering of a packer and its seating, formation of cracks in each of the zones, which correspond to intervals of parts of the horizontal shaft with insulation of the rest of its parts. With that, the lower end of a pipe string is located 1 m closer to the mouth from the distant formation interval; a string of flexible pipes is lowered into the above pipe string and it is equipped from below with an abrasive jet perforator; space between the pipe string and the string of flexible pipes is sealed at the well mouth. Groups of slit perforation holes are made with length of 20-30 cm and width of 15 mm with a phasing angle of 60° in every 1.5 m of the oil-saturated formation interval in the shank; reverse flushing is performed together with simultaneous movement of the string of flexible pipes from the mouth to the face throughout the length of the oil-saturated formation interval; the string of flexible pipes with a jet nozzle is removed, and hydraulic formation fracturing is performed with further fixation of a fracture by light-weight resin-coated propping agent with fraction size of 20/40 mesh in concentration of 1400 kg/m3 and its filling to the horizontal well shaft opposite the oil-saturated formation interval; the packer is removed; the pipe string is moved in the direction from the face to the mouth to the next oil-saturated formation interval; after that, the above operations are repeated starting from seating of the packer and ending with the packer removal in the rest oil-saturated formation intervals developed by the horizontal well shaft.

EFFECT: improving reliability of hydraulic formation fracturing and efficiency of fracture fixing.

4 dwg

FIELD: mining.

SUBSTANCE: method comprises the formation exposing by vertical well, tripping in the well on the pipe string of the water jet tool with even amount of injection nozzles and its placement in the preset interval of the formation, injection of driving fluid through injection nozzles of the water jet tool for caving in the formation, subsequent formation fracturing from caverns by the spray stagnation pressure in caverns. Meanwhile the water jet tool with a series of injection nozzles, located along the tool with the interval between nozzles in a line no more than two diameters of the casing is used. The water jet tool is rotated to the preset angle to change the direction of progressing of each subsequent fracture. The fractures are formed at driving fluid injection pressure in the casing below the side rock pressure. Before tripping of pipe string into the well in the bottom end of the water jet tool the rotating device and mechanical packer are installed. To compensate leakages and the wedging of fractures during the process of hydraulic formation fracturing an acid is added in volume equal to 20% of the volume of the driving fluid, the driving fluid is injected into the pipe string through the water jet tool into a cavern until fracturing, then into the annular space of the well an acid is injected to compensate the leakages and fracture wedging. The pressure of acid injection into annular space of the well amounts 85% from the pressure created in the pipe string during progressing of fracture, upon termination of progressing fracture and the wedging of fracture in the same direction raise a pipe string on 1 m, turn a pipe string on an angle applicable to a direction of forming of following fracture, and lowered, then the process operations are repeated.

EFFECT: improvement of accuracy of orientation of fractures, performance and reliability of fracturing of carbonate reservoirs.

3 dwg

FIELD: mining.

SUBSTANCE: method comprises the drilling of a horizontal well bore in oil saturated part of the productive formation of the well, tripping of the pipe string into the well, the forming of perforations and fractures using the a hydrofracturing of formation in the hole of horizontal well, successively, starting from the end of far from the vertical borehole axis. During the next hydrofracturing the section, through which hydrofracturing is performed, is insulated from another part of the string with a packer. During drilling of the horizontal well bore the permeability and porosity of rocks are determined and the intervals of the productive formation with low permeability and porosity of rocks are identified, and on completing of drilling the rock hydrofracturing pressure is determined in each interval of the horizontal borehole. Then the volumes of fracturing fluid and acid for each interval of the oil saturated part of the formation with low permeability and porosity are determined, then the pipe string is moved to the interval of the productive formation nearest to the borehole bottom, with low permeability and porosity, the mechanical packer is seated, from hole mouth using the pumping unit the gelled fracturing fluid is injected into the pipe string through nozzles of the water jet tool and reshape perforations, then, not stopping injection gelled of fracturing fluid on a pipe string, construct fracture pressure applicable to the given interval of the oil saturated part of the productive formation. After 30% drop of pressure of injection of gelled fracturing fluid in the pipe string the hydrofracturing fractures are formed, for this purpose into the annular space of the well an acid is injected at the variable flow rate ensuring maintaining of pressure of injection of gelled fracturing fluid in the pipe string 10% less than the fracture pressure for the given interval of the oil saturated part of the productive formation. The packer releasing is performed and the pipe string is removed from bottomhole to the mouth into the following interval of the oil saturated part of the formation with low permeability and porosity of rocks for forming perforations and conducting of a hydrofracturing of the formation with forming and progressing of fractures.

EFFECT: shortening time for formation hydrofracturing, improvement of performance and reliability of formation hydrofracturing.

3 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to subsurface formations processing in the production of hydrocarbons. Method of processing a subsurface formation crossed by a hole comprises: preparation of a processing fluid containing a viscoelastic surfactant with at least one degradable link, a hydrolysable material and a pH adjusting material. Note here that the latter has a pH value equal to or larger than 9 and contains a strongly alkaline substance and an oxidiser. The said processing fluid is injected in the subsurface formation. The invention is developed in dependent claims.

EFFECT: higher efficiency of the proppant transportation and decomposition at low temperatures.

21 cl, 1 tbl, 14 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises test injection of frac fluid and bundle of frac fluids with proppant, correction of frac project and execution of the main frac process. Well is equipped with extra string and tube space is cemented. At hydrofrac, components are injected via said extra string at communicated perforation interval and well top space at pressure lower than permissible for extra string and at low frac fluid flow rate.

EFFECT: intensified production at worn-out string.

1 tbl

FIELD: mining.

SUBSTANCE: as per method of hydraulic fracturing of underground medium, many sliding couplings are placed in a well passing into underground media; sliding couplings are placed in mutually spaced places along the well and provided with a possibility of control after arrangement in the well in any specified sequence; many signal devices are moved along a control line arranged in the well; each of the signal devices opens at least one of the multiple sliding couplings and performs hydraulic fracturing of underground media in any specified sequence in mutually spaced places along the well passing into underground media; sliding couplings are used at hydraulic fracturing and left in the well at performance of hydraulic fracturing.

EFFECT: optimisation of stresses created due to hydraulic fracturing from mutually spaced places along the well shaft.

16 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention is related to oil industry and may be used for multiple hydraulic fracturing of the formation in horizontal shaft of a well. The method includes running in of a packer to the well on the flow string, performance of hydraulic fracturing in the first interval, formation of proppant plug, performance of hydraulic fracturing in the second interval. In order to obtain screening proppant plug concentration of the injected proppant is increased sharply up to 1100 kg/m3 and injection is stopped artificially due to increase of hydraulic resistance. The volume of injected mixture with increased concentration is calculated with consideration of filter part coverage in the first interval upon destruction of the cross-linked gel and complete settlement of proppant in the well bore. Upon completion of works on hydraulic fracturing in the first area withhold process is made for the period of destruction and complete settlement of unflushed proppant.

EFFECT: improving the hydraulic fracturing efficiency.

FIELD: oil-and-gas industry.

SUBSTANCE: invention can be used for bed hydro frac. Proposed method comprises well wall perforation, lowering of string with packer, landing of packer, determination of total volume of gelated frac fluid, injection of said fluid in under-packer zone, creation in said zone of hydro frac pressure and development of fractures therein and fixation of said fractures by injection carrier fluid with proppant, holding of wells for pressure release, unpacking and removal of packer with string from the well. Note here that flexible string is lowered in pipe string so that bottom end of flexible string is located under pipe string end and at the bed centre. Space between pipe string and flexible string is sealed at wellhead to separate total volume of gelated frac fluid into two equal portions: frac fluid and proppant carrier, to inject in turns both in five cycle and in equal portions. For injection, proppant is used with density lower and higher than that of carrier fluid. In one cycle, fluid carrier and proppant are injected at a time in two equal portions: Carrier fluid with proppant of lower density is injected via pipe string with carrier fluid with proppant of higher density is injected via flexible string.

EFFECT: higher efficiency of hydro frac.

1 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: invention can be used in well exposing the bed with interleaving and inhomogeneous reservoirs. Proposed method comprises test injection of frac fluid and bundle of frac fluids with proppant, correction of frac project and execution of the main frac process. For said interleaving and inhomogeneous reservoirs that feature different filtration capacity of every stringers, main hydro frac is performed with the use of proppant fraction including initial fraction of 20/40 mesh and main coarse fraction of 12/18 mesh and larger at proppant concentration of not over 500 kg/m3. Concentration is increased smoothly in amount of not over 50 kg/m3 at every step starting from second step. At final step of proppant injection, fluid flow rate is decreased to constriction of wellhead pressure increase.

EFFECT: simulation of well exposing the inhomogeneous bed.

FIELD: oil and gas industry.

SUBSTANCE: method of water production zones isolation in the well includes running in of the flow string at perforated nipple tubing string. Two-component grouting mixture with lengthy aggregating period prepared at the day surface, flush fluid and the second portion of aggregating agent are injected to the tubing string. At that before running of the tubing string in the water production zone and its specific injectivity is identified. Depending on depth of the water production zone and specific injectivity the aggregating volume and time for two-component grouting mixture with short aggregating period is defined, at that the latter consists of two-component grouting mixture with lengthy aggregating period and the second portion of aggregating agent. The two-component grouting mixture with lengthy aggregating period is prepared and the following mixtures are injected in sequence: flush fluid with density equal to density of two-component grouting mixture with lengthy aggregating period, two-component grouting mixture with lengthy aggregating period, flush fluid with density equal to density of two-component grouting mixture with lengthy aggregating period. Then the second portion of the aggregating agent is injected with density equal to density of two-component grouting mixture with lengthy aggregating period. By-pass plug with binding head is installed in the tubing string and flushed at pressure of 0.5 MPa by flush fluid with density equal to density of two-component grouting mixture with lengthy aggregating period to tubular and annular space. Circulation is induced by flush fluid with density equal to density of two-component grouting mixture with lengthy aggregating period through the upper radial openings till density values are balanced in tubular and annular space. Then the rubbing string is uplifted and during lifting the second portion of the aggregating agent with density equal to density of two-component grouting mixture with lengthy aggregating period is injected through the perforated end of the perforated tube to the two-component grouting mixture with lengthy aggregating period. Thereafter two-component grouting mixture with short aggregating period is flushed along annular space to the water production zone by flush fluid with density equal to density of two-component grouting mixture with lengthy aggregating period.

EFFECT: increasing efficiency of insulation of water production zone in well.

1 ex, 2 tbl, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a propping agent and use thereof in hydraulic fracturing for oil and gas extraction. The ultralight propping agent is prepared from a mixture of raw materials comprising porcelain clay, pottery clay and kaolin and/or siliceous clay, in the following content, wt %: porcelain clay 5-85, kaolin and/or siliceous clay5-85, pottery clay 5-30. The ultralight propping agent with apparent specific gravity of 2.10 g/cm3 to 2.55 g/cm3 and volume density of 1.30 g/cm3 to 1.50 g/cm3 is prepared from a mixture of natural clays comprising porcelain clay, pottery clay and at least kaolin or siliceous clay, where alumina content is 5.5-35%. In the method of preparing said filler, high strength of the propping agent is achieved by controlling firing time in the range of 75-90 minutes and firing temperature of 1150°C to 1380°C. Sintered spherical granules prepared from a mixture of raw materials comprising porcelain clay, pottery clay and at least kaolin or siliceous clay, having a substantially circular or spherical shape, are characterised by a Krumbein coefficient of at least 0.8 with alumina content of 5.5-35%. The hydraulic fracturing method includes pumping into an underground formation a hydraulic fluid with flow rate and pressure sufficient for opening a fracture in the formation, and the fluid containing said filler is pumped into the fracture.

EFFECT: high strength of the propping agent and conductivity thereof.

29 cl, 13 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: claimed invention is aimed at creation of composition for cleaning formation in oil extraction. Composition of cleaning formation in oil extraction contains expandable polymer particles, which have anionic sections, and are linked with labile cross-linkers and stable cross-linkers, where said particles are combined with liquid and cationic cross-linking agent, capable of additional cross-linking of particles in case of degradation of labile cross-linker with formation of gel, in which said anionic section is selected from the group, consisting of polymerisable carboxylic acids and sodium, potassium and ammonium salts, and said cationic cross-linker is represented, at least, by one agent, selected from the group, consisting of Cr3+ Fe3+ Al3+, Ti4+ Sn4+, Zr4+ or their salts, their complexes or nanoparticles, which contain them, chelated cations of said metals or polyethylenimine (PEI). Also claimed is version of composition and method of increasing production of hydrocarbon liquids from underground oilfield.

EFFECT: polymer-containing compositions provide good resistance to flow with time, providing long-lasting effect of processing.

15 cl, 2 dwg, 2 ex

FIELD: oil and gas industry.

SUBSTANCE: invention refers to the oil and gas production industry and can find application in developing heterogeneous terrigene or carbonate producing beds. In the method for an oil bed development, involving the oil bed water-flooding, injection of water solution banks containing alkali, a polymer, a surfactant, a microorganism culture and a nutrient medium, into injection holes, and sampling of products from the production wells, at the initial stage a deposit is developed by water-flooding in an amount adequate to achieve the collected compensation of water-flood liquid sampling of not less than 50%; once the oil sampling reaches 70% of the initial recovered reserves, residual prospective oil distributed over specific 1 m2 is mapped; the worked-out compartments are detected to inject the above solution into the centre injection holes with the following proportions, wt %: alkali - no more than 5, polymer - no more than 1, surfactant - no more than 0.5, microorganism culture - no more than 0.05, nutrient medium - no more than 0.5, water - the rest with varying the concentration C of the ingredients in the above solution proportional to the specified prospective oil for each C centre is determined depending on Cnk=ynCmaxk, wherein k is a type of the ingredient, n is the number of the centre, y is a proportionality factor of each centre; y is calculated by a linear equation y=a·x+b, wherein x is the specific prospective oil of the centre, t/m2, a, b are linear equation factors determined if y for xmax equals to 0, and if xmin equals to 1 from a system of equations wherein xmax and xmin are the maximum and minimum specific prospective oil values, respectively; injection cycles of the bank injection are repeated if an oil flow rate decreases to the pre-injection level.

EFFECT: higher displacement factor and better oil recovery of the productive formation.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: invention refers to the oil and gas production, namely to formulations for water suppression, conformance control and oil and gas producing well killing. The emulsion formulation for water suppression, conformance control and well killing, containing hydrocarbon and water phases, an emulsifier containing a reaction product of fatty acids and amines as an active substance, non-ionic surfactants as an additive, and alcohol as a solvent, wherein the emulsifier contains the reaction product of the fatty acid R-COOH, wherein R=C5-C20, with amine R-N-(R'-NH2)n, wherein R=C4-C22, R'=C2-C4, n=0-2 as the active substance, in the following proportions of the emulsifier, wt %: above reaction product 2-80, non-ionic surfactant 2-60, alcohol - the rest, while the formulation contains the following proportions of the ingredients, wt %: hydrocarbon phase 2-25, emulsifier 0.1-5.0, water phase - the rest. The invention has been developed in the dependent claims.

EFFECT: higher stability, including thermal stability at 20-80°C, mechanical stability, lower corrosive activity, improved regulation of the emulsion rheology.

5 cl, 1 tbl, 5 ex

FIELD: oil and gas industry.

SUBSTANCE: invention refers to the oil and gas industry and can be used in developing heterogeneous terrigene or carbonate producing viscous-oil beds. In the method, which involves an oil bed water-flooding, injection of water solution banks containing alkali, a biopolymer, a surfactant, a bacterial culture and nutrient salts, into injection holes, and sampling of products from the production wells; deposit drilling is followed by mapping the formation permeability distribution in the wells with the formation permeability more than twice less than the average formation permeability; if the collected oil withdrawal is no more than 50% of the initial recovered reserves, the formation is hydraulically fractured; oil sampling findings are used to map the oil-viscosity compartment distribution; the above solution is injected in the compartments through the injection holes in the following proportions, wt %: alkali - no more than 5, biopolymer - no more than 1, surfactant - no more than 0.5, hydrocarbon-oxidising bacterial culture - no more than 0.1, nutrient salts - no more than 0.8, water - the rest with varying the concentration C of the ingredients in the above solution proportional to the specified OV for each C centre is determined depending on Cnk=ynCmaxk, wherein k is a type of the ingredient, n is number of the centre, y is a proportionality factor of each centre; y is calculated by a linear equation y=a·x+b, wherein x is the OV of the centre, mPa·s, a, b are linear equation factors determined if y for xmax equals to 1, and if xmin equals to 0 from a system of equations: wherein xmax and xmin are the maximum and minimum oil viscosities, respectively; injection cycles of the bank injection are repeated if an oil flow rate decreases to the pre-injection level.

EFFECT: higher displacement, coverage and recovery factors of the productive formation.

1 ex

Drilling mud // 2539081

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil producing industry. Water-base drilling mud includes clay and a stabilising polymer, being modified styrene plastic, which represents a product of free radical polymerisation of styrene with maleic anhydride in dried benzene medium modified by its cross-linking, ammonolysis and amide interchange during 3-4 hours with subsequent neutralisation of remaining benzene and maleic acid by solution of caustic soda, comprising links of styrene, maleic anhydride and modified links of the latter with the following ratio of components, wt %: gel powder 8.0; modified styrene plastic 0.1-0.25; water - remaining part, at that modified styrene plastic has the following structural formula: .

EFFECT: manufacturing of drilling mud with low values of shear strength and water loss, high values of viscosity and salt resistance, high thermal resistance and resistance to enzymes with simultaneous accessible and economically feasible manufacturing technology.

3 tbl, 1 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: composition for clay cake removal from face zone of low-permeability terrigenous seam contains the following elements in wt %: ammonium chloride - 20.0-60.0, mud acid - 6.0-12.0, acetic acid - 12-24, acetone-methanol solution or ethanol or isopropyl alcohol - 22-44.

EFFECT: higher efficiency of removal.

3 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of maintaining formation separation in a subterranean well, wherein the well bore penetrates one or more hydrocarbon-containing formations, the method comprising: (i) pumping a cement slurry comprising thermoplastic block-copolymer particles into the well, wherein the block-copolymer has the structure (A-b-B-b-A), where A is a glass-like or polycrystalline block, B is an elastomeric block; and (ii) allowing the cement slurry to set in order to form a cement sheath, wherein the occurrence of microannuli, cracks or defects in the cement sheath allows hydrocarbons from the formation to come into contact with the particles, allowing the particles to swell, and enabling the cement sheath to have self-healing properties. The invention also relates to use of said thermoplastic block-copolymer particles to self-healing properties to a cement formulation which is placed in a subterranean well penetrating one or more hydrocarbon-containing formations, wherein once set, the cement forms a cement sheath in which the particles swell upon coming into contact with hydrocarbons from the formation.

EFFECT: invention is developed in subclaims.

14 cl, 5 dwg, 10 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to compositions for increasing viscosity of heavy brine systems. Method of increasing viscosity of brine systems, used in underground repair of wells, includes: a) obtaining brine system, including hydrated polysaccharide and, at least, one polyvalent salt, where density of brine system constitutes more than approximately 1.2 g/cm3 and pH constitutes less than approximately 7, at least, one polyvalent salt is present in amount from approximately 5 wt % to approximately 90 wt % of the total weigh of brine system and b) addition of effective quantity of alkaline preparation, increasing viscosity of brine system, where alkaline preparation is selected from the group, consisting of amines, glycerophosphates of alkali metals, orthophosphates of alkali metals, hydroxides of alkali metals, carbonates, alkanolamines, silicates, citrates, phosphates, buffer solutions of thereof and their mixtures. In accordance with the second version method of increasing viscosity of brine systems, used in underwater repair of wells, includes: a) obtaining water brine system, including, at least, one polyvalent salt, where density of brine system constitutes more than approximately 1.2 g/cm3 and pH constitutes less than approximately 7, at least, one polyvalent salt is present in amount from approximately 5 wt % to approximately 90 wt % of the total weigh of brine system; b) addition of polysaccharide; c) addition of effective quantity of acidic buffer preparation into brine system to reduce pH of hydrochloric system, so that polysaccharide becomes able to be considerably hydrated in brine system, and d) addition of effective quantity of alkaline preparation, increasing viscosity of brine system, where alkaline preparation is selected from the group, consisting of amine, glycerophpsphates of alkali metals, orthophosphates of alkali metals, hydroxides of alkali metals, carbonates, alkanilamines, silicates, citrates, phosphates, buffer solutions of thereof and their mixtures. In accordance with other version method of obtaining brine system with increased viscosity, used in underground repair of wells, includes: a) addition of polysaccharide to water hydrochloric solution, including: (i) at least, one polyvalent water-soluble salt, present in amount from approximately 5 wt % to approximately 90 wt % of the total weight of brine system; (ii) density between 1.2 g/cm3 and 2.4 g/cm3 and (iii) pH value, smaller than approximately 7, due to which polysaccharide is capable of considerable hydration in hydrochloric solution, and b) addition of alkali preparation to increase pH of hydrochloric solution, with increase of brine system viscosity, where alkaline preparation is selected from the group, consisting of amines, glycerophosphates of alkali metals, orthophosphates of alkali metals, hydroxides of alkali metals, carbonates, alkanilamines, silicates, citrates, phoaphates, buffer solutions of thereof and their mixtures. In accordance with other version method of obtaining brine system with increased viscosity, used in underground repair of wells, includes: a) addition of polysaccharide to water hydrochloric solution, including: (i) at least, one polyvalent salt, present in amount from approximately 5 wt % to approximately 90 wt % of the total weight of brine system; (ii) density between 1.2 g/cm3 and 2.4 g/cm3; b) addition of affective quantity of acid to hydrochloric solution so that polysaccharide is capable of considerable hydration in hydrochloric solution and c) addition of alkaline preparation to increase pH of hydrochloric solution to value higher than 6, increasing viscosity of brine system, where alkaline preparation is selected from the group, consisting of amines, glycerophpsphates of alkaline metals, orthophosphates of alkali metals, hydroxides of alkali metals, carbonates, alkanolamines, silicates, citrates, phosphates, buffer solutions of thereof and their mixtures. Invention is developed in dependent items of the formula.

EFFECT: increased efficiency without application of cross-linking agents.

13 cl, 6 ex, 6 tbl

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

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

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

1 tbl

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