Multiple hydraulic fracturing of formation in well horizontal shaft

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises drilling the well horizontal shaft in oil-saturate section of production bed, cementing of annulus between casing and bed rock. Casing pipe is perforated in said well shaft oriented in azimuth by intervals with the help of slot perforator lowered in the well on string in a single trip. String with packer is lowered in the well to fit the packer in place. Fracturing fluid is injected via said string for hydrofracturing in said horizontal well shaft. Well shaft us drilled in the bed parallel with direction of minimum main strain. Plug is fitted at string lower end and two packers are arranged at flexing pipe string. Note here that through holes are made at the latter. Said flexing pipe string with packers is lowered into well shaft for hydraulic fracturing via perforated intervals by cutting of every interval of perforation on both sides. Bed fracturing is started from horizontal well interval nearby the bottom and fluid is forced via flexible pipe string via through holes at flow rate of 2 m3/min to produce transverse fractures from perforation interval relative to well shaft. Note here that fracturing fluid is composed of hydrocarbon-based cross-linked gel. Made fractures are secured by injection of proppant of 12/18 mesh fraction with cross-linked gel, a carrier fluid. Packers are removed to displace flexible pipe string for hydraulic fracturing of the bed in the next perforation interval. Then, above jobs are reiterated. Then, flexible piper string with packers is withdrawn from the well to lower pipe string therein. Packer is fixed at well vertical part for hydraulic fracturing by injection of fluid via horizontal well shaft to produce lengthwise fractures at flow rate of 8 m3/min. Linear gel is used as fracturing fluid. Said lengthwise fractures are secured by injection of ground quartz with linear gel as carrier fluid.

EFFECT: higher efficiency of fracturing.

2 dwg

 

The invention relates to oil industry and can be used in the development of oil deposits, in particular deposits with productive formations with low reservoir porosity and permeability by hydraulic fracturing.

The known method of multiple hydraulic fracturing in horizontal wells (patent RU №2472926, IPC E21B 43/267 publ. 20.01.2013, bull. No. 2), including the lowering of the packer into the well column pipe with its subsequent landing in the borehole, the formation of cracks across the filters successively in different intervals of the reservoir, penetrated by a horizontal wellbore, the flow of fracturing fluid through the filter installed in each of the relevant each of these intervals portions of the horizontal wellbore isolation rest, determine the direction of the horizontal wellbore relative to the direction of the minimum principal stress, then isolate the interval, subject to hydraulic fracturing, from the remaining plots of the horizontal wellbore landing dual packers, then open the valve, placed inside the column pipe between the dual packers in front of the filter, if the direction of the horizontal wellbore parallel to the direction of the minimum principal stress, hydraulic�ical fracturing produce a fix the bursting of the liquid with the formation of transverse cracks relative to the horizontal wellbore and the subsequent fastening of the transverse cracks fluid injection aluminosilicate proppant, gradually increasing its fractions from 20/40 16/30 meshes to the mesh, if the direction of the horizontal wellbore in a direction perpendicular to the minimum principal stress, hydraulic fracturing produces fix the bursting of the liquid with the formation of horizontal cracks relative to the horizontal wellbore and the subsequent fastening of horizontal cracks fix fluid with a lightweight proppant fraction 20/40 mesh, after hydraulic fracturing of the well is closed for technological pause for 0.5 hours, then at the wellhead on the column pipes set adjustable nozzle spout and produce waste proppants fluid from the reservoir through the column pipe at the wellhead prior to the closing of the valve, in the process of regulation spout fitting to ensure that the pressure in the column of pipes got 2-3 MPa less pressure when opening the well after the technological pause, and then produce raspaculo packer and moving the pipe string into another part of the horizontal wellbore, and the above process for conducting hydraulic fracturing in horizontal wellbore is repeated depending on the number of intervals of the horizontal wellbore, fitted with filters in different parts of the world.

The disadvantages of this method are:

- first, low effectively�you implement the method in the productive layer with low reservoir porosity and permeability, due to the weak attachment of proppant in the longitudinal and transverse cracks formed from the horizontal wellbore, so the subsequent extraction of transverse and especially longitudinal cracks formed of a productive formation with low reservoir porosity and permeability in the horizontal wellbore will be released grain of proppant that will lead to the closure of cracks and sharp decrease in throughput of cracks formation in the near-well zone;

- secondly, the high duration of the hydraulic fracturing associated with the hydromechanical slit perforation of the casing (liner) the descent of the punch on the column pipe;

- thirdly, the high physical and financial costs of implementation of the method related to the number of horizontal wellbore casing or liner with subsequent cementing.

The closest in technical essence is a method of hydraulic fracturing in horizontal wells (patent RU №2401942, IPC E21B 43/26, publ. 20.10.2010 G., bull. No. 29), which includes the drilling of horizontal well bore into the oil-saturated part of the productive formation by cementing the annular space between the casing and rocks of the productive formation horizontal well bore, p�Horacio casing, the descent of the tubing with the packer in the wellbore, perforations and the formation of cracks hydraulic fracturing injection of fracturing fluid into the horizontal wellbore sequentially, starting with the end farthest from the vertical axis of the wellbore, indicating a horizontal well bore from the producing formation, in which case the next hydraulic fracturing each perforated portion through which produce hydraulic fracturing, isolated from the rest of the columns packers, horizontal drilling of the wellbore is carried out in oil-saturated part of the productive formation by cementing the annular space between the casing and the rock of the horizontal wellbore and perforation of the horizontal wellbore, azimuth is oriented intervals produced using hydro-mechanical slot perforator, lowered into the well column pipe in one trip, and then pull the packers, clipping each interval equal to the length of the formed slit, from the rest of the columns, and fracturing in the horizontal part of the wellbore is produced sequentially, starting with the farthest from the vertical axis of the wellbore perforated section of the horizontal wellbore, and hydromechanic�die slit perforation performs two-way for the formation of cracks, which are arranged relative to each other at an angle of 180° in a vertical plane opposite each other relative to the axis of the horizontal wellbore in a single interval, or perform unilateral hydromechanical slit perforation by 180° in a vertical plane about the axis of the horizontal wellbore, alternately through each of the subsequent interval is staggered by the length of the formed slits or a small thickness of the productive formation and the presence of active bottom water produce unilateral hydromechanical slit perforation in the direction of the seam roof.

The disadvantages of this method:

- firstly, the low efficiency of the method in productive formation with low reservoir porosity and permeability, due to the lack of fixing the cracks, which leads to the closure of cracks and sharp decrease in throughput of cracks formation in the near-well zone;

- secondly, the low reliability of hydraulic fracturing related to the fact that the perforated interval, subject to hydraulic fracturing, is clipped on one side only, therefore increases the proppant into the horizontal wellbore;

- thirdly, the high duration of the hydraulic fracturing associated with the entire cycle of the technological process of conducting interval hydraulic fracturing in horizontal wellbore with the use of casing string.

The technical objectives of the proposal are to improve the effectiveness of hydraulic fracturing through the creation of a productive formation with low reservoir porosity and permeability of a branched network of fixed fractures and also increase reliability by minimizing the proppant into the horizontal wellbore, and the shortening of the hydraulic fracturing due to the acceleration of the process.

The technical problem solved by the method of hydraulic fracturing in horizontal wellbore that includes drilling a horizontal well bore into the oil-saturated part of the productive formation by cementing the annular space between the casing and rocks of the productive formation of the horizontal wellbore, the perforation of the casing in a horizontal well bore, oriented azimuthal intervals using hydromechanical slot perforator, lowered into the well column pipe for one trip, the descent of the tubing with the packer in the well, landing the packer, the pumping of the column of pipes of fracturing fluid and the formation of cracks hydraulic fracturing in horizontal wellbore.

What is new is that horizontal STV�l wells into the oil-saturated part of the productive formation are drilled in the reservoir parallel to the direction of the minimum principal stress, lowering the casing into the well and cemented, then on the column flexible pipes down hydromechanical slot perforator and perform perforation interval in a horizontal well bore, remove the column flexible pipes with hydromechanical slot perforator from the well, disassemble hydromechanical slot perforator, at the lower end of the column flexible pipes set in the cover and mounted on the column flexible pipes two packer between packers in a column of flexible pipes is performed through holes, then lowered into a horizontal well bore column of flexible pipes with the packers and produce interval hydraulic fracturing through the perforated intervals in the horizontal wellbore by cutting off each perforated interval with both parties, and interval hydraulic fracturing starting from the closest to the bottom interval of a horizontal well and produce injection of fracturing fluid through the column flexible pipes through the through hole with a flow rate of 2 m3/min with the formation of transverse cracks from the perforation interval relative to a horizontal wellbore, the fluid gap using cross-linked gel oil based, after the formation of transverse cracks produce their mounting fix the column pipe proppant� fraction 12/18 mesh with the carrier liquid - crosslinked gel, rapacuronium packers and moving column of flexible pipes for conducting hydraulic fracturing in the next interval of perforation, then the above-described process operation is repeated, starting with the planting of packers and ending with the movement of a column of flexible pipes in the next interval of perforation, depending on the number of perforation interval of the horizontal wellbore, then extract a column of flexible pipes with the packers from the well and lowered pipe string with the packer in the borehole, put the packer in a vertical part of the borehole and produce hydraulic fracturing injection of fracturing fluid through the column pipe through the horizontal wellbore with the formation of longitudinal hydraulic fractures with flow rate of 8 m3/min, the fluid gap use linear gel, and then produce the fastening of longitudinal cracks by injection of silica flour with the carrier liquid is a linear gel.

The essence of the proposal is that after you create the interval of transverse cracks about a horizontal wellbore produce clogging of the perimeter of the fracture proppant large fraction (12/18 mesh.), thus, in further carrying out hydraulic fracturing "General filter" by increasing the rate of injection is "inflating" the cracks and increase its �Irene, which leads to the bending of the surface transverse cracks in the direction of the principal stress, namely the development of longitudinal cracks and, as a consequence, the formation of a network of branched cracks in productive formation with low reservoir porosity and permeability by hydraulic fracturing.

Fig.1 and 2 schematically and sequentially illustrates the proposed method.

The method is implemented as follows.

Horizontal shaft 1 (see Fig.1) 2 wells drilled into the oil-saturated part of the productive layer 3 parallel to the direction of the minimum principal stress is σmin.

Pull the casing 4 into the borehole 2 and cement annular space 5 between the casing 4 and rocks of the productive formation 3 horizontal wellbore 1 wells 2.

Then on the column flexible pipes 6 in the horizontal wellbore of the casing 1 4 bore 2 is lowered hydromechanical slot perforator (Fig.1 and 2 not shown) and perform the perforation interval in the horizontal section 1 (see Fig.1) wells 2. For example, produce a hydromechanical perforation in four intervals 7', 7", 7"', 7"" (see Fig.1 and 2) horizontal wellbore 1 bore 2, thus use any known hydromechanical slit punch, for example, produced by LLC "Complex" (Ekaterinburg, Russia).

Remove the column flexible pipes 6 with hydromechanical slot perforator from the well 2, disassemble hydromechanical slot perforator. On the lower end of the column flexible pipes 6 install the plug 8 and is mounted on the column flexible pipes 6 two packer 9 and 10, between the packers 9 and 10 in the column flexible pipes 6 is performed through holes 11.

Packers 9 and 10 have the opportunity airtight trim each of the four intervals 7', 7", 7"', 7"" (see Fig.1 and 2) horizontal wellbore 1 borehole 2. To avoid the error in the landing and, as a result, leaking cut-off distance L (see Fig.1) between the packers 9 and 10 on the column flexible pipes 6 should be 5 m greater than the maximum length l of any of the four intervals 7', 7", 7"', 7"".

As the column flexible pipe 6 (see Fig.1 and 2) is used, for example, a column of flexible pipes with a diameter of 60 mm. as the packers 9 and 10 used furniture packers with anchor mechanical axial and rotary units PRO-AM-AG(f) or PRO-AM-YAG2 (f) (at 100 MPa) manufactured by scientific-production firm "Packer" (Oktyabrsky, Republic of Bashkortostan, Russian Federation).

Lowered into horizontal wellbore 1 wells 2 column flexible pipes 6 with a sealed bottom and are equipped with packers 9 and 10. Produce interval hydraulic fracturing and through the perforated�intervals of 7', 7", 7"', 7"" in the horizontal section 1 borehole 2. To do this, first make landings packers 9 and 10 and cut closest to the bottom of the perforated interval 7' horizontal wellbore 1 borehole 2. Produce hydraulic fracturing in the given interval of injection of fracturing fluid, which is used as a cross-linked gel oil based.

Cross-linked gel oil based with a flow rate of 2 m3/min on a column of flexible pipes 6 through the through holes 11 hits the perforated interval 7' horizontal wellbore 1 bore 2 with the formation of transverse cracks 12' relative to the horizontal wellbore 1 borehole 2. About the formation of transverse cracks 12' indicate the pressure drop injection and increase the injectivity of the reservoir 1. For example, when the injection of cross-linked gel into the formation 3 has reached a pressure of 30 MPa, due to the formation of transverse cracks 12' in the reservoir 3 there was a drop in pressure of injection of the crosslinked gel is 25%, i.e. to 22.5 MPa, and the injectivity of the reservoir 3 has increased by 50%, for example, flow rates of up to 4.5 m3/min.

The use of a column of flexible pipes 6 accelerates the process of carrying tripping operations and allows to reduce the length of hydraulic fracturing, and the use of dual packers can cut off the perforated interval subject.�algebraic fracturing, with two sides, which minimizes the proppant during hydraulic breaks subsequent perforation interval of the reservoir in the horizontal section 1 wells 2.

Produce mount transverse cracks 12' injection on the column flexible pipes 6 of proppant fraction 12/18 mesh grain size of 0.8-1.0 mm with the carrier liquid (crosslinked gel).

The proppant fraction 12/18 mesh grain size of 0.8-1.0 mm is manufactured according to GOST R 51761-2005 - aluminosilicate Proppants. Technical conditions" and is available Borovikovsky the refractories plant (Borovichi, Republic of Belarus).

Cross-linked gel oil based has a high viscosity in the reservoir that when it is injected into the reservoir with a flow rate of 2 m3rpm provides the creation of a broad, deep penetrating cracks with good filling of the propping material (proppant). During the degradation does not form a precipitate, does not damage the reservoir and the packing of proppant.

Rapacuronium packers 9 and 10 and move the column flexible pipes 6 in the direction of the wellhead 2 to conduct hydraulic fracturing in the next interval 7", where similarly repeat all process steps, starting from the clipping of the perforated interval 7" packers 9 and 10 and ending with the movement of a column of flexible pipes 6 in the next interval 7"'. Thus, the producing interval of hydraulic�cue fracturing with the formation of transverse cracks 12', 12", 12"', 12"" all perforation intervals 7', 7", 7"', 7"" in the horizontal section 1 wells 2.

To create transverse cracks 12', 12", 12"', 12"" (see Fig.1) in the reservoir 3 using cross-linked gel hydrocarbon-based dynamic viscosity 150 (JV) (see Chapter 3 of the monograph S. A. Ryabokon "Technological fluids for well completion and workover (OJSC NPO Burenie, 2006. S. 153), which comprises a solution of polymer (MO-HT) in the hydrocarbon cross-linking and the time destructor (MO-NT-hydrophobic modification PAA) My-T-Oil (Halliburton).

Next, remove the column flexible pipes 6 with the packers 9 and 10 from the well 2 and lower the column pipe 13 (see Fig.2) with the packer 14 in the borehole 2. Put the packer 14 in the vertical part of the borehole 2. The column pipe 13 (see Fig.2) is injected fracturing fluids (linear gel) in horizontal wellbore 1 borehole 2 with a flow rate of 8 m3/min, through transverse cracks 12', 12", 12"', 12"" form longitudinal cracks 15', 15", 15"', 15"" in the reservoir 3 with respect to the open horizontal wellbore 1 borehole 2. About the formation of longitudinal cracks 15', 15", 15"', 15"" show the pressure drop injection and increase the injectivity of the reservoir 3.

For example, when you fix a linear gel in the reservoir 3 has reached a pressure of 33 MPa, due to the formation of longitudinal cracks 15', 15", 15"', 15"" in the reservoir 3, a sub�Oslo pressure drop pumping the cross-linked gel 25% i.e., before the 24.75 MPa, and the injectivity of the reservoir 3 has increased by 30%, for example, with flow rates up to 10.4 m3/min.

Generate fastening of longitudinal cracks 15', 15", 15"', 15"" the fix the column pipe 13 fine sand, grain size 0.05-0.15 mm, for example quartz flour with the carrier liquid (linear gel).

As a small proppant used quartz flour having a grain size of 0.1 mm, which is produced by TU-001-16767071-99 (supplier of LLC Trading house "Quartz", Ekaterinburg, Russia).

Linear gel features a low-friction losses in pipes, with a large injection rate of 8 m3rpm allows you to penetrate deep into the layer 3 and provides a uniform proppant deposition of small transverse 12', 12", 12"", 12"" and longitudinal 15', 15", 15"', 15"" cracks.

To create longitudinal cracks 15', 15", 15"', 15"" of transverse cracks 12', 12", 12"', 12"" in the reservoir 3 with respect to the open horizontal wellbore 1 well 2 use linear gel with a dynamic viscosity of 30 (JV).

For example, use a linear water-based gel, which is prepared on water-soluble polymers of different nature of any known composition (for example, see the monograph by S. A. Ryabokon "Technological fluids for well completion and workover" OJSC NPO Burenie, 2006. - P. 118).

Increases the efficiency�spine realization of the way of a productive formation with low reservoir porosity and permeability due to attachment of transverse fractures large proppant fraction 12/18 mesh grain size of 0.8-1.0 mm, and longitudinal cracks - minor proppant grain size is 0.1 mm. Small grains of proppant bind large grains of proppant in the longitudinal cracks, eliminating their mobility. As a result excluded the closure of transverse cracks and the output of proppant into the open horizontal wellbore 1 borehole 2 in the reservoir 3, which saves them bandwidth. As a result in the productive layer 3 with low reservoir porosity and permeability formed an extensive network of fixed transverse 12', 12", 12"", 12"" and longitudinal 15', 15", 15"', 15"" cracks, which leads to increasing the effectiveness of hydraulic fracturing.

After hydraulic fracturing of a horizontal wellbore vent pressure in the borehole 2, rapacuronium packer 14 and removed from the well 2 pipe string 13 and a retainer 14. Lowered into the well 2 operational equipment (Fig.1 and 2 not shown) and run well into operation.

The proposed method of hydraulic fracturing in horizontal wellbore allows you to:

- to increase the efficiency of the method in productive formation with low reservoir porosity and permeability;

- reduce the length of hydraulic fracturing;

- to improve the quality of fracturing by minimizing the removal of Propp�in the horizontal wellbore.

Method of hydraulic fracturing in horizontal wellbore that includes drilling a horizontal well bore into the oil-saturated part of the productive formation by cementing the annular space between the casing and rocks of the productive formation of the horizontal wellbore, the perforation of the casing in a horizontal well bore, oriented azimuthal intervals using hydromechanical slot perforator, lowered into the well column pipe for one trip, the descent of the tubing with the packer in the well, landing the packer, the pumping of the column of pipes of fracturing fluid and the formation of cracks hydraulic fracturing in horizontal wellbore, wherein that a horizontal well bore into the oil-saturated part of the productive formation are drilled in the reservoir parallel to the direction of the minimum principal stress, casing is lowered into the well and cemented, then on the column flexible pipes down hydromechanical slot perforator and perform perforation interval in a horizontal well bore, remove the column flexible pipes with hydromechanical slot perforator from the well, disassemble hydromechanical slot perforator, at the lower end of the column flexible pipes set plug � mounted on the column pipe bending two of the packer, thus between packers in a column of flexible pipes is performed through holes, and then lowered into a horizontal well bore column of flexible pipes with the packers and produce interval hydraulic fracturing through the perforated intervals in the horizontal wellbore by cutting off each perforated interval with both parties, and interval hydraulic fracturing starting from the closest to the bottom interval of a horizontal well and produce injection of fracturing fluid through the column flexible pipes through the through hole with a flow rate of 2 m3/min with the formation of transverse cracks from the perforation interval relative to a horizontal wellbore, the fluid gap using cross-linked gel oil based, after the formation of transverse cracks produce their mounting fix the column pipe proppant fraction 12/18 mesh with the carrier liquid - crosslinked gel, rapacuronium packers and moving column of flexible pipes for conducting hydraulic fracturing in the next interval of perforation, then the above-described process operation is repeated, starting with the planting of packers and ending with the movement of a column of flexible pipes in the next interval of perforation, depending on the number of perforation interval of the horizontal wellbore, then �zavlekayut column of flexible pipes with the packers from the well and lowered pipe string with the packer in the borehole, put the packer in a vertical part of the borehole and produce hydraulic fracturing injection of fracturing fluid through the column pipe through the horizontal wellbore with the formation of longitudinal hydraulic fractures with flow rate of 8 m3/min, the fluid gap use linear gel, and then produce the fastening of longitudinal cracks by injection of silica flour with the carrier liquid is a linear gel.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: group of inventions is referred to intensification of hydrocarbons production from formation by hydraulic fracturing. The method of proppant induced aggregation in hydraulic fracture crack includes makeup of the proppant carrier fluid, which viscosity is increased by usage of polymer gel capable of syneresis; injection of the proppant suspension and the above fluid to the well; initiation of gel syneresis with formation of proppant aggregations. According to the second version the method includes initiation of polyelectrolyte complex formation with proppant aggregations. According to the third version the method includes makeup of the proppant carrier fluid containing polymer at temperature less than its critical solution temperature; injection of the proppant suspension and the above fluid to the underground formation at temperature more than the lowest limit of polymer critical solution temperature with formation of proppant aggregations.

EFFECT: inhomogeneous distribution of proppant in hydraulic fracture cracks, which increases conductivity and productivity of the well.

31 cl, 2 tbl, 12 ex, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: treatment method of underground hydrocarbon-containing formations involves the following: a) provision of a composition including a thickening initiator measuring pH, and a polymer capable of hydration in a certain pH range; b) pumping of a composition with pH value beyond the limits of the above pH range; c) activation of an action of pH thickening initiator for displacement of pH composition to the above range of its values, and d) provision of a possibility of increasing viscosity of the composition and shaping of a plug. According to another version, a processing method of underground hydrocarbon-containing formations involves the following: a) provision of a composition containing a polymer capable of hydration in a certain pH range; b) pumping of the composition with pH value beyond the limits of the above pH range; c) provision of a pH changing thickening initiator; d) activation of the action of the thickening initiator for displacement of pH composition to the above range of its values, and e) provision of a possibility of increasing viscosity of a composition and shaping of a plug. The invention has been developed in dependent claims.

EFFECT: improving efficiency of initiation and control of plug formation.

15 cl, 5 ex, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: in a carbonaceous oil deposit development method that includes drilling of horizontal wells with a core sampling from the productive formation, performance of core laboratory tests, acid treatment and multiple hydraulic fracturing of the formation in these wells, according to the invention the core is sampled at different sections along the whole length of the horizontal shaft. The sampled core is subjected to the laboratory tests to determine the fracturing pressure, at that the sections are identified along the shaft where the minimum fracturing pressure Pmin, MPa, and the maximum fracturing pressure Pmax, MPa is required. Each section is treated by acid; at that the acid concentration for each section is set as identical. During the acid treatment each treated section of the formation is isolated temporarily by packers from the remaining part of the well. Then multiple proppant hydraulic fracturing of the formation is made under pressure that does not exceed Pmax. At that at the sections, where Pmax is required the acid treatment is performed in a volume of Qmax, m3/m, at the sections where Pmin is required the acid treatment is performed in a volume not exceeding 10% of the maximum value. At the remaining sections the volume of the injected acid is defined proportionally to the obtained fracturing pressure in compliance with the following ratio: Qn=QminQmaxPminPmax(PnPmin)+Qmin, where Qn is the specific volume per meter of the thickness, which is required for the injection to the nth section of the formation along the horizontal shaft, m3/m, Pn is the required fracturing pressure at the nth section of the formation along the horizontal shaft, MPa.

EFFECT: improved sweep efficiency and increased oil recovery of the oil deposit.

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FIELD: oil and gas industry.

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EFFECT: improved reliability of hydraulic fracturing for low-permeable bed with clay layers and bottom water.

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FIELD: oil and gas industry.

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EFFECT: simulation of the well opening the low-permeable formation.

3 ex

FIELD: mining.

SUBSTANCE: method involves drilling of a horizontal well, lowering to a vertical part of the well of a casing string and its cementing, lowering of a pipe string with a packer to a well, seating of the packer, formation of fractures of formation hydraulic fracturing (FHF) in the horizontal well shaft by pumping via the pipe string of fracturing fluid, and fixation of fractures by pumping of carrier fluid with proppant. The horizontal shaft is drilled perpendicular to direction of minimum main stress. FHF is performed by pumping of fracturing fluid with flow rate of 2-3 m3/min with formation of a longitudinal fracture in the formation relative to the open horizontal part of the well; crosslinked gel is used as fracturing fluid; then, fixation of a longitudinal fracture is performed by pumping via the pipe string of proppant of large fraction with carrier fluid - crosslinked gel. Then, FHF is performed by pumping of fracturing fluid with flow rate of 7-9 m3/min; line gel is used as fracturing fluid; after that, fixation of branched FHF fractures is performed by pumping of proppant of small fraction with carrier fluid - line gel.

EFFECT: improving FHF efficiency and reliability.

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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

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: ceramics.

SUBSTANCE: invention relates to manufacture of molded ceramic materials for use as propping agent in production of liquid and gaseous fluids from bored wells. Method comprises briquetting and heat treatment of aluminosilicates kaolin at 1150-1250оС. Resulting mix is ground to average grain size 3-5 μm and loaded into granulator. Before granulation, 1.2-3.0% mineralizer and 5-10% plasticizer are added. Mix is moistened with dozed amount of organic binder and stirred to form granules. At the end of granulation, fired ground material for powdering granules is added in amount 1.2-3.0%. Granules are dried and screened to isolate desired fraction, which is subjected to final firing at 1370-1450оС for 30-60 min and then re-screened into commercial fractions.

EFFECT: enabled manufacture of granules having low loose density and high strength allowing their use at depths up to 14000 feet (4200 m).

3 cl, 1 dwg, 1 tbl, 3 ex

FIELD: oil and gas production.

SUBSTANCE: proppant used in oil production involving hydraulic fracturing of formation contains ceramic granules coated with novolac resins supplemented by catalytic aqueous urotropin solution in organosilicon emulsion. Proppant preparation method comprises preparing granules and coating them. The latter operation is carried out as follows. Granules are heated to 150-160°C, dry novolac resin and catalytic urotropin solution are added at stirring in two equal portions with respect to the weight of resin and urotropin. When dropping temperature achieves 95-100°C, organosilicon emulsion is added provide following proportions of ingredients: 5.0-8.0% of novolac resin, 1.5-3.0% of 33% urotropin solution, 0.1-0.3% of organosilicon emulsion, and ceramic granules - the rest. Granules are finally cooled. Organosilicon emulsion is prepared at emulsion-to-water ratio 1:10.

EFFECT: increased strength of ceramic proppant and improved its quality due to resin coating applied with separating emulsion.

2 cl, 1 dwg, 1 tbl, 2 ex

FIELD: oil and gas production.

SUBSTANCE: fluid contains, wt %: industrial-grade powdered lignosulfonates 26.4-31.7, potassium chloride 4.9-5.9, aluminum sulfate 1.2-1.50, borax 0.4-0.5, formation water 40.3-44.7, and sweet water in proportion to formation water as 1:(1.98-1.99).

EFFECT: improved process parameters due to improved structurally mechanical properties of fluid, raised viscosity thereof, high sand-retention ability, and possibility of controlling lifetime without loss in high technological characteristics.

1 tbl, 2 ex

FIELD: oil and gas production.

SUBSTANCE: in a method of preparing propping agent including grinding, hydration, molding, drying, and calcinations of raw material, the latter is natural bentonite clay containing more than 90% montmorillonite, molding of spherical granules of propping agent 200 to 400 μm and 420 to 850 μm in size involves spray drying technique and molding of granules more than 850 μm in size is accomplished using beading process, and calcinations is carried out at 600-650°C. Method is applicable for use in intensification of oil and gas inflow from producing beds.

EFFECT: reduced expenses of hydraulic fracturing of formation.

2 tbl

FIELD: oil and gas production.

SUBSTANCE: invention relates to production of proppants, i.e. splitting granules, used in oil and gas production via breakdown way. Proppant of invention is obtained from caked two-component aluminosilicate fees in the form of granules with density 2.2-3.0 g/cm3 and 0.2-2.5 mm in size consisting of nucleus and shell, wherein one of components of aluminosilicate feed, which forms granule nucleus is a low-alumina substance containing less than 30% of alumina: coal combustion ashes, preliminarily fired kaolin, nepheline, nepheline syenite, feldspar, shale, or alumina production slime waste, and other component of aluminosilicate feed, which forms granule shell, is a high-alumina substance containing above 70% alumina: alumina dust of electrofilters of aluminum hydroxide calcination furnaces, industrial alumina, preliminarily fired bauxite, and exhausted catalysts based on active alumina form. Feed contains 50.0-95.0% low-alumina substance and 5.0-50.0% high-alumina component. In a method for production of proppant from two-component feed including (i) granulation upon addition of binding component in mixer-granulator provided with plate cup rotating at constant speed and rotor-type stirrer whose rotation speed is varied in dependence of granulation stage, (ii) drying, (iii) sizing of fried granules, (iv) firing of granules in rotary furnace, and (v) sizing of fired granules to form commercial fractions, when obtaining above-indicated proppant, low-alumina substance is used in the first granulation stage and, after granules 0.15-2.0 mm in size are formed, second granulation stage comprises addition of high-alumina substance into granulator followed by further granulation until granules 0.2-2.5 mm in size are obtained. Preliminary firing of low-alumina substance (as defined above) is carried out at 700-1200°C and the same of high-alumina substance (as defined above) at 700-1400°C. Firing of dried granules id effected at 1100-1600°C. Binding substance is used in the form of aqueous suspension of an organic binder (carboxymethylcellulose, methylcellulose, low-grade lignosulfates) of aqueous suspension of clay, wherein concentration of suspended binder is 1.0-10.0%. Aqueous suspension is added during granulation process in amounts 10.0 to 40.0% of the weight of initial feed.

EFFECT: enabled production of proppants from accessible raw materials (production wastes) without complication of existent technology.

9 cl, 1 tbl, 14 ex

FIELD: oil production from drill-holes, particularly to stimulate productive beds by bed drainage and formation fluid filtering channel forming.

SUBSTANCE: method involves forming at least one opened horizontal well bore or one opened horizontal well bore with at least one opened side branch bore extending along the strike in productive area thereof; filling the bore with hydrophobic granular material, wherein bore and branch bore filling is performed in portions along with compacting each portion of granular material up to material subsidence and existent natural bed cracks opening under the action of material compaction; installing and fixing filtering unit in well bore. Device comprises sectional or continuous pipe string, conical flared body fixedly secured to pipe string. Arranged in the body is system including pusher with central through channel and with cone. The pusher is hung inside the body and connected to cylindrical spring so that the pusher may be axially displaced and perform self-oscillations. Flared body and pusher cone are axially joined and form valve couple. Freely sliding impact bush is located over pusher anvil.

EFFECT: increased hydrocarbon material output and increased oil and gas recovery factors.

4 cl, 1 ex, 3 dwg

FIELD: mining, particularly to weaken coal bed and to increase recovery of desorbed methane.

SUBSTANCE: method involves drilling well from well surface; casing the well; exposing coal bed; injecting working liquid in the coal bed, wherein the working liquid has pressure enough to perform hydraulic fracturing of the bed and flow rate providing elongated crack forming. Salt solution, gel with propane or gel decomposition substance are used as the working liquid. Propane content in gel is gradually increased from 50-100 kg/m3 to 500-600 kg/m3 as cracks are formed and fixed. The salt is potassium chloride or propant having particle diameters of 20-40 meshes. Coal bed exposing is performed by cutting casing pipe and cement ring in central bed zone within interval of 100 mm so that the ready hole has height of 50-100 mm. The coal bed may be also opened by coal bed drilling below casing pipe for depth of 50-100 mm.

EFFECT: increased formation weakening and increased methane recovery.

3 cl, 2 ex

FIELD: technology for increasing recovery of hydrocarbons from foliate geological formations, which contain absorbed condensed gaseous hydrocarbons, by processing such geological formations with dehydrating compositions, containing surfactants, which cause dampening of geological formation with oil or leave aforementioned formations dampened with oil.

SUBSTANCE: methods may be used for excitation of influx of fluid substance from geological formation into well, or hydro-acid fracture, or hydraulic fracture, during maintenance or major repairs and when increasing influx from natural cracks or from geological formations never subjected to influx stimulation.

EFFECT: increased water removal efficiency, minimization of migration of low dispersion particles, increased extraction of hydrocarbons from underground formations, containing absorbed and compressed gaseous hydrocarbons.

3 cl, 4 ex, 6 tbl

FIELD: measuring technique.

SUBSTANCE: method comprises allowing the main liquid to flow through the Coriolis flow meter, measuring the density of the main liquid, and transmitting the signal containing measured value of the signal to the control system, adding the filler to the main liquid, allowing the mixture to flow through the Coriolis flow meter, and transmitting the measured value of density to the control system.

EFFECT: enhanced accuracy.

19 cl, 5 dwg

FIELD: manufacture of granulated materials used as wedging filler and gravel filter for control of sand flow.

SUBSTANCE: proposed granulated material has particles coated with two or more layers of hardenable coat; coated particles include granulated substrate and at least one layer of first curable resin practically embracing the substrate and at least one layer of second curable resin practically surrounding at least one layer of first curable resin; amount of curing agent in layer of first curable resin and in layer of second curable resin is lesser than that at which resin is practically cured.

EFFECT: increased compressive strength; increased elasticity; high strength at curing; forming strong blocks of wedging filler at pumping granulated material into well.

86 cl, 1 dwg, 12 tbl

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