Method for formation hydraulic fracturing in horizontal open well shaft

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.

2 dwg

 

The invention relates to the oil and gas industry, in particular to a method of hydraulic fracturing in the open horizontal wellbore uncovered reservoir low reservoir permeability and porosity.

The known method of multiple hydraulic fracturing in horizontal wellbore (patent RU №2472926, IPC EV 43/267, publ. 20.01.2013, bull. No. 2), including lowering the packer into the well on a string of 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 supply of fracturing fluids through the filter installed in each of the respective each of these intervals portions of the horizontal wellbore isolation of other parts, thus determine the direction of the horizontal wellbore relative to the direction of the minimum principal stress, then isolate the interval subject to hydraulic fracturing - fracking - from other sections of the horizontal trunk landing dual packers, then open the valve, placed inside the pipe string between double packers in front of the filter, if the direction of the horizontal shaft parallel to the direction of the minimum principal stress, hydraulic fracturing place is and produce a discontinuous injection fluid with the formation of transverse cracks on the horizontal shaft, with the subsequent fastening of the transverse cracks by injection of aluminosilicate proppant, with a gradual increase its fractions from 20/40 to 16/30 mesh, if the direction of the horizontal shaft perpendicular to the direction of the minimum principal stress, hydraulic fracturing produce a discontinuous injection fluid with the formation of horizontal cracks on the horizontal shaft, with the subsequent fixing of the horizontal cracks by injection with a lightweight proppant with a grain size of 20/40 mesh, after fracturing the well close to the technological pause for 0.5 h, then at the wellhead on the string of pipe installed adjustable fitting and produce waste spout proppant fluid from the reservoir through the column pipe at the wellhead before the closing of the valve while in the process of spout control valve ensures that the pressure in the string of pipe got 2-3 MPa less pressure when opening the well after the technological pause, and then produce raspaculo packer and move the string of pipe to another part of the horizontal shaft, and the above-described process for conducting hydraulic fracturing in horizontal wellbore repeat depending on the number of intervals of the horizontal shaft fitted with filters in its various parts.

The disadvantages of the method are the I:

- first, the low efficiency of the method in the reservoir low reservoir permeability and porosity, due to the weak attachment of proppant in the longitudinal and transverse cracks formed from the horizontal wellbore, therefore, in the subsequent extraction of the transverse and especially longitudinal cracks formed in the reservoir low reservoir permeability and porosity, horizontal wellbore will go grain of proppant that will lead to the closure of cracks and sharp decrease in throughput of cracks formation in the near-wellbore zone;

- secondly, the long duration of fracturing associated with the need for fastening the casing (liner) in a horizontal wellbore, as well as hydro-mechanical slot perforation of the casing (shank) and subsequent interval of hydraulic fracturing in horizontal wellbore with trim packer each interval when the frac;

- thirdly, the high material and financial costs for implementation of the method associated with the service of horizontal wellbore casing (shank) with subsequent cementing;

- fourth, low reliability, due to the high probability is awn clogging of the productive formation during cementing of the casing (liner) in a horizontal wellbore, as well as the high probability of accidents dual packers in the work, due to the complications of planting packers and respecrive in each interval of the horizontal wellbore. In addition, when the dual design of the packers is almost impossible to ensure the integrity of both packers at high pressures (up to 40 MPa) during hydraulic fracturing.

There is a method of hydraulic fracturing in horizontal wellbore (patent RU №2401942, IPC EV 43/26, publ. 20.10.2010, bull. No. 29), including drilling, cementing horizontal borehole; lowering the pipe string with the packer in the well, the perforation and the formation of cracks hydraulic fracturing injection of fracturing fluid in a horizontal wellbore sequentially, beginning with the end farthest from the axis of the borehole, indicating a horizontal wellbore with the reservoir, while during the next hydraulic fracturing each perforated area through which produce hydraulic fracturing, isolated from the rest of the columns packers, while drilling the horizontal well bore is carried out in oil-saturated part of the productive formation with cementing the annular space between the casing and rock horizontal wellbore and perforation, azimuth oriented intervals produced using hydro-mechanical slot punch for one trip, then down the packers, cutting off each interval equal to the length of the formed slit, from the rest of the column and hydraulic fracturing in horizontal section of the wellbore to produce sequentially, starting with the furthest from the vertical axis of the wellbore, the perforated section of the horizontal wellbore, and hydromechanical slit perforation perform bilateral formation of cracks, which are located relative to each other by 180° in the vertical plane opposite each other relative to the axis of the horizontal wellbore in a single interval, or perform unilateral hydromechanical slit perforation rotated through 180° in a vertical plane about the axis of the horizontal wellbore, alternately through each subsequent interval is staggered by the length of the formed slit or at a small thickness of the productive formation and the presence of active bottom water produce unilateral hydromechanical slit perforation in the direction of the roof seam.

The disadvantages of this method are:

- first, the low efficiency of the method in the reservoir with low call is Cherskii filtration-capacitive properties, due to the lack of attachment of cracks, which leads to the closure of cracks and sharp decrease in throughput of cracks formation in the near-wellbore zone;

- secondly, low reliability, due to the high probability of clogging of the productive formation during cementing of the casing (liner) in a horizontal wellbore, as well as problems with clipping intervals fracturing using packers, namely the occurrence of accidents in the well associated with the risk of leaking planting packer, sliding packer horizontal wellbore, possible loss of integrity of the packer at high pressures (up to 40 MPa);

- thirdly, the long duration of fracturing associated with the need for fastening the casing (liner) in a horizontal wellbore, as well as hydro-mechanical slot perforation of the casing (shank) and subsequent interval of hydraulic fracturing in horizontal wellbore with trim packer each interval when the frac;

- fourth, high material and financial costs for implementation of the method associated with the service of the horizontal barrel shank with its subsequent cementing.

The closest in technical essence is a way is creating a network of cracks in rock formations to extract hydrocarbons from the formation (patent WO 2012083463 A1, IPC EV 43/267 from 22.12.2011), including the drilling of horizontal wells, the descent into the vertical portion of the well casing and cementing, the descent of the tubing with the packer in the borehole interval landing packer and the formation of a network of natural and emerging fissures in the formation (reservoir) by injection of an aqueous solution without sludge (frac fluid) into the well on the string of pipe and under conditions suitable for expansion, offset and (or) hydraulic connection of natural cracks, the formation of a large network of cracks, which is in hydraulic communication with a larger network of natural fractures, forcing many suspensions, containing carrier fluid medium (liquid medium) and large granular propping fillers (proppant), into the well by a series of injections (pointervalue).

The disadvantages of this method are:

- first, the low efficiency of the method in the reservoir low reservoir permeability and porosity due to fixing cracks large proppant, which leads to their rapid removal in horizontal wellbore almost immediately after starting the operation of the wells and, consequently, to the closure of cracks and sharp decrease in permeability (bandwidth) crack formation in the near-wellbore zone;

- secondly, low reliability, Bukovina problems with clipping intervals frac packers, namely, the occurrence of accidents in the well associated with the risk of leaking planting packer, possible loss of integrity of the packer at high pressures (up to 40 MPa);

- thirdly, the long duration of fracturing associated with the conducting interval of hydraulic fracturing in the open horizontal wellbore with trim packer each interval when the frac;

- fourth, high material and financial costs for implementation of the method associated with prolonged duration of implementation of the method.

The technical objectives of the proposals are to increase the effectiveness of hydraulic fracturing through the creation of a horizontal wellbore first longitudinal cracks, and then from longitudinal cracks network of branched cracks followed by filling in the cracks proppant different factions, allowing to minimize the proppant in the horizontal wellbore during subsequent operation of the well, thereby to eliminate the closure of cracks and to maintain permeability in the near well zone, and increase reliability by eliminating clipping each interval frac packers, shortening the duration of fracturing and the reduction of material and financial costs associated with implementing method.

A technical problem solved by way of hydraul the ical fracturing in the open horizontal wellbore, includes drilling of horizontal wells, the descent into the vertical portion of the well casing and cementing, the descent of the tubing with the packer in the well, landing packer, the formation of cracks hydraulic fracturing in horizontal wellbore injection on the column of fluid pipes break, fixing cracks by injection of a carrier fluid with proppant.

What's new is that the horizontal wellbore drilled at the seam perpendicular to the direction of the minimum principal stress, lowering a string of pipe with a packer in the well and put the packers in the vertical part of the borehole, produce hydraulic fracturing in the open horizontal wellbore injection of fracturing fluid through the string of pipe with a flow rate of 2-3 m3/min with the formation of longitudinal cracks in the reservoir relative to the open horizontal part of the well, and as of fracturing fluid used cross-linked gel, and then generate fastening of a longitudinal crack injection on the column of pipes proppant large fraction of liquid carrier - linked gel, and then produce hydraulic fracturing is the injection of fracturing fluid through the string of pipe through a horizontal well bore and the longitudinal hydraulic fracture with a flow rate of 7-9 m3/min, and as frac fluid use linear gel, and then produced the lead fastening branched cracks hydraulic fracturing injection of proppant fines with the carrier fluid is linear gel.

The invention consists in the fact that after creating a longitudinal vertical cracks produce clogging proppant perimeter cracks, so with further increase of the rate of injection is "inflating" cracks and increase its length, which leads to bending of the surface longitudinal cracks. When exceeding the bending stresses above the tensile strength of the reservoir rock is cracking, transverse plane of the longitudinal cracks. Upon further movement of the transverse cracks in the rock formation they inevitably spread in the direction of the minimum principal stress, which leads to the formation of branched cracks (see Fig.2).

In figures 1 and 2 schematically and sequentially shows the proposed method.

The method is implemented as follows.

Horizontal shaft 1 (see Fig.1) well 2 drilled at layer 3 perpendicular to the direction of the minimum principal stress is σmin.

Lower casing 4 in the vertical portion 5 of the bore 2 and cement.

In the proposed method of hydraulic fracturing in the open hole and produce a common filter, and not pointervalue unlike the prototype, which allows to reduce the duration of fracturing and to reduce material and financial costs of implementing method.

Later in the casing 4 well 2 put the number of the nnu pipes 6, for example the column tubing (tubing) with a diameter of 89 mm according to GOST 633-88 with the packer 7. Put the packer 7 in the casing 4 of the vertical portion 5 of the bore 2.

As packer 7 is used, for example, passing the packer to anchor mechanical rotary installation PRO-AM-AG(f) or PRO-AM-AG(f) (100 MPa) manufactured by scientific-production firm "Packer" (, Oktyabrsky, Republic of Bashkortostan, Russian Federation).

The proposed method can improve the reliability of performance of hydraulic fracturing in horizontal holes 1 hole 2 due to the exclusion interval planting packer in the horizontal section 1 bore 2 when the cut-off intervals frac packers, which eliminates the occurrence of accidents in the well associated with the planting of the packers in the horizontal section 1 wells 2.

Then we proceed to the hydraulic fracturing 3 in the open horizontal shaft 1 well 2. Determine the total volume of fracturing fluid for fracturing. The volume of fracturing fluid depends on the viscosity of fracturing fluid and filterability, the length of the horizontal wellbore and the height of the formation and permeability of rocks in the bottom zone of the well, the rate of injection fluid and the pressure of the gap.

According to experimental data, the volume of fracturing fluid for horizontal shaft 1, which revealed the reservoir 3 by a height of 5 m in length is 200 m, varies from 90 to 100 m3.

We will take for our wells, the total volume of fracturing fluid:

Vp=100 m3frac fluid, from which the volume of the fluid gap Vp1=50 m3- to create a longitudinal cracks 8 (see Fig.1) hydraulic fracturing, and the remaining volume of fracturing fluid Vp2=100 m3- 50 m3= 50 m3to create branched cracks 9', 9" ... 9n(see Fig.2) relative to the horizontal wellbore from longitudinal cracks hydraulic fracturing.

To create a longitudinal cracks 8 (see Fig.1) hydraulic fracturing to use the liquid gap, which used cross-linked gel with a dynamic viscosity of 150 CP. For example, using cross-linked gel hydrocarbon-based (see Chapter 3 of the monograph S. A. Ryabokon as the new "Technological the completion fluids and workover (JSC NPO Burenie, 2006, S. 153)), which includes the polymer solution (MO-NT), cross-linking in the hydrocarbon, and the time destructor (MO-NT-hydrophobic modification PAA) My-T-Oil (Halliburton).

The column pipe 6 pumped fluid gap (cross-linked gel) in outdoor horizontal well 1 well 2 with a flow rate of 3 m3/min to form a longitudinal crack 8 hydraulic fracturing relative to the open horizontal wellbore 1 well 2. About the formation of longitudinal cracks seen in the reduced-pressure injection and increase the injectivity of the reservoir 1. For example, when the injection of cross-linked gel into the reservoir 3 has reached a pressure of 30 MPa, due to the formation of longitudinal cracks 8 in the reservoir 3 has been falling pressure injection of cross-linked gel at 25%, i.e. to 22.5 MPa, while the injectivity of the reservoir 3 has increased by 50%, i.e. up to 4.5 m3/min

In the process of formation of longitudinal cracks 8 on the string of pipe 6 into the reservoir 1 was pumped liquid break - linked gel in the volume, for example, 20 m3. Generate fastening of the longitudinal cracks 8 injection on the column of pipes 6 large proppant 10, for example fractions 12/18 mesh (grain size of 0.8-1.0 mm) with the carrier fluid (crosslinked gel) in the remaining volume of the crosslinked gel 50 m3- 20 m3= 30 m3.

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

Cross-linked gel hydrocarbon-based has a high viscosity in the reservoir, so when it is injected into the reservoir with a flow rate of 3 m3rpm provides the creation of a wide, deep penetrating cracks with good filling wedge material (proppant). When degradation does not form a precipitate, does not damage the reservoir and gasket proppant.

Continue hydraulic fracturing 3.

To create branched cracks 9', 9" ... 9n(see Fig.2) hydraulic fracturing relative to the horizontal shaft 1 well 2 of longitudinal cracks 8 hydraulic fracturing use linear gel with a dynamic viscosity of 30 JV in the remaining volume of the liquid fracturing Vp2=50 m3.

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

The column pipe 6 (see Fig.2) inject the fluid gap (linear gel) in outdoor horizontal well 1 well 2 with a flow rate of 8 m3/min, and from longitudinal cracks 8 hydraulic fracturing are formed branched cracks 9', 9" ... 9nhydraulic fracturing relative to the horizontal shaft 1 well 2 of longitudinal cracks 9 hydraulic fracturing.

About the formation of branched (longitudinal and transverse) cracking 9', 9" ... 9nhydraulic fracturing indicate the pressure drop injection and increase the injectivity of the reservoir 1. For example, when the injection line of the gel in the reservoir 3 has reached a pressure of 33 MPa, due to the formation of longitudinal and transverse cracks 9', 9".... 9nhydraulic fracturing has occurred, the pressure drop injection of cross-linked gel at 25%, i.e. to 24,75 MPa, while the injectivity of the reservoir 3 has increased by 30%, i.e. to 10.4 m3/min

In the process of formation of branched cracks 9', 9".... 9nthe column pipe 6 into the reservoir 1 was akachan liquid break - linear gel volume, for example, 25 m3. Generate fastening of the longitudinal and transverse cracking 9', 9".... 9ndownload the string of pipe 6 proppant 11 small fraction, such as quartz flour with the carrier fluid (linear gel), the remaining amount of linear gel 50 m3- 25 m3= 25 m3.

As a small proppant used quartz flour with grain size of 0.05-0.15 mm which is produced according to TU-001-16767071-99, supplier LLC "Trade house "Quartz" (, Ekaterinburg, Russia).

Linear gel has a small friction losses in the pipes that the great download speed is 8 m3rpm allows you to penetrate deep into the reservoir and provides a uniform deposition of small proppant in the longitudinal fissure 8, and branched cracks 9', 9"... 9n.

Increases the efficiency of the implementation of the method in the reservoir low reservoir permeability and porosity due to the attachment longitudinal cracks 8 proppant large fraction, and branched cracks 9', 9".... 9nproppant fines. In the grain of proppant fines associated grain of proppant major faction in the longitudinal fissure 8, excluding the mobility of the latter, which eliminates the interlocking longitudinal cracks 8, and the output of proppant into the open horizontal well 1 well 2 reservoir 3 and saves it to prop the knymi capability.

The process of hydraulic fracturing a horizontal well bore is completed. Rapacuronium packer 7 and extracted from wells 1 column pipe 6 with the packer 7. Down in the hole 2 operational equipment (Fig.1 and 2 is not shown) and launch into operation.

The proposed method of hydraulic fracturing in the open horizontal wellbore can improve the efficiency of hydraulic fracturing through the creation of a horizontal wellbore first longitudinal cracks, and then from longitudinal cracks network of branched cracks, followed by filling in the cracks proppant different factions, allowing to minimize the proppant in the horizontal wellbore during subsequent operation of the well, thereby to eliminate the closure of cracks and to maintain permeability in the near well zone. Also, the proposed method can improve the reliability by eliminating clipping each interval frac packers, reduce the duration of fracturing and to reduce material and financial costs of implementing method.

The method of hydraulic fracturing in horizontal wellbore that includes drilling of horizontal wells, the descent into the vertical portion of the well casing and cementing, the descent of the tubing with the packer in the well, landing packer, the formation of t is Emin hydraulic fracturing in horizontal wellbore injection on the column of pipes of fracturing fluid, fixing cracks by injection of a carrier fluid with a proppant, wherein the horizontal wellbore drilled at the seam perpendicular to the direction of the minimum principal stress, lowering a string of pipe with a packer in the well and put the packers in the vertical part of the borehole, produce hydraulic fracturing in the open horizontal wellbore injection of fracturing fluid through the string of pipe with a flow rate of 2-3 m3/min with the formation of longitudinal cracks in the reservoir relative to the open horizontal part of the well, and as of fracturing fluid used cross-linked gel, and then generate fastening of a longitudinal crack injection on the column of pipes proppant large fraction of liquid carrier - linked gel, and then produce hydraulic fracturing is the injection of fracturing fluid through the string of pipe through a horizontal well bore and the longitudinal hydraulic fracture with a flow rate of 7-9 m3/min, and as frac fluid use linear gel, and then generate fastening of branched cracks hydraulic fracturing injection of proppant fines with the carrier fluid is a linear gel.



 

Same patents:

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.

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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.

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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.

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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: 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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