Carbonaceous oil deposit development method

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: Q n = Q min Q max P min P max (P n P min ) + Q min , 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.

1 dwg

 

The invention relates to the oil industry and may find application in the development of low permeability heterogeneous carbonate oil reservoirs.

Known method for hydraulic fracturing of carbonate reservoir, including perforation of the walls of the borehole in the desired interval channels depth not less than the length of the zone of stress concentration in rocks from the wellbore, the descent into the well of the column tubing with a packer, sealing the annulus above the packer perforated interval, the well is filled up the process liquid 0.2-0.4 volume of the wellbore. Injection into the well of the gel-like fluid gap are equal portions in 3-5 cycles with the fix after them portions acid containing 0.7-0.75 gel volume of fracturing fluid, upon completion of the last cycle the pumping of oil or fresh water is carried out in the fold column volume of tubes, followed by aging for 1-2 hours, remove the reaction products of the acid with the breed, remove the retainers and remove it with a column of pipes from the well (patent RF 2455478, CL. E21 W/267, E21 W/27, publ. 10.07.2012).

The disadvantage of this method is its low efficiency in conducting in a heterogeneous aquifer, particularly those containing low-permeability areas. Accordingly, the recovery of the known method of Nevis�Kai.

The closest to the technical nature of the proposed method is a method of hydraulic fracturing of carbonate reservoir, including perforation of the walls of the borehole in the desired interval channels depth not less than the length of the zone of stress concentration in rocks from the wellbore, the descent into the well of the column tubing with a packer, sealing the annulus above the packer perforated interval, conducting hydraulic fracturing involves injecting into the well of the gel-like fluid gap phases and acid. Hydraulic fracturing of carbonate formation is carried out sequentially in several stages, with the first stage is pumped gelled fracturing fluids in the amount of not less than 6 m3at the second stage is pumped gelled fracturing fluids mixed with propping agent, and as a propping agent used metal sphere fractional composition 12/18, or 16/20, or 20/40 mesh made of metal magnesium, wherein the propping agent is pumped portion with a gradual increase of its concentration in a mixture of gelled fracturing fluids, the third phase is injected displacement fluid - technical water in a volume equal to the internal volume lowered into the well column tubing, on the fourth floor�PE pumped hydrochloric acid in the amount of not less than 0.6-0.7 of the total volume of the prepared gel-like fluid gap, at the fifth stage is injected displacement fluid - technical water in a volume equal to the internal volume lowered into the well column tubing, plus 0.2 m3(patent RF №2509883, CL E 21 43/267, E21 W/27, publ. 20.03.2014 - prototype).

The disadvantage of this method is the low enrolment and low oil recovery in developing heterogeneous reservoir. Held in early technology provantage fracturing causes of fracture are on the site of the reservoir, requiring less pressure fracturing and characterized the best reservoir properties. Subsequent injection of acid leads not only to reactions with magnesium, but also to the breed, which further increases the permeability of the site. In the end, more low-permeability zones remain rough.

The proposed invention solves the problem of increasing the enrolment and the increase of oil recovery from oil reservoirs.

The problem is solved in that in the method of development of the carbonate oil reservoirs, including horizontal drilling with coring a productive formation, the laboratory testing of core samples, acid treatment and reuse of hydraulic fracturing in the wells, according to the invention the core samples taken at different locations along the entire length of the mountains�horizontal barrel, the selected core is carried out laboratory tests to determine the pressure of hydraulic fracturing, with the detected portions along the wellbore that require a minimum of PminMPa, and the maximum PmaxMPa, the pressure of hydraulic fracturing, conduct pre-acid treatment of each plot, and the concentration of acid for each section, ask the same, during the acid treatment, each treated area of the reservoir temporarily packers isolate from the rest of the wells, then carry out multiple property hydraulic fracturing under pressure not exceeding Pmaxand in areas where required Pmaxspend an acid treatment in the amount of Qmaxm3/m, where Pminacid treatment is carried out in a volume of not more than 10% of the maximum, i.e. Qmin=0...0,1·Qmaxin other areas the volume of the injected acid is determined in proportion to the received fracturing pressures according to the equation:

Qn=Qmin-QmaxPmin-Pmax(Pn-Pmin )+Qmin,

where Qnunit rate per meter of thickness, the volume of acid required for injection in the n-th section of the reservoir along a horizontal wellbore, m3/m

Pnis the required pressure of hydraulic fracturing on the n-th section of the reservoir along a horizontal wellbore, MPa.

Summary of the invention

The oil recovery, low permeability heterogeneous carbonate oil reservoirs, having sections with permeability, characterized by an order, and develop horizontal wells, is significantly affected by the reservoir sweep. To increase widely used acidizing and fracturing. However, heterogeneity along the horizontal wellbore leads to uneven development, because the plots vary in permeability, the desired pressure of hydraulic fracturing, rock density, etc., Existing technical solutions do not fully allow in such conditions along the horizontal wellbore multiple hydraulic fracturing and acid treatment and to increase enrolment and oil recovery. Low-permeability zones remain not involved in the development, and produced highly permeable and water out pretty quickly. The proposed invention Resch�is the task of raising the enrolment rate and the increase of oil recovery from oil reservoirs. The problem is solved as follows.

Fig. 1 is a schematic view of part of an oil reservoir, the reservoir which is penetrated by a horizontal wellbore with the process of carrying out acid treatment. Notations: 1 - reservoir, 2 - horizontal well, 3 is a horizontal barrel, 4 - flexible tubes, 5 - filter 6 - dual packers, I, II, III, IV - areas of layer 1 along the horizontal wellbore 3, wherein the required pressure of hydraulic fracturing, h1h2h3h4- the average net pay thickness of the respective sections I, II, III, IV.

The method is implemented as follows.

The plot of the oil reservoir, the reservoir 1 which is represented by carbonate reservoir and clean the oil area, open horizontal open borehole 2 by a horizontal barrel 3 (Fig. 1). In the process of drilling with layer 1 selected core in different locations along the entire length of the horizontal wellbore 3.

Next, the selected core is carried out laboratory tests to determine the pressure of hydraulic fracturing. Thus identify areas along the trunk that require a minimum of PminMPa, and the maximum PmaxMPa, the pressure of hydraulic fracturing. For example, it has identified four of the stratum 1 along the horizontal wellbore 3 - I, II, III, IV with the corresponding average net pay thickness h 1h2h3h4.

In areas where the required maximum pressure of the hydraulic fracturing design and carry out an acid treatment that requires a minimum pressure of hydraulic fracturing, acid treatment is carried out in a volume of not more than 10% of the maximum, i.e. Qmin=0...0,1·Qmax. According to research by injection of acid in such areas the volume is larger than 10% of the maximum, leads to uneven subsequent development of the reservoir and consequently the low oil recovery.

In other areas the volume of the injected acid is determined in proportion to the pressures of hydraulic fracturing. Proportionality is linear, therefore, knowing PminPmax, Qmin, Qmax, we can write the system of equations of the form y=A·x+B:

Qmin=APmin+BQmax=APmax+B(1)

where A and B are coefficients of proportionality.

From the system of equations we find:

A=Qmin-Qmax Pmin-Pmax, (2)

B=Qmin-PminQmin-QmaxPmin-Pmax(3)

Thus, in General, if Qnunit rate per meter of thickness, the volume of acid required for injection in the n-th section of the reservoir along the horizontal wellbore 3, m3/m, and Pnis the required pressure of hydraulic fracturing on this n-th site, MPa, then the necessary amount of acid can be determined from the relation, substituting in the linear equation of expression (2) and (3):

Qn=Qmin-QmaxPmin-Pmax(Pn-Pmin)+Qmin (4)

According to research such an approach allows us to treat acid bottomhole formation zone and align the productivity along the horizontal wellbore 3 for subsequent provantage fracturing. Also the acid treatment is carried out with this approach, reduces the differences in the required pressure value of hydraulic fracturing.

The process of conducting acid treatment is as follows: in the barrel 3 wells pull on the flexible pipe 4, a filter 5, and the front and rear of the filter 5 is provided with double packers 6. The filter 5 is lowered to the "toe" of the barrel 3, i.e. in the phase IV subacromial packers 6, acid is pumped in the amount of Q4, selling technical liquid, maintain the necessary time rapacuronium packers 6. Then move the filter 5 in the phase III and conduct the same operations. Similarly treated consistently to the "heel" of the well remaining sections. Moreover, the concentration of acid for each section, ask the same. Temporary isolation of the treated area of the reservoir packers 6 from the rest of the wells to prevent the ingress of acid in other areas.

Then design and carry out multiple property hydraulic fracturing under pressure not exceeding Pmaxby any of the known technologies. Hydraulic crack fix proppant odnais well-known brands.

The borehole 2 is allowed in the work. The development leads to full cost-effective production of oil deposits.

The result of implementation of this method is to increase the enrolment and the increase of oil recovery from oil reservoirs.

An example of a specific embodiment of the method

The plot of the oil reservoir, the reservoir 1 which presents domanic sediments, carbonate reservoir and clean the oil area, open horizontal open borehole 2 by a horizontal barrel 3 (Fig. 1) length of 400 m. the Thickness of the oil zone varies along the wellbore in the range of 8-15 m.

The reservoir lies at a depth of 1650 m, the permeability varies in the range of 1-50 MD, averaging 8 MD and a porosity of 12%, the initial reservoir pressure 16 MPa, the viscosity of the oil at reservoir conditions 15 MPa·s.

In the process of drilling with layer 1 selected core in different locations along the entire length of the horizontal wellbore 3.

Next, the selected core is carried out laboratory tests to determine the pressure of hydraulic fracturing. As a result identified four of the stratum 1 along the horizontal wellbore 3 - I, II, III, IV. Average net pay thickness areas are: h1=8 m, h2=12 m h3=15 m, h4=11 m. the Required pressure fracturing was: P1=33 MPa, P2=30 MPa, P3=26 MPa, P4=29 MPa.

Thus�time, Pmin=P3=26 MPa, and Pmax=P1=33 MPa.

At the site I, where Pmaxdesign and carry out the acid treatment, the volume and concentration of acid Qmaxexpect one of the known methods. Accept for treatment of a solution of hydrochloric acid Hcl with a concentration of 16% and a specific volume per meter of thickness Q1=Qmax=2.0 m3/m. taking into account the thickness of layer I of area get V1=2,0·8=16 m3.

In section III, where Pmindesign and conduct a treatment with hydrochloric acid of the same concentration with a specific volume Qmax=0,1·Qmax=0,1·2=0.2 m3/m. taking into account the thickness of the layer III of area get V3=0,2·15=3 m3.

In sections II and IV of the volume of the injected acid is determined in proportion to the received fracturing pressures and calculated according to the formula (4).

Q2=Qmin-QmaxPmin-Pmax(P2-Pmin)+Qmin=0,2-2,026-33 (30-26)+0,2=1,2m3/m

Q4=Qmin-QmaxPmin-Pmax(P4-Pmin)+Qmin=0,2-2,026-33(29-26)+0,2=1,0m3/m.

Taking into account the thickness of the layer sections II and IV, V2=1,2·12=14,4 m3and V4=1,0·11=11 m3.

The process of conducting acid treatment is as follows: in the barrel 3 of the bore 2 is lowered at the flexible pipe 4, a filter 5, and the front and rear of the filter 5 is provided with double packers 6. The filter 5 is lowered to the "toe" of the barrel 3, i.e. in the section IV, subacromial packers 6. For hydrochloric acid treatment wellbore zones are special units (for example, CA-320). Pumped acid in a volume V4=11 m3, selling technical liquid (oil). After pushed through the�ing acid solution into the reservoir, close the valve on the discharge line, leave the hole for the reaction of hydrochloric acid solution with the breed and watch the pressure gauge at the rate of pressure decay.

Then rapacuronium packers 6, moves the filter 5 in the phase III and conduct the same operations, the acid is pumped into the volume V3=3 m3. Similarly treated consistently to the "heel" of the well other areas of the reservoir with the volume of acid V2=14,4 m3and V1=16 m3. Bottom-hole zone of the well is cleaned from the reaction products by the sample is swabbed.

Design and implement multiple property hydraulic fracturing under pressure not exceeding Pmax=33 MPa. Also start with the last section IV and consistently carry out hydraulic fracturing, to the I phase. Hydraulic crack fix proppant some of the famous brands (20/40 mesh).

The borehole 2 is allowed in the work. The development leads to full cost-effective production of oil deposits.

As a result of the development, which has limited the flooding of producing well 2 to 98%, was obtained from the plot of the oil Deposit 135,6 thousand tonnes of crude oil, the enrolment 0,673 D. units, the oil recovery factor (ORF) - 0,330 D. prototype units, ceteris paribus produced 117,5 thousand tonnes of crude oil, the enrolment 0,584 D. units, the oil recovery factor (ORF) - 0,286 D. units of Increase of oil recovery factor by t�the reception method - 0,044.

The proposed method allows to increase the oil recovery factor.

Application of the proposed method will solve the problem of increasing the enrolment and the increase of oil recovery from oil reservoirs.


Method development of the carbonate oil reservoirs, including horizontal drilling with coring a productive formation, the laboratory testing of core samples, acid treatment and reuse of hydraulic fracturing in the wells, characterized in that the core samples taken at different locations along the entire length of the horizontal wellbore, the selected core is carried out laboratory tests to determine the pressure of hydraulic fracturing, with the detected portions along the wellbore that require a minimum of PminMPa, and the maximum PmaxMPa, the pressure of hydraulic fracturing, conduct pre-acid treatment of each plot, and the concentration of acid for each section, ask the same, during the acid treatment, each treated area of the reservoir temporarily packers isolate from the rest of the wells, then carry out multiple property hydraulic fracturing under pressure not exceeding Pmaxand in areas where required Pmaxspend an acid treatment in the amount of Qmaxm3/m, where the demands�I P minacid treatment is carried out in a volume of not more than 10% of the maximum, i.e. Qmin=0...0,1·Qmaxin other areas the volume of the injected acid is determined in proportion to the pressures of hydraulic fracturing, according to the ratio:
Qn=Qmin-QmaxPmin-Pmax(Pn-Pmin)+Qmin
where Qnunit rate per meter of thickness, the volume of acid required for injection in the n-th section of the reservoir along a horizontal wellbore, m3/m
Pnis the required pressure of hydraulic fracturing on the n-th section of the reservoir along a horizontal wellbore, MPa.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: acid composition for acid treatment of production and injection wells in carbonate and terrigenous reservoirs contains the following, wt %: hydrochloric acid (24% or 36%) 25.0-50.0, alkyl benzene sulphonic acid containing in an alkyl group 12-14 atoms of carbon, 0.1-2.0, citric acid 0.5-3.0, acetic acid 3.0-12.0, methyl alcohol 3.0-10.0, OS-20 preparation 0.5-2.5, IKU-118 corrosion inhibitor 1.0-5.0, hydrofluoric acid (40%) 0.0-7.5, Feriks iron stabiliser 0.0-5.0, and water is the rest. An acid treatment method of the bottom-hole zone of a carbonate, terrigenous or mixed formation involves pumping to the well of the acid composition in the amount of 1.0-5.0 m3 per 1 m of perforated thickness of the formation, its forcing-through into the formation, exposure for the reaction during not more than 8 hours and further removal of reaction products; as an acid composition, there used is the above said composition or its solution in fresh water at the ratio of the above said composition to fresh water, which is equal to 1:1-1:2 respectively. The treatment method is developed in claims.

EFFECT: creation of a composition for acid treatment, which has low corrosion rate at formation temperatures; considerable improvement of efficiency of acid treatment.

3 cl, 3 tbl, 4 ex

FIELD: oil and gas industry.

SUBSTANCE: in this method of acid longitudinal hydraulic fracturing of low-permeable terrigenous collector to inner cavity of the production casing a slot perforator is run in, walls of the production casing are cut by means of vertical disc cutters of the slot perforator with forming of two longitudinal slots opposed at different height points within the interval from the foot to the roof of the producing formation. Through jet nozzles of the slot perforator hydrocarbon-based process fluid is injected and through longitudinal slots in the production casing the process fluid is washed at pressure that does not exceed pressure of hydraulic fracturing and filtration channels are thus formed in cement stone behind the production casing and ambient rock in the bottom-hole zone of the formation, which pass deep into the producing formation. Upon formation of the filtration channels the slot perforator is removed and downhole equipment consisting of a high-pressure packer and a circulating valve is run in to the well at the flow string. The packer is packed over the roof of the producing formation and filtration channels are washed with hydrochloric acid of 12% concentration with flushing to the producing formation depth of hydrocarbon-based process fluid injected to the well earlier. Thereafter below-packer space of the well is flushed by thickened mud acid consisting of hydrochloric acid of 12% concentration, hydrofluoric acid of 3% concentration and mud thickener of carboxymethyl cellulose to the formation depth as fracturing fluid and proppant material with formation of fractured slot. Upon completion of acid hydraulic fracturing and fixation of fractured slot, the slot is washed by hydrochloric acid of 12% concentration with destruction of mud thickener of carboxymethyl cellulose. Then the over-packer space of the well is washed by creating circulation in annular space and tubing space by means of the circulating valve and influx is induced from the producing formation by reduction of backward pressure. Upon development the well is introduced into operation with remaining downhole equipment, which was run in to the well during process of hydraulic fracturing.

EFFECT: increased square area and depth of the producing formation penetration at elimination of swelling conditions for clays contained in the reservoir.

3 ex, 7 dwg

FIELD: oil and gas industry.

SUBSTANCE: well completion method involves pumping of an acid solution by circulation with a well mouth by means of a jet nozzle arranged on the end of a flexible flush-joint pipe. Simultaneously with circulation of the acid solution, the flexible flush-joint pipe is being lifted out of the well at a speed that is not higher than the speed of filling the well shaft with an acid solution. After the horizontal shaft is filled with the acid solution, squeezing of the acid solution to the formation is performed at stepped pressure rise and exposure at each step. Process exposure is performed for a reaction of the acid solution with the rock, and inert gas pumping, fixing of a level recovery curve, well killing and well development is performed. First, a tubing string with starting clutches and with a funnel on the end is lowered into the well at the interval of the shoe of the production casing. The flexible flush-joint pipe with a jet nozzle is lowered inside the tubing. Before the acid is pumped to the formation, the horizontal shaft of the well at an open annular space is filled through the flexible flush-joint pipe with a water solution of a surface active substance (SAS). When the annular space is closed, the water solution of SAS is pumped to the formation. Process exposure is performed before oil floats up into the well. Then, the acid solution is pumped via the annular space. Process exposure is performed for 2-4 hours for the reaction of the acid solution with the rock. The well shaft is flushed. The flexible flush-joint pipe with the jet nozzle is lifted out of the well. Inert gas pumping is performed via the annular space with liquid take-off via the tubing.

EFFECT: improving efficiency of acid treatment of a well.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: well completion method includes the injection of an acid solution by circulation with the wellhead by means of a jet nozzle placed at the end of a flexible flush-joint pipe, simultaneously with the acid solution circulation lifting of the flexible flush-joint pipe with a rate that does not exceed the rate of the borehole filling with the acid solution, upon filling of a horizontal borehole with the acid solution flushing of the acid solution to the formation with the staged pressure increase and the process withhold at each stage for the purpose of acid reaction with rock, injection of inert gas, recording of the level recovery curve, well killing and well development. A tubing string with starting clutches and with a funnel on the end is lowered into the well preliminarily at the interval of the shoe of the production casing. The flexible flush-joint pipe with the jet nozzle is lowered inside the tubing. Before the acid is flushed to the formation, the horizontal shaft of the well at an open annular space is filled through the flexible flush-joint pipe with a water solution of a surface active substance (SAS). At the closed annular space the water solution of the surface active substance is flushed to the formation, the process is withheld till oil flowing to the well. Then through the annular space the acid solution is flushed, the process is withheld for the purpose of the acid reaction with the rock, the borehole is washed, the flexible flush-joint pipe with the jet nozzle is lifted from the well. Inert gas injection is made through the annular space with the fluid sampling in the tubing string. Upon development of the well a geophysical survey is made for the horizontal borehole at the flexible pipe by thermometry and measurement by a flowmeter. Upon receipt of the survey results non-operated intervals are identified and by comparing geophysical data with final logging data non-operated intervals are identified in the horizontal borehole having high permeability and porosity. By running the flexible flush-joint pipe in, the jet nozzle is set in these intervals of the horizontal borehole, the jet nozzle end is thrusted to the horizontal borehole wall and the acid solution is circulated through the flexible flush-joint pipe, jet nozzle and tubing string until depression (channel) is formed in the rock and the surface area of the impact interval is increased. Then through the annular space the acid solution is flushed, the process is withheld for the purpose of the acid reaction with the rock, the borehole is washed, the flexible flush-joint pipe with the jet nozzle is lifted from the well. Inert gas injection is made through the annular space with the fluid sampling in the tubing string.

EFFECT: improving the acid treatment efficiency.

1 ex

FIELD: oil and gas industry.

SUBSTANCE: in the method acid process composition is injected to the well, withheld for reaction with further removal of reaction products from the formation. Before injection of the acid process composition, upon the last running in of tool for washing of the borehole before development a mixture of non-ionic surfactant with sulphamic acid at mass ratio of 0.003-0.005:1 in quantity of 1-3 wt % is introduced to drill mud containing high-molecular compounds and colmatant used for opening and washing of the producing formation. Then, upon the last running out of tool from the well and running in of tubing string the above drill mud is replaced by the acid process composition and the latter is withheld for reaction during at least four hours. The acid process composition consists of the following ingredients, by wt %: peroxide compound 0.5-3.0; sulphamic acid 5.0-10.0; non-ionic surfactant 0.005-0.02; mineralized water takes the remaining share. Density of the above process composition is equal to density of the drill mud used at opening of the producing formation or differs from it less than per 10%.

EFFECT: improved efficiency and producibility of colmatage removal from the bottomhole zone of the producer borehole, including inclined and horizontal wells, upon usage of the process fluid containing high-molecular compounds and colmatants.

7 cl, 4 tbl, 2 ex

FIELD: oil and gas industry.

SUBSTANCE: invention aims at restoring filtration characteristics of bottom hole areas of oil-and-gas wells disturbed while in service, with the use of hydroreactive metals. A method for the thermal-chemical treating of the bottom hole area of the well in the routine cycle mode: sodium feed in aluminium barrels enclosed in a hermetically sealed container onto the bottom hole, initiating a reaction of the above metals, keeping, lifting up the container in the hesitation mode equal to 5-10 min, descending the container at 0.2-1 m/minute.

EFFECT: more effective exposure for greater-depth productive formations and cost saving.

1 tbl, 1 ex

FIELD: mining.

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

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

3 dwg

FIELD: mining.

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

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

3 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: method of treatment of the well bottomhole zone with low bed pressure means well washing with fresh water, renewal of the production formation perforation on the basis 10 holes per running meter of well, formations saturation with fresh water to 6MPa. The first portion of hydrochloric acid solution is injected to the well in amount 2.0m3 and is held under bath mode for 2 h. Injection to the formation is performed by four stages. At first stage 6 times pulse injection to the formation of specified first portion of hydrochloric acid solution is performed under cycle mode, including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection of the specified portion is completed under continuous mode until complete release of the well bore from the hydrochloric acid solution. At the second stage 6 times pulse injection to the formation of the second portion of the hydrochloric acid solution is performed in volume 3.0m3 under cycle mode, including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection is completed under continuous mode. Then process holding for 3 h is performed for reaction. At the third stage the third portion of the hydrochloric acid solution on the basis 0.5m3 per running meter of the production formation is performed under continuous mode at pressure 1-6MPa, and holding for reaction for 3 h is performed. At the forth stage the 6 times pulse injection to the formation of the second portion of the hydrochloric acid solution is performed on the basis 1.0m3 per running meter of the production formation under cycle mode including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection is completed under continuous mode. Holding for 3 h for reaction is performed, then reaction products are removed by swabbing.

EFFECT: improving treatment efficiency of the well bottom-hole zone.

1 ex

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises recovery of core, making of core specimens and their analysis at electronic scanning microscope. Chemical reagent is forced through prepared specimens and sections are made at entry and exit of said chemical reagent. X-ray tomography is used to analyse the core specimens after forcing though of said chemical reagent. Images are compared to isolate the most efficient forms of solution channels. Numerical value of acid processing efficiency is calculated by computer processing of characteristics of images produced with the help of tomographic scanner. Minimum numerical value of said efficiency is selected as a criterion of the highest efficiency of acid processing. Note here that magnitude of stimulation is used as the numerical value of acid processing efficiency. Note here that, first, software is used for automatic determination of bored hole propagation volume. Then, acid solution penetration depth is computed. Now, stimulation magnitude is calculated by mathematical formula.

EFFECT: higher accuracy of efficiency and control over acid processing, fast determination.

3 ex, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes running of production string with packer in to the well, setting of the packer, hydraulic fracturing by injecting fracturing fluid through production string with packer to the producing reservoir with further proppant injecting through perforated interval in the low-permeable bed, pressure releasing from the well. Additionally perforated interval in the low-permeable bed is isolated temporary, the interval of clay layer is perforated using alternating charges of large diameter and deep invasion; then the production string with packer is lowered so that the lower end of the production string is at the level of clay layer roof, the packer is set in the well, the low-permeable bed is fractured with formation of cracks by injection of fracturing fluid along the production string through perforated intervals in clay layer. Then bank of oil-based cross-linked gel is injected to cracks in volume of 3-5 m3 with flow rate of 10 m3/min. Proppant moisture is used as proppant. Then cracks are reinforced by dosed injection of fracturing fluid and proppant mixture starting with concentration of 400 kg/m3 for proppant mixture with stepped increase of its concentration in fracturing fluid per 200 kg/m3 for each dose and flow rate of 5 m3/min. The proppant mixture is made at the wellhead with the following ratio of components, wt %: proppant 12/40 mesh - 30%; proppant 18/20 mesh - 30%; quartz flour - 40%. Upon completion of hydraulic fracturing of low-permeable bed temporary isolation is removed from the perforated interval of the low-permeable bed with formation of hydraulic connection between the borehole and created fracture.

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

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: in the method of well operation stimulation including test injection of breakdown fluid and package of breakdown fluid with proppant, correction of the breakdown project and performance of fracturing in low-permeable reservoirs having absolute permeability less than 1mD, hydraulic fracturing is made with injection of flush fluid on the basis of 1.0-3.0 m3 per 1 t of proppant using proppant fractions, which include only fine fraction with size less than 30/60 mesh with final concentration of proppant less than 300 kg/m3; at injection of the fluid flow rate of 3.5 m3/min and more and concentration of gel formation is set less than 2 kg/m3, with final underflush of the mixture in volume of 0.1-0.5 m3.

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.

2 dwg

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: mining.

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

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

3 dwg

FIELD: oil-and-gas industry.

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

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

21 cl, 1 tbl, 14 dwg

FIELD: oil-and-gas industry.

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

EFFECT: intensified production at worn-out string.

1 tbl

FIELD: 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

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