Method for gas well killing

FIELD: oil and gas industry.

SUBSTANCE: method includes blocking of a perforation interval by means of injection of a blocking liquid and its pushing with a killing fluid to a bottomhole and to a bottomhole area of a bed with simultaneous monitoring of pressure at a well head, gas relief and process settling. At the same time, prior to injection of the blocking fluid, a sand screen is formed by injection of a pulp of quartz sand with fraction of 0.6-1.2 mm in a carrier fluid in two portions with a flow rate of a carrier fluid, the value of which does not exceed the maximum permissible value, defined according to the formula. At the same time the volume of the quartz sand in the first portion of the pulp is calculated in accordance with the formula with further process settling of the well for the time determined according to the formula after injection of the first pulp portion. The volume of the quartz sand in the second pulp portion is taken as equal to the volume of suffosion channels produced in the sand screen. The blocking fluid is a certain composition. The blocking fluid volume is previously calculated according to the formula. Besides, at the moment of completion of blocking fluid pushing, hydrodynamic pressure is determined in a tubing string. Afterwards the process settling of the well is carried out. Further injection of the killing fluid into the well is carried out along the tubing string until it appears at the well head. At the same time the well head pressure is controlled in the annular space of the well by means of gas and blocking fluid relief, providing for pressure at the inlet to the tubing string as permanent and equal to the predetermined hydrodynamic pressure.

EFFECT: improved efficiency of gas well killing.

1 tbl

 

The invention relates to oil and gas industry, in particular for damping gas wells in major renovations in the conditions of disastrous acquisitions.

Analysis of the existing state of the art showed the following:

a well - known way of killing the well, including blocking the perforated interval by replacing downhole fluid blocking fluid and above it advocay fluid density less than the density of the blocking fluid, in which a portion of the blocking fluid crush in the near-wellbore area of the formation, the amount of blocking fluid determine, based on the productivity index of the well, and as the blocking of the liquid used in recipe, which has the following ratio of ingredients, wt.%:

Water-soluble salt of calcium12,5-43,5
Free ammonia0,1-2,0
The waste product of the pulp and paper
industry-based lignosulfonate5,0-25,0
Wood flour4,0-12,0
Water rest

(see RF patent №2104392 from 06.05.1996 on CL EV 43/12, SC 7/02, publ. 10.02.1998).

The disadvantage of this method of killing is its low efficiency plugging wells in the conditions of disastrous acquisitions. Due to the high logistical costs, because of the intense absorption and use of excessively large amounts of blocking fluid specified recipe. As a result of this used in the way blocking fluid penetrates deeply into the formation, the time to develop well after repair repeatedly increases and the permeability of the formation to recover almost impossible. This, in particular, is associated with the use of wood flour as a filler, because it has a high swelling capacity, and in combination with the waste product of the pulp and paper industry-based lignosulfonate and calcium salts may be formed in the pore space of the formation of hard-to-organo-mineral complex with enhanced adhesion to the rock formation. However, due to the low water content in the composition of the blocking fluid at the maximum quantities of calcium salts and wood flour on the reservoir rock is formed thick friable and fragile filtration cortex, does not prevent deep penetration of process fluids into the reservoir and the th contamination. As a result, the flow rate after repair is not restored. In this regard, this method of plugging the well and the specified blocking fluid inefficient for use in catastrophic acquisitions;

- as a prototype of the selected method of plugging gas wells, including blocking the perforated interval by feeding on the bottom of a well and in the near-wellbore area of the formation of the column tubing (tubing) blocking composition and subsequent injection into the well kill fluid, after pressing in the near-wellbore area of the formation of the blocking material in the annulus and nadakarni space pump kill fluid, then leave the hole on the technological vistaico with periodic drain remaining on the bottom hole gas cap, and as a blocking composition use solution containing, wt.%:

Sodium chloride10,0-20,0
Polymer Robus-G1,0-1,5
Waterthe rest,

and as the kill fluid - solution with a density less than the density of the blocking composition containing, in wt.%:

td align="left"> Sodium chloride
6,0-20,0
ASM6,0
Waterrest

(see RF patent 2347066 dated 28.11.2006 on CL EV 43/12, publ. 20.02.2009).

The disadvantage of this method is the lack of efficiency plugging gas wells under conditions of disastrous acquisitions, large logistical costs damping, increased time of completion and the inability to restore its flow rate by reducing the permeability of the formation.

According to the method of pumping fluid damping in the gas medium in the annular space, leads to the formation of isolated gas packs, which slowly emerge in a state of compression under pressure of the reservoir. It causes when opening their mouth in sudden expansion with gas release into the atmosphere and reducing the pressure on the formation. This may lead to samocvetniy well with the influx of a new portion of the gas, resulting in a possible emergency situation. Using this method it is not possible to reliably suppress a gas well in terms of disastrous acquisitions, as in the blocking part no filler, which is the basis for the formation of mud cake with sukupolvi and properties and structural and rheological parameters of this structure contribute to its penetration not only in the near-wellbore area of the formation, but the intense absorption of the high-permeability layer with deep penetration into him in all things perforation interval. Large amounts of absorbed blocking composition lead to increased costs for chemicals and materials for its preparation, expensive process of killing, increase the time and cost of development wells. As a result of contamination of the reservoir polymer composition Robus-G release occurs at elevated depression, which is unacceptable in wells with unstable cavernous bottom-hole zone, since entails the destruction of complications in the form of education sandy tubes and other

Also provided by way of technological sucks for 12 h for the structure formation of the blocking structure on the basis of the reagent Robus-G increases the time for killing the well, and the lack of filler to seal properties does not give the desired effect in terms of disastrous acquisitions.

The technical result that can be obtained by carrying out the proposed method:

- increases the efficiency of killing a gas well in terms of disastrous acquisitions due to pre-create reliable is the second sand screen in the wellbore and near-wellbore area of the formation and use of blocking fluid with improved structural and rheological properties, adhesion to the surface of the particles of the sand screen and bridging capacity;

- reduced logistical costs and time, by eliminating the absorption of liquids used in the killing;

- reduces the time of development wells and recovering its production rate after repair by maintaining the permeability of the formation.

The technical result is achieved by using a known method of plugging gas wells, including blocking the perforated interval by injection blocking fluid with a predefined value of the volume in the tubing and forcing her kill fluid to the borehole bottom and in the near-wellbore area of the formation with simultaneous control of pressure at the wellhead, the subsequent injection of kill fluid into the well, the gas release and technological sucks. Where before injection blocking liquid form sand screen by injection into the tubing slurry of silica sand fraction of 0.6-1.2 mm in the carrier fluid in two portions with a flow rate of the carrier liquid, the value of which does not exceed the maximum value defined by the formula

Qmax=SCP·υVit,

where Qmax- the maximum permissible flow rate of the carrier liquid, m3/s;

SCP- the cross-sectional area ZAT is obnova space, m2;

υVit- speed wool particles of quartz sand, m/S.

The volume of quartz sand in the first portions of the pulp are calculated according to the formula

,

where VP1- the volume of quartz sand in the first portion of the pulp, m3;

K - factor cavernosal well in the productive interval;

Dc- borehole diameter, m;

h is the interval of the productive formation from bottom to roof, m;

Δ - repression reservoir, PA;

Q is the flow rate of the carrier liquid, m3/s;

υcattlecritical speed of filtration flow of the carrier liquid, which starts the movement of particles of quartz sand, m/s;

gradP - pressure gradient, which causes movement quartz sand in absorbing channel wellbore zone, PA/m, followed by after placing the first portion of the pulp sludge process well at time T, defined by the formula

T=L/νVit,

where T - time process sludge well after downloading the first portion of the pulp;

L is the length of tubing, m,

and the volume of quartz sand in the second portion of the slurry is equal to the volume suffusion of channels formed in the sand screen, after the injection of the first portion of the pulp is determined by the formula

where k is the permeability of the sandstones is on screen, m2,

µ is the viscosity of the carrier liquid, PA·s,

and as a blocking liquid use composition, parts by weight:

The clay suspension 6%concentration100
Thermoelasticity reagent CMC - TC0,5-0,7
Powdered ogledaloto
reagent (PUDR)3-4
The disodium salt of the Ethylenediamine-N,N,N',N'-
tetraoxane acid, 2-water (Trilon B)of 0.2-0.3
Reagent plugging polycell f3-4,the

in volume VBJpre-calculated by the formula

,

where VBJ- the amount of blocking fluid, m3;

m - porosity sand sand screen;

VBGP- the amount of blocking fluid filtered into the sand screen, m3;

Vbra- the amount of blocking fluid adhesion to the inner surface of the tubing, m3,

and in the end forcing the blocking fluid determine the hydrodynamic pressure in N The T followed by technological sucks well, and the subsequent pumping of kill fluid into the well spend on the tubing before it appears on the mouth, thus regulate wellhead pressure to the annulus of the well by grazing and gas blocking liquid, providing the inlet pressure in the tubing is constant and equal to a previously defined hydrodynamic pressure.

The claimed method meets the condition of "novelty".

Killing the well in terms of disastrous acquisitions is material-intensive, technologically daunting task.

Proposed in the present method, a preliminary injection of slurry two portions of the quartz sand fraction of 0.6-1.2 mm for the formation in the borehole and in the absorbing drained channels wellbore zone sand screen with the formation on its surface of mud cake from the sequentially injected blocking fluid, preventing erosion of the sand in the absorbing channel layer considerably increases the efficiency of killing the well in terms of disastrous acquisitions, reduces the cost of materials by reducing the absorption process fluids.

The use of large sand - fraction 0,6-1,2 mm facilitates its rapid sedimentation and, due to its high permeability, and bulk mass, simplifies the development wells. As the carrier liquid use water, which due to its hydrophilicity and relatively low density and viscosity contributes to the formation of self-compacting sand screen. Set the properties of the selected sand (fraction of 0.6-1.2 mm) and the carrier liquid (a significant difference of their densities) causes a sufficiently high value of the speed of wool sand particles in the stream of the carrier liquid at a relative large flow of sand slurry. The use of silica sand fraction less than 0.6 mm economically and technologically impractical because it would lead to a waste of material and will increase the time, and the use of silica sand fraction more than 1.2 mm will lead to the absorption of significant amounts of the blocking fluid. The value of the flow rate of the carrier liquid must not exceed the maximum permissible value is determined based on the rate of wool particles of quartz sand υVitin the annular space

,

where 5,72 - constant of Rittinger when the flow around a spherical particle flow with a Reynolds number Re>60, m1/2/s

dh- diameter particles of quartz sand, m;

ρhis the density of particles of quartz sand, kg/m3;

ρWthe density of the carrier liquid, kg/m3.

is definitely the flow rate of the carrier prevents the removal of particles of sand in the annulus tubing and reduces the time of surgery, what contributes to the effectiveness of the proposed method.

The amount of quartz sand in the first portion of the pulp, calculated by the proposed formula, necessary and sufficient to fill the well in the productive interval of the formation from the bottom to the roof, taking into account cavernosal and the amount of absorbing all of the channels in the near-wellbore area of the formation. And the volume is sufficient to create at the entrance to cavity formation due to gravitational deposition of sand screen, temporarily resistant to repression of the liquid column. Does not require full fill them. This significantly reduces the time and material consumption. After injection of the total volume of the first portion of the sand, conduct technology sucks well long enough for sedimentation of all sand particles in the tubing. In this period of time in the well due to the absorption of part of the pulp decreases the level of the liquid to static, and, consequently, establishes the equilibrium pressure in the system is "well-formation". Sand, settling of the sand slurry located in the tubing, completely covers the entrance of the absorbing channels of the formation. There is a decrease in the intensity of acquisitions. However, pre-built sand screen is not resilient enough to suffusion processes that occur when the filter under the influence of repression of the carrier liquid and the other is low-viscosity fluids, used for killing the well and subsequent repair work. To fill the resulting suffusion channels in the sand screen after technological sludge wells are pumping a second portion of the pulp. The amount of quartz sand in the second portion of the slurry is equal to the volume of suffusion channels. In order to stop further development of suffosion processes, and to reduce material costs and time necessary to resolve the filtration of fluid into the reservoir. To do this, without a gap in time after the second portion of the sand slurry pumped blocking fluid. The amount which is calculated in advance, based on filling the first space has created a sand screen in the borehole from the bottom to the top of the reservoir, taking into account its filtration and adhesion to the inner surface of the tubing.

For the preparation of a blocking fluid use bentonite bentonite on THE 5751-002-58156178-02, thermoelasticity reagent CMC - TC on THE 2231-009-32957739-99, powdered ogledaloto reagent (PUDR) TU 39-01-247-79, disodium salt Ethylenediamine-N,N,N',N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652-73, reagent-plugging polycell F. on THE other 0392-002-32957739-98. The effectiveness of the blocking fluid is due to its ingredient composition comprising sodium alkali is eagency. When the hydrolysis of sodium compounds included in the composition of ingredients, there is an increase in hydrogen ion exponent (pH) of the dispersion medium of the blocking fluid. Produced in this sodium hydroxide (NaOH), in turn, activates the hydrolysis of silica (SiO2) the surface of the quartz sand that fills cavities, cracks and channels of absorption wellbore zone, forming therein a colloidal solution of silicic acid in accordance with the scheme

The presence of calcium ions (CA2+in technical or formation water used to prepare the blocking fluid and transferred to the aqueous phase during hydration of the clay in the presence of hydroxyl ions, leads to the formation of calcium hydrosilicate reaction

H2SiO3+Sa2++2OH-=CaSiO3·2H2O,

the binding agent (cement) link between the sand particles, clay component and peat filler (reagent-plugging polycell f) blocking fluid. As a result, the surface of the sand screen is formed of a durable, reinforced turf fibers the basis for the formation of mud cake, which not only reduces the flow of the dispersion medium blocking fluid formed in sand screen and the reservoir, but also C is its high strength prevents mechanical damage to his flows circulating in the well fluids. Blocking fluid has a low water yield not only a result of the above processes in the formation of a solid deposition of mud cake, but due to the use of sodium reagents for processing the clay suspension, the interaction of which is the formation of a complex of organo-mineral compounds, which significantly increases the viscosity of the dispersion medium of the blocking fluid. On the one hand, the formation of new high-molecular compounds (IUDs), on the other hand, the dispersion medium of the blocking fluid is condensed solid phase with a high specific surface, which together with peat particles and fibers stabilizes the organo-mineral complex locking system, increasing its structural and rheological characteristics: viscosity, dynamic and static shear stress. The table below shows the composition and technological parameters of the blocking fluid.

Table 1
№ p/pComposition, parts by weight
The clay suspension 6%CMC-TCUSRTrilon B Polycell f
11000,740,34
21000,530,23
31000,640,24
41000,420,12
51000,850,45
Known composition (similar)
6CaCl2NH3Waste Pro-BA PPMWood flour to 12.0Water
340,1100 43,9
Known composition (prototype)
7NaClPolymer Robus-GWater
201,578,5

Continuation of the table
Technological parameters
№ p/pρ, kg/m3η, MPa·sτabout, the AAACHC1/10, the AAAIn, cm3/30 minCork mmΔPblockMPa/mΔPreleasedMPa/ mKRR
11040378610/352,00,81,12 0,0630,95
2103523498/172,60,50,850,0460,97
3103832759/272,20,60,930,0540,95
4103215367/124,20,30,60of 0.0810,88
51042449814/381,80,91,14of 0.066 0,94
Known composition (similar)
61309539821/254,01,50,450,4760,23
Known composition (prototype)
71180Viscosity 18032/340,02,50,210,2780,37

ρ is the density, η is the structural viscosity, τaboutdynamic shear stress; CHC1/10static shear stress determine (rebeccasommer Farm 35 SA" company "Baroid"); - yield, determine the filter press "Baroid" when the differential pressure 0.1 MPa; ΔPblockthe pressure gradient block; ΔPreleasedthe pressure gradient release; KRR- recovery coefficient of permeability of the sand core, defined as the ratio of its PR is Nichelatti after release to permeability before treatment with the blocking fluid. That was due to the following physical and chemical processes with participation of reagents used in the composition of the blocking fluid. Thermoelasticity reagent CMC-TC is a sodium salt of carboxymethyl cellulose, modified aluminum salts, which increases the resistance of the polymer to the precipitating action of the cations of polyvalent metals. The structural formula of the molecule CMC-TC

.

The structural formula of Trilon B - disodium salt of ethylenediaminetetraacetic acid

through the aluminium cations knits CMCTS, forming a naval complex structure. theoretical structure of this macromolecule Navy

,

Present in the composition of the reagent-plugging polycell-f, representing peat filler, trisodium phosphate in the interaction with salts of polyvalent metals, located in the reservoir or process water for the preparation of blocking fluid, forms a fine precipitate of calcium phosphate by reaction

2Na3PO4·12H2O+3CaCl2=CA3(RHO4)2↓+6NaCl+12H2O.

This condensed solid phase not only increases sedimentation stability and structural and rheological properties of blocking fluid, but the strength and nature of the sticky mud cake on the border of the sand screen, collectively improves obstructive action of the blocking fluid. This plays an important role PUSR, representing a mixture of sodium salts of humic acids, which enhance peptization clay, which increases the viscosity and thixotropy of the blocking fluid. High alkalinity USR activates preventing erosion of the mud cake, and increasing its elasticity due to the swelling of the fibers and particles of peat filler, forming a mesh of reinforcing the frame. However, due to the fibrous structure of peat blocking fluid differs from the known fact that not penetrate into the formation to a greater depth even with its high permeability. This greatly facilitates its removal from the reservoir during the release in the process of completing repairs and is one of the main conditions for the restoration of its reservoir properties (coefficient of restitution of the core permeability after release is shown in the table).

The content in the composition of the blocking fluid CMC-TC is less than 0.5 parts by weight, PUSHR is less than 3 parts by weight, the Trylon B is less than 0.2 parts by weight, and reagent-plugging polycell f - less than 3 parts by weight does not provide the formation of organo-mineral complex locking system with the necessary technological properties appropriate to accomplish the technical the definition of the result.

The content in the composition of the blocking fluid CMC-TC more than 0.7 parts by weight, POSR more than 4 parts by weight, the Trylon B - more than 0.3 parts by weight, and reagent-plugging polycell f - more than 4 parts by weight of economically and technologically impractical because of the significant improvement of technological properties of a locking system when the number of these ingredients does not occur.

Through the use of a blocking fluid specified formulation in the proposed volume on the sand screen is the formation of mud cake with enhanced strength properties, preventing its destruction suffusion processes. In the end forcing the blocking fluid determine the hydrodynamic pressure in the tubing to pressure gauge installed on the discharge line of the pump. Carry out technological sucks well for the formation of a mud cake on the surface of the sand screen. Created by the system performs the function of a check valve, i.e. thereby prevents absorption of fluids, ensures the preservation of porosity and permeability of the reservoir, the possibility of filling the well kill fluid to the mouth, subsequent repairs at a constant repression regulated by normative technical documents (Rule b is safety in the oil and gas industry [Text]: PB-624-03: appr. By Gosgortekhnadzor of Russia 05.06.03. - Issue 4 - Vol. 08 Regulatory documents on safety, regulatory and permitting activities in the oil and gas industry. - M.: STC "Industrial safety", 2003. - 312 S.), and when creating a depression in the well is destroyed, so you can quickly and easily learn well. Pumped into the well through tubing kill fluid before it appears on the mouth. At this regulate wellhead pressure to the annulus of the well by grazing and gas blocking liquid, providing the inlet pressure in the tubing is constant and equal to a previously defined hydrodynamic pressure. Specified provides a constant pressure in the well, the integrity and reliability of the impenetrable screen, significantly reduces the time for fashion and the subsequent development of the well recovery rate upon completion of repairs.

The proposed sequence of operations allows to obtain the following: in strictly defined areas of the sand slurry to the result of the gravitational deposition of sand in the caverns, absorbing channels and cracks in the bottom-hole formation zone and the overlap of these channels in the borehole from the bottom to the top of the productive formation significantly reduces the absorption intensity of the blocking fluid having improved structural-rheological and adhesive is bridging properties to create on the surface of the sand screen filter cover, prevent its erosion, creating the necessary repression of strata filling the well kill fluid to the mouth. Reduced logistical costs and time of work, time of completion and time of recovery of its rate after repair by maintaining the permeability of the formation.

Thus, according to the above, to achieve the claimed technical result.

Not detected for existing sources known technical solutions, which have characteristics that match with the distinctive features of the present invention according to the claimed technical result.

The claimed method meets the condition of "inventive step".

In more detail the essence of the invention is described in the following example.

It is necessary to carry out the killing of the gas wells under conditions of disastrous acquisitions.

The source data

The inner diameter of the production string, de152 mm
The outer diameter of the production string, De168 mm
The diameter of the hole in the bit, Dc215,9 mm
Linuxprofessional columns, Le427,5 m
The productive interval of the formation (perforations), hof 415.3-427,5 m
The coefficient of cavernosal,1,21
The outer diameter tubing (tubing), Dtubing73 mm
The internal diameter of the tubing, dtubing62 mm
The length of the tubing, L404,6 m
The static fluid level in the well from the mouth while jamming
technical water, Harticle70 m
Pressure PPL3,1 MPa
The cross-sectional area pipe
space tubing, Stubing0,003 m2

For the formation of a sand screen in the absorbing interval pumped slurry containing quartz sand (fraction of 0.6-1.2 mm), the two portions. To determine the volume of quartz sand in both portions of the pulp pre-calculate the trace of the following values:

The repression of a reservoir is determined by the formula

ΔP=Harticle·ρW·g,

where ρWthe density of the carrier liquid, kg/m3;

g - free fall acceleration, m/s2.

Therefore

Δ=70·1000·9,81=686700 PA.

The critical speed of filtration flow of the carrier liquid, which starts the movement of particles of quartz sand, is determined by the formula

,

where ψ=1 - coefficient of resistance to the flow around the particle;

ρhis the density of particles of quartz sand, kg/m3;

dh- diameter particles of quartz sand, m

Therefore

.

The flow rate of the carrier liquid does not exceed the maximum value defined by the formula

Qmax=SCP·υVit,

where SCP- the area of the cross section of the annulus, m2.

,

.

Speed wool particles υVitdetermined by the formula

,

where 5,72 - constant of Rittinger when the flow around a spherical particle flow with a Reynolds number Re>60, m1/2/s

Therefore

.

Therefore

Qmax=0,014·0,18=0,0025 m3/s

The pressure gradient that causes the movement of sand in adsorbing to the patient by preswaging zone of the reservoir, determined by the formula

gradP=(ρhW)·g,

therefore

gradP=(2650-1000)·9,81=16186,5 PA.

Calculate the volume of quartz sand in the first portion of the pulp by the formula

,

where VP1- the volume of quartz sand in the first portion of the pulp, m3.

Therefore

The amount of quartz sand in the second portion of the pulp is determined by the formula

where VP2- the volume of quartz sand in the second portion of the pulp, m3;

k is the permeability of the sand screen, m2; for bulk mass of sand k=200·10-12;

µ is the viscosity of the carrier liquid, PA·S.

.

Determine the volume of the carrier liquid in the pulp from the calculation of the volume content of sand in it 5 of volume fractions by the formula

,

where VLs- the amount of the carrier liquid,

With the sand content in the carrier fluid, the volume fraction.

Therefore, the volume of the carrier liquid in the first portion of the pulp

.

The amount of the carrier liquid in the second portion of the pulp

Determine when technology sludge well after downloading the first portion of the sand by the formula

T=LpVit,

where T - time process sludge wells;

Lp- the length of the tubing, occupied by the pulp, M.

,

,

Lp=8816≤404,6,

hence Lp=404,6.

T=404,6/0,18=2248 with or 38 minutes.

Determine the volume of the blocking liquid VBJ

,

where m is the porosity of the sand, m=0,34.

- the amount of blocking fluid filtered into the sand screen, m3;

- the amount of blocking fluid adhesion to the inner surface of the tubing, m3.

,

where

µ is the viscosity of the blocking fluid, PA·s;

ρZGis the density of the kill fluid, kg/m3;

tbthe time of process sludge after injection of the blocking fluid, S.

,

where δ is the thickness of the adhesive layer, a blocking liquid in the tubing, 0,001 m

Therefore

,

VBJ=0.785·1,21·0,21592·(427,5-415,3)·0,34+0,02+0,08=0,28 m3.

As the blocking fluid is prepared to 0.28 m3composition containing, in parts by weight:

The clay suspension p=1030 kg/m3100
Thermoelasticity reagents - TC 0,7
USR4
Trilon B0,3
Reagent plugging polycell f4.

Determine the volume of kill fluid from the fill of the well to the mouth by the formula

.

Therefore

.

In the tube space of the pump tubing first portion of the sand slurry: 1.30 m3quartz sand 24.7 m3water (sand content in the pulp 0,05 about. shares) with a flow rate not exceeding 2.5 l/C.

After pumping the whole volume of the first portion of the pulp in the tubing stop pumping, conduct technology sucks well for 38 minutes.

Then in the tube space tubing sequentially inject the second portion of the sand slurry: 0.01 m3sand in 0,19 m3water (concentration of sand in the slurry of 0.05. shares), 0,28 m3the blocking fluid, which pushes fluid damping - raw clay suspension 6%concentration of density 1030 kg/m3with a flow rate not exceeding 2.5 l/s at the bottom of a well and in the near-wellbore area of the formation with simultaneous control of pressure at the wellhead.

In the end forcing the blocking fluid fluid damping determine gidrodinamicheskoe pressure in the tubing. Carry out technological sucks wells within 1 h of the Pump tubing in the well kill fluid before it appears on the mouth, thus regulate wellhead pressure to the annulus of the well by grazing and gas blocking liquid, providing the pressure in the tubing is constant and equal to a previously defined hydrodynamic pressure. Watch the hole at least 6 h (safety Rules in oil and gas industry). After 6 h in the absence of reduction of the fluid level in the well and gas evolution begin repair work.

Thus, the method of plugging gas wells meets the condition of "novelty, inventive step and industrial applicability", therefore, meets the condition of "patentability".

Method of plugging gas wells, including blocking the perforated interval by injection blocking fluid with a predefined value of the volume in the tubing - the tubing and forcing her kill fluid to the borehole bottom and in the near-wellbore area of the formation with simultaneous control of pressure at the wellhead, the subsequent injection of kill fluid into the well, the gas release and technological sucks, characterized in that it further before injection blocking fluid form a sand screen is ay injection into the tubing slurry of silica sand fraction of 0.6-1.2 mm in the carrier fluid in two portions with a flow rate of the carrier liquid, the value of which does not exceed the maximum value defined by the formula:
Qmax=SCP·υVit,
where Qmax- the maximum permissible flow rate of the carrier liquid, m3;
SCP- the area of the cross section of the annulus, m2;
υVit- speed wool particles of quartz sand, m/s,
the volume of quartz sand in the first portions of the pulp are calculated according to the formula:

where VP1- the volume of quartz sand in the first portion of the pulp, m3;
K is the coefficient of cavernosal well in the productive interval;
Dc- borehole diameter, m;
h is the interval of the productive formation from bottom to roof, m;
Δ - repression reservoir, PA;
Q is the flow rate of the carrier liquid, m3;
υcattlecritical speed of filtration flow of the carrier liquid, which starts the movement of particles of quartz sand, m/s;
gradP - pressure gradient, which causes movement quartz sand in absorbing channel wellbore zone, PA/m,
with the subsequent conduct after placing the first portion of the pulp sludge process well at time T, defined by the formula:
T=L/νVit,
where T - time process sludge well after downloading the first portion of the pulp, with;
L is the length of tubing, m,
and the amount of kvar is avago sand in the second portion of the slurry is equal to the volume of suffusion channels, formed in the sand screen, after the injection of the first portion of the pulp is determined by the formula:

where k is the permeability of the sand screen, m2,
µ is the viscosity of the carrier liquid, PA·s,
and as a blocking liquid use composition containing, in parts by weight:

The clay suspension 6%concentration100
Thermoelasticity reagent CMC - TC0,5-0,7
Powdered ogledaloto reagent USR3-4
The disodium salt of the Ethylenediamine-N,N,N',N'-
tetraoxane acid, 2-water-Trilon Bof 0.2-0.3
Reagent plugging polycell f3-4,the

in volume VBJpre-calculated by the formula:

where VBJ- the amount of blocking fluid, m3;
m - porosity sand sand screen;
VBGP- the amount of blocking fluid filtered into the sand screen, m3;
Vbra- the amount of blocking fluid adhesion to the inner surface of the tubing, m3/sup> ,
and in the end forcing the blocking fluid determine the hydrodynamic pressure in the tubing, followed by technological sucks well, and the subsequent pumping of kill fluid into the well spend on the tubing before it appears on the mouth, thus regulate wellhead pressure to the annulus of the well by grazing and gas blocking liquid, providing the inlet pressure in the tubing is constant and equal to a previously defined hydrodynamic pressure.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: design of low-angle and horizontal wells includes a technical string, an operating string and a lift string. The operating string is cemented above the productive formation roof. The operating string in the productive formation is divided into sections with casing packers, and sections include filter sections and sections of solid pipes. The lift string in the productive formation is equipped with operating packers, installed inside the sections of solid pipes of the operating string and groups of controlled valves equipped with calibrated inlet side holes arranged inside filter sections. A seat nipple is installed at the end of the lift string. Controlled valves and the nipple are made as capable of interaction with control devices lowered inside a lift string.

EFFECT: possibility to control an inflow from isolated sections of a low-angle or horizontal well shaft or their total selective water isolation.

3 dwg

FIELD: oil and gas industry.

SUBSTANCE: development method of heavy oil or bitumen deposit with control of well product extraction involves construction of upper injection and lower production wells with horizontal sections located one above another. At construction of wells their horizontal sections are equipped with filters installed opposite productive formation zones. Inside filter with non-perforated interval in production well there arranged is a shank provided with inlet holes dividing the filter into extraction zones. Besides, shank is equipped on the inner side with a stock with side channels. Inner space of stock is interconnected with inlet of pump lowered to production well on the tubing string with possibility of longitudinal movement of the tubing string together with pump and stock in the shank. Heat carrier is pumped through horizontal injection well with warming-up of the formation by creating the steam chamber, and product is extracted through horizontal production well. Thermograms of steam chamber are taken, the chamber's warm-up state is analysed for uniform heating and available temperature peaks, and considering the obtained thermograms, uniform heating of steam chamber is performed. Before the tubing is lowered to production well, first, stock is lowered with a shank concentrically arranged on it and fixed in transport position with a shear screw. Besides, on the outer side of the shank lower end there installed is heat-resistant packer; after the stock is lowered to production well, lower end of tubing is put on its upper end. Tubing is equipped with a pump. Tubing is lowered to production well till the packer is arranged at non-perforated interval of production well filter; after that, packer is installed by dividing the filter of production well into two extraction zones - initial and final. Uniform heating of steam chamber is performed by supplying the heat carrier through injection well. Penetration of heat carrier and/or formation water to the pump inlet is avoided by controlling the product extraction to the pump inlet from the initial extraction zone. Besides, product extraction volume is reduced in the initial extraction zone where temperature peaks occur. For that purpose, inlet shank holes corresponding to the initial extraction zone are made with reduction of carrying capacity from face to head, and side channels of stock are provided with possibility of alternating interaction with one of inlet shank hole in the initial extraction zone. This is performed by restricted longitudinal movement of pipe string together with pump and stock relative to shank by increasing or reducing the number of connection pipes on upper end of pipe string depending on the distance between inlet holes of the shank. Pipe string is fixed on the head of production well in the required position by means of a face plate on a supporting flange, and shank hole corresponding to the final extraction zone is made in the form of an open stock end.

EFFECT: improving the control of product extraction volume from extraction zones; simpler erection and lower metal consumption on the design.

3 dwg

FIELD: oil and gas industry.

SUBSTANCE: method of fluid extraction from the well is performed in the following way: the first adjustment at least of the first well equipment for fluid production is performed; the first set of input parameters is chosen, which includes at least one parameter referring to serviceability degree at least of one second well equipment and sets of parameters chosen from the group including the data referring to efficiency, pressure, temperature, presence of the chosen reagent, content of water, content of sand and flow rate of injected chemical reagents. The first set of parameters is used to be entered to the computer model, and the second adjustment at least of one first well equipment is performed, which will provide at least extension at least of one second well equipment or increase in completed well flow rate. Also, control system of operation of electric submersible pump is proposed, which contains information storage data base relating to operating range of submersible pump, and processor for adjustment at least of one first well equipment, which has the possibility of using at least one measured operating parameter of submersible pump and information stored in the data base.

EFFECT: invention allows performing the monitoring of well shaft state and serviceability degree of various equipment and taking actions, which will provide increased or optimum production of hydrocarbons from the well.

25 cl, 4 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to production of natural gas ad may be used in methane-coal well development. Proposed method comprises perforation of operation string in interval of production bed and its hydraulic fracturing. Thereafter, operation string is flushed. Settled fluid level allows defining initial counter pressure on productive coal bed. Production tubing with borehole pump is lowered into flow tubing, the pump being located under perforation interval. Well head is sealed. Borehole pump is used to reduce fluid level in well annuity space to below perforation interval together with injection of buffer gas therein at initial counter pressure on the bed. Thereafter, feed of buffer gas is interrupted. Said fluid level in annuity space is maintained by means of borehole pump. Inflow of bed fluid is caused by releasing excess pressure of buffer gas from annuity space in control over variation in gas quantitative and/or qualitative composition at well head. Change in released buffer gas composition allows defining the beginning of coal methane from productive bed. Now, rate of buffer gas pressure release is decreased.

EFFECT: higher efficiency of well development.

4 cl

FIELD: oil and gas production.

SUBSTANCE: proposed method consists in using tubing incorporating borehole pump and packer. Note here that borehole pump is equipped with check valve. Check valve is arranged close to and above the pump on tubing outer side to allow one-way fluid flow from tubing into tube space. Said tube space is filled with process fluid with corrosion inhibitor in required concentration. Pressure in tube space is maintained not exceeding tolerable magnitude by means of electric-contact pressure gage connected to borehole pump control unit. Reagent if injected into tubing from wellhead with tube space gate valve.

EFFECT: efficient injection, safe production of oil or gas.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: according to the method of oil-gas wells killing on deep water subsea deposits by pumping of certain volume of kill composition together with sea water into the well thus providing creation of killing spout in the well with timeless pressure on formation exceeding formation pressure not less than 1.2 times, as a killing composition, preventing immediate contact of cold sea water with overheated formation fluids and productive stratum of formation, large hydrophobic disperse system is used with density exceeding density of sea water more than 5 times in the volume ensuring in bottom-hole zone of the well creation of spout of large hydrophobic disperse system with height exceeding productive stratum formation opened by perforation not less than 3 times. Mentioned disperse system is a disperse system with volume of 70%, where as disperse medium hydrocarbon liquid is used, this liquid doesn't set solid under temperatures to -10°C, its density is not less than 0.860 g/cm3; as disperse phase a mixture of hard metal balls with diameter within 1-2 mm is used, 50% of this ball mixture volume have fusion temperature well over bottom-hole temperature, and the other 50% of this ball mixture volume have fusion temperature 10°C and more below bottom-hole temperature.

EFFECT: improving reliability of oil-gas wells killing on deep water subsea deposits with excessive temperature and pressure of productive formation.

3 cl, 2 tbl

FIELD: oil and gas industry.

SUBSTANCE: typical well operating equipment can include separator for separation of water from oil, in which the produced mixture of fluid media is obtained and mixture is divided into the corresponding water and oil flows. Water flow can be pumped back to the well. For that purpose, well system for water pumping speed control back to the well can be developed. Group of inventions provides the improvement of well flow control efficiency. Essence of inventions: well equipment designed for receiving fluid medium flows through the first and the second fluid medium flow passage channels is arranged in the well. The above equipment includes flow separation control having the device connected to the first channel and the device connected to the second channel, which are interconnected. Outlet flows in the first and the second channels are controlled by means of the control.

EFFECT: increasing outlet flow in one of the first and second channels in response to increase in outlet flow in the other of the first and the second channels by means of action on one of the above devices to keep constant ratio of outlet flows in the above channels.

16 cl, 6 dwg

FIELD: oil and gas production.

SUBSTANCE: method includes gaslift well operation by adjusting the flow rate of working and produced gas. The withdrawal of produced gas is done by tubing string and additional tubing string. The flow rate of working and produced gas is adjusted by opening and closing of driven shut-off elements in accordance to the control signals. Control signals come from automatic control unit and are generated according to the results of measured values compared with set parameter values. Note that the pressure is measured in the mouth and bottom hole, at the same time the flow rate of produced gas is measured. The flow rate of working and produced gas is adjusted in such a way to provide the specified well operation mode.

EFFECT: increase of well operation efficiency, reduction of level and removal of fluid accumulated in bottom-hole zone, provision of well operation stability.

2 cl, 1 dwg

FIELD: oil and gas production.

SUBSTANCE: system for use in the hole includes the string designed for location in the hole that consists of submersible electric pump, the first part of inductive coupler and completion section. Note that completion section is located in the well zone under development and includes the second part of inductive coupler, isolating packer, detection cable and electric device electrically connected to the second part of inductive coupler. Note that detection cable goes through the packer for provision of sensors to some well zones.

EFFECT: increase of system operation efficiency and collection of measurement data referred to the well characteristics.

28 cl, 7 dwg

FIELD: oil and gas industry.

SUBSTANCE: well of hydrocarbon raw material deposit, either gas one or gas-condensate one, includes production string with tubing string with underground operating equipment. Operating equipment includes at least a cutout valve with remote control, which is provided with an actuator, and well head with wellhead equipment. Wellhead equipment comprises casing head, tubing head on which there mounted is X-tree in the form of a fir tree, which includes shutoff members - master and side gate valves with actuators, as well as throttle valve adjacent to the latter, which controls the well flow rate and is provided with an actuator, and monitoring and control members - fuse insert and gas line pressure monitoring valve. Well is connected to control station by means of shutoff members, throttle valve and cutout valve. Control station is made in the form of a cabinet and includes pump accumulator plant and at least one control unit per well.

EFFECT: improving reliability and accident-free operation of gas well and simplifying the control of processes.

12 cl, 5 dwg

FIELD: mining industry.

SUBSTANCE: invention can be used in case of gas-lift operation of wells equipped by free piston-type installations. Invention envisages stopping well, connecting tube space and annular space in wellhead, recording bottom zone and wellhead pressures in tube and annular spaces, and computing well operation parameters using inflow curve plotted according to differences of bottom zone and wellhead pressures. Volume of produced fluid is found from potential output of formation and from condition of output of free piston. When comparing these volumes, parameters of well are computed in the base of minimum volume value.

EFFECT: optimized well operation.

2 dwg

FIELD: oil and gas extractive industry.

SUBSTANCE: foam-forming compound for shutting wells contains hydrocarbon liquid, mixture of surfactants, one of components thereof is water solution of lignosulphonate reagent of 25% concentration, herbal filling agent and 20% water solution of calcium chloride, as lignosulphonate agent reagent it contains powder-like technical lignosulphonate, and as other component of surfactant mixture - hexamethylentetramine, and as herbal filling agent - peat or grass flour with following ratio of components in percents of mass: hydrocarbon liquid 12-14, said water solution of technical powder-like lignosulphonate 17-21, hexamethylentetramine 0.17-0.63, peat or grass flour 3-6, said calcium chloride solution - the rest, while relation of mass portions between said water solution of technical powder-like lignosulphonate and hexamethylentetramine is 1: 0.01-0.03 respectively, as grass flour it contains pulverized herbal waste of grain bread production or similar substance.

EFFECT: higher efficiency.

2 cl, 18 ex, 1 dwg

FIELD: oil and gas extractive industry.

SUBSTANCE: compound includes water and inhibiting salt, as inhibiting salt contains processed electrolyte - side product during production of magnesium via electrolysis from carnallite, and additionally as reducer of filtering and thickener - carbooximethylcellulose polymer, and as colmatation agent - magnesium oxide with following relation of components in percents of mass: processed electrolyte - side product of magnesium production via electrolysis from carnallite 10.0-15.0, carbooximethylcellulose 2.5-3.0; magnesium oxide 1.0-2.0, water 80.0-86.5.

EFFECT: higher efficiency.

3 tbl

FIELD: oil and gas producing industry, in particular composition for killing of well.

SUBSTANCE: claimed polysaccharide gel contains sweet or mineralized water, polysaccharide gelling agent, boron cross-linking agent, diethanolamine, quaternary ammonium compounds, and mixture of non-ionic and anionic surfactant (complex surfactant). Mixture of water soluble oxyethilated alkylphenols and their sulphoethoxylates in form of sodium salts or salts with triethanolamine is used as complex surfactant in amount of 0.1-0.5 kg on 1000 l of water being the gel base. Polysaccharide gel is obtained by dissolution and hydration of polysaccharide gelling agent in sweet or mineralized water (preferably monovalent ion solution) followed by treatment of obtained polysaccharide solution with aqueous solution including boron cross-linking agent, diethanolamine, quaternary ammonium compounds, and complex surfactant.

EFFECT: well killing composition of improved quality.

2 cl, 6 ex, 1 tbl

FIELD: oil extractive industry.

SUBSTANCE: method includes mounting compressor pump in such a way, that input aperture of tail piece was positioned below bed sole. Prior to that water cone in face-adjacent zone is destroyed by draining water through tail piece, connected to lower suck-in valve of compressor pump cylinder, and along behind-pipe space through side suck-in valve of compressor pump cylinder. In case of increase of hydrocarbon contained in drained liquid beginning of water cone destruction is assumed. Draining is continued until destruction of emulsion in water cone, formed in non-homogenous porous environment of bed at limits of hydrocarbon-water and water-hydrocarbon, separation of water and hydrocarbon streams and bringing current water-hydrocarbon contact to initial position. Then during extraction water is drained through tail piece, and hydrocarbon - along behind-pipe space.

EFFECT: higher yield.

3 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes preparation of technological liquid - water solution of sylvinite ore mixture with chlorine calcium by solving a mixture of components in hot fresh technical water, drained from oil and water preparation plants or bed water. During solution of sylvinite ore mixture with chlorine calcium in bed water the latter is drained from the well at temperature 60-90°C. Technological liquid is produced with solution density 1.23-1.37 t/m3. Then prepared technological liquid is fed into well shaft a bit lower, oppositely to zone and above ceiling of productive bed with forming of hydraulic column above the latter. Then well shaft to the mouth is filled with water. Value of technological liquid hydraulic column of high density on basis of said mixture, fed into well shaft above ceiling of productive column of technological liquid is taken in amount, necessary and enough from well stopping conditions.

EFFECT: higher efficiency.

6 cl, 1 ex

FIELD: oil and gas production.

SUBSTANCE: water-based composition that can be used for killing of well during pullout of hole and well remedial work as well as for temporary abandonment of well contains, wt %: carboxymethylcellulose3.5-4.5, sodium hydroxide1.5-2.0, copper sulfate 0.3-0.4, and methanol 4.0-16.0.

EFFECT: improved rheological properties of composition and increased lifetime of formed gels.

1 tbl

FIELD: oil and gas industry.

SUBSTANCE: method includes serial pumping into well of buffer, blocking and pressing liquid, blocking liquid contains hydrocarbon base, acyclic acid, caustic soda and mineral filler with following relation of components in percents of mass: hydrocarbon base 41-72, acyclic acid 6.1-14.4, caustic soda 4.9-13.0, mineral filler the rest. Hydrocarbon base of blocking liquid is oil or oil processing products. As mineral filler blocking liquid has calcium carbonate with diameter of particles no less than 2 micrometers.

EFFECT: higher efficiency, simplified maintenance, simplified construction.

3 cl, 1 ex

FIELD: oil industry.

SUBSTANCE: at least one acoustic dynamic is mounted immediately on product pipe in oil well and acoustic characteristic of flowing environment flow is determined in product pipe. It is sent into surface controller, using product pipe. Using surface controller flowing substance flowing mode is determined, on basis of which working parameters of oil well are adjusted. Working parameters of oil well can be adjusted to detect Taylor mode of flow. For adjustment of working parameters throttle is used and/or controlled valve of oil well, controlling amount of gas, forces into product pipe. For determining mode of flow of flowing environment artificial neuron net can be used. It is possible is provide energy for acoustic sensor through product pipe. It is possible to determine additional physical characteristics of flowing substance, for example pressure and temperature.

EFFECT: higher efficiency.

3 cl, 22 dwg

FIELD: mining industry.

SUBSTANCE: system has first induction throttle, second induction throttle and controlled switch. Second induction throttle is positioned near second branch of pipeline structure. Controlled switch has two outputs. First switch output is electrically connected to pipeline structure on the side of induction throttles connection, where first and second branches of pipeline structure intersect. Second output of switch is electrically connected to pipeline structure on other side of at least one induction throttle. Pipeline structure can be positioned inside oil well, and can have casing string and operation tubing column. Also described is method for extracting oil products from oil well using said system.

EFFECT: higher efficiency.

4 cl, 10 dwg

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