KR20120051684A - Well completion method - Google Patents

Abstract

The method is applied to the oil and gas industry and can be used for the development of production layers. The production string 6 with the sealing device 7 is lowered into the well 1 and the drilling well 1 is divided into an upper cavity 8 and a lower cavity 9, wherein the sealing device ( With the help of 7) a fluid connection is established between the drilling well opening and the upper cavity and between the lower cavity and the production layer, respectively. Installation of the downhole equipment 10 and the check valve is carried out in stages. Washer fluid 4 is replaced with washer fluid 15. The downhole equipment 10 passes through the sealing device 7 and the fluid connection between the drilling hole, the lower cavity and the production layer is reestablished along the annular channel. The drilling well 1 is excavated using the downhole equipment 10 until the inflow of bed fluid occurs, and the differential pressure in the fluid system of the "drill opening-production bed" 3). The downhole equipment 10 is retracted from the lower cavity 9 upon completion of the excavation, the sealing device 7 is closed upon separation of the lower cavity 9 from the upper cavity 8 and the fluid connection between the production layer and the upper cavity Hang up. Technical solutions improve the efficiency and quality of technical operation and prevent undesirable entry of bed fluids.

Description

Drilling Well Formation Method {WELL COMPLETION METHOD}

TECHNICAL FIELD The present invention relates to the oil and gas industry, and relates to the excavation and operation of oil and gas wells, and may be used in the development of excavating and forming wells.

According to the known method of primary development of forming a drilling well during drilling for oil and gas, the optimum conditions for the main development are the drills of the Russian patents RU 2283418 C2, E21B21 / 00 dated September 10, 2006. Consists of the use of different configurations of fluids.

This known method relates to the selection of reagents added to the drill fluid according to the stage of operation performed in the development of the drilling well.

Another known method of drilling drilling is the primary development of the production layer of the Russian patents RU 2140521 C1, E21B33 / 13 of October 27, 1999, the fixing of the production string, and the secondary development of the production layer ( secondary development).

This known method provides an imbalance reduction with the overlapping of high-pressure formations by the product string during installation in the top of the product formation.

See also Russian Patents RU 2311526 C2, E21B34 / 06, filed November 27, 2007; In Russian patent RU 2250354 C2, E21B34 / 06 of April 20, 2005, a safety valve is disclosed which is used during the operation of oil and gas wells under pressure and controls downhole equipment.

To control the opening or closing of this known safety valve, a special tool is used, which is part of the drill, ie the production string, depending on the type of work performed.

Technical conditions for the development of the production layer are also known in that there is a constant hydrodynamic connection between the production layer and the drilling well opening, which is the drilling fill with washing liquid and the bed pressure gradient equivalent. generation of excess pressure (unbalance) in the production bed by washer fluid with increased density relative to pressure gradient equivalent ("Operation in the construction of drilling wells in the field of oil, gas and gas-condensate"). Unified Technical Regulations ", NPAOP 11.21.18-82).

The minimum allowable imbalance value should not be less than 3% of the bed pressure value:

P _h > 1.03 P _form

Where P _h is the hydrostatic pressure of the washer fluid column in the production bed;

P _form is the formation pressure.

When the washer fluid is pumped, the overbalance in the bottomhole (which accounts for the pressure of the jet coming from the bit nozzle and the pressure loss in the annulus) increases.

Equipped with production string, downhole equipment (drill string) and blowout prevention equipment, lowering production string to the top of production floor, installing downhole equipment (drill string), expected depth with washer fluid recirculated Well deepening, prevention of formation fluid inflow, lifting of down-hole equipment (drill strings), and fixing of producing formation gross intervals. A method of forming a well is known is known (AI Bulatov, PP Makarenko, VF Budnikov, Yu.M. Basarygin, "Theory and Practice of Drilling Well Formation". Rev. by AI Bulatov.-M .: OJSC "Publishing house" Nedra ", 1998. T.4)

This technical solution is accepted as the "closest analog" of the present invention.

In this "most similar form", bed fluid inflow during development of the production bed is prevented by the occurrence of an imbalance by the Usher fluid column, which results in absorption, increased washer fluid flow rate, and reduced effective permeability of the production bed. And a decrease in oil production.

Known methods of production bed development confirm that the presence of a constant fluid connection between the drilling well opening provided by the washer fluid and the production bed prevents undesired entry of bed fluid to the drilling well. This is accomplished by the generation of excess pressure in the production bed by the washer fluid. Excess of the washer fluid pressure above the bed pressure results in inevitable overflowing of the production bed.

The intensity and volume of absorption depends on the collecting properties of the layer developed and ranges from several cubic meters to tens or hundreds of cubic meters; In addition, the washer fluid entering the production bed significantly reduces the effective permeability, and thus the drilling productivity, which leads to a reduction in oil production and an increase in operating costs and time.

Thus, the value and usefulness of the imbalance in the production layer greatly affects the quality of the drilling wells that are constructed when the drilling wells are formed. Failure to develop leads to a degradation of the collecting characteristics of the production layer-its closure. This may be the result of a high difference between the production bed pressure and the drilling fluid pressure, the physico-chemical properties of the washer fluid, and the contact time between the drilling well opening and the production bed.

According to the present invention, technical operation is performed to prevent undesirable inflow of the bed fluid, thereby increasing the efficiency and quality, thereby solving the problem.

According to the invention, this problem is provided with a production string, downhole equipment (drill string), blowout prevention equipment, lowering the production string to the top of the production floor, installation step of the downhole equipment (drill string) A method of forming a drilling well, including drilling a drilling well to the expected depth with the washer fluid recirculated, preventing a bed fluid inflow, lifting a downhole equipment (drill string), and fixing the total spacing of the production bed. Is solved by using

The sealing device is at the bottom of the production string and divides the drilling well into an upper cavity and a lower cavity, wherein the "drilling well opening-upper cavity" and "lower cavity-production layer" are in corresponding fluid connection. Is rotatable.

Return valves and downhole equipment (drill strings) are installed step by step against the sealing device.

The washer fluid is replaced by generating a hydrostatic pressure less than the hydrostatic pressure in the bed.

Downhole equipment (drill strings) is passed through a sealing device that can be separated during drilling hole openings along the annular channel, upper cavity, lower cavity and the reestablishment of fluid connections between production layers and installation of downhole equipment (drill strings). do.

Drilling wells are excavated using downhole equipment (drill strings) located in the lower cavity of the sealing device until the inflow of bed fluid occurs, and the differential pressure in the fluid system of the "prediction opening-production layer" pressure is controlled using a check valve and a blowout protector.

The downhole equipment (drill string) is retracted from the lower cavity upon completion of the excavation, and the sealing device is closed upon separation of the lower cavity from the upper cavity and breaks the fluid connection between the production layer and the upper cavity.

Applicant has not identified any sources that contain data from the same technical solutions as the applied method.

Therefore, the applicant has a view that the present invention satisfies the "newness" (N) criterion.

The technical results at hand are the implementation of the fluid circulation of the washer fluid before and after the development of the production layer and the drilling, using check valves and blowout guards, by the installation of sealing devices and the dividing of the drilling well into the upper and lower cavities. By the installation and passage of downhole equipment (drill strings) through the sealing device in the re-establishment of the fluid connection between the positive opening, the upper cavity, the lower cavity and the production layer, between the drilling well opening and the upper cavity and with the lower cavity Establishment of fluid connections between layers, removal of downhole equipment (drill strings) from the lower cavity and with controlled differential pressure within the fluid system of the "prediction opening-production layer" using check valves and blowout protection. Later, digging and sealing the production layer until layer fluid inflow occurs, with the fluid connection between the production layer and the upper cavity disconnected. It comprises a value close.

The implementation of the distinguishing features of the invention determines a number of important technical effects.

When the washer fluid stops producing an imbalance in the production layer due to the installation of a sealing device on top of the production bed, this prevents undesirable inflow of the bed fluid, reduces the washer fluid flow rate and improves drilling productivity. .

Drilling splitting into the upper and lower cavities by the sealing device provides for the occurrence of fluidic connections between the drilling cavities and the upper cavities and between the lower cavities and the production layer, thus direct fluid between the production layer and the drilling cavities. Disconnect and prevent undesired entry of bed fluid.

During installation of the downhole equipment, a detachable, sealing device that reestablishes the fluid connection between the drilling hole, the upper cavity, the lower cavity, and the production layer, provides an operating time for the direct fluid connection between the production layer and the drilling hole. Limiting, thereby reducing the operating time of the bed fluid inlet.

By the downhole equipment (drill string) until the inflow of bed fluid occurs, with the adjustment of the differential pressure in the fluid system of the "prediction opening-production bed" controlled using check valves and blowout guards. Drilling well excavation prevents the inflow of layered fluid and increases the efficiency of drilling well formation.

This technical result cannot be achieved from the known properties; At the same time, no information on the impact of the distinctive features of the present invention on the achieved technical results is included in the publication, and the Applicant believes that the technical solutions applied meet the "progressive" (IS) criteria. Insist on the view.

The implementation of the technical solutions applied is confirmed by research, development and experimentation; Applicants confirm that they meet the "Industrial Availability" (IA) criterion, as the application may be applied to equipment widely used in the oil and gas production industry to implement the method.

In addition to the technical solutions applied to the present invention will be described below by the description of the embodiments with reference to the accompanying drawings.

1 is a view showing a well;
2 shows a drilling well with a seal;
3 is a view showing a drilling estimate in a driving state;
4 is a partial cross-sectional view of the sealing device.

The drilling well 1 with the opening 2 is prepared for operation on the primary development of the producing formation 5. Drilling well 1 is filled with washer fluid 4.

A blowout preventer 3 in the form of universal and ram-type preventers (FIG. 1) is installed in the opening 2 to prevent explosion of the production layer fluid, and the choke A manifold (FIG. 1) having a is installed for adjusting the intensity of the washer fluid flowing from the drilling well during the process operation in the drilling well 1 which is deepened.

The rotating guard (FIG. 3) is provided with an opening (2) during the process operation on the drilling well (1) and deepening on the opening for the sealing of downhole equipment (drill string) 10. Near the wall of the drilling well (1).

Downhole equipment (drill string) 10 includes a check valve (not shown). This check valve is lowered until the lower portion of the downhole equipment reaches the sealing device 7 (until the downhole equipment (drill string) 10 passes through the sealing device 7). (Drill string) 10 is installed in the production string 6 during the process.

At the top of the production layer 5, a production string 6 with a sealing device 7 is installed.

The sealing device 7 divides the drilling well 1 into an upper cavity 8 and a lower cavity 9 (FIG. 2).

The sealing device 7 is made, for example, in the form of a collet which can be separated during installation of the downhole equipment (drill string) 10.

The sealing device 7 comprises a housing 11, a bearing 13 and a sealing assembly 14. The housing 11 is made with a thread 12 for connection with the production string 6. The collet shaped sealing assembly 14 is located in the housing 11 which is fixed to the bearing 13.

The sealing device 7 is rotatable, can provide "closed" and "open" states, can pass through the downhole equipment (drill string) 10 and overlap the cross section of the production string 6. Can be.

The sealing device 7 shown is not intended to limit the invention but is an embodiment of the presented method.

The sealing device is in the form of any known device, which can meet reliable pressure requirements and can be separated during the interaction with the downhole equipment (drill string) to be installed through the downhole equipment in operation. It can also be done.

The method of the present invention is carried out as follows.

Drilling test 1 is filled with washer fluid 4.

The sealing device 7 is connected to the production string 6 Of production layer (5)  Into the top Descend .

The lowering of the sealing device 7 is carried out in the open state, and after the extrusion of the cement grout, the displacement of the cement plug below the sealing device 7 takes a "closed" state.

Drilling estimate (1)  It is divided into an upper cavity 8 and a lower cavity 9 by a sealing device 7.

The upper cavity 8 provides a fluid connection between the drilling well opening and the upper cavity.

The lower cavity 9 provides a fluid connection between the lower cavity and the production layer.

In this state, there is no direct fluid connection between the production layer and the drilling well opening.

With check valve Downhole  Equipment (drill string) 10 is installed in the sealing device 7.

Downhole equipment (drill string) 10 is installed after casing cementing and preparatory operations.

Return valves and downhole equipment (drill strings) 10 are installed step by step in the sealing device 7.

Washer fluid 4 has a lower fluid static pressure in the bed. hydrostatic pressure Washer fluid 15 is generated.

The washer fluid 4 is replaced with a washer fluid 15 whose fluid static pressure, summarized by the pressure loss in the annulus, meets the following requirements.

P _h + P _l <P _form

Where P _h is the hydrostatic pressure, P _l is the pressure loss in the annulus, and P _form is the formation pressure

Conditions that ensure the generation of a hydrostatic pressure lower than the bed pressure with the help of the washer fluid 15 make it possible to carry out further process operations without overbalance.

As the washer fluid 15, oil or petroleum product application is most preferred, in which case the collectors do not get wet with filtered water filtrates, and thus the effective permeability does not decrease.

Downhole  Equipment (drill string) 10 passes through the sealing device 7.

The sealing device 7 is opened while the downhole equipment (drill string) 10 passes through the sealing device 7 and the washer fluid 15 to the downhole equipment (drill string) 10 along the annular channel. The fluid connection between the drilling aperture, upper cavity, lower cavity and production layer is reestablished during pumping.

Of drilling (1)  Excavation deepening )silver Washer  Inflow signal into the circulation of the fluid 15 ( inflow  until a sign is triggered.

The anti-rotation tool (FIG. 3) is activated before developing the production layer 5 and after being lifted up to the opening 2, the washer fluid 15 is directed to the manifold and through the adjustable choke to the circulation system (FIG. 1). .

Further excavation of the drilling 1 is performed.

Evidence of the production layer 5 at which development begins is the growth of the flow strength coming into the opening 2. The intensity of the flow from the drilling estimate is controlled by the manifold choke (FIG. 1).

Of drilling (1)  Excavation Washer  Fluid outflow strength ( outflow intensity Is controlled by

The strength of the washer fluid outflow is controlled by the manifold choke (FIG. 1) of the blowout guard 3.

Of drilling (1)  Excavation is complete Washer  The circulation of the fluid 15 ends.

After completing the development of the production layer 5, the pumping of the washer fluid 15 is terminated; At this time, the check valve is automatically closed and the fluid connection through the internal channel of the pipe is broken.

Downhole  Equipment (10) On lift  follow Production  Break the fluid connection between the upper cavities.

After removal of the downhole equipment (drill string) 10 from the lower cavity 9 of the drilling well 1, the sealing device 7 is closed and the fluid connection between the production layer and the upper cavity is terminated; At this time, the lower cavity 9 is sealed from the upper cavity under constant formation pressure P _form ; At this time, product layer fluid inflow from the lower cavity into the upper cavity becomes impossible.

Additional actions are determined by the following correlation:

P _form -P _h <P _ws

Where P _form is formation pressure, P _h is hydrostatic pressure, and P _ws is the working pressure of the sealing device.

If the needs of this correlation are met, further lifting of the downhole equipment (drill string) 10 is possible.

If the difference between the hydrostatic pressure P _h and the bed pressure P _form of the washer fluid 15 in the upper cavity 8 is greater than the working pressure P _ws of the sealing device 7, the washer fluid 15 Is replaced with another fluid having a density that meets the requirements of the correlation, and then further lifting of downhole equipment (drill string) 10 may be performed.

Production (5) spacing ( interval Of) fixation ) Is performed.

In order to fix the spacing of the production layer 5, the bedding of the tail pipe (not shown) is lowered similarly to the lowering of the downhole equipment (drill string) 10; The aesthetics can then only overlap the lower cavity 9, in which case the sealing device 7 functions as a safety valve.

The proposed method can open any formation fluids including oil, gas, water or mixtures thereof.

The proposed method can be implemented in drilling estimates at any angle of inclination.

The proposed method enables the following:

Improving the efficiency and quality of process operation during well completion;

Preventing undesired entry of bed fluids without the occurrence of imbalances by washer fluids in the production bed;

Increased drilling productivity;

Reduced action time of the direct fluid connection between the production layer and the drilling well opening.

The proposed method can be applied to equipment widely used in the oil and gas production industry, whereby the applicant has the view that the present invention satisfies the "Industrial Availability" (IA) criterion.

1: Well estimated
2: opening
3 blowout preventer
4 washer fluid
5: producing formation
6: producing string
7: sealing device
8: Upper cavity (of drilling estimate 1)
9: Lower cavity (of drilling estimate 1)
10: Downhole equipment (drill string) with check valve
11: housing (of sealing device 7)
12: thread (on the housing 11)
13: bearing
14: sealing in the form of a collet
15: washer fluid

Claims (1)

It is equipped with producing string, downhole equipment (drill string) and blowout preventer, and lowers the production string to the top of producing formation. Installation, drilling of drilling rigs to the expected depth with circulating washer fluid, prevention of introduction of formation fluids, lifting of down-hole equipment (drill strings), and producing formation spacing A method of forming a well including a fixation of a bedding interval,
The sealing device is at the bottom of the production string and divides the drilling well into an upper cavity and a lower cavity, in fluid connection between the drilling well opening and the upper cavity and between the lower cavity and the production layer, respectively, the sealing device being rotated Possible;
Check valves and downhole equipment (drill strings) are installed step by step against the sealing device,
The washer fluid is replaced with a washer fluid that generates a hydrostatic pressure less than the formation pressure,
Downhole equipment (drill strings) is passed through a sealing device that can be separated during drilling hole openings along the annular channel, upper cavity, lower cavity and the reestablishment of fluid connections between production layers and installation of downhole equipment (drill strings). ,
Drilling wells are excavated with the aid of downhole equipment (drill strings) located in the lower cavity of the sealing device until the inflow of bed fluid occurs, whereby the differential pressure in the fluid system of the "drilling opening-production layer" ( differential pressure is controlled using check valves and blowout guards,
Downhole equipment (drill string) is removed from the lower cavity upon completion of excavation, wherein the sealing device is closed upon separation of the lower cavity from the upper cavity and breaks the fluid connection between the production layer and the upper cavity. .

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