BRPI0801203B1 - MONOCANAL TOOL FOR FRACTING CANNON ZONES AND THEIR OPERATING METHOD - Google Patents

Description

(54) Title: MONOCHANAL TOOL TO FRACTURE CANNON ZONES AND ITS

OPERATING METHOD (51) lnt.CI .: E21B 43/267; E21B 17/18 (73) Holder (s): PETROLEO BRASILEIRO S.A. - PETROBRAS (72) Inventor (s): JOSÉ MARCOS NOGUEIRA SIQUEIRA; VITAL CARDOSO LIMA; MAX SAMUEL AMADO NUNES; AMARO BARCELLOS; JOSÉ TRAJANO DE CASTRO (85) Date of the Start of the National Phase: 11/04/2008

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SINGLE-CHANNEL TOOL TO FRACTURE ZONING / CANONING AREAS AND ITS OPERATING METHOD *

FIELD OF THE INVENTION

The present invention relates to a new tool and method for hydraulic fracturing of the lithological layers located at the end of a vertical oil well. Under a totally different concept, the new fracturing tool proposed is based on a configuration that does not have an appendix for reverse circulation, a device normally used in window opening control, like most of the tools known in the art. Its applicability, however, becomes advantageous, as it ensures the manipulation of the tool without risk of loss of pressure or loss of the entire well.

DESCRIPTION OF RELATED TECHNIQUE

Oil reserves on Brazilian soil have been found in the marine subsoil, but subsequently, many oil wells of great economic value have been explored and opened in ever deeper waters. One of the characteristics of many of these wells is that after the grounding, the production area is horizontal. It is worth mentioning that this well configuration is only possible when the thickness of the lithological layer, at the ground level, is capable of containing the entire well section drilled horizontally.

However, there are geological formations in which the interval between successive lithological layers does not allow to safely house the entire horizontal section of a well. In these geological formations, the production area of the well is usually arranged in a vertical direction, and consequently passes through several lithological layers.

In completing vertical and horizontal wells, the aim is, among other objectives, to equip the production area with a production capture system protected by a sand containment system, which consists of at least one layer of filter element.

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Commonly used to capture production and retain impurities, a metal mesh tube, arranged concentrically and throughout the entire production area.

For the sake of prevention, a further layer of filter element is added around the wire mesh tube. For this, a method already known in the art is applied, in which successive layers of propant are laid, which fill the entire space between the outer surface of the wire mesh tube and the inner surface of the production area.

In horizontal wells, this process is carried out using a fluid flow with propant. The current circulates towards the bottom of the well, carrying the propellant elements through the space between the outer surface of the wire mesh tube and the inner surface of the well. This same stream of fluids, after leaving the propant elements properly seated, returns through a tool provided inside the wire mesh column. It can be seen, therefore, that the placement of propante in horizontal wells is carried out by fluid circulation.

The completion operation in vertical and directional wells obeys a characteristic method, different from the horizontal well completion method. Some differences deserve to be highlighted in order to better understand the proposed invention.

In horizontal wells, the well wall in the production area is generally uncoated, and the propellant can be laid by fluid circulation, as explained above. In order for the circulation described above to occur, it is necessary to provide the interior of the wire mesh column with a washing column. The stimulation, in turn, is done by a jet of acidic fluid at the end of the settling process.

In vertical wells, the inner wall of the well is coated, including

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in the production area, which makes the production area watertight. Thus, the stimulation must be prepared before the proponant settlement operation, using a specific method that fractures the lithological layer. The fracture must also be provided with a support agent, which prevents the fracture from closing during the productive life of the well. Then the propellant is installed by compaction.

As each lithological layer has particular mineralogical characteristics, properties and tensions effective and inherent to its formation, the completion of the production area arranged in a vertical direction needs to respect, in each canonization zone, specific parameters during its implementation.

This means that the cannoneering zone implemented within the range of a lithological layer will require a fracturing pressure different from that needed in another cannoneering zone arranged in another contiguous layer.

One of the known techniques for fracturing rock is hydraulic fracturing.

The technique initially consists of installing a lower shutter at the bottom of the production area (known in the technical environment as a “packet”), then drilling in the well lining, generating a set of cannons, in order to expose the rock formation behind the cladding wall. A production capture module, which includes a metal mesh column, is attached to the lower plug, and closed at its upper end by another plug.

From this stage, to perform the fracturing of the rock formation, it is necessary to provide a fracturing tool inside the production capture module, previously installed. Generally, the models of fracturing tools on the market have an appendix, of variable size, which can extend to a lower portion of the wire mesh column.

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It is through this fracturing tool that a procedure is performed for a complex process, the pre-fracturing process. However, in order for any of the existing tool models on the market to act, it is necessary that a sealing column provided with sliding windows is provided inside the wire mesh column.

The purpose of carrying out a pre-fracturing, comes from the need to generate a representative model, in which the properties and effective tensions of the stretch of geological formation in which the completion will take place are registered. Through this procedure, among other aspects that are also calculated from the data that are collected, it is determined the type of propante that will be used, and the maximum stress that must be reached to generate a fracture of ideal dimension.

To carry out pre-fracturing, a hydraulic fluid is injected into the cannoneed section of the production area, using some model of fracturing tool available on the market.

The injected fluid is trapped between a lower and an upper plug that seal the production area where completion is being carried out. Thus, the only possible flow direction to the fluid is through the cannonado towards the rock formation, which is also watertight.

The pressure is gradually increased until a sufficient value is reached to cause the rock to rupture by traction. In this way, a fracture in the rock begins, which is filled with a polymeric gel.

In the next step, the pumping of the fluid is interrupted and the monitoring of fluency in the fracture begins.

Monitoring is currently achieved through a reverse circulation column provided by current fracturing tools on the market. Said reverse circulation column is twin to the main column body of the tool, through which the pressurization of the production area is carried out.

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The monitoring takes place as follows: when interrupting the pumping of fluid into the production area, the pressure stabilizes momentarily. Over time after the interruption of pumping, the pressure changes inside the production area due to the fluency of the rock formation, which tends to close the gel-filled fracture.

The pressure curve is then measured using the reverse flow channel. This channel in turn is usually provided with an appendix.

The appendix and the reverse flow channel act as a communicating vessel between the production zone, which is under high pressure, and the annular well. A pressure monitoring system, focused on the wellhead, will register the characteristic profile of the stresses acting on the fracture.

With the data collected in this stage, the production area can already be definitively fractured, and, soon after, duly filled with a support agent and propante.

The propellant is installed by compaction using also the fracturing tool, which even during the installation allows to capture the internal pressure of the production area. The pressure reading during the installation of the propellant must repeat the results recorded by the monitoring.

After the propellant is settled, the entire production area must be sealed, so that a new completion cycle can be carried out in a subsequent rock formation section of the well.

In order to achieve the sealing of the section of the well whose completion has already been completed, it is necessary to seal the annular column of this section. For this, the flow allowed by the wire mesh column has to be canceled. This sealing is achieved, by means of the sealing column previously provided inside the metallic mesh column.

In current fracturing tools, appendages are

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arranged inside the sealing column, which in turn is provided with sliding windows. These windows must be closed by the appendix of the fracturing tool, while it is moved to the subsequent upper section, to start a new completion cycle.

At this stage, there are some frequent and common problems with several models of tools on the market.

One of the most common problems is the failure to close the sliding windows during the removal of the fracturing tool. When this occurs, the subsequent section is committed to completion. As long as it is not possible to carry out any type of sealing in said sliding windows other than the closed form, the completion activities are paralyzed.

Another problem is the risk of breaking the fracturing tool's appendix when moving to the next section.

When one of these two problems occurs, and a solution is not found, there is the possibility of total loss of the well, and of all the equipment already installed.

Due to these particularities, the operation in vertical wells requires increasingly specific tools and accessories for their completion, in order to guarantee the completion of the completion process, and to overcome the problems and limitations that arise with the increase in the depth of the wells.

Currently, in Brazil, the friable sandstones of the Campos Basin have been the main scenario for the application of the hydraulic fracturing technique in vertical wells, either to increase productivity or to control sand production. However, the risk of well loss inherent to the technique, when applied at great depths, meant that the research was focused on bringing definitive solutions that could eliminate this type of risk.

Following this new global trend, several solutions have already been

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proposals, among which we highlight one of them:

- US patent US 7,290,610 dated 11/06/2007, where a fracturing tool is proposed without the reverse circulation appendix. However, this solution is based on a valve driven by a flow differential that acts to replace the sliding windows. In practice, however, there is no guarantee of the performance of said valve in response to the applied flow differential.

These and other solutions presented so far, always use an independent communicating vessel, so that the pressure inside the production area can be monitored.

Adopting any of the solutions presented so far, in some stage of the pre-fracturing, fracturing or propante settlement operations, it will be necessary to act on valves or windows, which will control the circulation of fluid in the production area. This control is necessary for the completion of the next well section, and completion of operations before starting the well operation.

In order to eliminate the problems highlighted above, the technique of adopting communicating vessels in the fracturing tools should be discarded, and new equipment with totally new arrangements and configurations should be adopted.

An objective of the present invention is, therefore, to develop a new technology in the design of fracturing tools that allows to carry out the pre-fracturing, the fracturing and later the laying of the propant without the need to provide the tool with a reverse flow channel.

As a result of research in this sense, a mono-column fracturing tool was invented that performs the pre-fracturing operations, definitive fracturing and subsequently the propellant settlement, without the need for sliding windows provided to the sealing column, to be opened and closed several times over

8/23 the whole process.

The concern in the development of this new fracturing tool and its method aims to simplify and make the completion of vertical wells less expensive, offering a more effective option for hydraulic well fracturing, making it easy to apply to vertical wells of any length.

The invention described below is the result of continuous research following the completion of wells, whose focus is on simplification, cost reduction in fracturing operations and the offer of a high efficiency solution, and above all, does not offer any risk the loss of the well.

Other objectives that the mono-column fracturing tool and method of implementation, objects of the present invention aim to achieve are listed below:

The. Cheap costs, both material and handling.

B. Eliminate the possibility of failure in closing and opening operations of the sealing column sliding windows.

ç. Eliminate the possibility of breaking the fracture tool's appendix.

d. Eliminate the possibility of well loss.

and. Dramatically reduce the drilling time required to complete a well.

f. Eliminate the need for a reverse flow column to monitor pressure.

g. Standardize the quality of hydraulic fracturing in wells of any size.

H. Reduce the risk of personal, environmental and material accidents.

i. Reduce the handling time of the fracturing tool.

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j. Mitigate dependence on fracturing tools with increasingly complex technologies and operability.

SUMMARY OF THE INVENTION

In a first aspect, the invention comprises a single-column hydraulic fracturing tool, consisting of two distinct basic components, namely: an injection chamber, and a switch ring.

The main body of the single-column fracturing tool is mainly made up of the injection chamber and has a predominantly cylindrical external shape, with a configuration complementary to the internal configuration of the head of a production capture module.

The lower end of the injection chamber connects tightly to the base of the head, sealing the upper section of said module from its lower section. The lower end of the outer wall of the injection chamber is provided along its circumference with at least two holes. In an intermediate section, the outer wall of the injection chamber is reduced in diameter to form a channel.

Said channel is provided externally with the switch ring that surrounds its entire circumference. The channel is configured to be subdivided into three distinct and subsequent sections: in the upward direction, the first third of the channel is smooth and continuous, serving as a guide for the switch ring to slide. The second third of the channel is provided with a retarder to sudden pressure changes, and the third and last third is provided with a communication screen.

A belt covers the channel from its upper edge to the lower edge, leveling the outer wall of the single-column fracturing tool in the section of said channel.

Like the groove, the internal surface of the belt is also subdivided into three subsequent sections: in the upward direction, the first third of the belt is also smooth and continuous, serving as a guide for

10/23 that the switch ring can slide, but it is provided with at least one ventilation hole. The second third of the belt's internal surface is provided by a complementary configuration to the retarder of sudden pressure changes, which is provided to said channel, and the third and last third is smooth, and necessarily seals the contact between the belt and the edge top of the channel.

The switch ring has its side walls in contact with the channel surface and the internal surface of the belt respectively, forming a control chamber. Said control chamber has a fluid connection with the injection chamber. The switch ring is also provided with a smooth and straight upper surface and a lower surface with an area much larger than the area of said upper surface.

In a second aspect, the invention comprises an acidification method that briefly obeys the following steps:

- the single-fracturing tool is connected to the production capture module.

- starts the fluid pumping operation with the purpose of performing the pre-fracturing procedure.

- at specified pressure increments, the pumping can be momentarily interrupted, so that the value of the fluid pressure inside the production area can be monitored.

- when the pre-fracturing pressure is reached, the support gel is injected and the pumping is stopped.

- the pressure variation is monitored by means of instruments installed in the wellhead and concomitantly generating the profile of forces acting on the rock formation that was fractured.

- the fluid pumping operation is restarted in order to carry out the definitive fracturing procedure.

- when the pre-determined pressure for definitive fracturing is reached, the pumping is stopped.

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- the propant packaging procedure begins.

- as soon as the switch ring is activated, the completion of the proponant placement procedure is confirmed.

- the fluid pumping is stopped.

- the single-column fracturing tool is removed from the head of the production capture module.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below, together with the drawings listed below, which, purely by way of illustration, accompany this report, of which it is an integral part, and in which:

Figure 1A depicts, in schematic drawing, a vertical well and the fracturing tool of the STATE OF TECHNIQUE.

Figure 1B shows a horizontal well and the same fracturing tool as the STATE OF TECHNIQUE after the stage of laying the propellant.

Figure 2 shows a schematic sectional view of the mono-column hydraulic fracturing tool attached to the production capture module.

Figure 3 shows a schematic sectional view of the enlarged mono-column tool and a larger-scale detail of one of its components.

Figure 4 shows a schematic sectional view of the mono-column hydraulic fracturing tool attached to the production capture module, during the packaging stage of the propant. DETAILED DESCRIPTION OF THE INVENTION

The present invention refers to a new tool and method for hydraulic fracturing and subsequent settlement of propante in vertical and directional oil wells. This proposal aims to reduce the probe time dedicated to the fracturing process, and eliminate the risk

12/23 loss of the well. For a better understanding of the advantages that the single-column fracturing tool offers, it is necessary to clarify some details of the previous technique.

Using Figures 1A and 1B, it is possible to check the configuration of the basic elements that make up the models of conventional hydraulic fracturing tools (100) frequently used in oil well drilling operations, and to better understand the expensive and risky methodology of the technique above, to hydraulically fracture a productive zone, considered typical for vertical and directional wells that are found in Brazilian territory.

Figure 1A shows, in a schematic representation, the productive section of a vertical well, characterized by being a coated well (200), that is, a well with a standard coating, which isolates the annular well from the rock formation.

The purpose of a hydraulic fracturing tool is to carry out three essential compaction procedures, namely: pre-fracturing, definitive fracturing, settling of propante.

Figure 1A serves as a basis to illustrate both the pre-fracturing and the definitive fracturing stage.

The figure aims to represent the typical components presented in the current tools, where it is observed the existence of a structure with standard functions, which despite the constructive differences presented by each tool model currently on the market, can always be found in several tools.

In conventional hydraulic fracturing tools (100), there will always be a split body (101), which connects to the head (307) of the production capture module (300).

The lower end of the split main body (101) seals the upper section of the production capture module (300) from its lower section.

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The upper section of the production capture module (300) consists of its own head (307). The lower section of the said module, basically, consists of the metallic mesh column (301).

The metallic mesh column (301) has its inner chamber subdivided with a sealing column (302), giving rise to two watertight concentric sub-chambers (303) and (304).

The sealing column (302) at its lower end is sealed next to the lower plug (201) of the production area (400), and at its upper end, near the lower end of the head (307), by an upper plug ( 202).

The sealing column (302) is provided with sliding communication windows (305) that have the opening and closing command operated by means of the fracturing tools (100).

The guarantee of carrying out the command to open or close these windows is of paramount importance in the operating methods of current fracturing tools.

Failure to close these windows before starting a new fracturing cycle in the subsequent section of the well can invalidate all of the following procedures, such as;

- generate loss of probe time until obtaining a solution to seal the windows;

- inconveniently hydrate a section that has already been completed, incurring unwanted water production early in the well's production;

- lose the well.

On the other hand, the failure to open the sliding windows (305) at the end of the well completion, can prevent or hinder the production of hydrocarbons to flow normally to the production column.

Thus, the need to provide the production capture module (300) in its lower section with a sealing means, such as the

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fence (302), equipped with windows that must be opened and closed throughout the process, is one of the major problems of the current method, but until the moment essential for the currently existing models of hydraulic fracturing tools (100) operate.

This need arises from the configuration / method used by the current fracturing tools (100) to monitor the pressure in the production area during the pre-fracturing and definitive fracturing procedures.

In both procedures, the fluid (A) is pumped through an inlet (102) of the main body (101) split. The head (307) pressurizes through a communication window (103); hence the fluid is directed through injection holes (306) to the production zone (400), bounded and sealed by the lower (201) and upper (202) shutters.

By increasing the pressure inside the production zone (400), fractures (203) in the rock formation are generated.

In both pre-fracturing and definitive fracturing, pressure monitoring is obtained by counterflow (B), which penetrates the metal mesh column (301), passes through the sliding windows (305) and reaches the body's ascending path (104) main (101) bipartite. Through this route (104), fluid and pressure are communicated to the annular of the well, which is formed between the upper plug (202) and the wellhead (not shown). Thus, it is possible to monitor the pressure using reading instruments connected to the wellhead.

Some tool models use a kind of washing column, or drive attachment (105), which will command the opening or closing of the sliding windows (305).

Other models are devoid of such appendices, however all tool models separate at least two independent channels, the fluid pumping channel and the pressure monitoring channel.

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Despite the great risks that the handling of these sliding windows (305) represent, this performance paradigm has not yet been changed, since at the end of the pre-fracturing and the definitive fracturing, the propant must be placed around the mesh column. metal (301). As this process is carried out by means of tamping the propellant, the high pressure that is reached during the operation can damage the well in case the sliding windows fail to act (305).

Figure 1B represents the completion of the proponant settlement process by the PREVIOUS TECHNIQUE.

The fluid (A), now carrying elements of the propant, begins to deposit them, by tamping, from the bottom section of the production zone (400) upwards.

While the propellant is deposited in the permeable zone of the wire mesh column (301), the fluid (B) will have the ascension pathway (104) as an expansion chamber. This communication also allows monitoring of the pressure during the laying operation of the propellant.

When the propane level reaches a blind section of the production capture module (300) in which there is no longer the permeability offered by the metallic mesh column (301), an extremely compacted propane zone (Z) is formed, which seals the pumping fluidity, causing the pressure to reach very high values. Thus, the peak pumping pressure is restricted to the interior of the intake port (102) and the chamber between the upper plug (202) and the zone (Z) of extremely compacted propant.

At this very moment, the ascension route (104) loses the monitoring capacity, signaling the filling of the production area with propant. From there, the pumping can be stopped at any time, according to the project parameters, giving the process of

16/23 propante settlement as completed.

Then the tool is retracted, and while it is removed, it commands the opening or closing of the windows (305) of the sealing column (302), with the risk of breaking the drive appendix (105) within the said column.

Figure 2 presents a general and schematic sectional view of the single-column fracturing tool, object of the invention, coupled to a standard production capture module (300).

As can be easily seen, the single-column fracturing tool (500) also operates connected to the head (307) of a production capture module (300), and consists of two distinct basic components. The first component is an injection chamber (500 ’), and the second is a switch system (500”).

The primordial advantage of the current invention already stands out in its simplified configuration: the main body of the single-column fracturing tool (500) is mainly made up of the injection chamber (500 '), whose external shape is predominantly cylindrical, has a complementary configuration to internal configuration of the head (307) of the production capture module (300), making perfect coupling between them compatible.

The lower end of the injection chamber (500 ') connects tightly to the base of the head (307), sealing it in relation to the lower section of the production capture module (300).

However, the outer wall of the injection chamber (500 ') is fluidly connected to the annular chamber of the well (204), which is watertight. The annular well chamber (204) is limited by the space between the upper plug (202) and the wellhead (not shown), by means of a device known in the technical field as BOP (“Blow Out Preventor”).

By means of reading instruments connected to the wellhead, the

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current tool will allow monitoring of pressure during pre-fracturing and definitive fracturing procedures.

The lower end of the injection chamber wall (500 ') is provided along its circumference with at least one orifice (504), which has the function of injecting into the head (307), the fluid pumped through the column of work (not represented).

In an intermediate section, the single-column fracturing tool (500) is provided with a switch system (500 ”).

The switch system (500 ”) basically consists of a switch ring (502) together with some basic elements of mechanics, which will act in order to automatically control the pressure level to which the annular chamber (204) of the well will be subjected.

The outer wall of the injection chamber (500 ') is reduced in diameter to form a channel (503). The channel (503) is provided externally with said switch ring (502), which surrounds its entire circumference.

The actuation mechanism of the switch ring (502) can be better understood by viewing the enlarged image shown in Figure 3.

In this schematic representation, it can be seen in more detail that the channel (503) is subdivided into three distinct and subsequent sections. In the upward direction, the first third of the channel (503) is smooth and continuous, serving as a guide for the switch ring (502) to slide. In the second third, the channel surface (503) preferably has a toothed configuration (506), which together with an element provided with a band (508), will act as a retarder to sudden pressure changes. The third and last third of the mechanism is provided with a communication screen (507).

The belt (508), in turn, covers the channel (503) from its upper edge to the lower edge, leveling the outer wall of the

18/23 single-column fracturing tool (500) in the section of said channel (503).

Like the groove (503), the internal surface of the strap (508) is also subdivided into three distinct and subsequent sections:

In the upward direction, the first third of the strap (508) is smooth and continuous, complementing the support so that the switch ring (502) can slide, but it is provided with at least one ventilation hole (509).

In the second third, the internal surface of the brace (508) may have a toothed configuration (510) coinciding with the teeth (506) of said channel (503), or any other configuration that together with the teeth (506) of said channel (503), act like a labyrinth to attenuate peaks of overpressure.

The third and last third of the belt's internal surface is smooth, and necessarily seals the contact between the belt (508) and the upper edge of the channel (503).

The fluid (A) that is being pumped through the injection chamber (500 ') to the production zone (400), also reaches the annular chamber (204) of the well. The pressure is communicated from one chamber to the other due to the existence of said fluidic communication screen (507), provided in the channel (503). The fluid (C) passes through the communication web (507), then the retarder of sudden pressure changes, in the case consisting of the set of teeth (506 and 510), being finally discharged through the ventilation holes (509) in the space between the inner wall of the head (307) and the outer wall of the tool itself.

The switch ring (502) has its side walls in contact with the channel surface (503) and with the inner surface of the band (508) respectively, forming a control chamber (511) with them.

This chamber (511) has a fluid connection with the injection chamber (500 '). For a better performance of the switch ring (502), it must be provided with a sealing means in its

19/23 ends.

Figure 3 also shows a detailed enlargement of the switch ring (502). In this enlarged image, it is possible to notice that the switch ring (502) presents the upper surface with a smaller area than the lower surface. The upper surface (502A) is preferably smooth and straight, and the lower surface (502B) with an area much larger than the area of said upper surface. This difference in area between the upper and lower surfaces will cause the pressure to act differently on each of them. This differential will cause the switch ring (502) to move along the channel (503) in an upward direction, breaking a shear pin (512) and positioning itself over the ventilation holes (509), sealing them.

The advantages of this new conception of single-column fracturing tool (500) can be better understood from the presentation of the vertical or directional well fracturing method using the proposed single-column fracturing tool (500).

The method of pre-fracturing, fracturing and settling of vertical wells coated using the invention now proposed, can be visualized by following Figures 2 and 4. It consists of the following steps:

- The single-column fracturing tool (500) is connected to the production capture module (300), ensuring that the lower end of the injection chamber (500 ') connects tightly to the base of the head (307) , sealing the lower section of the production capture module (300).

- The fluid pumping operation begins in order to carry out the pre-fracturing procedure.

In this step, the fluid (A) pumped by the working column reaches the injection chamber (500 ’), being then injected through the holes (504) inside the head (307). Hence the fluid is directed through the holes

20/23 injection (306) to the production area (400), bounded and sealed by the lower (201) and upper (202) shutters.

When providing the production area (400) with the production capture module (300), it is mounted with a sealing column (302) inside, with its sliding windows (305) guaranteed to be closed.

Since there is nowhere to flow, the fluid (B) is pressurized inside the production zone (400) until a pressure value sufficient to generate the pre-fracturing in the cannoned zone (203) of the well is reached.

- Pressure increments can be monitored during pumping, as the fluid pressure inside the production area (400) is the same as that shown in the annular chamber (204) of the well, due to the fluid communication screen (507) provided in the channel (503).

Pre-fracturing and definitive fracturing of the rock formation are achieved by pumping fluid in a pressure range perfectly supported by the well lining structures.

The fluid (A) that is being pumped through the injection chamber (500 ’) also reaches the sealed annular chamber (204), matching the pressure in the two chambers. Thus, the pressure acting in the production zone (400) can be monitored by appropriate equipment located at the wellhead.

It is easy to see that the characteristic difference of the current invention for the existing equipment resides in the direct fluid communication between the production area (400), the injection chamber (500 ') and the annular chamber (204) of the well, eliminating the existence of a specific reverse flow channel in the tool body for the detection of pressure.

- When the pre-fracturing pressure is reached, the sustaining gel is injected and the pumping is stopped.

- The pressure variation is monitored by means of instruments installed in the wellhead and concomitantly generating the profile of forces acting on the rock formation that was fractured.

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- The fluid pumping operation is restarted in order to carry out the definitive fracturing procedure.

- When the pre-determined pressure for definitive fracturing is reached, the pumping is stopped.

- The procedure for packaging or laying the proponent begins.

In this stage, the propellant is pumped by the same fluid circulation circuit (A).

As already mentioned, the settlement of the proponant in canonized wells is characterized by the packaging being obtained through the hydraulic pounding of the elements of the propant in the production area (400), as shown in Figure 4.

In this step, as with the corresponding steps when using the tools available on the market, as the proponant is placed the pressure of the production area (400) and the annular chamber (204) of the well increase.

When the proponent reaches a “blind level” around the wire mesh column (301), there is a possibility that the pressure will rise abruptly.

Likewise, in the tool now proposed, the formation of a zone of high compaction and low permeability on the surface of the settled propellant, does not prevent the spread of pressure between the production zone (400) and the annular chamber (204) of the well; the tool adopts the switch system (500 ”), as a safety mechanism, avoiding the exposure of the well casing along its annulus to sudden pressure variations.

- As soon as the switch ring (502) acts, it will be confirmed the filling of the production zone (400) with propant, and the completion of the propant settlement procedure can be interrupted from this limit, according to predetermined pressure parameters. punch.

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- The fluid pumping stops.

- The single-column fracturing tool (500) is removed from the head (307) of the production capture module (300).

It should be noted that this step does not offer any risk as to the possibility of breaking some part of the tool inside the head (307). Nor is there any risk of closing the circulation windows inside the wire mesh column (301), as they have previously been closed and tested on the surface.

One of the main factors that makes the proposed proposal feasible is the elimination of some of the operational problems, already mentioned above, during the traditional fracturing process.

One of these problems is related to the working time of the probe in situations of failure of the closing control of the sliding windows.

Another problem is when the well has more than one production zone, and the fracturing method must be repeated sequentially in the upper zones. In these cases, as a production capture module (300) is already pre-assembled with a sealing column (302) inside, with its sliding windows (305) guaranteed to be closed, the method can be automatically replicated successively in as many subsequent zones as there are , as there will be no risk of leakage, just at the end of the last cycle, using a tool common to the technique, open all windows only once, to make way for production.

One of the unquestionable advantages of the proposed invention is, therefore, the elimination of any risk of loss of well due to failure in the activation of the sliding windows (305), or the breaking of some appendix of the fracturing tool inside the sealing column (302). ).

The invention has been described here with reference to its preferred embodiments. It must, however, be clear that the invention

23/23 is not limited to these embodiments, and those with technical skills will immediately realize that changes and substitutions can be adopted without evading the inventive concept described here.

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Claims (2)

1/5 1) replicate the method from its initial stage, in each subsequent upper production zone; 10 2) open all sliding windows (305), of all production capture modules (300), at once, at the end of the last cycle. Petition 870180047709, of 06/05/2018, p. 12/19 1.- MONOCHANAL TOOL TO FRACTURE CANNON ZONES, characterized by being constituted by two distinct basic components, namely: an injection chamber (500 ’), and 5 a switch system (500 ”), the main body of the mono-column fracturing tool (500) being mainly constituted by the injection chamber (500’); said chamber has a predominantly cylindrical external shape, with a configuration complementary to the internal configuration of the head (307) of the production capture module 10 (300); the lower end of the injection chamber (500 ') connects tightly to the base of the head (307), sealing the upper section of said module from its lower section; the lower end of the injection chamber wall (500 ') is provided along its circumference with at least one orifice (504); in an intermediate section, the outer wall of the 15 injection chamber (500 ') is provided with a switch system (500 ”), 2.- MONOCHANAL TOOL FOR FRACTURING CANNON ZONES, according to claim 1, characterized in that the switch system (500 ”) consists of a diameter reduction provided to the injection chamber wall (500 ') in order to form a 20 channel (503); said channel (503) being provided externally with a switch ring (502) which surrounds its entire circumference; the channel (503) is subdivided into three distinct and subsequent sections, in the upward direction, the first third of the channel (503) smooth and continuous, serving as a guide so that the switch ring (502) can slide, in the 25 second third the channel surface (503) has a retarder to sudden pressure changes, in the third and last third it is provided with a communication screen (507); additionally, a band (508) covers the channel (503) from its upper edge to the lower edge, leveling the outer wall of the single-column fracturing tool (500) in the 30 section of said channel (503); such as the channel (503), the surface Petition 870180047709, of 06/05/2018, p. 9/19 2/4 inner strap (508) is also subdivided into three subsequent sections: in the upward direction, the first third of the strap (508) is smooth and continuous, serving as a guide for the switch ring (502) to slide, but being provided with at least one orifice (509) of 5 ventilation; in the second third, the internal surface of the belt (508) is provided by a complementary configuration to the retarder of sudden pressure changes provided to said channel (503); in the third and last third, be smooth, and necessarily seal the contact between the brace (508) and the upper edge of the channel (503); said switch ring (502) has its walls 10 sides in contact respectively with the channel surface (503) and with the internal surface of the band (508), forming a control chamber (511); said control chamber (511) has a fluid connection with the injection chamber (500 '); said switch ring (502) is further provided with an upper surface (502A) and a lower surface 15 (502B) with an area much larger than the area of said upper surface and also with a sealing means at its ends, 3. - MONOCHANAL TOOL TO FRACTURE CANNON ZONE AREAS, according to claim 1, characterized by presenting a retarder of sudden pressure changes provided to the 20 said channel (503), which is preferably composed of a set of teeth respectively provided to the surfaces of the channel (503) and the strap (508) in order to fit together forming a labyrinth to the fluid flow during peaks of overpressure , 4. - MONOCHANAL TOOL TO FRACTURE AREAS OF CANHONING, according to claim 1, characterized in that there is a difference in area between the upper and lower surfaces of the switch ring (502), causing the pressure to act differently on each one of them, and that this differential causes the switch ring (502) moves along the channel (503) in the direction 30 ascending positioning over the ventilation holes (509), Petition 870180047709, of 06/05/2018, p. 10/19 3/4 5.- METHOD OF OPERATING THE SINGLE-CHANNEL TOOL TO FRACTURE CANNON ZONE AREAS described in claim 1, characterized by comprising the following steps: a) connect the single-column fracturing tool (500) 5 in the production capture module (300), ensuring that the lower end of the injection chamber (500 ') connects tightly to the base of the head (307), sealing it from the lower section of the capture module of the production (300); B) start the fluid pumping operation with the purpose of performing the pre-fracturing procedure; c) pressure increases are monitored during pumping, using the pressure displayed in the annular chamber (204) of the well; D) the support gel is injected, and when the pre-fracturing pressure is reached, the pumping is stopped; e) pressure variation is monitored by means of instruments installed in the wellhead and concomitantly generating the profile of forces acting on the rock formation that was 20 fractured; f) the fluid pumping operation is restarted in order to carry out the definitive fracturing procedure; g) once the pre-determined pressure for definitive fracturing has been reached, the 25 packaging or laying of the propellant; whose filling of the production zone (400) will be confirmed as soon as the switch ring (502) acts; h) the procedure for the settlement of propante is concluded from this limit, according to predetermined parameters of Punching pressure; Petition 870180047709, of 06/05/2018, p. 11/19 4/4 i) the fluid pumping is stopped; j) the single-column fracturing tool (500) is removed from the head (307) of the production capture module (300), 6.- OPERATING METHOD OF THE SINGLE-CHANNEL TOOL FOR 5 FRACTURE CANNON ZONES according to claim 5, characterized in that when there is more than one production zone, additionally comprise the following steps: 2/5