MX2013013045A

MX2013013045A - Pressure and flow control in drilling operations.

Info

Publication number: MX2013013045A
Application number: MX2013013045A
Authority: MX
Inventors: Christopher J Bernard
Original assignee: Halliburton Energy Serv Inc
Priority date: 2011-05-09
Filing date: 2011-05-09
Publication date: 2014-02-17
Also published as: CA2832720C; EP2707570A1; AU2011367855A1; MX340331B; WO2012154167A1; EP2707570A4; MX350433B; CA2832720A1

Abstract

A well drilling system includes a flow control device regulating flow from a rig pump to a drill string, the flow control device being interconnected between the pump and a standpipe manifold, and another flow control device regulating flow through a line in communication with an annulus. Flow is simultaneously permitted through the flow control devices. A method of maintaining a desired bottom hole pressure includes dividing drilling fluid flow between a line in communication with a drill string interior and a line in communication with an annulus; the flow dividing step including permitting flow through a flow control device interconnected between a pump and a standpipe manifold.

Description

PRESSURE AND FLOW CONTROL IN DRILL OPERATIONS FIELD OF THE INVENTION The present description generally relates to equipment used and operations performed in conjunction with well drilling operations and, in a manner described herein, more particularly provides pressure and flow control in drilling operations.

BACKGROUND OF THE INVENTION Perforation with controlled pressure is well known as the technique for accurately controlling the downhole pressure during drilling by using a closed circular crown and a means for regulating the pressure in the circular crown. The ring gear is typically closed during drilling through the use of a rotary control device (RCD, also known as a rotary control valve or rotary control valve) that closes around the drill pipe as it rotates.

SUMMARY OF THE INVENTION Therefore, it will be appreciated that improvements in the technique to control the pressure could be beneficial. flow in drilling operations.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of a system for drilling wells and a method embodying the principles of the present disclosure.

Figure 2 is a schematic view of another configuration of the well drilling system.

Figure 3 is a schematic block diagram of a system for pressure and flow control that can be used in the system and method for drilling wells.

Figure 4 is a flow diagram of a method for making a connection for a drill pipe that can be used in the system and methods for drilling wells.

Figure 5 is a schematic block diagram of another configuration of the pressure and flow control system.

Figures 6, 1 and 8 are schematic block diagrams of various configurations of a predictive device that can be used in the system for pressure and flow control of Figure 5.

Figure 9 is a schematic view of another configuration of the well drilling system.

Figure 10 is a schematic view of another configuration of the well drilling system.

DETAILED DESCRIPTION OF THE INVENTION In Figure 1, a system for well drilling 10 and an associated method that can incorporate the principles of the present disclosure are illustrated schematically and schematically. In the system 10, a bore 12 is drilled by rotating a drill 14 on one end of a drill pipe 16. The drilling fluid 18, commonly known as mud, is circulated downwardly through the drill pipe 16 , outside the drill 14 and upwards through a circular ring 20 formed between the drill pipe and the drill 12, to cool the drill bit, lubricate the drill pipe, remove cuttings and provide a measure of the pressure control in the drill. bottom of well. A non-return shut-off valve 21 (typically a flail-type check valve) prevents the flow of drilling fluid 18 upwardly through drill pipe 16 (eg, when connections are made in the drill pipe) .

Control of downhole pressure is very important in controlled pressure drilling, and in other types of drilling operations. Preferably, the Pressure at the bottom of the well is controlled precisely to avoid excessive fluid loss in the formation of soil surrounding the borehole 12, undesired fracturing of the formation, unwanted influx of formation fluids in the borehole, etc. .

In drilling with typical controlled pressure, it is desired to maintain the pressure at the bottom of the well just slightly higher than a pore pressure of the formation, without exceeding a fracture pressure of the formation. This technique is especially useful in situations where the margin between pore pressure and fracture is relatively small.

In typical sub-balanced perforations, it is desired to maintain the pressure at the bottom of the well somewhat lower than the pore pressure, thereby obtaining a controlled influx of fluid from the formation. In the typical overbalanced drilling, it is desired to maintain the pressure, at the bottom of the well, somewhat higher than the pore pressure, avoiding with this (or at least mitigating) the entry of the fluid coming from the formation.

Drilling fluid 18 can be used to add nitrogen or another gas, or other lighter weight fluid, for pressure control. This technique is useful, for example, in sub-balanced drilling operations.

In system 10, additional control is obtained over the pressure at the bottom of the well by closing the circular crown 20 (for example, by isolating it from communication with the atmosphere and allowing the ring corona to be pressurized at or near the surface) using a rotary control device 22 (RCD). The RCD 22 seals around the drill pipe 16 above a well head 24. Although not shown in Figure 1, the drill pipe 16 could be extended upwardly through the RCD 22 for connection to, for example , a rotary table (not shown), a vertical pipe 26, Kelley (not shown), a top drive and / or other conventional drilling rig.

The drilling fluid 18 exits the wellhead 24 via a wing valve 28 in communication with the circular crown 20 below the RCD 22. The fluid 18 then flows through the pipes for return of sludge 30, 73 to a manifold regulator 32, which includes redundant regulators 34 (only one of them could be used at a time). Retro-pressure is applied to the ring gear 20 by a variable flow restriction of the fluid 18 through the operating regulators 34.

The greater the flow restriction through the regulator 34, the greater the back pressure applied to the circular crown 20. In this way, the pressure at the bottom of the well (for example, the pressure at the bottom of borehole 12, the pressure in a shoe of the tubing at the bottom of the well, the pressure in a particular formation or area , etc.) can be adjusted conveniently by varying the back pressure applied to the ring gear 20. A hydraulic model, as will be described in more detail below, can be used to determine a pressure applied to the ring gear 20 at or near of the surface which will result in a desired pressure at the bottom of the well, such that an operator (or an automated control system) can easily determine how to regulate the pressure applied to the ring wheel on or near the surface (which can be conveniently measured) to obtain the desired pressure at the bottom of the well.

The pressure applied to the ring gear 20 can be measured at or near the surface via a variety of pressure sensors 36, 38, 40, each of which is in communication with the ring gear. The pressure sensor 36 detects the pressure below the RCD 22, but above a chain of control valves (BOP) 42. The pressure sensor 38 detects the pressure at the well head below the BOP chain 42 The pressure sensor 40 detects the pressure in the pipes for return of mud 30, 73 upstream of the multiple regulator 32.

Another pressure sensor 44 detects the pressure in the vertical pipe 26. Still, another pressure sensor 46 detects the pressure downstream of the regulator manifold 32, although upstream of a separator 48, a stirrer 50 and a mud pit 52. Sensors Additional features include temperature sensors 54, 56, a Coriolis flow meter 58, and flow meters 62, 64, 66.

Not all of these sensors are necessary. For example, the system 10 could include only two of the three flow meters 62, 64 > 66. However, the input of all available sensors is useful for the hydraulic model in determining what is the pressure applied to the circular crown 20 that should be during the drilling operation.

Other types of sensors can be used, if desired. For example, it is not necessary that the flow meter 58 be a Coriolis flow meter, since instead a turbine flow meter, an acoustic flow meter or another type of flow meter could be used.

In addition, the drill pipe 16 can itself include sensors 60, for example, for directly measuring the bottomhole pressure. These sensors 60 may be of the type known to those skilled in the art.

Technique such as pressure during drilling (P D), measurement while drilling (MWD) and / or drilling (LWD). These sensor systems in the drill pipes generally provide at least one pressure measurement, and can also provide a temperature measurement, the. detection of drilling pipe characteristics (such as, vibration, weight on the drill, shaking, etc.)? training characteristics (such as resistivity, density, etc.) and / or other measurements. Various forms of wired or wireless telemetry (acoustic, pulse pressure, electromagnetic, etc.) can be used to transmit the sensor measurements at the bottom of the well to the surface.

If desired, 10 additional sensors could also be included in the system. For example, another flow meter 67 could be used to measure the flow rate of fluid 18 leaving the well head 24, another Coriolis flow meter (not shown) could be interconnected directly upstream or downstream of a sounding pump 68, etc.

If desired, fewer sensors could be included in system 10. For example, the output of the polling pump 68 could be determined by counting the pumping, instead of using the flow meter 62 or any other flow meters.

Note that the separator 48 could be a 3 or 4 phase separator, or a mud and gas separator (sometimes referred to as a "sludge separator degasser"). However, in the system 10 the separator 48 is not necessarily used.

The drilling fluid 18 is pumped through the vertical pipe 26 and inside the drill pipe 16 by the sounding pump 68. The pump 68 receives the fluid 18 coming from the mud pit 52 and makes it flow through a vertical pipe distributor 70 towards the vertical pipe 26. The fluid then flows down through the drill pipe 16, upwards through the circular crown 20, through the pipes for mud return 30, 73, to through the manifold regulator 32, and then via the separator 48 and the agitator 50 to the mud pit 52 for conditioning and recirculation.

Note that, in the system 10 as described above, the regulator 34 can not be used to control the back pressure applied to the annulus 20 for control of the downhole pressure, unless the fluid 18 is let it flow through the regulator. In conventional over-balanced drilling operations, there will be a lack of fluid flow 18, for example, whenever a connection is made in drill pipe 16 (for example, to add another section of drill pipe to the drill pipe as drilling is deepened 12), and the lack of circulation, will require that the Pressure at the bottom of the well is regulated only by the density of the fluid 18.

In the system 10, however, the flow of the fluid 18 through the regulator 34 can be maintained, even though the fluid does not circulate through the drill pipe 16 and the annulus 20, while a connection is being made in the drill pipe. In this way, pressure can still be applied to the ring gear 20 by restricting the flow of the fluid 18 through the regulator 34, even though a separate back pressure pump may not be used.

When the fluid 18 is not circulating through the drill pipe 16 and the ring gear 20 (for example, when a connection is made in the drill pipe), the fluid is flowed from the pump 68 to the regulator manifold 32 via a diverting pipe 72, 75. In this way, the fluid 18 can bypass the vertical pipe 26, the drill pipe 16 and the ring gear 20, and can flow directly from the pump 68 towards the pipe for return of mud. , which remains in communication with the circular crown 20. The restriction of this flow by the regulator 34 will thereby cause pressure to be applied to the circular ring 20 (for example, in the typical perforation with controlled pressure).

As shown in Figure 1, both the diverter pipe 75 and the mud return pipe 30 are in communication with the annulus 20 via a single pipe 73. However, the bypass pipe 75 and the mud return pipe 30 could be separated instead of connected to the well head 24, for example, by using an additional wing valve (eg, below RCD 22), in whose case each of the pipes 30, 75 could be in direct communication with the circular crown 20.

Although this could require some additional tubing at the drilling site, the effect on the ring crown pressure could be essentially the same as that of the connection of the diverting pipe 75 and the pipe for return of the mud 30 to the common pipeline. 73. In this way, it should be appreciated that various different configurations of the components of the system 10 can be used, without departing from the principles of this description.

The flow of the fluid 18 through the bypass pipe 72, 75 is regulated by a regulator and another type of flow control device 74. Pipe 72 is upstream of the diverter flow control device 74, and piping 75 is downstream of the diverter flow control device.

Fluid flow 18 through vertical pipe 26 is substantially controlled by a valve or other type of flow control device 76. Note that flow control devices 74, 76 can be controlled independently, which provides substantial benefits to system 10, as will be described in more detail below.

Because the flow velocity of the fluid 18 through each of the vertical and deflection pipes 26, 72 is useful in determining how much downhole pressure is affected by these flows, in Figure 1, the meters are represented. of flow 64, 66 interconnected in these pipes. However, the flow velocity through the vertical pipe 26 could be determined even if only the flow meters 62, 64 are used, and the flow rate through the bypass pipe 72 could be determined, even if only In this way, it is to be understood that it is not necessary for the system 10 to include all the sensors represented in Figure 1 and described herein, and in instead the system could include additional sensors, different combinations and / or types of sensors, etc.

In another beneficial feature of the system 10, a device for diverting flow control 78 and a flow restrictor 80 can be used to fill the vertical pipe 26 and the drill pipe 16 after a connection is made in the drill pipe. , and to equalize the pressure between the vertical pipe and the pipes for return of sludge 30, 73 before opening the device for flow control 76. Otherwise, a sudden opening of the device for flow control 76 before they are filled the vertical pipe 26 and the drill pipe 16 and pressurized with the fluid 18 could cause an undesirable transient pressure in the ring gear 20 (for example, due to the flow to the regulator manifold 32 which will be temporarily lost while the vertical pipe and the drill pipe is filled with the fluid, etc.).

Upon opening the device for deflection flow control of the vertical pipe 78 after a connection is made, the fluid 18 is allowed to fill the vertical pipe 26 and the drill pipe 16, while a substantial majority of the fluid continues to flow through the bypass pipe 72, allowing this a continuous controlled application of pressure to the circular crown 20. After the pressure in the vertical pipe 26 has been equalized with the pressure in the pipes for return of sludge 30, 73 and the bypass pipe 75, the device for control of flow 76 can be opened, and then, the flow control device 74 can be closed to slowly divert a greater proportion of the fluid 18 from the bypass pipe 72 to the vertical pipe 26.

Before a connection is made in the drill pipe 16, a similar process can be performed, except in reverse, to gradually divert the flow of the fluid 18 from the vertical pipe 26 to the diversion pipe 72 in preparation for the adding more drill pipe to the drill pipe 16. That is, the flow control device 74 can be opened gradually to slowly divert a larger proportion of the fluid 18 from the vertical pipe 26 to the bypass pipe 72, and then, The device can be closed for flow control 76.

Note that the device for flow control 78 and the flow reducer 80 could be integrated in a single element (eg, a flow control device having a flow restriction therein), and the flow control devices 76, 78 could be integrated into a single flow control device 81 (eg, a single regulator that can be gradually opened to slowly fill and pressurize vertical pipe 26 and drill pipe 16 after a drill pipe connection is made and, then, open fully to allow maximum flow during drilling).

However, because typical conventional drilling rigs are equipped with the flow control device 76 in the form of a valve in the vertical pipe distributor 70, and the use of the vertical pipe valve is incorporated in the usual drilling practices, flow control devices 76, 78 that can be operated individually are currently preferred. The flow control devices 76, 78 are, at the moments referred to collectively below as if they were the individual flow control device 81, although it should be understood that the flow control device 81 may include the devices for individual flow control 76, 78.

Another alternative is representatively illustrated in Figure 2. In this configuration of the system 10, the flow control device 78 is in the form of a regulator, and flow reducer 80 is not used. The flow control device 78 shown in FIG. 2 allows more precise control over the flow of fluid 18 in vertical pipe 26 and drill pipe 16 after A connection of the drill pipe is made.

Note that. each of the flow control devices 74, 76, 78 and regulators 34 can preferably be controlled remotely and automatically to maintain a desired bottomhole pressure by maintaining a desired pressure in the ring crown at or near the bottom of the well. surface. However, any one or more of these flow control devices 74, 76, 78 and regulators 34 could be controlled manually without departing from the principles of this disclosure.

In Figure 3, a system for pressure and flow control 90 that can be used in conjunction with the system 10 and the associated methods of Figures 1 and 2 is representatively illustrated. The control system 90 is preferably fully automated, although it is You can use some human intervention, for example, to protect against an improper operation, initiate certain routines, update parameters, etc.

The control system 90 includes a model hydraulic 92, an interface for data acquisition and control 94 and a controller 96 (such as a programmable logic controller or PT.C, a properly programmed computer, etc.). Although these elements 92, 94, 96 are shown separately in Figure 3, any or all of them could be combined into a single element, or the functions of the elements could be separated into additional elements, other elements could be provided and / or additional functions, etc.

The hydraulic model 92 is used in the control system 90 to determine the desired pressure in the annulus at or near the surface to achieve the desired pressure at the bottom of the well. Data such as well geometry, fluid properties and compensation well information (such as geothermal gradient and pore pressure gradient, etc.) are used by hydraulic model 92 to perform this determination, as well as Real-time sensor data obtained by the data acquisition and control interface 94.

In this way there is a continuous bi-directional transfer of data and information between the hydraulic model 92 and the data acquisition and control interface 94. It is important to appreciate that the data acquisition and control interface 94 operates to maintain a flow substantially continuous real-time data from the sensors 44, 54, 66, 62, 64, 60, 58, 46, 36, 38, 40, 56, 67 to the hydraulic model 92, such that the hydraulic model has the information necessary to adapt to the changing circumstances and to update the desired pressure in the circular crown and the hydraulic model works to supply the substantially continuous data acquisition and control interface with a value for the desired pressure in the ring gear.

A suitable hydraulic model for use as the hydraulic model 92 in the control system 90 is the REAL TIME HYDRAULICS (TM) provided by Halliburton Energy Services, Inc. of Houston, Texas, USA. Another suitable hydraulic model is that provided with the name IRIS (TM), and yet another is available from SINTEF of Trondheim, Norway. Any hydraulic model can be used in the control system 90 according to the principles of this description.

An interface for obtaining and controlling data suitable for being used as the data acquisition and control interface 94 in the control system 90 are SENTRY (TM) and INSITE (TM) provided by Halliburton Energy Services, Inc. Any interface for obtaining and monitoring Appropriate data control can be used in the control system 90 according to the principles of this description.

The controller 96 operates to maintain a desired set pressure in the annulus by controlling the operation of the regulator for return of sludge 3. When a desired updated pressure of the ring wheel is transmitted from the data acquisition and control interface 94 to the controller 96, the controller uses the desired pressure in the ring gear as a preset value and controls the operation of the drive 34 in a way (for example, increasing or decreasing the resistance of the flow through the regulator as necessary) to maintain the preset pressure in the ring gear 20. The regulator 34 can be closed more to increase the flow resistance, or open more to decrease the flow resistance. flow resistance.

The maintenance of the set pressure is carried out by comparing the set pressure with a pressure measured in the ring gear (such as the pressure detected by any of the sensors 36, 38, 40), and decreasing the flow resistance through of regulator 34 if the measured pressure is greater than the set pressure, and increase the flow resistance through the regulator if the pressure measured is less than the set pressure. Of course, if the set and measured pressures are equal, then no adjustment of the regulator 34 is required. This process of Preference is automated, in such a way that no human intervention is required, although if desired human intervention can be used.

The controller 96 can also be used to control the operation of the flow control devices of the vertical pipe 76, 78 and the device for the bypass flow control 74. The controller 96 can, thus, be used to automate the processes of diverting the flow of the fluid 18 from the vertical pipe 26 to the diversion pipe 72 before making a connection in the drill pipe 16, then diverting the flow from the diversion pipe to the vertical pipe after it is make the connection, and then resume normal circulation of fluid 18 for drilling. Again, no human intervention may be required in these automated processes, although if desired, human intervention may be used, for example, to initiate each process, in turn, to manually operate a component of the system, etc.

Referring now further to Figure 4, a schematic flow chart for a method 100 for making a drillpipe connection in the well drilling system 10 using control system 90 is provided. Of course, the method 100 can be used in other systems for well drilling, and with other control systems, according to the principles of this description.

The process for connecting the drill pipe starts at step 102, at which the process starts. A drill pipe connection is typically made when the drill 12 has been sufficiently drilled in such a manner that the drill pipe 16 must be lengthened to further drill.

In step 104, the output of the flow quantity of the pump 68 can be decreased. By decreasing the flow magnitude of the fluid outlet 18 coming from the pump 68, it is more convenient to keep the regulator 34 within its most effective operating variation (typically, between about 30% to about 70% of maximum opening) during the connection process. However, this step is not necessary if, for example, the regulator 34 could otherwise remain within its effective operating variation.

In step 106, the set pressure changes due to the reduced flow of fluid 18 (e.g., to compensate for the decreased friction of the fluid in the annulus 20 between the drill 14 and the flange valve 28 resulting in a circulation density. reduced equivalent). the interface for obtaining and controlling data 94 receives indications (e.g., from sensors 58, 60, 62, 66, 67) that the flow magnitude of fluid 18 has decreased, and hydraulic model 92 in response determines that a pressure changed in the annulus to maintain the desired pressure at the bottom of the well, and the controller 96 uses the desired change pressure in the annulus as a preset value to control the operation of the regulator 34.

In a slightly over-balanced controlled pressure drilling operation, the preset pressure could probably increase, due to the reduced equivalent circulation density, in which case the flow resistance through the regulator 34 could be increased in response. However, in some operations (such as sub-balanced drilling operations in which gas or other lightweight fluid is added to drilling fluid 18 to decrease downhole pressure), the set pressure may decrease (for example, due to the production of liquid at the bottom of the well).

In step 108, the restriction to the flow of the fluid 18 is changed through the regulator 34, due to the desired change in pressure in the annulus in step 106. As discussed above, the controller 96 controls the operation of the regulator 34. , in this case changing the restriction to the flow through the regulator to obtain the set changed pressure. Also, as discussed above, the set pressure could increase or decrease.

In the flow chart of Figure 4, the steps 104, 106 and 108 to be performed concurrently are represented, because the set pressure and restriction of the sludge return regulator can vary continuously, either in response to each other, in response to the change in the output of the mud pump and in response to other conditions, as discussed above.

In step 109, the device for diverting flow control 74 is gradually opened. This deflects a gradually increasing proportion of the fluid 18 to flow through the bypass pipe 72, rather than through the vertical pipe 26.

In step 110, the set pressure changes due to the reduced flow of the fluid 18 through the drill pipe 16 (for example, to compensate for the decreased friction of the fluid in the annulus 20 between the drill 14 and the flange valve 28 resulting in a reduced equivalent density of circulation). The flow through the drill pipe 16 is substantially reduced when the diverting flow control device 74 is opened, because the diverting pipe 72 becomes the path of least resistance to flow and, therefore, the fluid 18 flows through the bypass pipe 72. The data acquisition and control interface 94 receives indications (e.g., from the sensors 58, 60, 62, 66, 67) that the flow quantity of the fluid 18 through the drill pipe 16 and the ring gear 20 has decreased, and the hydraulic model 92 in response determines that the changed pressure of the ring gear is desired to maintain the desired pressure at the bottom of the well, and the controller 96 uses the desired pressure changed in the annulus as a preset value to control the operation of the regulator 34.

In a slightly over-balanced controlled pressure drilling operation, the set pressure could probably increase, due to the reduced equivalent density of circulation, in which case the flow restriction through the regulator 34 could be increased in response. However, in some operations (such as sub-balanced drilling operations in which gas or other lightweight fluid is added to drilling fluid 18 to lower downhole pressure), the set pressure could decrease (for example, due to the production of liquid at the bottom of the well).

In step 111, the restriction on the flow is changed of fluid 18 through regulator 34, due to the desired change in pressure in the annulus in step 110. As discussed above, controller 96 controls the operation of regulator 34, in this case changing the restriction to flow through the regulator to get the set pressure changed. Also, as discussed above, the set pressure could increase or decrease.

In the flow diagram of the figure represents that steps 109, 110 and 111 will be performed concurrently, because the pressure set and the regulator for return of sludge can vary continuously, either in response to each other, in response to the opening of the device for deflection flow control 74 and in response to other conditions, as discussed above. However, these steps could be performed non-concurrently in other examples. step 112, the pressures in the vertical pipe 26 and the ring gear 20 at or near the surface (indicated by the sensors 36, 38, 40, 44) are equalized. At this point, the deflection flow control device 74 must be fully open, and substantially all of the fluid 18 is flowed through the diversion pipe 72, 75 and not through the vertical pipe 26 (because the deviation pipe represents the path of least resistance). The static pressure in the vertical pipe 26 must be substantially equal to the pressure in the pipes 30, 73, 75 upstream of the regulator manifold 32.

In step 114, the device for flow control 81 of the vertical pipe is closed. The diverting flow control device 78 of the vertical pipe separately must already be closed, in which case only the valve 76 could be closed in step 114.

In step 116, a discharge valve of the vertical pipe 82 (see Figure 10) could be opened to discharge pressure and fluids from the vertical pipe 26 in preparation for the breaking of the connection between the Kelley or the upper drive and the drill pipe 16. At this point, the vertical pipe 26 is vented to the atmosphere.

In step 118, the Kelley or upper drive is disconnected from the drill pipe 16, another piece of drill pipe is connected to the drill pipe, and the Kelley or upper drive is connected to the top of the drill pipe . This step is carried out in accordance with conventional drilling practice, with at least one exception, since it is conventional in the practice of drilling, turning off the pumps probes while a connection is being made. However, in the method 100, the polling pumps 68 preferably remain on, although the valve of the vertical pipe 76 is closed and all the flow is diverted to the regulating manifold 32 to control the pressure of the ring gear. The check valve 21 prevents upward flow through the drill pipe 16, while a connection is made with the probing pumps 68 on.

In step 120, the discharge valve of the vertical pipe 82 is closed. The vertical pipe 26, in this way, is again isolated from the atmosphere, although the vertical pipe and the newly added piece of drill pipe are practically empty (ie, you do not fill with fluid 18) and the pressure in it is at or near the ambient pressure before the connection is made.

In step 122, the device for deflection flow control of the vertical pipe 78 (in the case of the valve and the flow reducer configuration of FIG. 1) is opened or gradually opened (in the case of the configuration of the regulator of figure 2). In this way, the fluid 18 is allowed to fill the vertical pipe 26 and the newly added piece of the drill pipe, as indicated in step 124.

Over time, the pressure in the vertical pipe 26 will equalize the pressure in the annulus 20 at or near the surface, as indicated in step 126. However, virtually all of the fluid 18 will continue to flow through the pipeline. of deviation 72 at this point. The static pressure in the vertical pipe 26 should be substantially equal to the pressure in the pipes 30, 73, 75 upstream of the regulating manifold 32.

In step 128, the flow control device of the vertical pipe 76 is opened in preparation for diverting the flow of the fluid 18 to the vertical pipe 26 and thereby through the drill pipe 16. The device for flow control of deviation of the vertical pipe 78 then it closes. Note that, by pre-filling the vertical pipe 26 and drill pipe 16, and equalizing the pressures between the vertical pipe and the ring gear 20, the step of opening the flow control device of the vertical pipe 76 causes no undesirable significant transient pressure in the ring gear or pipes for return of sludge 30, 73. Practically all of the fluid 18 will continue to flow through the bypass pipe 72, rather than through the vertical pipe 26, even though it is opened the device for flow control of the vertical pipe 76.

Considering the flow control device of the vertical pipe 76, 78 separately as a single flow control device of the vertical pipe 81, then, the flow control device 81 is gradually opened to slowly fill the vertical pipe 26 and the drill pipe 16, and then fully open when the pressures in the vertical pipe and the ring gear 20 are substantially equalized.

In step 130, the deflection flow control device 74 gradually closes, thereby diverting an increasing proportion of fluid 18 to flow through vertical pipe 26 and drill pipe 16, instead of through the diverting pipe 72. During this step, the circulation of the fluid 18 starts through the drill pipe 16 and the drill 12.

In step 132, the set pressure changes due to the flow of the fluid 18 through the drill pipe 16 and the ring gear 20 (for example, to compensate for the increased fluid friction resulting in an increased equivalent density of the flow) . The data acquisition and control interface 94 receives indications (e.g., from sensors 60, 64, 66, 67) that the flow magnitude of fluid 18 through bore 12 has increased, and hydraulic model 92 in response determines that a changed pressure in the annulus is desired to maintain the desired pressure at the bottom of the well, and the controller 96 uses the desired pressure changed in the annulus as a value required to control the operation of the regulator 34. The desired pressure in the circular crown may either increase or decrease, as discussed above for steps 106 and 108.

In step 134, the restriction for the flow of the fluid 18 is changed through the regulator 34, due to the desired change pressure in the annulus in step 132. As discussed above, the controller 96 controls the operation of the regulator 34 , in this case changing the restriction to the flow through the regulator to obtain the set changed pressure.

In the flow diagram of Figure 4, it is shown that steps 130, 132 and 134 are performed concurrently, because the set pressure and regulator restriction for sludge return can vary continuously, either in response to each other, in response to the closure of the deflection flow control device 74 and in response to other conditions, as discussed above.

In step 135, the output of the flow quantity from the pump 68 can be increased in preparation to resume perforation of the sounding 12. This magnitude of increased flow keeps the regulator 34 at its optimal operating variation, although this step (as with step 104 discussed above) may not be used if the regulator is otherwise maintained in its optimal variation of operation.

In step 136, the set pressure changes due to the increased flow of fluid 18 (for example, to compensate for the increased friction of the fluid in the annulus 20 between the drill 14 and the flange valve 28 resulting in an increased equivalent density. of circulation). The data acquisition and control interface 94 receives indications (e.g., from sensors 58, 60, 62, 66, 67) that the flow magnitude of the fluid 18 has increased, and the hydraulic model 92 in response determines that desires a changed pressure in the annulus to maintain the desired pressure at the bottom of the well, and the controller 96 uses the desired changed pressure in the annulus as a preset value to control the operation of the regulator 34.

In a slightly over-balanced controlled pressure drilling operation, the set pressure could probably decrease, because the density increases circulation equivalent, in which case the flow restriction through the regulator 34 could be decreased in answer.

In step 137, the restriction to fluid flow 18 is changed through regulator 34, due to the desired pressure changed in the ring gear in step 136. As discussed above, controller 96 controls the operation of regulator 34, in this case change the restriction to the flow through the regulator to obtain the set changed pressure. Also, as discussed above, the set pressure could increase or decrease.

In the flow diagram of Figure 4, it is shown that steps 135, 136 and 137 will be performed concurrently, because the set pressure and the regulator restriction for mud return can vary continuously, either in response to each other, in response to the change in the. output of the mud pump and in response to other conditions, as discussed above.

In step 138, boring of the borehole 12 is resumed. When another connection is needed in the drill pipe 16, steps 102 to 138 may be repeated.

In the flow chart of Figure 4, steps 140 and 142 for the connection method 100 are included to emphasize that the control system 90 continues to operate throughout the method. That is, the data acquisition and control interface 94 continues to receive the data from the sensors 36, 38, 40, 44, 46, 54, 56, 58, 62, 64, 66, 67 and provides the data suitable to the hydraulic model 92. The hydraulic model 92 continues to determine the desired pressure in the corresponding circular crown to the desired pressure at the bottom of the well. The controller 96 continues to use the desired pressure in the ring gear as a set pressure to control the operation of the regulator 34.

It will be appreciated that all or most of the steps described above can be conveniently automated using the control system 90. For example, the controller 96 can be used to control the operation of any or all of the devices for flow control 34, 74 , 76, 78, 81 automatically in response to the entry of the data acquisition and control interface 94.

The human intervention preferably can be used to indicate to the control system 90 when it is desired to start the connection process (step 102), and then indicate when the drill pipe connection has been made (step 118), although practically the All other steps could be automated (for example, by properly programming the software elements of the control system 90). However, it is envisioned that all steps 102 to 142 can be automated, for example, if a Drilling sounding with suitable upper drive (or any other drilling sounding that allows drill pipe connections to be made without human intervention).

Referring now further to FIG. 5, another configuration of the control system 90 is representatively illustrated. The control system 90 of FIG. 5 is very similar to the control system of FIG. 3, although it differs at least in that they are included in FIG. the control system of figure 5 a predictive device 148 and a data validator 150.

Predictive device 148 preferably comprises one or more neural network models for predicting various parameters in the well. These parameters could include the outputs of any of the sensors 36, 38, 40, 44, 46, 54, 56, 58, 60, 62, 64, 66, 67, the preset output of pressure in the circular crown from the hydraulic model 92, the positions of the flow control devices 34, 74, 76, 78, the density of the drilling fluid 18, etc. Predictive device 148 can predict any parameter in the well, and any combination of parameters in the well.

Predictive device 148 is preferably "ready" to enter present and past real values for the parameters to the predictive device. The terms or "weights" in the predictive device 148 can be adjusted based on output derivatives of the predictive device with respect to the terms.

The predictive device 148 may be prepared to input the data obtained during drilling into the predictive device, while connections are made in the drill pipe 16, and / or during other stages of a drilling operation in general. The predictive device 148 may be ready to enter the predictive device data obtained while drilling at least one prior to the sounding.

The preparation may include entering predictive device 148 data indicative of past errors in predictions produced by the predictive device. The predictive device 148 can be prepared by entering the data generated by a computer simulation of the well drilling system 10 (including drilling, well, equipment used, etc.).

Once prepared, the predictive device 148 can accurately predict or estimate what value one or more parameters should have in the present and / or future. The predicted parametric values can be supplied to the 150 data validator to be used in your data validation processes.

Predictive device 148 does not necessarily comprise one or more neural network models. Other types of predictive devices that can be used include an artificial intelligence device, an adaptive model, a nonlinear function that generalizes to real systems, a genetic algorithm, a linear system model, and / or a non-linear system model, combinations of these, etc.

The predictive device 148 can perform a regression analysis, perform the regression in a non-linear function and can use granular calculation. An output of a first main model can be input to the predictive device 148 and / or a first main model can be included in the predictive device.

The predictive device 148 receives the current parametric values from the data validator 150, which may include one or more digital programmable processors, memory, etc. The data validator 150 uses various pre-programmed algorithms to determine if the measurements of the sensors, the positions of the device for flow control, etc., received from the data acquisition and control interface 94 are valid.

For example, if a current parametric value received is outside an acceptable variation, unavailable (for example, due to a sensor that is not working) or differs by more than a predetermined maximum amount from a predicted value for that parameter (for example, due to a malfunctioning sensor) ), then, the data validator 150 can signal that the current parametric value will be "invalid". The invalid parameter values may not be used to prepare the predictive device 148, or to determine the desired set pressure in the ring gear by the hydraulic model 92. Valid parametric values could be used to prepare the predictive device 148, to update the model 92, for registration to the data base of the data acquisition and control interface 94 and, in the case of the desired set pressure in the ring gear, transmitted to the controller 96 to control the operation of the devices for flow control 34, 74, 76, 78.

The desired set pressure in the ring gear can be communicated from the hydraulic model 92 to each of the data acquisition and control interfaces 94, the predictive device 148 and the controller 96. The desired set pressure in the ring gear is reported from the hydraulic model 92 towards the interface for obtaining and controlling data for registration in its database, and for retransmit to the data validator 150 the other current parametric values.

The desired set pressure in the ring gear is communicated from the hydraulic model 92 to the predictive device 148 for use in predicting the future preset values of pressure in the ring gear. However, the predictive device 148 could receive the predetermined value of the desired pressure in the ring gear (together with the other current parametric values) from the data validator 150 in other examples.

The desired pressure preset value in the ring gear is communicated from the hydraulic model 92 to the controller 96 for use in the event of a malfunction of the data acquisition and control interface 94 or the data validator 150, or otherwise the output of these other devices is not available. In these circumstances, the controller 96 could continue to control the operations of the various flow control devices 34, 74, 76, 78 to maintain / achieve the desired pressure in the circular crown 20 near the surface.

The predictive device 148 is prepared in real time, and is capable of predicting the current values of one or more measurements of the sensors based on the outputs of the minus some of the other sensors. In this way, if a sensor output is not available, the predictive device 148 can supply the lost sensor measurement values to the data validator 150, at least temporarily, until the sensor output becomes available again. If, for example, during the processes for connecting the drill pipe described above, one of the flow meters 62, 64, 66 malfunctions, or their output is otherwise unavailable or invalid, then the data validator 150 You can replace the predicted flow meter output for the current flow meter output (or does not exist). It is contemplated that, in current practice, only one or two of the flow meters 62, 64, 66 can be used. In this way, if the data validator 150 fails to receive the valid output from one of those flow meters , it would no longer be possible to carry out the determination of the proportions of the fluid 18 flowing through the vertical pipe 26 and the diversion pipe 72, but for the output of the parametric values predicted by the predictive device 148. It will be appreciated that measurements of the proportions of the fluid 18 flowing through the vertical pipe 26 and the bypass pipe 72 are very useful, for example, in calculating the equivalent density of circulation and / or the frictional pressure by the 92 hydraulic model during the process for connecting the drill pipe.

The validated parametric values are communicated from the data validation device 150 to the hydraulic model 92 and to the controller 96. The hydraulic system 92 uses the validated parametric values, and, possibly, other data streams, to calculate the pressure presently present at the bottom of the well at the point of interest (for example, at the bottom of the borehole 12, in a problem area, in a tubing shoe, etc.), and the desired pressure in the circular ring 20 near the necessary surface to achieve a desired pressure at the bottom of the well.

The data validator 150 is programmed to examine the individual parametric values received from the data acquisition and control interface 94 and determine whether each remains in a predetermined variation of expected values. If the data validator 150 detects that one or more parametric values received from the data acquisition and control interface 94 is invalid, it can send a signal to the predictive device 148 to stop the preparation of the neural network model for the defective sensor, and stop the preparation of the other models that depend on the parametric values coming from the sensor defective to prepare.

Although the predictive device 148 can stop the preparation of one or more neural network models when a sensor fails, it can continue to generate predictions for sensor output or defective sensors based on other sensor inputs that continue to work towards the predictive device. With the identification of a defective sensor, the data validation device 150 can replace the parametric values of the predicted sensor from the predictive device 148 for the controller 96 and the hydraulic model 92.

Additionally, when the data validator 150 determines that a sensor has a malfunction or its output is not available, the data validation device may generate an alarm and / or a subsequent warning, identifying the sensor with malfunction, thereby that an operator can perform a corrective action.

The predictive device 148 is also preferably capable of preparing a neural network model representing the output of the hydraulic model 92. A predicted value for the preset value of the desired pressure in the ring gear is communicated to the data validator 150. If the Hydraulic model 92 has difficulty generating adequate values or is not available, the validation device data 150 can replace the preset value of the desired pressure in the ring gear with the controller 96.

Referring now further to Figure 6, an example of the predictive device 148, separated from the rest of the control system 90, is representatively illustrated. In this view, it can be seen that the predictive device 148 includes a neuron network model! 152 that outputs the predicted current values (yn) and / or futures (yn + i, yn + 2, · · ·) for a parameter y.

Several different current and / or past values for the parameters a, b, c, ... are entered into the neural network model 152 to prepare the neural network model, to predict the values and parametric, etc. Parameters a, b, c, and, ... can be any of the measurements of the sensor, the positions of the device for flow control, the physical parameters (for example, weight of the mud, depth of the sounding, etc.), etc., described above.

The current and / or past actual and / or predicted values for the parameter y can also be entered into the neural network model 152. The differences between the current and predicted values for the parameter y can be useful in the preparation of the network model neuronal 152 (for example, to minimize differences between current and predicted values).

During the preparation, weights are assigned to the various input parameters and those weights are automatically adjusted in such a way that the differences between the current and predicted parametric values are minimized. If the fundamental structure of the neural network model 152 and the input parameters are properly selected, the preparation could result in very little difference between the current parametric values and the predicted parametric values after an adequate preparation time (and preferably short).

It may be useful for a single neural network model 152 to output the predicted parametric values for only a single parameter. Multiple neural network models 152 can be used to predict values for the respective multiple parameters. In this way, if one of the neural network models 152 fails, the others will not be affected.

However, efficient resource utilization could prevent a single neural network model 152 from being used to predict multiple parametric values. This configuration is representatively illustrated in Figure 7, in which the neural network model 152 outputs predicted values for the multiple parameters w, x, y ....

If multiple neural networks are used, it is not necessary that all neural networks share the same tickets. In an example representatively illustrated in Figure 8, two models of neural networks 152, 154. are used. The neural network models 152, 154 share some of the same input parameters, although the model 152 has some parameter input values. which does not share model 154, and model 154 has parameter input values that are not inputs for model 152.

If 'a neural network model 152 outputs predicted values only for an individual parameter associated with a particular sensor (or other source for a current parametric value), then, if the sensor (or other source of current parametric values) fails, the neural network model that predicts its output can be used to supply the parametric values while the operations remain uninterrupted. Because the neural network model 152 in this situation is used only to predict values for a single parameter, the preparation of the neural network model can be conveniently stopped as soon as the sensor failure (or other source of values) occurs. current parametric parameters), without affecting any of the other neural network models that are being used to predict other parametric values.

Referring now further to Figure 9, another representative and schematically illustrated system configuration for well drilling 10. The configuration of figure 9 is similar in most aspects to the configuration of figure 2.

However, in the configuration of Fig. 9, the flow control device 78 and the flow restrictor 80 are included with the flow control device 74 and the flow meter 64 in a flow diverting unit 156 separately . The flow deflection unit 156 can be supplied as a "hull" for convenient transportation and installation at a sounding site for multiple regulator 32, the pressure sensor 46 and the flow meter 58 can also be provided as a separate unit.

Note that the use of flow meters 66, 67 is optional. For example, the flow through the vertical pipe 26 can be deduced from the outlets of the flow meters 62, 64, and the flow through the pipe for return of sludge 73 can be deduced from the outputs of flow meters 58, 64.

Referring now further to Figure 10, another configuration of the well drilling system 10 is representatively and schematically illustrated. In this configuration, the flow control device 76 is connected upstream of the vertical pipe distributor of the probing 70. This arrangement has certain benefits, such as, no modifications are needed to the vertical pipe distributor of the borehole 70 or the pipeline between the manifold and the Kelley, the discharge valve of the vertical borehole of the borehole 82 can be used to vent the vertical pipe 26 as in normal drilling operations (it is not necessary to change the process by the probing equipment, nor is there a need for a separate vent pipe of the unit to divert the flow 156), etc.

The flow control device 76 may be interconnected between the probe pump 68 and the standpipe 70 using, for example, quick connectors 84 (such as striking joints, etc.). This will allow the flow control device 76 to be conveniently adapted for interconnection in various plumbing pump pipes.

A fully automated and specially adapted flow control device 76 (eg, automatically controlled by the controller 96) can be used to control the flow through the vertical pipe 26, instead of using the conventional vertical pipe valve in a vertical tube distributor of the borehole 70. The device for total flow control 81 can be adapted to be used as described herein (for example, to control the flow through the vertical pipe 26 together with the deflection of the fluid 18 between the vertical pipe and the bypass pipe 72 to thereby control the pressure in the circular crown 20, etc.), instead of for conventional drilling purposes.

It can now be fully appreciated that the above description provides substantial improvements to the technique of pressure and flow control in drilling operations. Among these improvements is the incorporation of the predictive device 148 and the data validator 150 in the system for pressure and flow control 90, whereby the outputs of the sensors and the hydraulic model 92 can be supplied, even if these outputs of the sensor and / or hydraulic models become unavailable during a drilling operation.

The above description provides a system for drilling wells 10 for use with a pump 68 that pumps drilling fluid 18 through a drill pipe 16, during drilling of a drill 12. A flow control device 81 regulates the flow from the pump 68 to the inside of the drill pipe 16, with the flow control device 81 which will be interconnected between the pump 68 and a vertical pipe distributor of the borehole 70. Another device for controlling the flow 74 regulates the flow from the pump 68 to a line 75 in communication with a circular ring 20 formed between the drill pipe 16 and the borehole 12. The flow is allowed simultaneously through the devices for flow control 74, 81 .

The flow control device 81 can be operated independently of the operation of the flow control device 74.

The pump 68 may be a borehole pump in communication via the flow control device 81 with a vertical pipe 26 for supplying the bore fluid 18 to the interior of the bore pipe 16. The system 10 is preferably free of charge. any other pump that applies pressure to the circular crown 20.

The system 10 can also include another flow control device 34 that variably restricts flow from the ring gear 20. An automated control system 90 can control the operation of the flow control devices 34, 74 to maintain a desired pressure. in the circular crown while making a connection in the. drill pipe 16. The control system 90 can also control the operation of the operation of the device for flow control 81 to maintain the desired pressure in the annulus while the connection is made in the drill pipe 16.

The above description also describes a method for maintaining a desired downhole pressure during a well drilling operation. The method includes the steps of: dividing the flow of the drilling fluid 18 between a pipe 26 in communication with the interior of a drill pipe 16 and a pipe 75 in communication with a circular crown 20 formed between the drill pipe 16 and a probing 12, the flow division step including allowing flow through a flow control device of the vertical pipe 81 interconnected between a pump 68 and a vertical bore tube distributor 70, the vertical pipe distributor 70 will be interconnected between the device for flow control of the vertical pipe 81 and the drill pipe 16.

The flow division step may also include allowing a flow through a diverting flow control device 74 interconnected between the pump 68 and the ring gear 20, while allowing a flow through the device for flow control of the flow. vertical tube 81.

The method also includes the step of closing the device for controlling the flow of the vertical pipe 81 after equalizing the pressures in the pipe 26 in communication with the interior of the drill pipe 16 and the pipe 75 in communication with the ring gear 20.

The method may include the steps of: making a connection in the drill pipe 16 after the step of closing the device for flow control of the vertical pipe 81, then allowing a flow through the device for flow control of the vertical pipe 81 while allowing a flow through the device for deflection flow control 74; and then closing the device for diverting flow control 74 after the pressures are equalized again in the pipe 26 in communication with the interior of the drill pipe 16 and in the pipe 75 in communication with the ring gear 20.

The method also includes the step of allowing a flow through another device for flow control (eg, a regulator 34) continuously during the division of flows, closing the device for flow control of the vertical pipe, making a connection and the closing steps of the device for controlling the flow of deviation, maintaining with this a desired pressure in the circular crown corresponding to the desired pressure at the bottom of the well.

The method also includes the step of determining the desired pressure in the ring gear in response to the input of the sensor measurements to a hydraulic model 92 during the drilling operation. The step of maintaining the desired pressure in the annulus may include automatically varying the flow through the flow control device (eg, a regulator 34) in response to the comparison of a pressure measured in the annulus with the desired pressure. in the circular crown.

The above description also describes a method 100 for making a connection in a drill pipe 16, while maintaining a desired pressure in the bottom of the well. Method 100 includes the steps of: pumping a drilling fluid 18 from a drilling mud pump 68 and through a sludge return regulator 34 during method 100 to make the total connection; determining a desired pressure in the ring gear corresponding to the desired pressure at the bottom of the well during method 100 to make the total connection, the ring gear 20 that will be formed between the drill pipe 16 and a bore 12; regulate the flow of drilling fluid 18 through the regulator for return of sludge 34, maintaining with this the desired pressure in the circular crown, during method 100 to make the total connection; Increase the flow through a device for diverting flow control 74 and decreasing flow a. through a flow control device of the vertical pipe 81 interconnected between the drilling mud pump 68 and a vertical drilling tube distributor 70, thereby diverting at least a portion of the drilling fluid flow from a pipe 26 in communication with an interior of the drill pipe 16 towards a pipe 75 in communication with the circular crown 20; avoid flow through the device for flow control of the vertical pipe 81; then make the connection in the drill pipe 16, and then decrease the flow through the diverter flow control device 74 and increase the flow through the flow control device of the vertical pipe 81, deviating thereby at least another portion of the drilling fluid flow to the pipe 26 in communication with the interior of the drill pipe 16 coming from the pipe 75 in communication with the ring gear 20.

The steps of increasing the flow through the device for deflection flow control 74 and decreasing the flow through the flow control device of the vertical pipe 81 may also include allowing simultaneous flow through the deflection flow control devices of the vertical pipe 74, 81.

The steps for decreasing the flow through the device for controlling the bypass flow 74 and increasing the flow through the device for flow control of the vertical pipe 81 comprise, in addition, simultaneously allowing the flow through the devices for control of the flow. deflection flow of the vertical pipe 74, 81.

The method 100 may also include the step of equalizing the pressure between the pipe 26 in communication with the interior of the drill pipe 16 and the pipe 75 in communication with the ring gear 20. This pressure equalization step is preferably carried out afterwards. of the step of increasing the flow through the device for control of bypass flow 74, and before the step of decreasing the flow through the device for flow control of the vertical pipe 81.

The method 100 also includes the step of equalizing the pressure between the pipe 26 in communication with the interior of the drill pipe 16 and the pipe 75 in communication with the ring gear 20. This step of equalization of the pressure of preference is carried out after the step of decreasing the flow through the device for control of deflection flow 74, and before the step of increasing the flow through the device for flow control of the vertical tube 81.

The step for determining the desired pressure in the ring gear can include determining the desired pressure in the ring gear in response to the input of the sensor measurements to a hydraulic model 92. The step of maintaining the desired pressure in the ring gear can include varying automatically the flow through the regulator for return of the mud 34 in response to the comparison of a pressure measured in the ring gear with the desired pressure in the ring gear.

The steps to decrease the flow through the device for flow control of the vertical pipe 81, preventing a flow through the device for flow control of the vertical pipe 81 and increasing the flow through the device for flow control of the vertical pipe 81 can be controlled automatically by a controller 96.

It should be understood that the various embodiments of the present disclosure described herein may be used in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present description. The modalities are simply described as examples of useful applications of the principles of description, which are not limited to any of the specific details of those modalities.

In the above description of the representative embodiments of this description, the directional terms, such as "previously", "later", "upper", "lower", etc., are used for convenience to refer to the attached drawings. In general, "above", "above", "up" and similar terms refer to a direction towards the surface of the earth along a sounding, and "below", "below", "down" "and similar terms refer to a direction away from the surface of the earth along the sounding.

Of course, one skilled in the art could, with careful consideration of the above description and representative embodiments of the description, easily appreciate that many modifications, additions, substitutions, deletions, and other changes can be made to the specific embodiments, and these changes are contemplated by the principles of the present description.

Accordingly, the above detailed description should be clearly understood to be provided by way of illustration and example only, the spirit and scope of the present invention will be limited only by the appended claims and their equivalents.

Claims

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as property CLAIMS:

1. A system for drilling wells for use with a pump, which pumps the drilling fluid through a drill pipe during the drilling of a drill, the system characterized in that it comprises: a first flow control device that regulates the flow coming from the pump into an interior of the drill pipe, the first flow control device will be interconnected between the pump and a vertical pipe distributor of the borehole; a second device for flow control that regulates the flow coming from the pump through a pipe in communication with a circular ring formed between the drill pipe and the borehole; Y wherein a flow is simultaneously allowed through the first and second flow control devices.

2. The system according to claim 1, characterized in that the first device for flow control is operable independently of the operation of the second device for flow control.

3. The system according to claim 1, characterized in that the pump is a pump for drilling muds in communication via the first flow control device with a vertical pipe to supply the drilling fluid to the interior of the drill pipe.

4. The system according to claim 1, characterized in that the pump is a pump for drilling mud, and wherein the system is free of any other pump that applies pressure to the ring gear.

5. The system according to claim 1, further characterized in that it comprises a third device for flow control that variably restricts the flow coming from the circular corona, and wherein an automated control system controls the operation of the second and third devices for control of flow to maintain a desired pressure in the circular crown while making a connection in the drill pipe.

6. The system according to claim 5, characterized in that the control system also controls the operation of the first device for flow control automatically to maintain the pressure desired in the circular crown while making the connection in the drill pipe.

7. A method of maintaining a desired pressure in the bottom of the well during a well drilling operation, the method characterized in that it comprises the steps of: dividing the flow of the drilling fluid between a pipe in communication with an interior of a drill pipe and a pipe in communication with a circular crown formed between the drill pipe and a drill; Y the step of dividing the flow that includes allowing a flow through a first device for flow control interconnected between a pump and a distributor of vertical tube of probe, the distributor of vertical tube will be interconnected between the first device for control of flow and the drill pipe.

8. The method in accordance with the claim 7, characterized in that the step for dividing the flow further includes allowing a flow through a second flow control device interconnected between the pump and the annulus, while allowing a flow through the first device for control of the flow. flow.

9. The method in accordance with the claim 8, further characterized in that it comprises the step of closing the first device for flow control after the pressures in the pipe in communication with the inside of the drill pipe and the pipe in communication with the ring wheel are equalized.

10. The method in accordance with the claim 9, further characterized in that it comprises the steps of: making a connection in the drill pipe after the closing step of the first device for flow control; then allowing a flow through the first device for flow control, while allowing the flow through the second device for flow control; Y then closing the second device for flow control after equalizing again the pressures in the pipe in communication with the interior of the drill pipe and in the pipe in communication with the ring gear.

11. The method in accordance with the claim 10, further characterized in that it comprises the step of allowing a flow through a third device for flow control continuously during the division of flow, first closing the device for flow control, making a connection and secondly the steps for close the device for flow control, maintaining with this a desired pressure in the circular crown corresponding to the desired pressure at the bottom of the well.

12. The method in accordance with the claim 11, further characterized in that it comprises the step of determining the desired pressure in the ring gear in response to the input of the sensor measurements to a hydraulic model during the drilling operation.

13. The method in accordance with the claim 12, characterized in that the step of maintaining the desired pressure in the annulus further comprises automatically varying the flow through the third flow control device in response to the comparison of a pressure measured in the annulus with the desired pressure in the annulus. circular.

14. A method for making a connection in a drill pipe, while maintaining a desired pressure in the bottom of the well, the method characterized in that it comprises the steps of: pump a drilling fluid from a pump for drilling mud and through a regulator for return of mud during the method to make the total connection; determine a desired pressure in the circular crown that corresponds to the desired pressure at the bottom of the well during the method for realization of the total connection; regulate the flow of the drilling fluid through the regulator for return of sludge, maintaining with this the desired pressure in the circular crown, during the method for realization of the total connection; increase the flow through a device for flow control of diversion and decrease the flow through a device for flow control of the vertical pipe interconnected between the pump for drilling mud and a vertical pipe distributor of drilling, diverting with this at least a first portion of the drilling fluid flow coming from a pipe in communication with an interior of the drill pipe towards a pipe in communication with a circular crown; avoid flow through the device for flow control of the vertical pipe; then make the connection in the drill pipe; Y then decrease the flow through the diverting flow control device and increase the flow through the flow control device of the vertical pipe, thereby diverting at least a second portion of the drilling fluid flow into the communication pipeline with the inside of the drill pipe coming from the pipe in with the circular crown.

15. The method according to claim 14, characterized in that the steps of increasing the flow through the device for controlling flow of deviation and decreasing the flow through the device for flow control of the vertical pipe further comprise simultaneously allowing a flow to through devices for flow control of deflection and vertical pipe.

16. The method according to claim 14, characterized in that the steps of decreasing the flow through the device for control of flow deviation and increasing the flow through the device for flow control of the vertical pipe further comprise simultaneously allowing a flow to through devices for flow control of deflection and vertical pipe.

11. The method according to claim 14, further characterized in that it comprises the step of equalizing the pressure between the pipe in communication with the interior of the drill pipe and the pipe in communication with the annulus, the step of equalizing the pressure will be made after the step of increasing the flow through the device for flow control of deviation, and the step of equalizing the pressure will be made before the step of decreasing the flow through the device for flow control of the vertical tube.

18. The method according to claim 14, further characterized in that it comprises the step of equalizing the pressure between the pipe in communication with the interior of the drill pipe and the pipe in communication with the ring crown, the step of equalizing the pressure will be made after of the step of decreasing the flow through the device for flow control of deflection, and the step of equalizing the pressure will be made before the step of increasing the flow through the device for flow control of the vertical tube.

19. The method according to claim 14, characterized in that the step of determining the desired pressure in the ring gear further comprises determining the desired pressure in the ring gear in response to the input of the sensor measurements to a hydraulic model.

20. The method according to claim 14, characterized in that the steps of decreasing the flow through the device for flow control of the vertical tube, prevent flow through the device for flow control of the vertical pipe and increase the flow through of the device for flow control of the vertical pipe are automatically controlled by a controller.