MXPA99005959A - Well drilling system with closed circulation of gas drilling fluid and fire suppression apparatus - Google Patents

Abstract

A well drilling system (40) for drilling with gaseous drilling fluid, particularly natural gas, in a closed circulation path including an enclosure or bell nipple (42) mounted on a wellhead between the wellbore (22) and a rotary control head (84) for the system (40). The enclosure (42) redirects the flow of cuttings laden gaseous drilling fluid being circulated out of the well and includes a plurality of fire extinguishing fluid injection nozzles (92) arranged to inhibit or extinguish fire within the enclosure (42) and the rotary control head (84). Drill cuttings are separated from the gaseous drilling fluid in a pressure vessel (50) which includes separator baffles (184) and a drill cuttings port (176) and valve arrangement (178, 179, 182) for dumping samples and substantial quantities of drill cuttings collected within the pressure vessel (50) during operation of the system. The enclosure (42) and the fire extinguishing system may be used in conjunction with operations using conventional liquid drilling fluids and conventional liquid-solids separation equipment.

Description

WELL DRILLING SYSTEM WITH CLOSED CIRCULATION OF GASEOUS PUNCH FLUID AND APPARATUS FOR SUPPRESSION OF FIRE.

FIELD OF THE INVENTION The present invention relates to systems and methods for drilling wells, including the closed circulation of a gaseous drilling fluid, including an apparatus for the separation of drill debris, and which also include fire suppression methods and an apparatus for the suppression of fires located in the head of the well. The modalities of the system allow the hypoco thought, improved drilling, using natural gas as a drilling fluid.

BACKGROUND OF THE INVENTION The continuous and substantial efforts to recover hydrocarbon fluids from underground deposits have led to the understanding that the damage caused to the subterranean telluric formation, which reduces the recovery of the hydrocarbon fluid, can occur through the use of conventional liquid drilling fluids, such as the so-called drilling muds. These fluids, which usually comprise water or refined hydrocarbon liquids, a bulking agent, viscosity modifiers and substances for the prevention of circulation loss, can invade the formation of the perforation cavity while the fluids are circulated during the process of perforation, and may result in damage to the formation with respect to efforts to recover hydrocarbon fluids from it. The penetration of the drilling fluids into the formation occurs, of course, when the pressure forces of the fluids in the well exceed the natural pressure of the formation. However, conventional drilling techniques include maintaining a positive net pressure or also known as overcompensated, of the upper drilling fluid, above the formation pressure, to minimize contamination of the drilling fluid, with the formation fluids. , and to minimize the possibility of the well explosion. Efforts to overcome the potential of the damage created by drilling using liquid drilling fluids, or conventional slurries, in overcompensated conditions, have resulted in the development of drilling techniques known as overcompensated techniques, where the hydrostatic pressure of the drilling fluid that is in the well, is maintained at a value less than the pressure of the formation, to minimize the penetration of drilling fluids into the formation, from the interface of the walls of the drilling cavity. In addition, where the conditions of the training permit, drilling works have been carried out using drilling fluids, compressed air, natural gas, and other gases. When environmental and economic conditions allowed the use of natural gas as a drilling fluid, in a system known as an open circulation system, this technique was widely used. However, the commercial value of natural gas and environmental considerations have resulted in the substantial elimination of drilling works where natural gas is used as the circulation fluid, since it is vented to the atmosphere or "burned" after returned from drilling with drilled debris drilled. Drilling using compressed air as the fluid for debris removal also tends to oxidize formation fluids, in situ, and increases the danger of ignition of combustible gases produced by formation, such as natural gas, when they are mixed with the compressed air found in the circulation system. In addition, until now, other problems associated with the operation of a closed gas circulation system, for the drilling of wells, have prevented the use of these systems with inert gas or with compressed air. The use of natural gas as a fluid for the evacuation of drilling debris, in particular, in a well drilling system, it has certain advantages in undercompensated work conditions. Natural gas is often found in abundance in hydrocarbon reservoirs and in surrounding formations, and may be a product of the reservoir itself in many formations. The use of natural gas, as a drilling fluid, reduces the dangers of working in an overcompensated condition, because the gas minimizes the damage caused to the formation, in reservoirs that produce or store hydrocarbons, both liquid and gas, and, in fact, it can improve the productivity of the formation due to its miscibility with the liquids of the formation and its effectiveness as a driving fluid. In addition, drilling works carried out through the use, in the drilling, of pressure conditions known as hypocompensated or substantially hypocompensated, can possibly lead to the achievement of an increase as large as 10 times in the speed of penetration into geological deposits under pressure and in hard rock formations such as hard sand, dolomite and limestone. This increase in penetration speed is achieved due to the fact that the telluric formations are much weaker under tension than under compression. Therefore, by reducing the pressure in the drilling, which would exert a compression in the formation, at the point of penetration of the same, this dramatic increase in penetration rates can be achieved, particularly with a closed circulation system that uses gas as drilling fluid. However, a closed gas circulation system presents certain problems, which include separating the debris from sounding and sampling the gas circulation system, treating the gas to be suitable for recirculation to the drill string and the drilling cavity, or for the discharge to a pipeline for the transport of gas, as well as the control of the well to prevent unwanted explosions or fires that result from the presence of a combustible fluid. These problems have been substantially overcome by the present invention, as will be appreciated by those skilled in the art, from reading the following summary and detailed description of the system, its components and operating methods in accordance with the present invention. the invention.

SUMMARY OF THE INVENTION The present invention provides an improved drilling system for drilling wells in telluric formations, particularly formations capable of producing hydrocarbon fluids. The present invention also provides a drilling system having means for the closed circulation of a gaseous drilling fluid, particularly natural gas, such as drilling fluid. The present invention further provides a circulation system for a gaseous drilling fluid, which includes a unique system for the separation of gas, liquids, and debris from drilling, which includes an apparatus for sampling and recovery of gas. the drilling debris. The present invention further provides a drilling system that has an improved fire suppression and a control means to inhibit the ignition of a gas or oil stream that goes out of control of a well, to extinguish a burning well if ignition occurs. , and to cool the current and the equipment of the well after the extinction of a fire. The system can be advantageously used with a gaseous drilling fluid as well as with other types of drilling fluids, including conventional liquid, drilling foams and fluids, or so-called drilling muds. In accordance with one aspect of the present invention, a drilling system is provided for drilling an underground telluric formation, which includes an arrangement of components adapted for the closed circulation of a gaseous drilling fluid, particularly, for example, natural gas. The closed circulation system includes a single apparatus for separating the solids from the fluid, comprising a closed container for separating and recovering the debris from sounding and for sampling the composition of the sound debris, at selected intervals. According to another aspect of the invention, a drilling system is provided that includes a means for fire suppression, comprising a confinement member in the well head, to redirect the flow of drilling debris carried with a fluid of perforation, and the confinement member is provided with an arrangement of fluid injection nozzles for extinguishing the fire. According to a further aspect of the present invention, a confinement member for extinguishing or suppressing fires, is located in a structure of the well head, which may include a protective device or head member, rotating, against explosions , for a closed circulation system of a drilling fluid, particularly a circulation system for a gaseous drilling fluid. The confinement member and system for fire prevention and extinction can also be used with open circulation systems using liquid drilling fluids.

In accordance with still another aspect of the present invention, a method and system for drilling a well with a drilling fluid in a hypocompensated working pressure condition are provided. The method of the invention contemplates the closed circulation of a pressurized, gaseous drilling fluid, which includes the separation of the debris from sounding, and the distribution or recompression and recirculation of the fluid. The present invention also provides a method that advantageously compares the flow velocity of the drilling fluid returning from the drilling cavity, with the flow velocity of drilling fluid entering the drilling cavity, and the pressure of the fluid entering. to perforation, to detect excessive pressures, a potential explosion condition of the well and / or loss of circulation. A method of drilling is also contemplated wherein a predetermined pressure change in the pressure of the fluid residing in the annulus of the drilling cavity is compared with the actual rapid variation of the pressure, which results from the movement of the drill pipe. , in and out of the well, and where the speed of movement of the drill pipe, in and out of the well, is controlled to prevent more than one predetermined change in the hydrostatic pressure of the drilling fluid into the well of drilling.

Those skilled in the art will further appreciate the advantages mentioned above and the superior features of the invention, together with other important aspects thereof, upon reading the following detailed description, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevation view, somewhat schematically, of a well drilling system in accordance with the present invention; Figure 2 is a schematic plan view of the confinement member or short junction tube, flow diverter, showing a preferred arrangement of firefighting fluid injection nozzles; Figure 3 is a vertical view, of the central section, of the diverting confinement member of the drilling fluid flow and arrangement of the explosion protection apparatus or rotary control head, in accordance with the invention; Figure 4 is an elevation view, in a generally schematic form, of a modified drilling system and a fire extinguishing fluid injection system; Figure 5 is a detailed sectional view of one of the fire extinguishing fluid injection nozzles in the arrangement of Figure 4; Figure 6 is a side elevational view, partly in section, and somewhat schematically, of a drilling fluid separating apparatus and drilling detritus, according to the invention; Y Figure 7 is an elevation view, schematically, of another drilling system, in accordance with the present invention.

DESCRIPTION OF THE PREFERRED MODALITIES In the following description, similar elements are marked, throughout the specification as well as in the drawings, with the same reference numbers, respectively. The drawings are not necessarily to scale and many elements are presented somewhat generalized or schematic to provide greater clarity and conciseness.

Referring to Figure 1, a somewhat schematic system illustrates a system for drilling a well in a telluric formation 20 which is being penetrated by a drilling cavity 22. The drilling cavity 22 can be formed by a drilling apparatus rotating, conventional, not shown, including a bar or drill column 24, sectional and elongated, having a conventional rotating auger 26 connected to the lower distal end of the drill rod or column. A single-pass valve or also a check valve 28 is placed on the drill string to allow the fluid used to evacuate the drill debris to flow through the drill string and out through holes. suitable in the drill bit 26 and upwards in the annulus 30 of the drill. The drill rod or column 24 extends through an appropriate casing 32, above the open cavity portion of the perforation 22 shown, and the casing extends upward and includes a surface casing portion 34 of conventional construction. The surface tubing 34 extends somewhat above the surface 36 of the ground, at the entry point of the drilling cavity 22 and has supported thereon a conventional explosion protection apparatus, generally designated 38. The apparatus 38 may or may not be present in a well drilling facility using the system of the invention. The drilling system of the invention is illustrated in Figure 1, is generally designated 40, and is adapted to perform drilling of well 22 to a selected depth, using a gaseous drilling fluid, preferably gas natural. The use of natural gas, such as drilling fluid, for the evacuation of drilling debris from bore 22, through casings 32 and 34, it is advantageous because, in many well drilling procedures to recover hydrocarbon fluids, an abundant supply of natural gas is available. More importantly, perhaps, the use of natural gas as a drilling fluid minimizes damage to the telluric formation 20. The drilling system 40 is adapted to include components that can be supported on the explosion protection apparatus 38 or that can be mounted directly on a flange 35 of the surface tubing 34. One of the important elements of the drilling system 40 is a tubular confinement member, generally cylindrical, for controlling and diverting the flow of drilling fluid loaded with debris, which leaves the perforation by the surface tubing 34 and by suitable conduits 38a which are in the explosion protection apparatus 38. This confining member, sometimes called a short bell-shaped splice tube, is a tubular member 42, generally cylindrical, having a lower transverse flange 44 which is adapted to be mounted on a splice flange 38b of the apparatus or explosion protection 38. A conventional re-plugging flange 45 is connected to the confining member 42 and forms part thereof, and is spaced apart from the flange 44. The confining member 42 of the present invention includes a section 46 of a transversely extending discharge conduit and connected to a suitable conduit 48 leading to an apparatus for the separation and storage of detritus, generally designated with the number 50. A flow meter 52 is interposed in the conduit 48 between the confinement member 42 and the apparatus 50, and is connected to a suitable control and register system 54 for recording the flows of the drilling fluid and any other fluid that may enter the bore 22 from the telluric formation 20, while drilling it. As shown, suitable control valves 53a and 53b are interposed in conduit 46. By way of example, the flow meter 52 may be of the ultrasonic type that is commercially available, such as a gas flow meter that is sold, under the trademark UltraTap, by Daniel Flow Products, Inc., Houston, Texas , or of a type available from Alphasonics, Inc., Austin, Texas, as its Alpha 5000 model. The gas drilling fluid, separated from the bore debris, in the apparatus 50, then flows through line 55, directly into a series of devices for the dehydration of gas and for the separation of gas and liquids, indicated, generally, with numbers 62 and 64. A stream of gas and liquid and / or solid particles, dragged, can also abandon the apparatus 50 by the duct 55a which is connected to a separator 56 by which liquids and / or fine solid particles are separated from the gaseous stream. The gas, substantially free of solids, exits the separator 56 via a conduit 65 which is also connected to the conduit 55 and a gas dehydrator 62 and a final liquid separator or trap 64. Accordingly, two gaseous drilling fluid streams can leaving the apparatus 50, and the solids in the form of particles, as well as some liquids, are retained in the apparatus 50 and are eventually removed therefrom, as will be described in greater detail herein. The separator 56 is provided with a suitable conduit 58 having a control valve 60 interposed therein, wherein the fine solid particles and liquids can be periodically or continuously discharged from the separator 56. The separator 56 can be centrifugal type, as indicated by the schematic illustration of Figure 1. The conduit 65 can be manipulated to connect to a distributor 68 that can be operated to recirculate gas to and through the gas compressors 66, which at the example handle are shown connected in a parallel relationship. The compressors 66 discharge pressurized gas to a manifold 70 which is connected to a line for the return of fluid 72 through which the gas flows towards a conventional rotary probe head 74 connected to the upper end of the column or drill rod 24. The upper end of the drill rod 24, in the exemplary embodiment presented in Figure 1, includes a conventional rotary driver member, also known as a drag rod 76. The gas drilling fluid can also be supplied to the drilling rod. distributor 68 through a gas collection pipe, gas distribution pipeline or by so-called gas sales pipeline 71, functionally connected to the distributor 68 as shown. The pressurized gas from line 71 can be supplied directly to the return line 72, as indicated in Figure 1, if the pressure in line 71 is sufficient. The gas treated by the system 40 and discharged through the conduit 65 can be returned to the transport pipe 71a which can be connected to the pipe 71 by suitable valves 71b and 71c. The control valves 71d, 71e and 71f can be operated to control the flow of gas from conduit 65, line 71a, or distributor 68, in a selected manner. In addition, the processed return gas, coming from the conduit 65, towards the pipe 71a, may require compression with a suitable compressor 66a. Accordingly, the gas can be introduced into the closed circulation system, from the line 71, either directly or through the valve 71c, the distributor 68 and the compressors 66. The gas can be returned to a line 71a from the duct 65, through the valve 71e and the compressor 66a or a section of the duct in which the check valve 71f is interposed. Of course, the gas can be recirculated from the conduit 65 to the compressors 66, through the valve 71d and the distributor 68. The valves 71b, 71c, 71d and 71e are appropriately located to allow the flow paths of the gas described above. The driving rod 76 extends through a conventional turntable 78 supported on a portion of a sounding platform 80. Conventional elements such as a sounding tower and the turnstiles, functionally connected to the probe head 74 a through a suitable lifting wire and a hook assembly, they are not shown or described so as not to impair the clarity and conciseness of the description. Those skilled in the art will recognize that the system of the present invention does not require that the perforation be carried out by a rotary drill rod driven by a conventional rotary table. The drilling apparatus may include an apparatus known as a top-drive apparatus, not shown, in place of the probe head 74. The lower end of the drill rod 24 may also include, instead of the rotating drill 26, a hammer or drilling tool of the type that works by percussion, and that is commercially available, also not shown. The drilling work can also be carried out with a reconditioning, hydraulic probing platform, or with a roller pipe, used as a drill rod, and using the system and method of the invention at the same time. The drilling cavity 22 need not be vertical and this may be inclined or may actually extend in a substantially horizontal direction, at least by a portion thereof. The drilling system 40 also uses an apparatus known as a rotary explosion prevention apparatus, or control head, commercially available, placed between the turntable 78 (or a drive from above or another connection between the drill rod and the lifting device. mentioned above) and the confinement member 42. One mode of a control head, rotating, or explosion protection apparatus, used in the present invention, is designated, generally, with the number 84 and is conveniently mounted on the flange 45 of the confining member 42. The rotating head 84 may be of a type that is commercially available. A preferred type for use with the system 40 is manufactured by Williams Tool Company, Inc., of Fort Smith, Arizona, as its Model 7000 or 9000 Series Rotary Control Head. The swivel head 84 also includes a secondary discharge 88 for the discharge of fluid, which extends therefrom to conduct the fluid under pressure from the drilling cavity 22 and from the rotating head. However, under normal working conditions of the system 40, all the debris from the borehole and the evacuation fluid from the bore debris flowing from the bore pass through the conduit 48 and into the separation apparatus 50. In the branching conduit 88 are interposed with the appropriate valves 90a and 90b and these can be operated to allow fluid to flow through this conduit and into the apparatus 50 or to a pit for debris disposal, not shown, under selected working conditions. The operation of the drilling system 40 can be carried out by filling or "loading" the conduits for the fluid, of the system, which include the drill rod 24, the annulus 30 of the perforation, the confinement member 42, the conduit 46. , 48, the pressure vessel comprising the apparatus 50, the conduits 55, 55a and 65 and the elements interposed therebetween, the compressors 66, the distributor 70 and the discharge pipe 72, with the pressurized gas. This gas can be extracted from gas collection pipes or so-called gas sales pipes, 71 and / or 71a and, during drilling, any excess gas in the system can be subjected to controlled discharge to the lines 71 or 71a. When starting one or both compressors 66, the pressurized gas is communicated by means of the distributor 70, by the return line 72 and towards the hollow drill rod 24, through the probe head 74, in a manner conventional, for discharge in the annulus of the drilling cavity, while drilling works are carried out. The pressurized gas discharged from the auger 26 into the drilling cavity 22 carries the drilling debris therein, and transports them up the annulus 30, through the confinement member 42 and then into the apparatus 50. The gas it can be recirculated through the system 40 or it can be extracted from the pipe 71 and returned to the pipe 71a, while the solids from drilling detritus and any liquids from the formation or foam injected into the gas stream, are separated from the gas flow in the apparatus 50, 56, 62 and 64. The separating apparatus 50 can also be adapted to separate liquids, as well as fine solid particles, from the gas stream entering the apparatus through the conduit 55a. Accordingly, in drilling operations where only solid drilling debris with relatively large particle sizes are generated, conduit 55a and separator apparatus 56 can be omitted or disconnected, and substantially solid-free gas can be conducted from the apparatus 50, directly through conduit 55 and into gas dehydrator 62 and into liquid trap 64. However, if relatively large amounts of formation fluids are being generated, in the liquid form, or gases are being generated of densities different from that of the gaseous drilling fluid, these fluids can be separated together with the fine particles of the formation, if they are generated, in the separator 56 and the gas substantially free of liquid and solids can be conducted from the separator 56, through conduit 65 and treatment devices 62 and 64, towards the compressors 66. The separator device 56 may be a multi-stage separator of a type necessary to provide a three-phase separation, ie the separation of the gaseous drilling fluid from liquids and solids entrained in it and, possibly, also the separation of gases of different densities, from the gaseous drilling fluid. The drilling works are preferably carried out under hypocompensated conditions, with the gas circulation system, closed, described above, to minimize the gas loss in the telluric formation 20. However, the gas entering the formation will perform a minimal damage and can, in fact, eventually improve the production of hydrocarbon fluids from a desired production area. Typically, wells can be drilled from a depth of up to 3,049 meters (10,000 feet) to 4,573 (15,000) feet using a closed gas circulation system of the present invention to evacuate drilling debris from drilling 22. An advantage of system 40 described herein is that the risk of ignition of natural gas within the drilling cavity is substantially eliminated when said gas is used as a drilling fluid, as compared to the use of compressed air as drilling fluid . The probability that a fuel mixture will develop during drilling work is really greater with the use of compressed air as a drilling fluid, in the event of the invasion of hydrocarbon gases into the drilling cavity during work of drilling, particularly when drilling in a hypocompensated condition. However, since the annulus 30 of the perforation and the closed gas circulation system, described herein, are substantially devoid of oxygen during drilling work, the likelihood of an explosive mixture developing within the closed gas circulation system. The working pressures as well as the volumes of the gas flow, used in the drilling, will, of course, depend on the diameter of the drilling cavity 22, the depth of the drilling cavity and the debris evacuation speed, required . The working parameters used for drilling with compressed air as a fluid for the evacuation of drilling debris, can be used to determine working conditions with natural gas as a fluid for the evacuation of drilling debris, for example. , an appropriate compensation for the density of the fluid. Although the probability of combustion of the gas, in the fluid circulation system described above, is minimal, the confinement member 42 is adapted to provide (1) the extinction of any fire that may develop in the confinement member or in the explosion protection apparatus 38 or in the annulus 30 of the perforation and the progress of the fire to the confinement member, and (2) the inhibition of the ignition of a stream of well fluids, liquids and / or gases, which flow through it. The confinement member 42 is provided with an arrangement of fire extinguishing fluid injection nozzles, which can be connected to a source of fire extinguishing fluid such as a chemical type in the form of fine particles, which is transported by a inert gas compressed and injected into the confinement member 42 to prevent, in particular, the destruction of the rotary control head 84 by fire; the destruction of the entire sounding platform and any environmental degradation resulting from that fire. Water can also be injected into the confining member 42 to inhibit ignition, to extinguish a fire and act as a cooling medium after the fire extinguishes. Referring now to Figures 2 and 3, and Figure 3 in particular, the confinement member 42 includes a generally cylindrical-shaped wall 43 extending between the flanges 44 and 45, of suitable thickness and material, together with the flanges, to satisfy the pressure of the system and the fire classification requirements. As shown in Figure 3, an interior space 90 is provided within the confinement member 42, as defined by the wall 43, and at least three nozzles 92 for the injection of fire extinguishing fluid are arranged or arranged, of which two are shown in Figure 3, preferably separated at the same distance and around the circumference of the confinement member, as shown. The convergent nozzles 92 are oriented to inject extinguishing fluid or fire suppression, towards the head 84, preferably intersect the inner surface 43a of the wall 43, at an angle of about 30 degrees and are in communication with the respective tubular cups 93. , which project radially and which are circumferentially spaced, on the outside of the confining member 42, as shown in Figure 2. The nozzles 92 may be positioned at other angles, including the 90 degree, with respect to the surface 43a of the wall. An auxiliary branch line 95, shown in Figure 3, also opens into the space 90 for auxiliary purposes, such as filling the annulus 30, for example, with a suppression fluid.

A convenient arcuate manifold 94 is provided, Figure 2, which extends partially around the confinement member 42 and which is preferably characterized by a hose or flexible steel tube, such as that of a type manufactured by Coflexip, Houston, Texas. The branching conduits 96 extend from the manifold 94 to the respective lock valve and check valve assemblies 97 that are connected to the respective cups 93 positioned with the pattern shown in Fig. 2. The opposite ends of the manifold 94 they are connected to suitable valves 98 and 100 which are, respectively, in communication with a water supply conduit 102 and with a supply conduit 104 for a fire extinguishing composition based on dry, fluidized chemical products. As further shown in Figure 3, the control head 84 includes an inner chamber 110 which is in communication with the space 90 and with the discharge conduit 88. The control head can also be of a type that does not have a flow path in the discharge of the fluid, such as that provided by the conduit 88. A sealing member, annular, 112, is placed in the chamber 110 and is hermetically coupled to the driving rod 76 in a known manner. Accordingly, the eruptions of fires within the chamber or space 90, or that can progress towards them, can be extinguished or suppressed through the injection of a mixture of fire extinguishing material in the form of fine particles, such as bicarbonate of potassium, transported into the confinement member or short coupling tube 42, through the injection nozzles 92. The nozzles 92 are desirably oriented to discharge the fire extinguishing material directly into the sealing member 112 to minimize any tendency of the fire to destroy this member or, in the case of a catastrophic failure of the sealing member, to extinguish or inhibit the fire in any fuel fluid stream flowing through the control head 84 and below or above the floor 81 of the sounding platform 80. Referring further to FIGS. 1 and 2, the fire extinguishing fluid s and supplies the feed conduit 104 from a suitable reservoir 116 which may be characterized by a fire extinguishing unit containing a conventional dry chemical, such as one of the type sold by Ansul Fire Protection Division of Wormald, United States, Inc. , Marinette, Wisconsin, for example, as one of its dry chemical systems, mounted on slide, of the S-3000 series. These systems are capable of discharging substantial quantities of fluidized, fire-extinguishing material, such as potassium bicarbonate in particulate form, entrained in a stream of nitrogen gas. As also shown in Figure 1, the confining member 42 may include a suitable pressure and / or temperature sensor 120, functionally connected to the controller 54 to detect the conditions of pressure and temperature in the confinement member. and causing the operation of the controller 54 to cause the reservoir 116 to discharge a pressurized stream, chemical extinguishing chemical, or water, in the space 90, through the injection nozzles 92. Valves 122 and 124 are suitable, remotely controlled, they are interposed in conduits 102 and 104 upstream of valves 98 and 100, not shown in Figure 1, to control the flow of fire extinguishing fluids, towards confining member 42. A small reservoir 126 of fire extinguishing fluid, can be connected to the distributor 94 by means of a suitable control valve 128, as shown in Figures 1 and 2, to analyze the operating capacity of the system, occasionally. As shown in Figure 2, a water reservoir 123 and a pump 125 are connected to the conduit 102 by a control valve 122. Typical dimensions for the confinement member comprise a cylindrical wall of forged steel or sleeve portion 43. about 25.4 cm (10.0 inches) in diameter, a total length of about 60.96 cm (24.0 inches) to 114.3 cm (45.0 inches) and a branch pipe 46 or conduit for the return flow of the drilling fluid, which has a nominal diameter of approximately 15.24 m (6.0 inches). The nozzles 92 have a nominal diameter of approximately 5.08 cm (2.0 inches) at their inlet ends and approximately 0.635 cm (0.25 inches) at their outlet ends. The nominal value of the pressure supported by the confining member 42 can be, for example, comparable to that of the explosion protection apparatus 38, and that of the control head 84. Typical working pressures for the gaseous drilling fluid, in a closed gas circulation system, to drill a cavity approximately 8.5 inches in diameter, using a drill pipe with a diameter of 8.89 cm (3.5 inches) to 10.16 cm (4.0 inches) in diameter, they are in the range, for example, of approximately 175.8 kg / cm2 (2,500 psig). The quantities of fire extinguishing fluids, including those available from conduits 102 and 104, and the fluid flows required for the prevention or extinction of a fire, can be based on a method for predicting the physical damage resulting from a fire. fire that erupts in the head of a particular well. For example, the functional capabilities of the system for inhibiting and extinguishing fires of the invention can be predetermined based on a method used to anticipate the amount of fluid flowing from the well (based on reservoir conditions and of the characteristics of the dimensions of the well), the forces that will probably exist at the point of explosion in the well, the velocity profile of the components of the well current, the impact arc of the explosion current in the well, based on the speed profile captured in drawings of the substructure of the sounding platform or production platform, the combustion profile of the components of a well current that is likely to burn in the impact arc, the temperature profile of the current of the burning pit, adjusted for a prevailing wind condition, and a drainage profile of the portion of the well current that is not likely to come into flame s, and the profile can be superimposed on maps taken in elevation, from a sounding platform, to the profile of an ocean current and to the topography of the terrain. At least some of these factors will be used to determine the dimensions of the confinement member 42 as well as the expected flows and volumes of the fire extinguishing fluids, required for supply to the confinement member 42 and other parts.

Referring briefly to Figures 4 and 5, a modified drilling system according to the invention is illustrated, which is generally designated 140. Drilling system 140 is similar to system 40 with the except that the confining member 42 is replaced by the flange 142 of generally circular shape, which can be placed between the connecting flange 85 which is on the rotary control head 84 and a coupling flange 144 of a short section of the riser or sleeve 146 placed between the flange 142 and the exit flange 38b of the explosion prevention apparatus 38, as shown in Figure 4. As shown in Figure 5, the flange 142 is provided with several separate and convergent nozzles 148, of which one is shown, which are each connected to an accessory 150 that can be manipulated to connect to the distributor 94 through a check valve. n 97 and the conduit 96, by which it can be injected, material for extinguishing or fire suppression, into the interior chamber 110 of the rotating control head 84, when necessary. In the drilling system 140, the main conduit for the return of the fluid carrying the drilling debris, is the branch conduit 88 of the rotary control head 84 and is of a suitable diameter to handle the drilling fluid stream loaded with the detritus. A flow meter 52 is connected to the duct 88 and the drilling debris is conveyed through the duct 48 from the duct 88 to the separating apparatus described hereinabove. The drilling system 140 is also adapted to include a somewhat more elaborate separation of the drilling fluid from both liquids and solids entrained therein, and where the flow of solid drilling debris can be substantial. In this regard, a centrifugal separator 50a is connected to the duct 48 to separate the gas and solids from the fluid stream for debris evacuation, and wherein the mixture of gas and solids is then conducted to the separator apparatus 50 while that the liquids and some gas are led to an additional separator 50b, which mainly comprises means for separating the gas from the liquid and for the separation of liquids of different densities. Liquids, such as oil and water, are separated from the gas in the separator 50b and can be separated from each other and stored in appropriate tanks 50c 'and 50c ", while the substantially liquid-free gas can be conducted through from a conduit 141 to the devices 62 and 64 and then, through the conduit 65, to the compressors 66 or to the pipe 71a.The gas and solids are separated in the apparatus 50 and the gas substantially free of solids is conducted through a duct 55 to the devices 62 and 64 and to the duct 65, as illustrated With reference now to Figure 6, the separating apparatus 50 is shown, partially in section and configured for operation with any of the systems described above. apparatus 50 comprises a cylindrical pressure vessel, generally elongated, having a cylindrical side wall 160 and opposite, somewhat hemispherical head portions, suitably welded to side wall 160 p to form a closed container that withstands high pressures. The apparatus 50 includes an inlet conduit 166 for the fluid that carries the probing debris, and this conduit intersects the head 162 and is adapted to be connected to the conduit 48, as shown. The conduit 166 has a discharge, curved, end portion 168, which directs the flow of drilling fluid loaded with debris, onto a replaceable, inclined wear plate 170, suitably placed so that it can be removed, in the space inside 171 of apparatus 50, and placed on separate supports 172 and 174, respectively. The plate 170 is inclined towards a section of the discharge conduit 176 connected to the separate valves 178 and 179 which have a section of conduit 180 for debris sampling, interposed therebetween and in communication with an orifice for pressure relief , provided with a valve, and a valve 182 interposed therein to purge and decrease the gas pressure within the conduit section 180. A first series of baffles 184, spaced apart from each other, and extending to down and through the interior space 171 of the apparatus 50. A second series of separate baffles 186 extends upwards and forms, with the deflectors 184, a serpentine flow path between the space 171 and a space 173 downstream of the last deflector 186 , so that the drilling fluid loaded with debris and other substances entering space 171, will cause, due to the substantial change of direction, that a large portion of solid probing debris, in particular, separates from the fluid stream. The current will progress through the serpentine flow path, provided by the plates or deflectors 184 and 186 of the separator, to the space 173 where the substantially solid-free gas can then pass to the conduit 55 through a section of the discharge conduit 188. If the gas stream is also charged with liquids from the formation or with injected foams, for example, it is probable that these fluids are separated in the space 173 and collected in the space between a baffle 186 and the head 164. A discharge chute 190 opens into the space 173 and is connected to a motor-driven valve 192, which motorized actuator 194 is connected to a suitable float or level control 196, placed in the space 173. Accordingly, the apparatus 50 can operate automatically to discharge liquid and gaseous drilling fluid, through valve 192 and conduit 55a, when space 173 accumulates or n particular level of liquid. A suitable relief valve 198 is also connected to the apparatus 50 and operated to discharge the fluid that is in the space 173, through a conduit 200 and into a suitable reservoir or pit (a) when inside the apparatus 50. There is a condition of excessive pressure. Since particulate solids will accumulate in space 171 including spaces 201 and 202 that lie between deflectors or plates 186 of the separator, second and third discharge conduits 204 and 206 flow into these spaces and are connected to a arrangement of valves 178, 179 and conduits for the collection of samples 180, respectively. An orifice or gate for purging and decreasing pressure is provided, and a valve 182 for the second and third conduits 180, respectively. Accordingly, the detritus that meet in the spaces 171, 201 and 202 can be periodically discharged to the conduits 180, opening the valves 178, respectively, while the valves 179 are maintained in a closed condition. After the valves 178 are closed again, the valves 182 can be operated to purge and relieve pressure within the conduits 180, and then the valves 179 can be opened to empty the contents of the conduits 180 and perform the analysis of the drilling debris and transporting the drilling debris in larger quantities to a location removed from the apparatus 50 for disposal. Valves 178, 179 and 182 can be automatically controlled to operate sequentially, to maintain spaces 171, 201 and 202 in a desired working condition. In addition, suitable vibrating means 210, mounted on an outer surface of the apparatus 50, or otherwise associated therewith, and functioning automatically, or as desired, may be interposed. Each vibrator means 210 includes, or is connected to, a plate or surface 211, inclined, for the discharge of the solids, to cause the solids in the form of particles, placed in the spaces 171, 201 and 202, to flow towards the discharge conduits 176, 204 and 206, respectively, to facilitate emptying of the spaces 171, 201 and 202 of the solid particles. The vibrator means 210 may be of a type that is coraerially available. Access to interior spaces 171, 201 and 202 can be made through a suitable gate 212 located in side wall 160 and having a cover 214, removable, thereon. For the working conditions described above, the pressure vessel of the apparatus 50 can have a total length of approximately 2.74 m (9.0 feet), a diameter of approximately 0.90 m (3.0 feet), and can be constructed as a pressure vessel that support the gas working pressures described above in the present description, and conventional engineering methods and materials can be used for those pressure vessels. The replaceable wear plate 170 may be formed of a hardened material or may have a particularly abrasion resistant coating applied thereon to reduce the wear rate of the plate. Referring now to Figure 7, a drilling system 340 is illustrated which includes many of the components used in the drilling system 40, and those components are adapted, as required, for operation with a liquid fluid used in the Evacuation of drilling debris, such as a conventional drilling mud. In the drilling system 340, the rotary control head 84 is not used and the confining member 42 can be operated to discharge the drilling fluid loaded with debris, through the branch conduit 46 and an appropriate flow meter 342 which is connected to a controller 344 to supply the convenient data, such as the expenditure of the fluid loaded with drilling debris, which returns from a drilling cavity 22. The flow meter 342 is preferably of the electromagnetic type, such as that which It is available at the Schlumberger Measurement Division, Greenwood, South Carolina, as one of its FLUMAG series meters. The conduit 48 may be operated to discharge the drilling fluid in an apparatus suitable for debris separation, or shale shaker 346, which discharges debris-free drilling fluid, into a storage tank or pit 348. The fluid The drilling fluid is made to circulate from the pit or tank 348, by means of suitable pumps 350 connected to a fluid inlet distributor 349 and to a discharge pipe 352, for the return of the fluid, by which the drilling fluid is circulated again to through a probe head 74 and the driving member 76 of the drill rod, up to the drill rod 24, for its circulation through the drill 26 and upwards and through the annulus 30 to evacuate the drilling debris from the drilling cavity 22. A suitable flow meter 358 is interposed in the discharge pipe 352 and a pressure sensor 360 is also interposed in the discharge pipe 352, where indicated. The detector 360 is preferably one of the electronic type that is commercially available and can be placed in the portion known as a vertical pipe portion, line 352, at the base of the sounding tower or at a location close to it. The detector 360 may be connected to a visual reading device in the vertical tube location mentioned above, whereby the personnel working on the platform can check the pressure conditions continuously. The flow meter 358 and the pressure sensor 360 can be operated to adequately transmit the signals to the controller 344 whereby the flow rate of the pumps 350 to the drill rod 24, can be compared with the flow rate of the fluid leaving the bore 22, through the confinement member 42, as determined by the flow meter 342. The controller 344 can be operated to detect a predetermined change in the pressure detected by the detector 360 and a predetermined difference in the flow of the fluid, as measured by the flow meters 342 and 358. If the fluid flow, as measured by the meter 342, differs from the flow measured by the meter 358, by a predetermined amount, it is can detect with greater accuracy and more anticipation, a tendency of well 22 to explode, or to cause at least one effect known as "shaking", than if conventional measurement techniques were used, and therefore the well can be controlled at will . The drilling system 340 also includes a control means for controlling a stop of the equipment, such as that of the maneuvering lathe for raising and lowering the drill rod 24. As shown in Figure 7, a schematic diagram of a conventional rotating maneuvering lathe, 366, having a conventional drum brake mechanism 368 for the rope, which is operated to be controlled by an actuator 370 that applies braking forces to a hoisting rope 372 that is connected to the probe head 74, in a conventional manner, including a hook 373 for the probe head. When members 24a of the drill rod are added, in sections, to a drill string, during a "trip" into the drill hole 22, a counter 374 can be operated to count the number of members or sections of the drill. drill bar, added to the drill string. The counter 374 may also be adapted to measure the length of each bar section counted, or the lengths of the sections of the bar may be determined. The number of sections of the drill bar, and thus the length of the drill rod that is inserted in the bore, correlates with the fluid pressure and with the expense measured in the discharge pipe 48 by the meter 342 and that results from the displacement of the drilling fluid as the drill rod is lowered into the drilling cavity. As the members 24a of the drill rod, in sections, are added to the drill bar 24, any increase in the pressure of the cavity, resulting from the insertion of the drill rod additionally into the bore, for example a trip into the well, after replacing the bit 26, can be controlled to minimize the speed of insertion of the drill rod into the cavity, to prevent the pressure of the drilling fluid found in the annulus 30 from exceeding an amount default In this way a hypocompensated perforation condition can be maintained, from the well, with a liquid drilling fluid or with a drilling mud, and at the same time excessive pressures in the drilling fluid can be avoided that can cause the penetration of the drilling fluid. within the range of interest of the formation or within a zone of loss of mud, and then result in the undesired descent in the head of hydrostatic pressure in the perforation. Accordingly, the pressure measured in the discharge pipe 48, as well as in the drill rod 24, can be verified, and if this pressure exceeds a predetermined value of "water hammer" the braking action can be applied to the brake 368 of the operating lathe 66 to minimize the speed of insertion of the drill rod 24 back into the drilling cavity 22. Expense values can be entered into the discharge pipe, pump expense values, and predetermined pressure values. , to a suitable program that works in a digital computer or in a central processing unit (CPU, by its acronym in English) indicated with the number 345 in Figure 7. The CPU 345 may be connected to suitable interface circuits 347 and 349 to receive the control signals and to transmit them to the actuator 370, respectively. The controller 344 may be provided, as shown, with suitable visual reading devices 344a, 344b, 344c and 344d. Accordingly, improved methods for operating the drilling system 340 in a hypocompensated pressure condition, within the bore 22, can be carried out by inspecting the flow of the drilling fluid returning from the well, compared to the flow of the fluid from the borehole. drilling pumped into the well. Any change in pumping pressure can also be inspected to provide an adequate alarm signal. In addition, during the replacement of a drill rod in the well, the pressure of the fluid in the well can be inspected and controlled to provide a maximum change in pressure as a result of drilling fluid displacement in the well during insertion of a drill bar inside it. Although preferred embodiments of the present invention have been described in detail herein, those skilled in the art will recognize that various substitutions and modifications may be made to the invention without departing from the scope and spirit of the appended claims.

Claims (42)

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

1. In a system for drilling a well in an underground telluric formation, comprising: an elongated drill rod, which can be extended into a drilling cavity which forms the well and which can be operated to conduct a gaseous fluid for evacuation of drilling debris, inside the drilling cavity, in order to evacuate the drilling debris thereof; a well head including means that form a seal in the drill rod and a confining member that forms an interior space for fluid conduit, located around the drill rod, the confining member includes a discharge conduit for driving the fluid used for the evacuation of the drilling debris, from the drilling and through the confinement member; a pressure vessel connected to the discharge conduit, which includes means for separating the debris from sounding in the form of solid particles, from the gaseous fluid for the evacuation of the debris from sounding; and, a compressing means that can be operated to discharge a pressurized gaseous fluid used for the evacuation of the drill debris into the drilling cavity.

2. The drilling system according to claim 1, characterized in that it includes a conduction element that interconnects the compressor element with the pressure vessel, for driving, the fluid used for the evacuation of drilling detritus, substantially free of solids, towards the compressor element.

3. The drilling system according to claim 2, characterized in that it includes a fine particle separating device, interposed between the pressure vessel and the compressor element, to separate the fine particle solids, the evacuation fluid from the debris probing.

4. The perforation system according to claim 2, characterized in that it includes a gas and liquid separating means, interposed in the perforation system, between the pressure vessel and the compressor element.

5. The drilling system according to claim 1, characterized in that the means forming the seal comprises a rotating control head which is functionally connected to the confining member and which forms a substantially hermetic seal around a section of the drill rod, to prevent the flow of evacuation fluid from the drilling debris, from the drilling system.

6. The drilling system according to claim 5, characterized in that it includes: a source of fluidizable fire extinguishing material; and, nozzle element for the discharge of fluid, which operates to inject fire extinguishing fluid into the interior space, to minimize the ignition of the evacuation fluid from the debris probing, in a region of the drilling system near the control head.

7. The drilling system according to claim 6, characterized in that it includes a distributing means that interconnects the fluidizable fire extinguishing material, supply, with a plurality of nozzles for the discharge of the fluid, to discharge the fluidized fire extinguishing material, inside of the confinement member.

8. The drilling system according to claim 1, characterized in that the drilling debris evacuation fluid comprises natural gas.

9. The drilling system according to claim 1, characterized in that the pressure vessel includes a portion for retaining the drilling debris separated from the evacuation fluid from the drilling debris, returning from the drilling cavity, and means for discharging the drilling cavities. drilling debris from the pressure vessel, for sampling the debris and emptying the pressure vessel, from time to time.

10. The drilling system according to claim 1, characterized in that it includes a flange interposed in a conduit, between the drilling cavity and the pressure vessel, and at least one fire extinguishing fluid injection nozzle, in the flange for the injection of the fire extinguishing material into a flow path of the drilling debris evacuation fluid, which returns from the drilling cavity.

11. In a system for drilling a well in an underground telluric formation, the system includes an elongated drill rod that can extend into a drill hole that penetrates the telluric formation and means that form a circulation path for the evacuation fluid of the drilling debris, which is circulated through the drill bar and through an annulus of the drilling cavity, formed between the wall of the drilling cavity and the drilling bar, the improvement is characterized by: member interposed in the circulation path, comprising a main duct section, generally cylindrical, forming a confining member and a branch duct section intersecting the main duct section, to conduct the evacuation fluid loaded with debris of sounding, away from the main duct section, and means for connecting the main duct section ipal to a rotary seal for the drill rod; at least one nozzle in communication, by fluid flow, with the main conduit section; and, a source of fire extinguishing fluid, functionally connected to at least one nozzle element, to discharge the fire extinguishing fluid into the flow path of the discharge fluid loaded with debris, to suppress combustion of combustible materials in the evacuation fluid.

12. The improvement according to claim 12, characterized in that the main duct section includes an array of nozzle elements placed at positions spaced from one another, around a circumference of the main duct section, and functionally connected to the source of the duct. fire extinguishing fluid to inject the fire extinguishing fluid into the main duct section.

13. The improvement according to claim 12, characterized in that it includes a distributor connected to the fire extinguishing fluid source and to the nozzle element, to discharge the fire extinguishing fluid from a reservoir of fire extinguishing fluid, to the distributor.

14. The improvement in accordance with the claim 13, characterized in that it includes a conduit interconnecting the tank and the distributor, and another conduit interconnecting a water source with the distributor and a control valve element interposed in the conduits, respectively.

15. The improvement according to claim 11, characterized in that the section of the conduit includes a re-plug flange at one end thereof.

16. The improvement according to claim 11, characterized in that at least one nozzle element is placed on a flange, generally annular, interposed in the flow path, between the drilling cavity and the section of the branch duct.

17. The improvement according to claim 11, characterized in that at least one, between the fluid flow capacity of the at least one nozzle element, and the amount of fluid available from the source, is based on parameters selected from a group consisting of of the expected amount of fluid flowing from the well, the velocity profile of the fluid components of the well stream emanating from it, a shock arc of an exploding well current, against the structure adjacent to the well head , the combustion profile of the components of the well current that will probably go into flames in the shock arc, and the temperature profile of the well current if it catches fire.

18. In a system for drilling a well in an underground telluric formation, including an elongated drill rod extending into a drilling cavity, the drilling cavity includes a wellhead through which the drill rod extends. perforation, a closed circulation system of gaseous drilling fluid, because it comprises: a confinement member operatively connected to the well head to receive gaseous drilling fluid loaded with drilling detritus, coming from the drilling cavity; a control head operatively connected to the drilling cavity, for receiving a portion of the drill rod and for forming therewith a substantially fluid-tight seal, and preventing leakage of the drilling fluid from the system; and, a pressure vessel, functionally connected to the confinement structure, to receive the drilling fluid loaded with the probing debris, coming from the confinement member, the pressure vessel includes an interior space to receive the fluid therein. perforation loaded with the drill debris, and to separate a substantial portion of the solid drilling debris, from the drilling fluid, the pressure vessel includes an element for discharging, from the pressure vessel, the drilling fluid substantially free of debris, and an element for discharging the drilling debris from the pressure vessel, from time to time, without releasing a substantial amount, of the drilling fluid, from the pressure vessel into the atmosphere.

19. The system according to claim 18, characterized in that the element for discharging the debris probing, from the pressure vessel, comprises a discharge conduit, and a valve element interposed in the discharge conduit, to allow an amount of the Polishing debris pass through the discharge conduit, without unloading, from the pressure vessel, a substantial amount of the drilling fluid.

20. The system according to claim 19, characterized in that it includes: a plurality of deflectors, separated, and placed in the pressure vessel, and forming, between them and between the pressure vessel, separate interior spaces; and, the element for unloading the debris probing, comprising a discharge conduit that is in communication with each of the spaces, and a valve element interposed in the discharge conduits to allow a number of debris probing, pass through the discharge conduits without discharging, from the pressure vessel, a substantial amount of the drilling fluid.

21. The system according to claim 20, characterized in that it includes a vibrating element placed in the interior spaces, respectively, to effect the movement of the sound debris residing in the interior spaces, towards the discharge conduits, respectively.

22. The system according to claim 18, characterized in that the pressure vessel includes an inlet conduit in communication with the confinement member, to receive the drilling fluid loaded with the debris, in the interior space, and the inlet conduit is directed towards a wear plate, removable, placed in the interior space and in the access gate element formed in the pressure vessel to have access to the interior space.

23. The system according to claim 18, characterized in that the pressure vessel includes a liquid collection space, for receiving liquids entrained with the drilling fluid, a discharge gate element in communication with the liquid collection space, to receive the liquid and drilling fluid, and a control element for discharging the liquid and drilling fluid, from the liquid collection space, in response to the accumulation of a predetermined quantity of liquid, in the collection space of liquid.

24. The system according to claim 18, characterized in that it includes a valve element for pressure relief, functionally connected to the pressure vessel and to a discharge conduit, to discharge the pressurized fluid from the pressure vessel.

25. The system according to claim 18, characterized in that it includes a separating element connected to the pressure vessel to receive the drilling fluid, thereof, and to separate at least one of the solids and liquids from the drilling fluid that leaves the pressure vessel. .

26. The system according to claim 18, characterized in that it includes a separating element interposed between the confining member and the pressure vessel, to separate the solid particles and the gaseous drilling fluid, from the liquids entrained with the fluid being drilled, and element of conduit interconnecting the separator element with the pressure vessel, to conduct the drilling fluid towards the pressure vessel.

27. The system according to claim 26, characterized in that it includes a compressor element for circulating the drilling fluid to the drilling cavity, and a conducting element that connects to the pressure vessel to drive the drilling fluid, substantially free of solids, towards the drilling fluid. compressor element.

28. The system according to claim 27, characterized in that it includes a gas and liquid separator element connected to said first separating element, for separating the gaseous drilling fluid, from the liquids entrained therein, from the underground formation; and conductive element connected to the gas and liquid separator element and to the compressor element.

29. A method for drilling a well within an underground telluric formation, with a drilling system that includes an elongated drill rod that can be extended into a drilling cavity, an element for the conduction of the gaseous fluid for the evacuation of debris from drilling, through the drill bar, into an annulus of the drilling cavity formed between the drilling cavity and the drilling bar, and element to remove the drilling debris from the evacuation fluid of the drill debris, which it comes out of the drilling cavity, which comprises the steps of: circulating the evacuation fluid through the drilling cavity, for driving the drilling debris therein; separating the drilling debris from the evacuation fluid; and, carry out at least one of: (1) compressing and recirculating the evacuation fluid, through the drilling cavity, which has been separated from the drilling debris, and (2) discharging the free drainage fluid from the drilling fluid. detritus, to the distribution conduit while evacuation fluid is circulated, through the drilling cavity, from a source of supply.

30. The method according to claim 29, characterized in that it includes the step of separating the liquids from the evacuation fluid, before the compression of the evacuation fluid.

31. The method according to claim 29, characterized in that it includes the step of providing natural gas as the evacuation fluid.

32. The method according to claim 29, characterized in that it includes the step of maintaining the pressure of the evacuation fluid, in the perforation cavity, at a pressure lower than that natural of the formation, during the drilling of the well.

33. The method according to claim 29, characterized in that it includes the step of maintaining the pressure of the evacuation fluid, in the drilling cavity, at a pressure greater than the pressure of the formation.

34. The method according to claim 29, characterized in that it includes the step of providing evacuation fluid, fresh or replenishing, from a pressurized gas conduit connected to one of a gas reservoir, to a collection conduit system, and a gas supply conduit system.

35. A method for drilling a well within an underground telluric formation, in a pressure condition, either hypocompensated or overcompensated, within a well cavity that forms the well, the method is carried out with a drilling system that includes a elongated drill rod, which extends into the drilling cavity, and which is formed of interconnected sections of drill rods, an element for conducting the evacuation fluid from the drill debris, through the drilling cavity, including an annulus of the piercing cavity, formed between the piercing cavity and the piercing bar, the method comprises the steps of: measuring the pressure of the piercing fluid leaving the piercing cavity, during the entry of at least a portion of the drill rod, inside the drilling cavity; and, controlling the speed of entry of the drill rod, into the cavity, to minimize any increase in the hydrostatic pressure of the drilling fluid in the cavity.

36. The method according to claim 35, characterized in that it includes the step of counting the number of perforation bar sections, added to the drill rod that are inserted inside the perforation cavity.

37. The method in accordance with the claim 35, characterized in that the step of controlling the speed of entry of the drill rod into the drilling cavity comprises controlling a braking action on the maneuvering lathe which is operatively connected to the drill rod to raise and lower the drill. Drill bar with respect to the cavity.

38. The method in accordance with the claim 36, characterized in that it includes the step of controlling the length of the drill rod sections, added to the drill rod.

39. The method according to claim 35, characterized in that it includes the step of measuring at least the flow or pressure of the drilling fluid flowing through a conduit to drive the drilling fluid into the well, in order to detect a change in the flow rate and pressure.

40. A method for drilling a well into an underground telluric formation, in a hypocompensated pressure condition, within a wellbore that forms the well, the method is carried out with a drilling system that includes an elongated drill rod, which extends within the drilling cavity, element for driving the fluid used for the evacuation of drill debris, through the drill rod and towards an annulus of the drilling cavity, formed between the cavity and the drill rod , and element for recirculating the fluid used for the evacuation of the debris probing, after the elimination of the drilling debris thereof, the system includes pump element for pumping the evacuation fluid of the debris probing, substantially free of those debris, towards the drill rod, the method comprises the steps of: measuring the flow of the evacuation fluid from the debris probing qu e leaves the drilling cavity; measure the flow of evacuation fluid from the drill debris, towards the drill rod; measure the difference between the flows; and, controlling the flow of probing debris evacuation fluid from the drilling cavity to minimize uncontrolled flow of fluid from the drilling cavity.

41. The method according to claim 40, characterized in that it includes the steps of: measuring the pressure of the evacuation fluid of the debris probing, which is conducted through the drill rod; and, generating an alarm signal when the pressure varies from a predetermined pressure range.

42. The method according to claim 41, characterized in that the step of measuring the pressure is carried out by measuring the pressure in a vertical pipe section, of the conduit element for the fluid, leading to the drill rod. SUMMARY OF THE INVENTION The present invention relates to a well drilling system (40) for drilling with a gaseous drilling fluid, particularly natural gas, in a closed circulation path that includes a confining member or short coupling tube in the form of bell (42) mounted on a well head, located between the drilling cavity (22) and a rotating control head (84) for the system (40). The confining member (42) redirects the flow of the gaseous drilling fluid, loaded with drilling debris, which is circulated out of the well, and includes a plurality of fire extinguishing fluid injection nozzles (92), arranged or arranged to inhibit or extinguish the fire inside the confining member (42) and the rotating control head (84). The drilling debris is separated from the gaseous drilling fluid in a pressure vessel (50) including separating baffles (184) and a gate (176) for debris drilling and a valve arrangement (178, 179, 182) to empty the samples and substantial quantities of drilling debris collected inside the pressure vessel (50) during the operation of the system. The confining member (42) and the fire extinguishing system can be used together in procedures using liquid, conventional drilling fluids, and conventional equipment for the separation of liquids and solids. The most representative figure of the invention is number 1.