Abstract:
An apparatus for producing oil from a well comprises a flexible semi-circular shaped skirt with an indentation. A plurality of rods is secured to the skirt and form radially emanating channels in the skirt. The skirt is secured to a hollow drill string via the indentation. The drill string has a drill bit at one end, a distal section above the drill bit, and a holding section above the distal section to which the skirt is operatively coupled. A movable sleeve is selectively wrapped around the skirt to keep the skirt in a closed position. A release that is interactive with the sleeve selectively allows the skirt to move from the closed position to an open position, and an outer area covered by the skirt increases as the skirt moves from the closed position to the open position. The open skirt abuts against and plugs the well.

Description:
RELATED APPLICATIONS 
       [0001]    The Application claims priority to provisional application, Ser. No. 61/360,851 filed on Jul. 1, 2010, the disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The disclosed subject matter is directed to the production of oil from an oil well, and to a technology for eliminating the flow of oil and gas from a blowout. 
       BACKGROUND 
       [0003]    Drilling a well for the production of oil is an involved process, and different types of drill strings may be used to effectuate the drilling. A drill string is a column or string of drill pipe, and the term drill string is loosely applied to the assembled collection of the drill pipe, drill collars, and a drill bit. Drill collars are thick walled pipes that, by virtue of their heavy weight, aid the drill bit in the drilling process. Drilling fluid, which is also known as “mud” by those versed in the art and which consists of carefully tailored solids and chemicals, is pumped down the inside of the hollow drill string. The mud cools the drill bit as it drills, stabilizes the rock in the well walls, and lifts the rock cuttings generated by the drilling up to the surface. The mud can then be recycled and re-used. Instead of a rigid drill pipe, the drill string may comprise flexible coiled tubing. A drill string with a rigid drill pipe generally has to be assembled joint by joint, the successive sections being added with increasing depth of the well; a coiled tubing drilling string, on the other hand, comprises flexible tubing instead of the rigid drill pipe, and need not be assembled joint by joint. A coiled tubing drilling string, therefore, can be tripped in and out of the well at a much faster speed than a drill string with a rigid drill pipe. Similarly, hybrid drill strings, which combine the rigidity of the drill pipe but reduce, if not eliminate, the need to assemble the pipe in parts, may also be employed. Coiled tubing drill strings and hybrid coiled tubing drill strings are known in the art. 
         [0004]    Once an oil well is drilled, it may be plugged and abandoned as a dry hole. If, however, oil is to be produced from the well, the well must undergo a process referred to as “well completion.” To complete the well, the hole of the well may be cased. Casing involves aligning the wall of the well with hollow pipes made of steel or other suitable materials. Generally, these pipes are of different diameters, which are joined together to make a continuous hollow tube. The diameters of these pipes are dependent upon the depth or level of the well, and are selected under a program referred to as a “casing program.” 
         [0005]      FIG. 1  depicts a conventional casing program, and shows how the pipes decrease in diameter with increasing well depth. A conductor pipe  10  has the greatest diameter, and is connected to surface casing  12 . The surface casing  12  is in-turn connected to an intermediate casing  14 , which is adjoined to a production casing  16 , the surface casing  12  having a greater diameter than the intermediate casing  14 , and the intermediate casing  14  having a greater diameter than the production casing  16 . Casing is integral for the production of oil from a well, as without the casing, the well may collapse and close. Moreover, casing protects the well stream from outside incumbents, such as water or sand etc. The casing is cemented to the walls of the well, which helps to permanently position the casing within the well. Cement slurry, which consists of cement and certain additives, is pumped into the well. The cement slurry displaces the existing mud in the well, and seals the outside of the different casings to the well hole walls. 
         [0006]    The well-completion may be of different types. Open-hole completion refers to a well that is drilled to the top of the hydrocarbon reservoir where it is not cased. Open-hole completions are generally used for reservoirs that are well-known and defined. On the other hand, cased-hole completions require the casing to be run into the reservoir. After the cement slurry dries, perforations  18  are created in the sides of the well by a perforation gun. These perforations  18  perforate through the production casing  16  and the cement, and allow the hydrocarbons outside the well hole to enter into the well stream. Tubing  20  may then be used to bring the oil up to the surface. A wellhead and a Christmas tree are generally installed at the surface of the well, and include tubing heads, casing heads, valve controls etc., to provide surface control of the subsurface conditions of the well. 
         [0007]    Sometimes, because of a miscalculation, malfunction, or unexpected subsurface conditions etc., a blowout occurs. A blowout is the uncontrolled release of crude oil and/or natural gas from an oil well or gas well after pressure control systems have failed. Often, to remedy the situation, a relief well is drilled close to the production well. Drilling a relief well that attempts to penetrate the rather narrow pipe of the blowout well that is buried in sea-bed many thousands of feet below the sea floor is a complex and timely process, which does not have a very high probability of success. The relief well trajectory has to be guided with electromagnetic signals, and the drilling bit for the relief well must be directed until it is running adjacent and parallel to the blowout well, in preparation for penetrating the casing of the blowout well. Next, the relief well must inject the blowout well with drilling mud and cement in an attempt to stem the flow of oil and gas under very high pressure. As manifested by a recent spill, the development and implementation of plans for such an effort may take many months, and have not always been successful for various reasons, including for example, insufficient density of the drilling mud. 
       SUMMARY 
       [0008]    The present invention discloses apparatus and methods for the production of oil, and to stop the flow of oil and gas from a blowout well. 
         [0009]    According to one embodiment, an apparatus for producing oil from a well comprises a flexible semi-circular shaped skirt, which has a curved edge and an internal edge. The internal edge has an indentation at its center, which divides the internal edge into two segments. A plurality of rods, each having a front end and a rear end, are secured to the skirt and form radially emanating channels in the skirt. The front ends are secured adjacent the indentation, and the rear ends are secured adjacent the skirt curved edge. The skirt is secured to a hollow drill string via the indentation, and the internal edge segments are secured to each other. The drill string has a drill bit at one end, a distal section above the drill bit, and a holding section above the distal section to which the skirt is operatively coupled such that rear ends of the rods are farther away from the distal section than the front ends. A movable sleeve is selectively wrapped around the skirt to keep the skirt in a closed position. A release that is interactive with the sleeve selectively allows the skirt to move from the closed position to an open position, and an outer area covered by the skirt increases as the skirt moves from the closed position to the open position. 
         [0010]    In another embodiment, a method to produce liquid from a well comprises the steps of first producing an apparatus that has a flexible semi-circular shaped skirt which has a curved edge and an internal edge. The internal edge has an indentation at its center, and divides the internal edge into two segments. A plurality of rods is secured to the skirt, and form radially emanating channels in the skirt. The rods have a front end and a rear end, the front ends are secured adjacent the indentation, and the rear ends are secured adjacent the skirt curved edge. A hollow drill string has a drill bit at one end, a distal section above the drill bit, and a holding section above the distal section. The distal section is configured to have openings to allow the liquid to flow into the drill string. The holding section is operatively coupled to the skirt at the indentation, such that rear ends of the rods are farther away from the distal section than the front ends, and the internal edge segments are secured to each other. Next, a movable sleeve is selectively wrapped around the skirt to keep the skirt in a closed position. A release that is interactive with the sleeve selectively allows the skirt to move from the closed position to an open position, and an outer area covered by the skirt increases as the skirt moves from the closed position to the open position. The apparatus is lowered past a lower most point of the well into a liquid layer by rotating and advancing the drill bit. The release is then activated after the apparatus has been submerged in the liquid layer. Next, the string is hoisted towards the surface as if to trip the string out, and this motion thereby causes liquid to fill into the skirt and plugs the liquid well with the skirt. Openings are provided in the distal section to allow the liquid to enter into and be transported by the drill string towards a surface. 
         [0011]    According to yet another embodiment, a method to stop a flow of liquid and gas from a blowout comprises the steps of first producing an apparatus that has a flexible semi-circular shaped skirt having a curved edge and an internal edge, the internal edge having an indentation at its center that divides the internal edge into two segments. The apparatus further has a plurality of rods that are secured to the skirt and form radially emanating channels in the skirt. The rods have front and rear ends, and the front ends are secured adjacent the indentation and the rear ends are secured adjacent the skirt curved edge. The apparatus further comprises a hollow drill string having a drill bit at one end. The skirt is operatively coupled to the drill string such that rear ends of the rods are farther away from the drill bit than the front ends, and the internal edge segments are secured to each other. Second, the method includes lowering of the apparatus past a lower most point of the well into a liquid layer by rotating and advancing the drill bit, the advancement being at a speed greater than the speed of the outflow. Third, the drill string is released and allowed to move back towards the surface, which fills liquid into the skirt and plugs the well with the skirt. Finally, the plugged well is filled with mud and cement and sealed permanently. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of a PRIOR ART casing program. 
           [0013]      FIG. 2  is a perspective view of a tipi skirt according to an embodiment set forth herein; 
           [0014]      FIG. 3  is a perspective view of the tipi skirt in an open position; 
           [0015]      FIG. 4  is a perspective view of the tipi skirt while it is in a closed position on a drill string; 
           [0016]      FIG. 5  is a side elevation view of the tipi skirt on the drill string as it is lowered into a well; 
           [0017]      FIG. 6 . is a side elevation view of the tipi skirt in operation to plug an oil well. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The disclosure set forth herein provides an apparatus and methods for producing oil from an oil well, as well as stopping the flow of oil and gas from a blowout. 
         [0019]      FIGS. 2 and 3  show a tipi skirt  100  in accordance with the current invention. The TIPI skirt  100  is constructed of strong fabric  102 , which is composed of Kevlar or other suitably strong, flexible and generally impermeable materials. As shown in  FIG. 2 , the fabric  102  is cut in the shape of a semi-circle, and has a curved edge  104  and an internal edge  106 . A semi-circular indentation  108  is cut into the fabric  102  at around the center of the internal edge  106 , and has a curved edge  108   c . The indentation  108  need not, however, necessarily be semi-circular. As shown in  FIG. 2 , the indentation  108  divides the internal edge  106  into two segments  106   a , and  106   b.    
         [0020]    A plurality of rods  110 , which are made of high tensile strength metal such as high alloy steel, titanium, or other suitably rigid materials, are then sown into the fabric  102  or glued thereon. The rods  110 , which have a front end  110   f  and a rear end  110   r , extend from the curved edge  104  to the indentation curved edge  108   c , and divide the fabric  102  into a plurality of channels  112 ; said differently, the rod rear ends  110   r  are adjacent the fabric curved edge  104 , and the rod front ends  110   f  are adjacent and extend up to the indentation curved edge  108   c . As the perimeter of the skirt curved edge  104  is greater than the perimeter of indentation curved edge  108   c , the distance between the rear ends  110   r  of two successive rods is usually greater than the distance between those same rods&#39; front ends  110   f . There may be a dozen or more of these rods  110  in every tipi skirt  100 . 
         [0021]    As shown in  FIG. 3 , the skirt  100  is secured to a rigid ring  114  via the indentation  108  ( FIG. 2 ), and the internal edge segments  106   a , and  106   b  are secured to each other. The segments  106   a , and  106   b  may be secured to each other by sewing them together, or by other known methods such as stapling or gluing etc. The skirt  100  thus produced is conical in shape, similar to a Tipi (tepee) tent. The skirt  100  can be opened, or it can be closed, much like a tent or umbrella, as discussed in further detail below, and akin to an umbrella, an outer area covered by the skirt  100  is greater when the skirt  100  is in the open position than when the skirt  100  is in the closed position (compare, for e.g., the closed skirt in  FIGS. 4 and 5  to the open skirt in  FIG. 6 ). The skirt  100 , in conjunction with the drill that was used to drill the well, can be used for the production of oil. Instead of using the production casing  16  and tubing  20  as discussed in the background section ( FIG. 1 ), or even if the production casing  16  is present, the skirt  100  is affixed to a hollow drill string  200 , as shown in  FIG. 4 . The drill string  200  has a drill bit  204  at a lower end, which is used to cut the rocks to drill the well. The drill string  200  also has a hollow distal section  206  above the drill bit  204 , and a hollow holding section  207  above the distal section  206 . 
         [0022]    The distal section  206  of the hollow drill string  200  may or may not be modified to have windows  202  ( FIG. 5 ). If present, these windows  202  can be hydraulically or mechanically opened and closed from an oil rig (not shown). Or, much like the perforations  18  made in the production casing  16  ( FIG. 1 ), a perforation gun can be lowered into the hollow drill string  200  and create similar perforations in the distal section  206 . 
         [0023]    The skirt  100 , with the aid of the ring  114 , is secured to the holding section  207  ( FIG. 4 ). The diameter of the string  200  and the drill bit  204  must be less than the diameter of the intermediate casing  14  ( FIG. 1 ) (and the well hole and production casing  16 , if used) such that the string  200  can be lowered through the entirety of the well. The skirt  100  is initially placed on the holding section  207  in a closed position, i.e., the skirt  100  is wrapped around the string  200 . Maintaining the closed position of the skirt  100  may be effectuated by a hydraulically activated sliding sleeve  208  ( FIGS. 4 and 5 ), as is known in the art. Or, the sliding sleeve  208  may be mechanically controlled from the rig. The sleeve  208  may also be a lock or release that, for example, is radio controlled. Similarly, the sleeve  208  can be slid from the skirt  100  and made to rest at a section of the string  200  above the skirt  100 , or moved such that the sleeve  208  no longer hinders the opening of the skirt  100 . 
         [0024]    As shown in  FIG. 5 , the string  200  can now be lowered into the well, such that the distal section  206  and the skirt  100  are fully submerged in the oil reservoir beneath a lower most point of the well hole  211  (or a lower most end of the production casing  212 , if present, as shown in  FIG. 6 ). The sliding sleeve  208  is now slid or opened, which in-turn allows the skirt  100  to open. Much like umbrellas, which often needs to be agitated and shook after their respective sleeves have been unlocked to ensure that the umbrella opens properly, the skirt  100  may also be vigorously agitated and shook (“jarred”) after the sleeve  208  no longer constrains the skirt  100 , to ensure that the skirt  100  opens, at least to some degree. The string  200  may now be hoisted back towards the surface, as if to trip the string  200  out. This upward motion of the drill string  200  causes the attached skirt  100  to fill with oil and fully unfold/open; the drill string  200  continues to move towards the surface, which causes the open skirt  100  to surround, be anchored by, and plug the well hole, as shown in  FIG. 6 , and stop the upward motion of the string  200 . Cameras could be used in conjunction with the string  200  to ensure proper placement of the skirt  100 . In effect, the closed skirt  100  is slid past the lower most part of the well hole  211  into the oil layer, or the production casing end  212  ( FIG. 6 ), where the skirt  100  is opened, thereby increasing an outer area covered by the skirt  100 , and the open skirt  100  abuts against and plugs the hole  211 . 
         [0025]    The windows  202  (if available, as shown in  FIGS. 5 and 6 ) can now be opened remotely from the rig. Or, if the string  200  does not have windows  202  (as in  FIG. 4 ), a perforation gun can be lowered into the string distal section  206  and create perforations on the sides of the distal section  206 . Much like the production casing  16  and tubing  20  in  FIG. 1 , oil will enter the drill string  200  through the windows  202  or perforations, and will rise up to the surface where it can be collected after the drill string  200  is operatively connected to the Wellhead and Christmas tree. 
         [0026]    Once production is complete, heavy mud and cement slurry can be pumped into the drill string  200  and the wellhead to seal the well. This technology will help minimize the chance of a blowout because the pressure in the oil layer is controlled by the operator of the skirt  100 ; in effect, the pressure created is allowed to act only on the sides of the drill string  200  through the windows  202  or perforations. Moreover, in the case of a blowout, as the hole of the oil well is plugged by the skirt  100 , the oil will be unable to reach the surface with high pressure, but will deflect off the skirt  100  and remain in the reservoir, or come up to the surface via the string  200 , where it can be properly stored and processed. 
         [0027]    This technology can also be used to stop the flow from a blowout that has already occurred. As the blowout from a well generates the outflow at a high pressure, it is difficult to pour cement slurry into the well to seal the well hole, i.e., the cement slurry is pushed out before it gets a chance to dry. As explained in the background section, drilling a relief well can also be an arduous task. Notwithstanding the high pressure of the outflow, the string  200 , with the skirt  100  attached to the holding section  207  can be advanced into the well by rotating and advancing the drill bit  204 , so long as the speed of the rotating/advancing drill bit  204  is greater than the speed of the outflow. Calculations to measure the speed of the outflow are known in the art, and depend on known or readily computable values, such as the length and the volume of the oil well. It should be noted that the speed of the rotating/advancing drill bit  204  should preferably only be slightly greater than the speed of the outflow, which would minimize the disturbance created by the drill bit  204 , and otherwise facilitate the progression of the string  200  against the outflow in a more controller manner. Also, the pressure of the outflow will eliminate the need for a sliding sleeve  208  to keep the skirt  100  in a closed position, as the outflow of oil will exert pressure on the fabric  102  and keep the skirt  100  in a closed position by itself; thus, a sliding sleeve  208  may or may not be used with the skirt  100  where the skirt  100  is being used to stop an existing blowout. Or, a sleeve  208  comprising of plastic may be used, which may readily shred once the skirt  100  has advanced and opened up beyond the end of the well  211  or the production casing  212 . 
         [0028]    As in the scenario for production, the diameter of the string  200  and the drill bit  204  must be less than the different types of casings and the well hole, so that the skirt  100  can be submerged into the oil reservoir beyond the lower most point of the well hole  211  and/or the end of the production casing  212 . As with production, cameras may be used to guide the movement of the drill string  200 . The string  200  with the skirt  100  is lowered into the blowout well, and advanced a distance beyond the length of the well, or the end of the production casing  212  if present ( FIG. 6 ), until the whole skirt  100  is immersed into the oil layer. The drill bit  204  is rotated and advanced to aid in the progression of the skirt  100  against the outflow. Once the skirt  100  has progressed beyond the lower most point of the well  211  or the end of the production casing  212 , the drill string  200  is released. If the skirt  100  has a sliding sleeve  208 , the sleeve  208  is slid over or opened so that it no longer curtails the skirts&#39;  100  opening. 
         [0029]    The pressure of the oil alone will try to push the drill string  200  out of the well, which will cause the skirt  100  to fill with oil and open. Additionally, as in production, the skirt  100  may be agitated by jarring the drill string  200  to ensure that the skirt  100  opens at least to some degree, so as to enable the skirt  100  to fill with oil and open completely. The opened skirt  100  will abut against the opening of the well and act like a stop as depicted in  FIG. 6 . The pressure of the oil will push on the skirt  100  and maintain its conical shape. Thus, the skirt  100  will sustainably cover the end of the blowout well like a stop. By virtue of its geometrical shape, the skirt  100  will be kept in place and not be easily knocked off. 
         [0030]    All the distances used above should be well calculated in advance so that the operation is done very quickly: the drill string  200  is sent down the well rapidly and then released, allowing the chain of events to unfold by itself to stop the leak. At that time, the pressure in the well is neutralized and flow is stopped, and an operator may begin pouring drilling mud and cement into the wellhead and drill string  200  immediately until the well is filled up. As discussed, the drill string  200  with rigid pipes is increased in length by adding sections joint by joint, so as to enable the drill string  200  to reach a lower most point of the well  211  ( FIGS. 5 and 6 ). Where the skirt  100  is being used to stop an existing blowout, coil tubing drill string  200  or a hybrid coil tubing drill string  200  may be used instead of a jointed drill string  200 , with the skirt  100  secured to a rigid section of the coiled tubing drill string  200 . As is known in the art, the already assembled hybrid coil tubing can then simply be run into the well and tripped out, without the need to be assembled joint by joint. This would provide the added benefit of not having to spend any more time assembling the drill string  200  while it is being advanced into the well, and thus, not interfering with the speed of its progression against the pressure of the blowout oil. In this way, the skirt  100  can be immersed beyond the lower most point of the well  211  or the end of the production casing  212  in a prompt manner. 
         [0031]    Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. 
         [0032]    It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.