Patent Publication Number: US-11047176-B2

Title: Method and device to supply liquid to a drill pipe

Description:
SCOPE OF THE INVENTION 
     The present invention relates to a method for drilling a well through a formation from a drilling installation, for the recovery of fluids, where a drill pipe made up of a number of drill pipe sections is lead down into the formation and is supplied with liquid fluid from a fluid delivery system before one or more new drill pipe sections connected to the installations drill floor successively is screwed onto the upper end of the drill pipe, where there is used a filling pipe formed with a downwardly extending pipe spigot that is lead down into the opening of the drill pipe section during assembly to start the fluid filling as stated in the preamble of the following claim  1 . 
     The invention also relates to a filling pipe as apparent in claim  10 . 
     The invention is particularly applicable for recovery of hydrocarbon containing fluids from formations, but is also applicable for water drilling, such as drilling in underground formations for fresh water or for the exploration of geothermal heat. 
     In particular the invention is dealing with a new tubular tool for filling of liquid in drill pipe or casing pipe, where there are two different dimensions between the top drives saver sub, and the drill pipe or casing going into the well. 
     BACKGROUND OF THE INVENTION 
     There are strict requirements for drilling operations to be safe and effective. Operations taking place on and around the drill floor is always subject to continuous improvements. On every field, also on the Norwegian continental shelf, all activities are logged and analyzed down to seconds. From these analyzes statistical reports are generated that is used in the dialog between the onshore organization and the offshore organization to improve the operations quality on all levels. 
     It has been found that some operations are inexpedient more time-consuming than necessary. For example the process of filling drill pipe with drilling fluid, when the dimensions of the saver sub in the top drive and the tubular to be conveyed into the well are different. 
     The background for filling this pipe regularly, as an example every 1000 meters, is that differential pressure occurs between the inside and the outside of the drill pipe when the drill pipe is not filled with drilling fluid. Inside the drill pipe there will be air, because the drill string is not self filling, since there is a check valve installed in the drill string that prevents drilling fluid from entering the drill string from below. 
     Reference to the Prior Art 
     Today there are mainly two methods to perform the supply of liquid to the drill pipe: 
     1. Top filling of drill pipe: 
     Top drive with saver sub is lowered to just above the drill pipe in the rotary table. The drill pipe is then filled with fluid directly from the saver sub, which is not connected to the drill pipe, with a limited number of liters per minute, since air has to be displaced from the inside of the drill string. 
     2. Screw in a drill pipe crossover (X/O) on the top of the drill pipe and in the saver sub connected below the drilling machine: the crossover unit is designed with compatible tread dimensions and is mounted between the saver sub and the drill pipe. After the connection is made up fluid can be supplied from above without spills onto the deck. 
     Problems with Known Technique. 
     1. Top filling of drill pipe: 
     The problem with this method is that it is time consuming and that it can produce a lot of spillage on the drill floor and adjacent areas, as mentioned above. 
     2. Connect a drill pipe crossover (X/O) to the drill pipe and to the saver sub: 
     For this there will always be need for at least two persons on drill floor, since placing the filling pipe (X/O) into the drill string needs to be done by means of a winch. One person is needed to be responsible for the lift by the winch and another person guiding the filling pipe (X/O) to the top of the drill pipe. 
     In addition this operation is time consuming, since one needs to make up the drill pipe crossover (X/O) to the drill string and to the saver sub with a predefined torque. 
     As regards to the state of the art, it should also be referred to the following patent publications US-2014/0069660,US 2007/0181346, WO 2010/089572, US 2010/0206583 and US 2004/0000405. 
     Object of the Present Invention 
     It is an object to bring about a new method and a new tool to fill a drill pipe with fluid as the drill pipe is extended with new drill pipe sections.
         Further it is and object to bring about a solution without treads where one can use an effective and time saving component during filling the process.   Another object with the invention is to bring about a manually manageable device that quickly can be mounted between the saver sub and the drill pipe, so that fluid can be added to the drill pipe.   It is also an object with the invention to bring about a filling pipe without special sealing rings in connection to the pipe end surfaces which lies against the contact surface of the upper saver sub and respectively the upwardly extending drill pipe. Instead one seeks to exploit the metal to metal seal resulting from the opposing metal surfaces.       

     SUMMARY OF THE INVENTION 
     The method according to the invention is characterized by the use of a filling pipe without threads with two main parts defined by an upper sleeve and a lower sleeve, and that includes mutual intermediate seal surfaces, and the filling pipe&#39;s seal towards the fluid delivery system, respectively towards the top of the drill pipe is produced by the weight of the overlying fluid delivery system towards the filling pipe&#39;s circular upper and lower seal surfaces. 
     According to a preferred embodiment occurring overpressure is displaced through one or more bleeding channels through the filling pipe&#39;s wall parts and which each comprises an overpressure valve which opens for flow outwards at a given fluid overpressure. 
     According to yet another preferred embodiment it is used an overpressure valve in the form of a burst disc and/or a spring-loaded closing device which normally closes against a seat and by overpressure against the spring force is lead out of the closing position against the seat. 
     Preferably it is used a filling pipe with stepped annular abutment surfaces to be adapted to the choice of drill pipe sections with different end dimensions. 
     Particularly preferably it is when occurring overpressure brings the fluid to flow between the two channels through a annular shaped track (a recession) in the outer wall of the upper pipe, or through a track (a recession) in the inner wall of the lower pipe, for the case where the bores/channels is not lining up. 
     Preferably is use of a filling pipe where the upper and lower abutment surface is equipped with metal seals, or sealing gaskets such as O-rings to improve said seal. 
     According to yet another preferred embodiment occurring air from the drill pipe is displaced through a channel through the filling pipe&#39;s wall. Further to avoid fluid to flow out of the pipe through the air channel when the drill string is filling up towards the supply pipe, a connected float is brought to float to a upper position and close the air outlet channel, while occurring air that later are released down in the drill pipe again leads the float to again sink and open the air outlet channel. 
     Preferably, it is used a float with a upper seal (lip seal) that abuts the lower edge of a chin in the inner pipe&#39;s upper sleeve and produces said sealing and closure of the air outlet channel. 
     The device according to the invention is characterized by that the filling pipe is threadless, and consist of to pieces and defined by an upper inner sleeve which is jointed with a lower outer sleeve with mutual intermediate ring seals. 
     According to a preferred embodiment the wall of the filling pipe comprises one or more bleed off channels that preferable is formed with an overpressure valve for diversion of fluid with to high fluid pressure. 
     Preferably the overpressure valve is a burst disc, or a spring-loaded closing device which normally closes against a seat and by overpressure against the spring force is lead out of the closing position against the seat. 
     It is particularly preferred if the filling pipe ( 10 ) comprises stepped annular abutment surfaces to be adapted to the choice of drill pipe sections with different end dimensions. 
     Preferably the upper and lower abutment surfaces is equipped with extra annular shaped sealing, such as O-rings. 
     The filling pipe comprises preferably a channel through the pipe&#39;s wall for diversion of air from the drill pipe. The deaeration channel comprises a connected float arranged to be switched between closing position when in contact with drilling fluid, and a deaeration—open position in contact with occurring air released from down inside the drill pipe. 
     It will appear that the filling process is more efficient by inserting a two piece filling sleeve (also named a SmartSleeve) manually in between the saver sub and the drill pipe. The upper and lower end of the filling pipe do not need to include annular formed sealing elements, but can be pure metal to metal seals which satisfactorily seals the surfaces between the saver sub and the filling sleeve, as well as between the filling sleeve and the drill pipe using the weight the drilling machine exercises. 
     Since the filling sleeve alternatively can be a plastic pipe, one will achieve a satisfactory plastic-to-metal seal. 
     The result is that one quickly can insert a SmartSleeve with upper and lower clean end surfaces (metal/plastic), after which saver sub is lowered and the transitions between saver sub and filling pipe respectively filling pipe and newly installed drill pipe is completely sealed. After a sufficient amount of fluid is filled, the operation is performed in the opposite order, where the insertion of new drill pipe sections can proceed. 
     The filling sleeve according to the invention, which is a threadless X/O, will be an effective and time saving component during filling of drill pipe or casing. 
     One also achieves a filling sleeve that increases flexibility since it can be used even with variations in drill pipe end dimensions, without having to change the saver-sub dimensions. This applies especially to cases where the pipe section threads are not compatible with the drilling machines saver sub. During a drilling operation it is in fact not uncommon to have different dimensions on the drill pipes. A filling pipe with the mentioned stepped annular abutment surfaces can directly be adapted to different drill pipe dimensions. 
    
    
     
       DESCRIPTION OF FIGURES 
       Preferred embodiments of the invention will hereinafter be described in more detail with reference to the accompanying drawings, in which: 
         FIG. 1  shows an introductory variant of a filling pipe according to the invention, inserted between the drilling machine and a drill pipe. 
         FIG. 2  shows a vertical section of a preferred construction of a filling pipe according to the invention, comprising a construction with two pipe pieces. 
         FIG. 3  shows a vertical section off the pipe construction with two pipe pieces from  FIG. 2 , comprising one or more bleed off channels with overpressure valve, showed in two variants. 
         FIG. 4  shows a vertical section of yet another variant, where there in addition to the bleed off channel in  FIG. 3  is formed a deaeration channel through the two pipe walls. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS OF THE FILLING PIPE 
     Initially, reference is made to  FIG. 1  which shows a threadless filling pipe (or—sleeve)  110 . The filling pipe is suitable to be inserted between the fluid supply system to a drilling machine  20  and drill pipe  30  to be able to supply drilling fluid (showed with arrow  100 ) without leakage off drilling fluid. The figure shows the three elements in order, and a torque tool  40  which later is used to screw the saver sub to the top of the drill pipe  30  as showed in the figure. Both ends of the pipe comprises annular formed sealing surfaces, which especially preferred is made up off the pure metal end surfaces  12 / 14 ,  16 / 18 . The lower part off the pipe  110  comprises a downwardly extending pipe spigot  17  directed to lead towards the inlet  31  of the drill pipes  30  top part. 
     The top part of the filling pipe  110  comprises therefor an annular surface  12  oriented to lie against the lower annular surface  22  of the drilling machines saver sub  20 . The figure also shows a variant with a second annular shaped shoulder surface  14  placed radially within and below the first annular surface  12 , in the form of a step down. 
     The lower part of the filling pipe comprises also mutual stepped annular surfaces  16 ,  18 , shaped as chins. The annular surface  18  is consequently situated radially within the annular surface  16 .  FIG. 1  shows how the upper annular surface/surfaces  12 , 14  in the filling pipe is directed to lie against the end surface  22  of the associated drilling machines saver sub, so that complete sealing is achieved. According to the invention this will give sufficient seal when the pipe is held down due to the saver subs weight. Preferably seal is achieved using pure metal sealing surfaces. According to an alternative embodiment the upper and lower sealing surfaces  12 , 14 , 16 , 18  can if needed be equipped with gaskets such as O-rings to improve said seal. 
     Further it is showed how the lower annular surface/surfaces  16 , 18  on the filling pipe is adjusted to lie against the top surface edge  31  associated the drill pipe  30  extending upwards, so that complete sealing is achieved. 
       FIG. 2  shows a two piece filling sleeve  110  that according to the invention is in the form of an upper  50  respectively a lower sleeve  52 . The sleeve  50  constitutes an upper part with upward facing annular surfaces  12  and  14  equivalent to the embodiment in  FIG. 1 . The lower part of the upper sleeve  50  comprises a downward extending pipe spigot  54  adapted to be brought down inside a channel  41  in the lower sleeve  52 . The upper sleeve  50  thus has a T-shaped cross section, while the lower sleeve has a corresponding U-shaped inner channel  51  which accommodates the pipe spigot  54 . 
     The pipe spigot&#39;s  54  lower annular surface  43  lies against a shoulder  55  in the bore  51  of the lower sleeve  52 . The annular shaped top surface  47  of the lower sleeve  54  forms the sealing abutment against a corresponding chin  49  in the upper sleeve  50 . 
     The upper sleeve  50  is adapted to be screwed into the outer sleeve  52  so that mentioned annular surfaces  47 / 49  respectively  43 / 55  is pushed against each other and forms a seal. Alternatively can the two parts  50  and  52  be joined by an interference fit. 
     For easy manual operation the sleeve is preferably made of light metal, plastic (particular reinforced plastic) or a composite. 
     A Second Preferred Embodiment of the Filling Pipe According to  FIG. 3  Includes a Bleed Off Channel with an Inserted Overpressure Valve. 
     It is showed in  FIG. 3  a construction of a bleed off channel in the feeding pipe  110  to let out fluid if the fluid pressure gets to high. The construction implies that in the pipe  110  is drilled one or more channels through the pipes wall(s) to establish a closable fluid connection, in the form of a channel  56 , between the filling pipe&#39;s longitudinal inner channel  41  and the area  53  outside the pipe  110 . Each channel  56  comprises a valve which initially is closed, but at a given pressure opens the channel to let out fluid (gas) to depressurize the filling system. 
     In the given example it is showed two channels  56   a , 57   a  respectively  56   b , 57   b  through the two pipe parts  50 - 52  and to the inside, this is to show two possible pressure-relievers that can lead fluid out when overpressure occurs in the channel  41 . 
     The channel on the figures right side comprises a burst-disc  51  with a plate form that blocks the channel  56   a . At elevated pressure, burst plate  51  bursts out and opens channel  56   a.    
     According to the variant showed to the left on the figure, the channel comprises a barrier ball  60  that by the help of a spring  62  is pushed from the outside and inwards into the channel  56   b  against a annular seat  64 , this constitutes a positon where the ball  60  close for flow from the channel  41  in the feeding pipe. If the inner pressure exceeds the force from the spring  62 , the ball  60  will be pushed outwards, compressing the spring  62  and the channel opens for fluid flow out through the seat. Both of the two solutions works as a bleed off channel at occurrence of overpressure. 
     As  FIG. 3  shows, the bleeding channel extends obliquely upwards from the outside and through the wall of the lower pipe part  52  and into the channel  57   a  in the pipe wall of the upper pipe part  50  and ends in its inner wall against the duct  41 . 
     As the figure shows, the channel  56  ( 56   a ,  57   a  and  56   b ,  57   b ) passes through the two pipe walls  52  and  54 , and comprises pure circular holes through the walls, one obliquely for further to extend radially through the upper tube  50 . 
     In order to ensure a fluid connection between the two bores, an annular groove  53  (a recess) is provided in the outer wall of the inner pipe  50 . Alternatively, such an annular groove or recess may be formed in the inner wall of the lower pipe  52 . This for the case where the bores/channels  57   a - 56   a  or  57   b - 56   b  did not completely line up during the mating of upper and lower tubes  50 ,  52 . Then liquid fluid which may flow into the channel will first be introduced into the radial bore, then floating around the annulus  53 , to flow further through the duct  56 . The two bore holes/bores  57  ( 57   a  and  57   b ) and  56  “points” thus against a 360 degree milled ring groove  53  in the outer wall of the upper tube  50 , i.e. in its extended pipe spigot  54  which extends down into the channel  51 . This causes fluid to flow into ring groove  53  until it hits the bore (borehole)  56  and can pass further through the channel and towards the blast disc  51  or ball valve  60 . 
     Ventilation of Air 
     According to a preferred embodiment, it is formed a second radially directed bleed channel  70   a ,  71   a ;  70   b ,  71   b  through the pipes  50 , 52  wall parts below the first bleed off channel  56 . This channel is intended to ventilate air that flows/is displaced in the drill string as it is filled with drilling fluid. This bore/channel  70   a ,  71   a ,  70   b ,  71   b , which is angled correspondingly from the outside obliquely upwardly through the lower pipe  52 , then with an angle downwards through the extension spigot of the upper pipe  50  and is fully open for the outflow of the air. 
     To avoid outward flow of fluid through the same air-bore/channel  70   a , 71   a ;  70   b , 71   b  and out on the drill floor area on the platform, a float valve is installed adjacent to the channel  70   a , 71   a ;  70   b , 71   b . This is showed in  FIG. 4  in a third variant of the filling sleeve. 
     If/when the fluid level rises upwards to the same level as the channel  70 , it will flow out through the channel and out on the drill floor and spill the working areas of the operators. That is way it is formed an annular stepped recession  80  around the whole circumference of the pipe part  54 . The recession  80  defines together with the inside of the outer sleeve  52  an annular space  82  in which an annular float  84  (floating ring), is mounted. This assembly is formed adjacent to the bottom of the inner sleeve  50  so that it is exposed to the inner channel  41  further down through the supply pipe towards the drill pipe. The float is formed in a material with lower density than the fluid that is filled in the pipe, and which gives the rising fluid level in the drill pipe. On the upper an lower circumferential surfaces of the float i.e. the surfaces that shall form the seal in upper respectively lower position, is formed as compressible sealing elements  86  in the form of so called elastic lip seals. 
     The float  84  is further of a form corresponding to the defined space  82  but it is shorter in axial direction, so that it can function as a glide/slide with a space for movement up and down in axial direction i.e. to slide up and down axially. In its upper position it covers completely the channel  70  and fully closes for flow through this channel  70 . 
     When the drill string is filled with fluid up to the supply pipe, the float will float to its upper position when the fluid level reaches this point, this results in that the channel with the upper part of lip seal that abuts the lower edge of the chin  87  in the inner pipe  50 , and prevents fluid from flowing out from the pipe and contaminate the work deck of the operators. When the air pockets down in the drill pipe gradually is released and flows upwards the float will, in contact only with air, sink down again to its down position, and will open the channel  70  for flow since the float materials density is higher than that of air. Air can then flow out through the channel  70   a , 71   a ; 70   b , 71   b.    
     A favorable consequence of this is that one can pump fluid downward with pressure through this supply pipe that do not need threaded connection with the drill pipe or the filling machinery.