Patent Publication Number: US-11639635-B2

Title: Riser running tool with liquid fill and test

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present document is based on and claims priority to U.S. Pat. No. 11,359,439, filed Oct. 10, 2019, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to systems and methods for running marine drilling riser. More specifically, the present disclosure relates to a marine riser tool configured to fill one or more external auxiliary lines of the riser with liquid and/or test such auxiliary lines. 
     BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     A drilling riser includes a relatively large-diameter pipe that connects a subsea blowout preventer (BOP) stack to a surface rig. The large-diameter pipe is configured to take mud returns to the surface. In addition to the large-diameter main tube, many drilling risers include a plurality of high-pressure external auxiliary lines. These auxiliary lines can include high pressure choke and kill lines for circulating fluids to the BOP, and usually power and control lines for the BOP. 
     As the drilling riser is being installed, a riser running tool is often used to grip the next section or joint of riser at its upper end while the previous joint of riser is held in place by a spider system at the drill floor. After stabbing and connecting pins and boxes of the two riser joints together, the riser running tool lowers the joint or riser through drill floor and into the sea water. Periodically, after several riser joints have been run, the auxiliary lines have to be filled with liquid to reduce risk of damage due to external sea water pressure. Additionally, the auxiliary lines are often pressure tested to detect possible leaks after a number of riser joints have been run. In order to perform the liquid filling and/or pressure testing of the auxiliary lines, one or more hoses need to be moved across the drill floor and connected. Ordinarily the connection, filling and pressure testing process is somewhat time consuming, so the filling and testing are only carried out after a predetermined number of joints have been installed. For example, in some cases the connection, filling and testing is only carried out every 8, 10 or 13 joints. 
     SUMMARY 
     This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining or limiting the scope of the claimed subject matter as set forth in the claims. 
     According to some embodiments, a drilling riser running tool is described that is adapted to connect and run riser joints for use in a drilling process. The system includes: a riser joint interface configured to securely hold a first riser joint at a top end such that with a top drive system above the riser running tool, the first riser joint can be lowered towards a second riser joint being held by its top end near a drill floor; an auxiliary tube interface configured to provide liquid filling of a first auxiliary tube on the first riser joint after connection of the first and second riser joints; and a liquid filling system configured to provide filling of the first auxiliary tube with liquid (e.g. sea water) while the first and second riser joints are being run. 
     According to some embodiments, the drilling riser running tool can also include a second auxiliary tube interface configured to provide liquid filling of a second auxiliary tube on the first riser joint after connection of the first and second riser joints and while the first and second riser joints are being run. 
     According to some embodiments, the drilling riser running tool also includes a pressure testing system configured to pressurize the auxiliary tubes after liquid filling and test the first tubes for leaks under pressurization. According to some embodiments, the liquid filling system also includes a liquid line passing from the top drive to the auxiliary tube interface. 
     According to some embodiments, a method of running a riser system is described. The method includes: interfacing a riser running tool with a top end of a first riser joint, the interfacing including forming a seal between a liquid filling and testing system and auxiliary tube(s) on the first riser joint; lowering a bottom end of the first riser joint towards a top end of a second riser joint being held stationary at a drill floor; connecting the bottom end of the bottom end of the first riser joint to the top end of the second riser joint; releasing the top end of the second riser joint at the drill floor and running the first and second riser joints downwards; and while running the first and second riser joints, filling the auxiliary tube(s) with liquid. According to some embodiments, the method can also include pressure testing the auxiliary tube(s) while running the riser joints. 
     According to one or more embodiments of the present disclosure, a system includes a top drive system: a drillings riser running tool adapted to connect and run riser joints for use in a drilling process, the drilling riser running tool configured to be deployed by the top drive system; a fluid line configured to run from the top drive system to the drilling riser running tool, the drilling riser running tool including: a tool head module configured to engage and hold a first riser joint at a top end such that with the top drive system above the drilling riser running tool, the first riser joint can be lowered towards a second riser joint being held near a drill floor, wherein the first riser joint includes: a central tube; and a first auxiliary line, and a liquid filling system configured to provide liquid filling of the first auxiliary line via the fluid line after connection of the first and second riser joints and while the first and second riser joints are being run. 
     A method according to one or more embodiments of the present disclosure includes deploying a drilling riser running tool using a top drive system disposed above the drilling riser running tool; using a tool head module of the drilling riser running tool to engage and hold a first riser joint, the first riser joint including a first auxiliary line; lowering the first riser joint towards a second riser joint being held near a drill floor; connecting the first and second riser joints using the drilling riser running tool; and filling the first auxiliary line with liquid via a fluid line running from the top drive system to the drilling riser running tool while the first and second riser joints are being run. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject disclosure is further described in the following detailed description, and the accompanying drawings and schematics of non-limiting embodiments of the subject disclosure. The features depicted in the figures are not necessarily shown to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form, and some details of elements may not be shown in the interest of clarity and conciseness. 
         FIG.  1    shows a drilling system with an improved riser running tool is deployed at a marine wellsite, according to some embodiments; 
         FIG.  2    shows further detail of a drilling system with an improved riser running tool being deployed at a marine wellsite, according to some embodiments; 
         FIG.  3    shows further detail of an improved riser running tool, according to some embodiments; 
         FIG.  4    is a partial cross section illustrating further detail of an improved riser running tool, according to some embodiments; and 
         FIG.  5    is a block diagram illustrating further details relating to operating a riser running tool, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. These described embodiments are only exemplary of the present disclosure. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. Like reference numerals are used herein to represent identical or similar parts or elements throughout several diagrams and views of the drawings. 
     According to some embodiments, an enhanced riser running tool is described that is configured to perform sea water fill up and pressure testing of the riser auxiliary lines. Once connected, the riser running tool is capable of filling up the auxiliary lines while tripping down the riser joint, and then run a pressure test when the lines are filled up with water. 
       FIG.  1    shows a drilling system with an improved riser running tool deployed at a marine wellsite, according to some embodiments. The drilling system  100  is being deployed on a vessel, such as a drillship, or on a floating platform positioned above subsea wellhead  108  on sea floor  106 . According to some other embodiments, the drilling system  100  is being deployed from a fixed platform above wellhead  108 . Drilling system  100  is shown lowering BOP stack  140  down through sea water  104  for connection to wellhead  108 . The BOP stack  140  can include various components such as a wellhead connector, blowout preventors, annular diverters, subsea flexjoint(s) and riser adapter(s). Above BOP stack  140  are a number of riser joints below seawater surface  102  of which riser joint  132  is shown. Shown below drill floor  130  and passing through moon pool door  128  are further riser joints  134 ,  136  and  126 . Riser joints  134  and  136  are shown with buoyancy modules. Mux cable line  124  is also shown being deployed below drill floor  130 . Diverter  122  is also visible below rotatory table and drill floor  130 . Above the drill floor  130  is “dog house”  112  and spider  118 , which is shown currently holding the uppermost flange of riser joint  126 . The riser running tool  110  is shown holding the next riser joint  116  above the spider  118 . The riser running tool  110  is being deployed by top drive system  120 . Also shown on the right side is a new riser joint  114  in the horizontal position that can be deployed by the riser running tool following the attachment of riser joint  116  to riser joint  126  and the lowering or running of riser joint  116 . 
       FIG.  2    shows further detail of a drilling system with an improved riser running tool being deployed at a marine wellsite, according to some embodiments. In  FIG.  2   , the rotary table  242  and the gimbal  240  are visible. Also visible is the upper most portion  226  of lower riser joint  126  that is being held by spider  118 . An alignment module  230  is also shown mounted on spider  118  which can be configured to facilitate automatic rotational alignment between the lower riser joint  126  and upper riser joint  116 , and reduce risk of damage as is described in further detail in the co-pending patent application entitled “Riser Running Tool with Automated Alignment and Load Compensation,” filed on even date herewith, hereinafter referred to as the “co-pending patent application,” and which is incorporated herein by reference. A processing system  232  is shown in “dog house”  112 , although it could be located in part or wholly in another location at the drill site. According to some embodiments, processing system  232  includes a general-purpose data processor and other computer components such as storage and input/output modules and is configured to carry out control processing tasks including the water fill-up and/or pressure test of the auxiliary lines. 
     At the upper end of riser joint  116 , tool head module  210  of riser running tool  110  is shown engaging and holding riser joint  116  at its upper end  216 . A hydraulic and test fluid supply line  222  is run from the top drive  120  to the riser running tool  110  and is configured to supply hydraulic power and control as well as to supply filling and pressure testing fluid to the riser auxiliary lines. Also visible in  FIG.  2    are bale arms (including bale arm  220 ) and weight compensation pistons (including piston assembly  260 ) which can be used to facilitate weight/load compensation to reduce the risk of damage, as is described in further detail in the co-pending patent application. 
       FIG.  3    shows further detail of an improved riser running tool, according to some embodiments. Tool head module  210  is shown engaged with upper end  216  of riser joint  116 . Riser joint  116  includes a large central tube  310  configured to carry fluid such as drilling mud from the wellhead to the surface. Riser joint  116  also includes a number of auxiliary lines  312 ,  314  and  316 , which can include high pressure choke and kill lines for circulating fluids to the BOP, as well as power and control lines for BOP operation. According to some embodiments, tool head module  210  grips onto the riser joint  116  by inserting a portion into the box section of the main tube  310  and expanding a split ring that engages grooves on the inner portion of the main tube  310 . Also, visible more clearly in  FIG.  3    is the second bale arm  320  and the second piston assembly  360 . 
       FIG.  4    is a partial cross section illustrating further detail of an improved riser running tool, according to some embodiments. The lower portion of tool head module  210  includes riser bore pin assembly  414  that is shaped to fit into the box section of each riser joint&#39;s main central tube. The assembly  414  includes a split ring  420  that can be expanded under hydraulic power (e.g. from line  222 , although the hydraulic connection is not shown). When split ring  420  is expanded, protrusions on the split ring outer surface securely engage grooves on the inner portion of the riser&#39;s main bore such that the riser can be safely and securely lifted and positioned for deployment (or storage). Also shown is a main bore vent line  450  that is configured to provide testing of the main riser tubing. According to some embodiments, the riser running tool can be configured to perform pressure testing on the main riser bore (e.g. tube  310  shown in  FIG.  3   ). In cases where testing of the main riser bore is being tested sealing can be provided between assembly  414  and the inner surface of central tube  310  (shown in  FIG.  3   ). 
     Auxiliary line testing subassembly  416  includes a box  412  to automatically engage the upper pin of an auxiliary line (e.g. line  316  shown in  FIG.  3   ). The box  412  is configured to form a seal with the auxiliary line when the central pin assembly  414  is engaged with the central tube (e.g. tube  310  shown in  FIG.  3   ). Testing subassembly  416  includes a fluid port  410  that is attached to line  222  as shown. While only a single testing subassembly  416  is shown for clarity in  FIG.  4   , according to some embodiments, riser running tool head module  210  includes a plurality of testing subassemblies that matches the number of auxiliary lines being used with the particular riser being run. For example, in many cases the riser system will include five auxiliary lines and in this case the tool head module  210  will include five testing subassemblies  416 , each being connected to a fluid supply line  222 . According to some embodiments, line  222  includes separate fluid supply lines running to each of the testing subassemblies. For example, in case there are five auxiliary lines and tool head module  210  includes five testing subassemblies  416 , then line  222  includes five separate fluid supply channels with one running to each of the five testing subassemblies. Running separate supply lines can increase flow rate and reduce fill-up time. Each of the testing subassemblies is configured to automatically sealingly connect to the respective auxiliary line upon engagement between the central pin assembly  414  and the central tube (e.g. tube  310  shown in  FIG.  3   ). By automatically forming sealed fluid communication with each auxiliary line in the riser joint, filling and testing of the auxiliary lines can commence as soon as the riser joint is “latched” or fixed (e.g. with bolts) to the riser being held in the spider. 
     Also shown in  FIG.  4    is the central body of the riser running tool being separated into two sections: lower section  402  and upper section  404 . Relative movement between the two sections  402  and  404  is controlled by piston assemblies  250  and  350 , as well as the external forces from the top drive and the attached riser joint(s). A hydraulic control system  430  is included that is configured to measure and control the hydraulic pressure in the piston assemblies  250  and  350  for facilitating weight/load compensation, as is described in further detail in the co-pending patent application. According to some embodiments, the upper section  404  has a box connection  422  that is configured to interface with the saver sub on the top drive system (e.g. NC50 threaded box connection). 
       FIG.  5    is a block diagram illustrating further details relating to operating a riser running tool, according to some embodiments. In block  510 , the riser running tool stabs and engages the upper end of the next riser joint to be installed. In some cases, the next riser joint will be in a horizontal position (such as joint  114  shown in  FIGS.  1  and  2   ), and other cases it might be in a vertical position. In some cases, the engagement takes place by radially expanding of a split ring such as split ring  420  shown in  FIG.  4    where the raised portions of the split ring engage and lock on to matching grooves formed on the inner portion of the main tubing of the riser joint. Also performed along with the engagement of the central riser bore, fluid connections are made with each of the auxiliary lines of the riser joint. This can be made, for example, by engagement of each testing subassembly (such as testing sub  416  shown in  FIG.  4   ) with each auxiliary line. In block  512 , the riser running tool and the top drive system, raises and positions the riser joint such that lower end of the riser joint is above the upper end of riser joint being held by the spider. In cases where it is in a horizontal position, this step includes bringing the riser joint into vertical alignment. In block  514 , the top drive lowers the riser running tool and riser joint being held to mate with the lower riser joint being held in the spider. In block  516  the two riser joints are fixed or “latched” together, such as with bolts. Once the two joints are latched, the filling and testing of the auxiliary line can commence (blocks  520  and  522 ). Note that the filling and testing of the auxiliary lines can take place in parallel with the relating of the riser from the spider and lowering or running of the riser (block  518 ). The test procedure (block  522 ) includes steps according to the specification of the line and generally includes pressurising the line to a predetermined level, holding or waiting for at the pressure for a predetermined length of time while measuring any pressure loss. Based on the measurements the test is passed or failed. Assuming no test failure, in block  524  the top of the joint is held by the spider and the riser running tool is disengaged. Note that the liquid fill (block  520 ) and/or the pressure test (block  522 ) can be optionally performed for each joint, or they can be performed after a number of joints. In one example, the auxiliary lines are filled for every joint and the test is performed only every other joint (or every third joint, etc.). In another example, the auxiliary lines are filled and tested only every other joint. The ability to fill and test auxiliary lines with much greater flexibility can result in significant cost savings due to a reduced risk of leaks since filling of the auxiliary lines occurs more often. Furthermore, significant cost savings can result from improved leak detection, since testing more frequently means leaks are often detected earlier leading to reduced cost of repair. 
     Although most of the foregoing has been described with respect to marine drilling risers, according to some embodiments the techniques described herein are applied to other types or risers such as tie-back drilling riser and production riser that have auxiliary tubes or lines. 
     While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims. 
     The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for” or “step for” performing a function, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f). While the subject disclosure is described through the above embodiments, it will be understood by those of ordinary skill in the art, that modification to and variation of the illustrated embodiments may be made without departing from the concepts herein disclosed.