News Column

Patent Issued for Apparatus and Method for Managed Pressure Drilling

February 5, 2014

By a News Reporter-Staff News Editor at Journal of Engineering -- From Alexandria, Virginia , VerticalNews journalists report that a patent by the inventors Kozicz, John ( Spring, TX ); Juran, Tim ( Cypress, TX ); Legault, Andy ( Houston, TX ); Black, Sandy (Cupar, GB); Mackay, John (Inverurie, GB); Niven, Scott ( Aberdeen , GB); Sneddon, Iain ( Scotland , GB), filed on January 6, 2011 , was published online on January 21, 2014 . The patent's assignee for patent number 8631874 is Transocean Sedco Forex Ventures Limited ( George Town Grand Cayman , KY). News editors obtained the following quote from the background information supplied by the inventors: "Presently a number of hydrocarbon drilling techniques have been proposed to better manage pressures within or exerted upon a wellbore during drilling activities. Broadly, these techniques encompass two categories of wellbore pressure control. In the first, a 'closed loop' circulating system is employed. This is usually accomplished by installing a rotating control device ('RCD') similar to that described in, Williams et al U.S. Pat. No. 5,662,181. The RCD is positioned on top of a conventional blow-out preventor. In this system, the RCD directs the flow of drilling mud from inside and atop the wellbore so that drilling mud may be monitored and so the pumping rate can be regulated. In the second, various methods of using multiple columns of drilling fluids with different densities to manipulate the drilling fluid pressure gradient within the wellbore or adding a pumping system to boost wellbore fluids from the well. Fluid density levels effect the fluid pressure gradient within the wellbore and help boost fluids from the well. "Due to limitations in the physical characteristics of existing marine risers present pressure management techniques cannot be implemented without substantial additional cost and/or time. For example, the method and apparatus disclosed in U.S. Pat. No. 6,273,193 (Hermann et al) employs a concentric inner riser and related elements (support, sealing mechanisms, etc.). However, the Hermann et al method and apparatus require the marine riser system to be substantially disassembled before the concentric riser can be deployed. Disassembling the marine riser system adds significant time and cost to the drilling operation. Additionally, the system of Hermann et al leaves the upper end of the marine riser system unpinned to the underside of the rig. This results in the potential for differential movement of the riser away from the well centerline that could cause eccentric side loading of wellbore annular sealing element. Further, the Hermann et al method employs the upper annular blow-out preventor of the existing BOP to effectively seal and isolate the annulus between the lower end of the concentric riser and the lower end of the marine riser rendering it unavailable for its primary well control function. "Hannegan et al. U.S. Pat. No. 6,263,982 describe a method and apparatus where a RCD is installed on top of a marine riser in a manner similar to Hermann et al method and apparatus. The Hannegan method and apparatus has similar limitations with respect to the time and cost of installing and operating the system. Additionally, without an concentric riser, the burst pressure capacity of the conventional marine riser limits the maximum annular pressure that may be imposed. "The present invention overcomes these limitations by enabling a conventional marine riser that is easily configured and reconfigured to conduct dual gradient and annular drilling capabilities." As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "The present invention is directed to a drilling system and method that manages pressure within a riser during drilling operations. Specifically, the drilling system employs a main marine riser having a plurality of fluid inlet and outlet conduits, concentric inner riser supported within the main marine riser, a riser rotating control device, and a plurality of annular seals disposed within the annular space between the main marine riser and concentric inner riser. These elements work in cooperation to manage the fluid density in the riser and to control influxes of abnormally pressurized fluids into the risers. The present invention provides an efficient method of preventing blowouts and other potentially disastrous consequences of drilling though formations with water, natural gas, pockets of frozen methane gas, or other underground fluid reservoirs. "A preferred embodiment of the inventive pressure management system is a concentric riser support body that includes a tubular body, a riser annular seal within the tubular body that is configured to sealingly engage a concentric tubular member when the seal is actuated, a concentric riser annular seal within the tubular body below the riser annular seal that is configured to sealingly engage a concentric riser member when actuated, and a concentric riser support within the tubular body below the concentric riser annular seal that is configured to supportingly engage a concentric riser member. The pressure management system may further include a tubular body with a concentric riser fluid inlet above the concentric riser annular seal and a concentric riser annular fluid inlet below the concentric riser annular seal. "The tubular body of the support body may include a concentric riser fluid outlet above the concentric riser annular fluid inlet. The fluid inlets and outlet may be opened, closed, or partially opened. Further, the inlets and outlets may include at least one flow meter. "The concentric riser support body of the preferred embodiment may also include a bottom that is configured to mate with a marine riser pipe and a top that is configured to mate with a telescopic joint, or combinations thereof. The support body may also include a plurality of concentric riser fluid conduits below the riser annular seal, which conduits may include valves that may me independently controlled or controlled as a single value, or combinations thereof. The fluid conduits may also be configured as fluid inlets and fluid outlets. "A preferred embodiment of the pressure management system includes a riser, a riser support connected to the riser, a telescopic joint connected to the riser, a concentric riser support body between the riser telescopic joint and the riser support, and a concentric riser inside the riser and the concentric riser support body. The concentric riser may be sized to create an annular space between the concentric riser and the riser. The concentric riser annular seal may be configured to sealingly engage the concentric riser when the seal is actuated. The concentric riser annular seal is designed to prevent fluid in the annular space between the riser and the concentric riser from flowing past the concentric riser annular seal when the seal is actuated. "The concentric riser system may also include a riser rotating control device positioned within the riser and above the concentric riser. The riser rotating control device may include a riser rotating control device pipe section (sized to create an annular space between the riser rotating control device pipe section and the riser) and a riser rotating control device seal operably positioned within and/or exterior to the riser rotating control device pipe section. "The preferred concentric riser system may also include a concentric riser support body that includes a riser annular seal that is designed to sealingly engage the riser rotating control device pipe section when the seal is actuated. The concentric riser support body may also include a plurality of concentric riser fluid channels and a concentric riser annular channel spaced below the plurality of concentric riser fluid channels. "The concentric riser system may also include flow sensing equipment connected to at least one of the plurality of concentric riser fluid channels. The flow sensing equipment may be configured to measure flow volume and pressure inside the at least one of the plurality of concentric riser fluid channels. The concentric riser system may also include a lower concentric riser annular seal positioned inside the riser and adapted to sealingly engage the concentric riser when actuated. The lower concentric riser annular seal is positioned in close proximity to the bottom of the concentric riser. "In addition to structural embodiments, the invention includes a preferred method of managing pressure and/or riser fluid density. The preferred method includes injecting a fluid of a first density through a drill pipe, injecting a fluid of a second density through an annular space between a riser and a concentric riser, mixing the two fluids below the concentric riser, and returning the mixed density fluid toward the top of the riser in the annular space between the drill pipe and concentric riser. "The method may further include the step of retrieving the mixed density fluid through a port in fluid communication with the top of the concentric riser. The method may also include the step of measuring relevant fluid flow parameters of the mixed density fluid as it is retrieved from the port in fluid communication with the top of the concentric riser. The method may also include the steps of measuring relevant fluid flow parameters of the fluid of the first density, measuring relevant fluid flow parameters of the fluid of the second density, and comparing the parameters of the fluids of the first and second density with the mixed density fluid. Additionally, the comparison may result in controlling a blow out preventor in response to the step of comparing the fluids. Control may include changing the second density responsive to well parameters. The preferred method may also include sealing the annular space between a riser and riser rotating device before the step of injecting the fluid of the second density. "Another preferred embodiment is a drilling system that includes a drilling platform, a main drilling riser connected to the drilling platform, where the main drilling riser includes a plurality of lengths of riser tubulars coupled at generally opposed ends, a blow-out preventor connected to the main drilling riser, a concentric riser within the main drilling riser, where the concentric inner riser comprises a plurality of lengths of riser tubulars coupled at generally opposed ends, and one or more annular seals connected to the main drilling riser, wherein the annular seals are configured to isolate pressure in the annular space between the main and concentric riser and below the annual seal. "The drilling system may also include one or more riser fluid inlet conduits connected to the main riser, wherein the riser fluid inlet conduit is configured to receive fluid. The drilling system may also include one or more riser fluid outlet conduits connected to the main riser, wherein the riser fluid outlet conduit is configured to discharge fluid. "The concentric riser of the drilling system may be configured to receive fluid from a drill pipe and discharge the fluid to a drilling fluid processor. At least one of the annular seals of the drilling system may measure the pressure in the annular space between the main riser and the concentric riser and below the annular seal. The annular seals may be configured to open and close in the event of fluid influx into the main riser or the concentric riser so that pressure within the risers is controlled. The riser fluid inlet conduit may be configured to introduce fluid into the annular space between the main riser and the concentric riser, and wherein the concentric riser is configured to receive fluid from the annular space between the main riser and the concentric riser and discharge fluid to the fluid processing equipment. "The drilling system may also include a riser fluid inlet conduit that is configured to introduce fluid into the annular space between the main and concentric riser, and wherein the concentric riser is configured to receive fluid from the annular space between the main riser and the concentric inner riser, and wherein a riser rotating seal is configured to close so that fluid is discharged through the one or more fluid outlet conduits. "The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention." For additional information on this patent, see: Kozicz, John; Juran, Tim; Legault, Andy; Black, Sandy; Mackay, John; Niven, Scott; Sneddon, Iain. Apparatus and Method for Managed Pressure Drilling. U.S. Patent Number 8631874, filed January 6, 2011 , and published online on January 21, 2014 . Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=86&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4295&f=G&l=50&co1=AND&d=PTXT&s1=20140121.PD.&OS=ISD/20140121&RS=ISD/20140121 Keywords for this news article include: Transocean Sedco Forex Ventures Limited . Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Journal of Engineering


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