WO2019014428A1 - Systèmes et procédés de forage sans riser à pression gérée - Google Patents

Systèmes et procédés de forage sans riser à pression gérée Download PDF

Info

Publication number
WO2019014428A1
WO2019014428A1 PCT/US2018/041784 US2018041784W WO2019014428A1 WO 2019014428 A1 WO2019014428 A1 WO 2019014428A1 US 2018041784 W US2018041784 W US 2018041784W WO 2019014428 A1 WO2019014428 A1 WO 2019014428A1
Authority
WO
WIPO (PCT)
Prior art keywords
wellbore
drilling
annulus
fluid
drillstring
Prior art date
Application number
PCT/US2018/041784
Other languages
English (en)
Inventor
Thomas B. HOWES
Ahmed S. SHIMI
Original Assignee
Bp Corporation North America Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bp Corporation North America Inc. filed Critical Bp Corporation North America Inc.
Publication of WO2019014428A1 publication Critical patent/WO2019014428A1/fr

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
    • E21B21/001—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor specially adapted for underwater drilling
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
    • E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/12—Underwater drilling
    • E21B7/128—Underwater drilling from floating support with independent underwater anchored guide base

Definitions

  • Embodiments disclosed herein generally relate to wellbore drilling operations. More particularly, embodiments disclosed herein relate to managed pressure drilling (MPD) systems and associated methods for controlling wellbore pressure during the drilling operation.
  • MPD managed pressure drilling
  • Deepwater offshore drilling operations may encounter formations having reduced tolerances between the formation's natural pore pressure and fracture gradient (PPFG). Additionally, the effect of annular friction pressure (AFP) from the circulation of drilling fluid between a platform of the drilling system and the wellbore may increase the bottom hole pressure (BHP) in the wellbore, thereby reducing the drilling margin or tolerance between the formation's pore pressure and fracture gradient. Therefore, the ability to control loss circulation and influxes from the formation may be limited, and further, it may be necessary in some applications to isolate portions of the formation from pressure in the wellbore with planned or unplanned casing or liner strings affixed to an inner surface of the wellbore.
  • PPFG formation's natural pore pressure and fracture gradient
  • An embodiment of a method for drilling a wellbore with an offshore, riserless drilling system comprises pumping a drilling fluid from a drilling vessel down a first drillstring and into an annulus within a subterranean wellbore, pumping the drilling fluid from the annulus of the wellbore to the drilling vessel with a subsea pump, applying backpressure to the drilling fluid in the annulus of the wellbore with the subsea pump, and preventing fluid flow from the annulus of the wellbore to the surrounding environment as the drilling fluid is pumped from the drilling vessel into the annulus of wellbore.
  • the method further comprises applying backpressure to the drilling fluid with the subsea pump at the seabed.
  • the method further comprises opening a recirculation valve of a recirculation conduit extending between a suction and a discharge of the subsea pump to apply hydrostatic pressure to the drilling fluid in the annulus of the wellbore.
  • the method further comprises selectively applying hydrostatic pressure to the annulus from a column of fluid extending from the seabed.
  • the method further comprises removing the first drillstring from the wellbore, and applying hydrostatic pressure to the annulus of wellbore from the column of fluid with the first drillstring removed from the wellbore.
  • the method further comprises selectively isolating the hydrostatic pressure of the support fluid from the annulus.
  • the method further comprises isolating the annulus of the wellbore from hydrostatic pressure of seawater in the ambient environment above the seabed. In some embodiments, the method further comprises adjusting a pump rate of the subsea pump to control the amount of backpressure applied to the drilling fluid in the annulus of the wellbore. In certain embodiments, the method further comprises removing the first drillstring from the wellbore and transporting the first drillstring to the drilling vessel, and inserting a second drillstring into the wellbore as the first drillstring is being transported to the drilling vessel.
  • Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods.
  • the foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood.
  • the various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS
  • Figure 1 is a schematic view of an embodiment of a well system shown in a first configuration in accordance with principles disclosed herein;
  • Figure 2 is a schematic view of the well system of Figure 1 shown in a second configuration in accordance with principles disclosed herein;
  • Figure 3 is a schematic view of the well system of Figure 1 shown in a third configuration in accordance with principles disclosed herein;
  • Figure 4 is a schematic view of another embodiment of a well system in accordance with principles disclosed herein;
  • Figure 5 is a chart of an embodiment of a pore pressure and fracture gradient of a terranean formation of the well system of Figure 4 in accordance with principles disclosed herein;
  • Figure 6 is another schematic view of the well system of Figure 4 in accordance with principles disclosed herein.
  • the term “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to... .”
  • the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections.
  • the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis.
  • system 100 for drilling a subsea wellbore 10 that extends into a terranean formation 3 from a sea floor or seabed 5 is shown.
  • system 100 generally includes a drilling vessel or platform 102 disposed at a surface or waterline 7 of the seawater 9 (i.e. , at the waterline), a blowout preventer (BOP) stack 104 disposed at the seabed 5, and a marine riser system 106 extending between BOP stack 104 and the drilling vessel 102.
  • Wellbore 10, BOP stack 104, and riser system 106 share a common central or longitudinal axis 105.
  • drilling system 100 may comprise additional components not shown in Figure 1 , such as a subsea wellhead and a lower marine riser package (LMRP).
  • LMRP lower marine riser package
  • Drilling vessel 102 of drilling system 100 includes a drilling floor 108 and a derrick 1 10 supported on the drilling floor 108. Drilling floor 108 of vessel 102 also supports a surface pump 1 12, such as a mud pump, and a choke or choke manifold 1 14, as will be described further herein.
  • drilling vessel 102 is a floating offshore structure, and more particularly, a floating semi- submersible platform.
  • the drilling vessel e.g. , drilling vessel 102
  • Riser system 106 includes a modified riser joint 1 18 that comprises a flow spool 120, a riser annular BOP 121 , an annulus containment device 122, and a mid- riser or subsea pump 126.
  • containment device 122 is a rotating control device (RCD), and thus, may also be referred to as RCD 122.
  • RCD 122 may also be referred to as RCD 122.
  • containment device 122 may comprise other annular containment devices.
  • Riser joint 1 18, including flow spool 120, annular BOP 121 , RCD 122, and pump 126 are positioned subsea or beneath the waterline 7.
  • riser joint 1 18 is spaced from the seabed 5, with a portion of riser system 106 extending between BOP stack 104 and riser joint 1 18.
  • bypass conduit 128 extending between a first port or fluid connection 130 formed in the riser joint 1 18 and a second port or fluid connection 132 also formed in the riser joint 1 18.
  • bypass conduit 128 comprises a suction conduit 134 extending between first port 130 and a suction of subsea pump 126, and a discharge conduit 136 extending between a discharge of subsea pump 126 and second port
  • bypass conduit 128 provides a fluid conduit or passageway that extends around or bypasses RCD 122.
  • suction conduit 134 includes a first valve 134V proximal first port 130 for selectively isolating first port 130 while discharge conduit 136 includes a second valve 136V proximal second port 132 for selectively isolating second port 132.
  • a drilling fluid return conduit 138 extends between a third port or fluid connection 140 formed in the flow spool 120 of riser joint 1 18, and the choke manifold 1 14.
  • Return conduit 138 includes an actuatable return valve 138V configured to selectively isolate choke manifold 1 14 from the third port 140 of flow spool 120.
  • subsea pump 126 is a positive displacement pump.
  • drilling system 100 may include a plurality of return conduits 138 extending between flow spool 120 and choke manifold 1 14.
  • Marine riser system 106 of drilling system 100 can function as a conduit for transporting drilling fluid through seawater 9 between the drilling vessel 102 and the
  • BOP stack 104 disposed at the seabed 5. Specifically, drilling fluid is pumped from surface pump 1 12 along an inlet flowpath (indicated by arrows 20) that extends through an inlet conduit 1 16 into a central bore or passage of a tubular drillstring 142
  • drilling fluid (shown with dashed lines) that is suspended from vessel 102 and extends through marine riser system 106, BOP stack 104, and into wellbore 10.
  • the drilling fluid exits drillstring 142 via a drill bit 144 disposed at a lower end of drillstring 142, and flows into wellbore 10 proximal a lower terminal end or bottom 12 of wellbore 10.
  • the drilling fluid may then circulate upwards from wellbore 10 through an annulus 146 extending radially between drillstring 142 and the inner surfaces of wellbore 10, BOP stack 104, and riser system 106, as will be discussed further herein.
  • BOP 121 of riser joint 1 18 includes an annular member actuatable between a radially outer position allowing fluid flow through the portion of annulus 146 extending through BOP 121 and a radially inner position that sealingly engages an outer surface of drillstring 142, thereby restricting fluid flow through the portion annulus 146 formed in BOP 121 .
  • first port 130 is positioned below the annular seal provided by annular BOP 121 when the annular member thereof is in the radially inner position.
  • Drilling system 100 includes a plurality of configurations for controlling bottom- hole pressure (BHP) in wellbore 10, where each configuration provides a separate or distinct flowpath for circulating drilling and/or wellbore fluid from wellbore 10 to drilling vessel 102. More specifically, in the embodiment of Figure 1 , drilling system 100 comprises a first configuration 103 that includes a first drilling fluid return or recirculation flowpath (indicated by arrows 22 in Figure 1 ). In first configuration 103, valves 134V, 136V, 138V are each disposed in a closed position, isolating subsea pump 126 and choke manifold 1 14 from fluid flow in annulus 146.
  • BHP bottom- hole pressure
  • first drilling fluid return flowpath 22 extends entirely through annulus 146 to drilling vessel 102, where neither annular BOP 121 nor RCD 122 are in sealing engagement ith the outer surface of drillstring 142. In other words, drilling fluid flowing along first return flowpath 22 does not flow through either subsea pump 126 or choke manifold 1 14.
  • circulation of the drilling fluid along inlet flowpath 20 and return flowpath 22 is provided by surface pump 1 12.
  • BHP in wellbore 10 is provided by the hydrostatic or head pressure of the vertical column of drilling fluid extending between drilling vessel 102 and the bottom
  • BHP in wellbore 10 is only provided by the hydrostatic pressure of the vertical column of drilling fluid extending between the bottom 12 of wellbore 10 and drilling vessel 102, amounting to a loss of
  • drilling system 100 comprises a second configuration 107 that includes a second drilling fluid return or recirculation flowpath
  • an inner housing or seal assembly 124 is installed within the RCD 122 of riser joint
  • seal assembly 124 is configured to sealingly engage the outer surface of drillstring 142, including when drillstring 142 rotates within riser system 106.
  • seal assembly 124 of RCD 122 divides annulus 146 into a first or lower annulus 146A extending longitudinally between the lower terminal end of drillstring 142 disposed in wellbore 10 and seal assembly 124, and a second or upper annulus 146B extending between seal assembly 124 and the upper end of riser system 106 at drilling vessel 102.
  • the sealing engagement provided by seal assembly 124 prevents or restricts fluid communication directly between annuli 146A, 146B.
  • valves 134V, 136V each remain in the closed position while return valve 138V is actuated into the open position.
  • fluid flow between annuli 146A.146B is restricted while fluid flow from lower annulus 146B to choke manifold 1 14 is permitted via return conduit 138.
  • the annular sealing element of annular BOP 121 remains in the radially outer position to allow relative for rotation of drillstring 142.
  • drilling fluid returns to drilling vessel 102 via second return flowpath 24 which extends through lower annulus 146B, return conduit 138, and choke manifold 1 14.
  • the circulation of drilling fluid along inlet flowpath 20 and second return flowpath 24 forms a closed-loop fluid system, allowing for the rapid detection of changing fluid conditions in wellbore 10 (e.g., detection of influx or fluid loss between wellbore 10 and formation 3, etc.).
  • Choke manifold 1 14 is a fluid choke configured to provide for the rapid and controlled restriction of fluid flow (e.g., via adjusting the position of the choke) along second return flowpath 24.
  • choke manifold 1 14 allows an operator of drilling system 100 to controllably restrict or choke the flow of drilling fluid along second return flowpath 24 to rapidly control the amount of backpressure applied against the drilling fluid flowing along second return flowpath 24, including drilling fluid disposed in wellbore 10.
  • the BHP in wellbore 10 may be rapidly and precisely controlled via controlling the amount of backpressure applied to the drilling fluid flowing along second return flowpath 24 using choke manifold 1 14.
  • the rapid and precise control of BHP in wellbore 10 provided by choke manifold 1 14 may allow for the explorative drilling of terranean formations that have relatively limited or reduced drilling margins (e.g., the margin between the formation's pore pressure and fracture gradient at a given vertical depth).
  • the BHP control provided by choke manifold 1 14 may be used to maintain a relatively constant BHP that does not deviate towards either the pore or fracture pressures of formation 3.
  • choke manifold 1 14 may also be useful when reacting against rapidly changing fluid conditions in wellbore 10.
  • Choke manifold 1 14 offers the potential for some terranean formations to be drilled more economically by reducing the number of, or eliminating the use of, liner or casing strings or joints installed in wellbore 10 to isolate sections of wellbore 10 from pressure therein, where the installation of liner or casing strings generally increases the time and money necessary to drill wellbore 10.
  • drilling system 100 comprises a third configuration 109 that includes a third drilling fluid return or recirculation flowpath (indicated by arrows 26 in Figure 3).
  • seal assembly 124 remains installed within RCD 122, return valve 138V is actuated into the closed position, and valves 134V and 136V are each actuated into the open position.
  • fluid flow from lower annulus 146A to choke manifold 1 14 is restricted by the closure of return valve 138V.
  • valves 134V and 136V allows for fluid flow in lower annulus 146A to bypass seal assembly 124 via bypass conduit 128 of riser joint 1 18.
  • third configuration 109 of drilling system 100 drilling fluid returning to drilling vessel 102 from wellbore flows along third return flowpath 26 which extends through lower annulus 146B, bypass conduit 128 (thus extending around the seal formed by seal assembly 124 against drillstring 142), and upper annulus 146A to drilling vessel 102.
  • the subsea pump 126 of riser joint 1 18 is activated to pump drilling fluid from lower annulus 146A into upper annulus 146B and drilling vessel 102.
  • both surface pump 1 12 and subsea pump 126 are used to circulate the drilling fluid between drilling vessel 102 and wellbore 10 along inlet flowpath 20 and third return flowpath 26, respectively.
  • the subsea pump 126 of riser joint 1 18 may be operated in a first or pumped-riser mode and/or a second or hybrid mode. Particularly, in the pumped-riser mode of subsea pump 126, subsea pump 126 is operated consistently at the same pump rate as surface pump 1 12 to thereby compensate or reduce the effects of Equivalent Circulating Density (ECD).
  • ECD Equivalent Circulating Density
  • the AFP applied to the drilling fluid as it flows from wellbore 10 to drilling vessel 102 via riser system 106 increases the BHP in wellbore 10, a phenomenon sometimes referred to as ECD effect.
  • BHP in wellbore 10 may be maintained at or close to the equivalent static density (ESD) of the drilling fluid disposed in riser system 106.
  • ESD equivalent static density
  • a statically balanced or overbalanced mud weight (MW) may be considered a boundary condition requiring the removal or substantial reduction of the ECD effect and a BHP equivalent to the ESD of the drilling system.
  • MW statically balanced or overbalanced mud weight
  • subsea pump 126 which comprises a positive displacement pump in the embodiment of Figure 3 is operated for a predetermined period of time at a pump rate that varies from the pump rate of surface pump 1 12.
  • subsea pump 126 is operated at a pump rate less than the pump rate of surface pump 1 12 for a predetermined period of time to trap or apply backpressure to the drilling fluid flowing along third return flowpath 26 in lower annulus 146B.
  • subsea pump 126 is operated at the same pump rate as surface pump 1 12, with a predetermined amount of backpressure trapped in the drilling fluid flowing through the portion of third return flowpath 26 extending through lower annulus 146A, where the amount of backpressure trapped therein is determined by the duration of the predetermined period of time and the differential between the pump rates of pumps 126 and 1 12 during the predetermined period of time.
  • subsea pump 126 is operated at a pump rate that is 10 gallons per minute less than the pump rate of surface pump 1 12 for a period of 30 seconds, then 5 gallons of drilling fluid will be trapped in lower annulus 146A, thereby pressurizing the drilling fluid in lower annulus 146A by a predetermined amount dictated, at least in part, by the compressibility of the drilling fluid disposed therein. Further, the amount of backpressure trapped in lower annulus 146A remains trapped therein (as long as circulation of drilling fluid via pumps 1 12 and 126 is maintained) following the increase in pump rate of subsea pump 126 to match the pump rate of surface pump 1 12.
  • the amount of backpressure trapped in lower annulus 146A may be reduced or eliminated by operating subsea pump 126 at a relatively greater pump rate than surface pump 1 12 for a predetermined period of time. For instance, following from the example described above, if subsea pump 126 is operated at a pump rate that is 10 gallons per minute greater than the pump rate of surface pump 1 12 for a period of 30 seconds, then the 5 gallons of drilling fluid trapped in lower annulus 146A will be released therefrom.
  • the pump rate of subsea pump 126 may be rapidly controlled.
  • the benefits of rapid and precise control of BHP in wellbore 10 provided by second configuration 107 of Figure 2, as well as the benefit of removing or eliminating the ECD effect provided by the pumped-riser mode of subsea pump 126 of third configuration 109 may be achieved through the hybrid mode of subsea pump 126 of third configuration 109.
  • system 200 for drilling subsea wellbore 10 is shown.
  • system 200 generally includes a drilling vessel or platform 202 disposed at waterline
  • a ram blowout preventer (BOP) 204 disposed at the seabed 5
  • a flow spool 206 an annular BOP 208
  • an annular containment device 210 disposed at the seabed 5
  • a wellbore containment device 214 a subsea pump 216 disposed at the seabed 5
  • an auxiliary marine riser or conduit 218 extending from the subsea pump 216 to the drilling vessel 202.
  • Wellbore 10, ram BOP 204, flow spool 206, annular BOP 208, and containment devices 210 and 214 share a common central or longitudinal axis 205 while subsea pump 216 and auxiliary riser 218 are laterally or horizontally spaced from central axis
  • drilling system 200 may comprise additional components, such as a subsea wellhead not shown in Figure 4.
  • Drilling vessel 202 of drilling system 200 includes a drilling floor 220 and a derrick 222 supported on drilling floor 220. Drilling floor 220 also supports a surface pump 224 and an inlet fluid conduit 226 in fluid communication therewith.
  • subsea pump 216 comprises a positive displacement pump.
  • a suction conduit 228 extends between a port 230 in flow spool 204 to a suction side of subsea pump 216, where a discharge side of pump 216 feeds into a lower end of auxiliary riser 218.
  • drilling vessel 202 comprises a floating offshore structure, and more particularly, a floating semi-submersible platform, similar to the embodiment of drilling vessel 102 shown in Figure 1 .
  • drilling vessel 202 may comprise other vessels, such as drilling ships and the like.
  • drilling system 200 also includes a tubular drillstring 234 suspended from drilling vessel 202 into wellbore 10. Unlike the embodiment of drilling system 100 shown in Figures 1 -3, the drillstring 234 of drilling system 200 does not extend through a marine riser system, and thus, drilling system 200 may be described as being a "riserless" drilling system 200. Thus, at least a portion of the outer surface of drillstring 234 is directly exposed to the seawater 9 of the surrounding environment.
  • Ram BOP 204 of drilling system 200 includes one or more actuatable rams configured to seal wellbore 10 from the surrounding environment (e.g., seawater 9) in emergeny situations, including in response to the detection of a rapid influx of fluid from formation 3 into wellbore 10.
  • Annular BOP 208 includes an actuatable annular member configured to seal an annulus 236 formed between the outer surface of drillstring 234 and the inner surfaces of wellbore 10, ram BOP 204, and spool 206.
  • annular BOP 208 may be actuated when a seal assembly of annular containment device 210 is changed.
  • Flow spool 206 provides a fluid connection between annulus 236 and suction conduit 228 via port 230.
  • annular containment device 210 is an RCD including an inner housing or seal assembly 212 disposed therein and configured to seal against the outer surface of drillstring 234, including when drillstring 234 rotates within an outer housing of
  • containment device 210 may comprise other annular containment devices.
  • drillstring 234 may include an installation or running tool configured to convey and install seal assembly 212 within
  • wellbore containment device 214 is configured to prevent drilling or wellbore fluids disposed in wellbore 10 from escaping into the surrounding environment (e.g., seawater 9) when drillstring 234 is tripped out of or removed from wellbore 10, as will be discussed further herein.
  • spool 206, annular BOP 208, RCD 210, and wellbore containment device 214 are each coupled to ram BOP 204 and are disposed at or proximal the seabed 5, as shown in Figure 4.
  • drillstring 234 of drilling system 200 provides a conduit for transporting drilling fluid through seawater 9 between the drilling vessel 202 and ram BOP 204 disposed at the seabed 5.
  • drilling fluid is pumped from surface pump 224 along an inlet flowpath (indicated by arrow 30) that extends through inlet conduit 226 into a central bore or passage of drillstring 234.
  • the drilling fluid exits drillstring 234 via a drill bit 238 coupled to a lower end of drillstring 234 and flows into wellbore 10 proximal the bottom 12 of wellbore 10.
  • auxiliary riser 218 in the embodiment of Figure 4 is a marine riser, in other embodiments, auxiliary riser 218 may comprise other fluid conduits, such as tubular strings, hoses, and the like.
  • surface pump 224 pumps the drilling fluid into wellbore 10 along inlet flowpath 30 while subsea pump 216 pumps the drilling fluid from the seabed 5 to the drilling vessel 202 at the waterline 7.
  • the seal assembly 212 of RCD 210 seals against the outer surface of drillstring 234 as drillstring 234 rotates therein and the drilling fluid is circulated along flowpaths 30 and 32.
  • RCD 210 isolates the hydrostatic pressure of the column of seawater 9 extending vertically above RCD 210 from the drilling fluid disposed in wellbore 10 and annulus 236.
  • RCD 210 may transfer the force applied thereagainst by the hydrostatic pressure of seawater 9 in the ambient environment to the seabed 5 or a support structure disposed at the seabed 5. In this manner, the column of seawater 9 extending above the RCD 210 will not influence BHP in wellbore 10.
  • subsea pump 216 may be operated at the same pump rate as surface pump 224 to lift the drilling fluid flowing along return flowpath 32 to drilling vessel 202 and thereby substantially reduce or eliminate the ECD effect of the drilling fluid flowing through auxiliary riser 218.
  • subsea pump 216 in the embodiment of Figure 4 is positioned at the seabed 5, further reducing or eliminating any ECD effect of the circulating drilling fluid of drilling system 200.
  • the isolation of hydrostatic pressure of seawater 9 from the BHP in wellbore 10 prevents said hydrostatic pressure from interfering with the control of BHP in wellbore 10 by subsea pump 216.
  • subsea pump 216 may be operated in a hybrid mode to quickly and precisely control BHP in wellbore 10. For instance, subsea pump 216 may be operated at a pump rate that is less than the pump rate of surface pump 224 for a predetermined period of time to trap or apply a predetermined amount of backpressure to the drilling fluid flowing into the suction side of subsea pump 216 from wellbore 10. Following the predetermined period of time, the pump rate of subsea pump 216 may be increased to match the pump rate of surface pump 224 to thereby maintain the desired backpressure trapped in wellbore 10.
  • subsea pump 216 may be operated at a pump rate greater than the pump rate of surface pump 224 for a predetermined period of time to reduce the backpressure trapped in wellbore 10.
  • the embodiment of subsea pump 216 shown in Figure 4 may control BHP in wellbore 10 at the seabed 5.
  • a light or low density drilling fluid may be used to drill wellbore 10 relative to conventional MPD systems, such as conventional MPD systems that utilize dual gradient fluid systems to produce an annular pressure profile that resembles the PPFG trend of the terranean formation (e.g., formation 3) being drilled.
  • BHP in the wellbore 10 of drilling system 200 may be continuously managed with a low density drilling fluid (e.g. , a drilling fluid having a density approximately between 12 and 15 pounds per gallon (PPG) in some embodiments) by applying backpressure to the drilling fluid flowing along the portion of return flowpath 32 extending between wellbore 10 and suction conduit 228.
  • a low density drilling fluid e.g. , a drilling fluid having a density approximately between 12 and 15 pounds per gallon (PPG) in some embodiments
  • PPG pounds per gallon
  • BHP in wellbore 10 may be managed to provide a constant overbalance relative to the pore pressure of formation 3 with an increased margin to the fracture gradient of formation, thereby reducing the risk of lost circulation of drilling fluid to the formation 3.
  • FIG. 3 An exemplary PPFG chart 300 for the terranean formation 3 of Figure 4 is shown in Figure 5.
  • PPFG chart 300 indicates pressure (in pounds per gallon equivalent (PPGE)) on an X-axis thereof and true vertical depth (e.g., from waterline 7) on a Y-axis thereof.
  • PPFG chart 300 illustrates an exemplary pore pressure gradient 302 and an exemplary fracture pressure gradient 304 of formation 3.
  • PPGE chart 300 illustrates an exemplary BHP profile 306 of the wellbore 10 of drilling system 200.
  • BHP profile 306 must generally be maintained between the pore pressure and fracture gradients 302 and 304, respectively, to prevent either fluid influx into wellbore 10 from formation 3 or the fracturing of formation 3.
  • the active BHP control provided by subsea pump 216 allows for the BHP profile 306 to be curved as indicated by the curved sections 308 of the BHP profile 306 shown in Figure 5.
  • subsea pump 216 may be operated in the hybrid mode to periodically or intermittently trap increasing amounts of backpressure in wellbore 10 to thereby gradually increase BHP in wellbore 10 such that the curved sections 308 of BHP profile 306 mirror the curved profiles 302 and 304 of the formation 3.
  • wellbore 10 may be drilled to a greater vertical depth relative to other drilling systems, including other MPD systems (e.g., by allowing for the use of a relatively less dense drilling fluid, etc.), before a liner or casing string must be installed to isolate sections of the wellbore from fluid pressure therein.
  • the BHP control provided by subsea pump 216 may eliminate the need for installing any liner or casing strings within wellbore 10 during the drilling thereof.
  • drillstring 234 may be occasionally tripped out of wellbore 10 to allow for the installation of equipment in wellbore 10 or for other purposes, as shown in Figure 6.
  • drilling fluid may no longer be circulated between drilling vessel 202 and wellbore 10.
  • backpressure trapped in wellbore 10 from the hybrid operation of subsea pump 216 is maintained (and thus, BHP in wellbore 10 may be maintained) even when circulation of drilling fluid through inlet flowpath 30 and return flowpath 32 has ceased.
  • pressure regulator 232R when circulation of drilling fluid is ceased, pressure regulator 232R can be actuated to allow a predetermined amount of hydrostatic pressure from drilling fluid disposed in auxiliary riser 218 to be applied against the drilling fluid disposed in wellbore 10. In this manner, the BHP provided in wellbore 10 prior to the ceasing of circulation of drilling fluid through wellbore 10 may be maintained once circulation has been stopped. Additionally, pressure regulator 232R can actively control BHP in wellbore 10 during tripping of drillstring 234 by varying the amount of hydrostatic pressure applied to the fluid disposed in wellbore 10 from the column of fluid disposed in auxiliary riser 218.
  • BHP in wellbore 10 can be quickly and precisely controlled via subsea pump 216 while drilling fluid is circulated along inlet flowpath 30 and return flowpath 32 and pressure regulator 232R may be used to quickly and precisely control BHP in wellbore 10 when drilling fluid is not being circulated between drilling vessel 202 and wellbore 10.
  • wellbore containment device 214 acts to prevent fluids in wellbore 10, such as drilling or wellbore fluids, from escaping into the surrounding environment (e.g., the seawater 9).
  • wellbore containment device 214 may actively control fluid pressure therein to maintain a hydraulic or fluid barrier between the fluids of wellbore 10 and the surrounding environment.
  • wellbore containment device 214 comprises a fluid seal between the fluids of wellbore 10 and the surrounding environment.
  • drilling system 200 comprises a riserless drilling system with drillstring 234 exposed directly to the seawater 9
  • drilling system 200 may perform dual activity drilling operations with increased efficiency relative to drilling systems that include a marine riser about its respective drillstring.
  • a second drillstring (not shown) may be suspended from drilling vessel 202 that is offset from longitudinal axis 205, where a lower end of the second drillstring is positioned proximal the seabed 5.
  • the second drillstring may be repositioned (e.g., by laterally repositioning drilling vessel 202 relative wellbore 10) to align with longitudinal axis 205, and tripped-in or inserted into containment device 214 and wellbore 10. In this manner, the second drillstring may be inserted into wellbore 10 as the drillstring 234 is tripped towards the drilling floor 220 of drilling vessel 202, thereby reducing the time required for performing the dual activity operation.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Mechanical Engineering (AREA)
  • Earth Drilling (AREA)

Abstract

Cette invention concerne un procédé de forage d'un puits de forage avec un système de forage en mer sans riser, le procédé comprenant le pompage d'un fluide de forage à partir d'un navire de forage vers le bas d'un premier train de tiges de forage et dans un espace annulaire à l'intérieur d'un puits de forage souterrain, le pompage du fluide de forage de l'espace annulaire du puits de forage vers le navire de forage avec une pompe sous-marine, l'application d'une contre-pression au fluide de forage dans l'espace annulaire du puits de forage avec la pompe sous-marine, et le blocage d'un écoulement de fluide de l'espace annulaire du puits de forage vers l'environnement ambiant lorsque le fluide de forage est pompé à partir du navire de forage dans l'espace annulaire du puits de forage.
PCT/US2018/041784 2017-07-14 2018-07-12 Systèmes et procédés de forage sans riser à pression gérée WO2019014428A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201762532655P 2017-07-14 2017-07-14
US62/532,655 2017-07-14

Publications (1)

Publication Number Publication Date
WO2019014428A1 true WO2019014428A1 (fr) 2019-01-17

Family

ID=63036516

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2018/041784 WO2019014428A1 (fr) 2017-07-14 2018-07-12 Systèmes et procédés de forage sans riser à pression gérée

Country Status (1)

Country Link
WO (1) WO2019014428A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021086200A1 (fr) * 2019-10-30 2021-05-06 Enhanced Drilling As Agencement et procédés de colonne montante à pompage multimode
WO2023073022A1 (fr) * 2021-10-28 2023-05-04 Noble Drilling A/S Ensemble tête de puits sous-marin destiné à être utilisé dans des opérations de forage sans colonne montante

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090236144A1 (en) * 2006-02-09 2009-09-24 Todd Richard J Managed pressure and/or temperature drilling system and method
WO2012003101A2 (fr) * 2010-07-01 2012-01-05 Agr Subsea A.S. Système et procédé permettant de réguler la pression dans un puits de forage
US20120227978A1 (en) * 2009-11-10 2012-09-13 Ocean Riser Systems As System and method for drilling a subsea well
US20150275602A1 (en) * 2012-06-01 2015-10-01 Statoil Petroleum As Apparatus and method for controlling pressure in a borehole
US20170175466A1 (en) * 2014-04-15 2017-06-22 Halliburton Energy Services, Inc. Forming a subsea wellbore

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090236144A1 (en) * 2006-02-09 2009-09-24 Todd Richard J Managed pressure and/or temperature drilling system and method
US20120227978A1 (en) * 2009-11-10 2012-09-13 Ocean Riser Systems As System and method for drilling a subsea well
WO2012003101A2 (fr) * 2010-07-01 2012-01-05 Agr Subsea A.S. Système et procédé permettant de réguler la pression dans un puits de forage
US20150275602A1 (en) * 2012-06-01 2015-10-01 Statoil Petroleum As Apparatus and method for controlling pressure in a borehole
US20170175466A1 (en) * 2014-04-15 2017-06-22 Halliburton Energy Services, Inc. Forming a subsea wellbore

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021086200A1 (fr) * 2019-10-30 2021-05-06 Enhanced Drilling As Agencement et procédés de colonne montante à pompage multimode
GB2605287A (en) * 2019-10-30 2022-09-28 Enhanced Drilling As Multi-mode pumped riser arrangement and methods
GB2605287B (en) * 2019-10-30 2024-01-31 Enhanced Drilling As Multi-mode pumped riser arrangement and methods
US11891861B2 (en) 2019-10-30 2024-02-06 Enhanced Drilling As Multi-mode pumped riser arrangement and methods
WO2023073022A1 (fr) * 2021-10-28 2023-05-04 Noble Drilling A/S Ensemble tête de puits sous-marin destiné à être utilisé dans des opérations de forage sans colonne montante

Similar Documents

Publication Publication Date Title
US9816323B2 (en) Systems and methods for subsea drilling
EP2900898B1 (fr) Procédé de forage pour forer un trou de forage souterrain
EP2499328B1 (fr) Système et procédé pour le forage d'un puits sous-marin
CA2881416C (fr) Systeme de forage a regulation de la pression dote d'un mode de controle du puits
US10920507B2 (en) Drilling system and method
US6571873B2 (en) Method for controlling bottom-hole pressure during dual-gradient drilling
WO2019014431A1 (fr) Systèmes et procédés de forage à pression gérée de façon hybride
US9068420B2 (en) Device and method for controlling return flow from a bore hole
US10273766B1 (en) Plug and play connection system for a below-tension-ring managed pressure drilling system
US20060180312A1 (en) Displacement annular swivel
WO2019014428A1 (fr) Systèmes et procédés de forage sans riser à pression gérée
US10435980B2 (en) Integrated rotating control device and gas handling system for a marine drilling system
US20170175466A1 (en) Forming a subsea wellbore
US11585171B2 (en) Managed pressure drilling systems and methods
NO20210037A1 (fr)
Saptharishi Optimization of Well Performance by Dual Gradient Drilling-A Literature Analysis

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18746544

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18746544

Country of ref document: EP

Kind code of ref document: A1