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
  • E21B7/00—Special methods or apparatus for drilling
  • E21B7/24—Drilling using vibrating or oscillating means, e.g. out-of-balance masses
• • 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
  • E21B23/00—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells
  • E21B23/001—Self-propelling systems or apparatus, e.g. for moving tools within the horizontal portion of a borehole
• • 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
  • E21B28/00—Vibration generating arrangements for boreholes or wells, e.g. for stimulating production
• • 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
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
  • E21B33/14—Methods or devices for cementing, for plugging holes, crevices or the like for cementing casings into boreholes

Definitions

• This application relates to the drilling of an earthen bore, cementing of a casing in an earthen bore, improving drill bit service life and improving bonding between a cement liner installed around a casing in an earthen bore.
• a drill string may comprise slick (i.e., constant diameter) drill collars or enlarged (relative to the mid-section of the joints) drill collars.
• the drill bit is coupled to a casing. Drill cuttings are removed from the bore by circulating drilling fluid through a fluid passage in the drill string (which, in drilling applications, may be a drill string or a casing) to the drill bit, and back to the surface through an annulus between the drill stringand the earthen bore.
• the drill string advances through the bore at a rate of penetration of the drill bit.
• the drill string may rotate along with the drill bit.
• the drill bit may rotate independently of the drill string using a bottom hole assembly (BHA) that includes a mud motor powered by pressurized drilling fluid to rotate the drill bit.
• BHA bottom hole assembly
• the weight or load imparted to the drill bit by the drill string is a factor that determines the rate of penetration.
• An attempt to stabilize the rate of advance of a drill string through a bore having a highly deviated section uses an oscillating valve disposed within a BHA coupled to the drill string. Pressurized drilling fluid may be pumped through the fluid passage in the drill string to drive the oscillating valve to vibrate the BHA and reduce frictional resistance to advance of the drill string through the bore.
• An oscillating valve powered by pressurized drilling fluid may consume a substantial portion of the mechanical energy provided to the BHA, leaving less mechanical energy to drive the mud motor and/or to circulate and remove drill cuttings.
• a float device such as a float shoe or a float collar, may be coupled to the casing, and the casing may be run into the bore and positioned within a targeted interval.
• the casing may also be radially positioned (or "centered") within the bore using casing centralizers, such as bow spring centralizers, coupled at intervals along the casing to provide an annulus between the casing and the bore.
• casing centralizers such as bow spring centralizers
• Cement slurry is pumped through the casing with cementing plugs to facilitate displacement of the slurry through the float device and into the annulus.
• the cement slurry solidifies to provide a protective cement liner around the casing.
• an inner cementing string may be run through the casing and stung into a mandrel, for example, a mandrel in a float device, and cement slurry may be delivered through the inner cementing string and the float device to the annulus.
• the quality of the cement liner may be improved by conditioning the cement slurry within the annulus while and/or or after the cement slurry is displaced into the annulus.
• the cement slurry may be conditioned by agitation to induce turbulent fluid flow, disrupt fluid channeling and promote bonding of the cement liner to the bore.
• Reciprocation and/or rotation of the casing using the drilling rig are conventional methods of agitating a cement slurry.
• casing In substantially vertical bores, where casing hangs primarily in tension, casing is more easily reciprocated and/or rotated within the bore.
• reciprocating or rotating the casing may be difficult because the weight of the casing (and contents) bears heavily on the floor, or downwardly disposed side, of the bore.
• casing rotation and/or reciprocation within a highly deviated section of a bore causes unwanted wear and stress on the casing, on the casing centralizers and on rig equipment used to move the casing within the bore.
• a first aspect of the invention is a method of stabilizing drill bit loading to extend the usable life of a drill bit comprising the steps of coupling a drill bit to a drill string (which may be a casing used in a casing while drilling application), coupling a vibration generator to the drill string, coupling a power source, such as a battery, to the vibration generator, running the drill string into a bore to engage the drill bit with an end of the bore, rotating the drill bit to extend the bore, and activating the vibration generator to vibrate a portion of the drill string within a highly deviated section of the bore to reduce frictional resistance to advance of the drill string and thereby stabilize drill bit loading.
• a drill string which may be a casing used in a casing while drilling application
• a vibration generator to the drill string
• a power source such as a battery
• a second aspect of the invention is a method of reducing frictional resistance to advance of a tubular through a highly deviated section of a drilled earthen bore comprising the steps of coupling a vibration generator to the tubular, e.g., a casing, coupling a power source, such as a battery, to the vibration generator, running the tubular into a bore, and activating the vibration generator to vibrate a portion of the tubular within a highly deviated section of the bore to reduce frictional resistance to advance of the casing and thereby stabilize advance of the casing through the bore towards the targeted interval.
• a vibration generator to the tubular
• a power source such as a battery
• a float device such as a float shoe or a float collar
• the vibration generator used in the first, second and third aspects described above may be activatable using a pressure sensor disposed in communication with the power source to detect an activating condition.
• a pressure sensor may be disposed to detect the pressure in a fluid passage in the drill string, the casing, in a sub or in the float device.
• the pressure sensor may be coupled to a microprocessor programmed to monitor readings of the pressure sensor and to recognize an activating condition or sequence.
• the pressure sensor may detect a first predetermined pressure threshold, followed by a pressure trough lasting for a predetermined interval of time, followed by a second predetermined pressure threshold, altogether comprising a sequence of events recognizable by the microprocessor.
• the microprocessor may close an electrical circuit to provide current from the a power source to a motor to activate the vibration generator. A subsequent predetermined event or sequence may be used to deactivate the vibration generator.
• a method of conditioning a cement slurry may comprise coupling the vibration generator to a float device, such as a float shoe or float collar.
• Another embodiment of the method of conditioning a cement slurry may comprise coupling the vibration generator to one or more drillable components, such as a float device, so that the vibration generator and the float device may be drilled or destroyed to provide an unrestricted passage through the casing to facilitate further extension of the bore after the cementing step.
• the frame may then be coupled to a drill string (as in the first aspect), a casing (as in the second aspect) being used for drilling, or a casing (as in the third aspect) being cemented within a targeted interval of a bore, run into the bore, and the apparatus may then be activated, for example, using the method described in the fourth, fifth and sixth aspects, to impart vibrations to the frame to stabilize the advance of a tubular (as in the first and second aspects) and/or condition a cement slurry (as in the third aspect).
• a power source for providing energy to a motor may, in one embodiment, comprise a battery having a high power-density including, but not limited to, a nickel- cadmium battery, a nickel-metal-hydride battery or a lithium-ion battery. While high power-density batteries may provide for optimal performance of the vibration generator, a conventional lead acid battery may also be used.
• a mass to be spun to produce vibrations may, in one embodiment, comprise an elongate member of a high density material, such as lead, or it may comprise a substrate to which weighted attachments are secured to provide a mass center offset from an axis about which the mass is spun. It will be understood that factors affecting the frequency and magnitude of vibrations includes the weight of the mass, the offset between the axis of rotation and the mass center, the angular velocity of spinning of the mass and the relative size of the sub, float device or other frame to which the mass is secured.
• FIG. 1 is an illustration of a drilling rig on the earth's surface and a drill string extending from the rig into an earthen bore.
• Fig. IA is a section view taken at position 1A-1A along the drill string of Fig. 1.
• Fig. 2 is a section view of one embodiment of a vibrating sub having a vibration generator and coupled within a drill string adjacent a drill bit.
• FIG. 3 is an illustration of a drilling rig on the earth's surface and a casing being installed in a targeted interval in a highly deviated section of the bore.
• Fig. 3A is a section view taken at position 3A-3A along the casing of Fig. 3.
• Fig. 4 is a section view of an alternate embodiment of a drill sub having a vibration generator.
• Fig. 5 is a section view of an embodiment of a float device having a vibration generator.
• Fig. 1 is an illustration of a drilling rig 1 on the earth's surface 5 and a tubular 8 extending from the rig 1 into an earthen bore 2 drilled into the earth's crust 3.
• a drill bit 50 and a vibration generator 10 are coupled to the tubular 8.
• the vibration generator 10 is illustrated in Fig. 1 as being disposed within a highly deviated section 7 of the bore 2.
• a highly deviated section 7 is a section of the bore 2 disposed at a substantial angle from vertical.
• the highly deviated section may be horizontal.
• the tubular 8 in Fig. 1 may comprise a drill string or a casing, the latter being likely in casing while drilling applications.
• Fig. IA is a section view taken at position 1A-1A on Fig. 1.
• Fig. IA illustrates the nature of the frictional resistance to advance of the tubular 8 and a bore 2 in a highly deviated section (see reference number 7 of Fig. IA) of the bore 2.
• Fig. IA illustrates how the weight of the tubular 8 (and contents) bears downwardly on the supporting floor, or downwardly disposed side, of the bore 2.
• the large reaction force applied by the bore 2 to support the tubular 8 substantially increases frictional resistance to advance of the tubular 8 through the bore 2.
• Fig. 2 is an enlarged section view of the embodiment of the vibration generator 10 of Fig. 1 comprising a sub 12 having a first threaded connection 12A, a second threaded connection 12B, and a fluid passage 22 therebetween.
• the fluid passage 22 illustrated in Fig. 2 deviates from an axis 88 of the tubular 8.
• the first threaded connection 12A of the sub 12 is coupled to a mating connection 8A of an adjacent tubular segment 8B of the tubular 8
• the second threaded connection 12B of the sub 12 is coupled to a mating connection 5OA of the drill bit 50 (not shown in section) disposed against the end 2A of the bore 2.
• a mass 14 rotatably coupled to the sub 12, a motor 18 coupled to the mass 14 and a power source 20 coupled to the motor 18 through electrical conduit 29.
• Activation of the motor 18 using the power source 20 spins the mass 14 on an axis including the axle first portion 14A and axle second portion 14B, but offset from a mass center 14C.
• FIG. 3 is an illustration of a drilling rig 1 on the earth's surface 5 and a casing 30 disposed in a targeted interval in a highly deviated section 7 of the bore 2.
• a plurality of centralizers 52 are received on the casing 30 at intervals along the casing 30 to provide an annulus 28 between the casing 30 and the bore 2.
• a float device 60 is coupled to the casing 30 to facilitate displacement of cement slurry from a fluid passage (not shown) within the casing 30 and into the annulus 28.
• Fig. 3A is a section view taken at position 3A-3A along the casing of Fig. 3 and illustrates the stand-off between the casing 30 and the bore 2 provided by the bow springs 52a of the centralizer 52.
• the resulting annulus 28 receives a cement slurry 69 therein to form a cement liner upon curing of the cement slurry.
• vibration of the casing 30, especially vibration having a radial displacement as will be generated by the apparatus illustrated in Figs. 3, 4 and 5, will condition the cement slurry 69 within the annulus 28 and promote improved cement liner bonding to the bore 2.
• Fig. 4 is a section view of an alternate embodiment of a vibration generator 30 comprising a sub 32 having a first connection 3OA with threads 31A, a second connection 3OB with threads 31B, a fluid passage 42 therebetween, and a vibration generator 30 comprising a mass 34, a motor 38 coupled to the mass 34, and a power source 40 coupled to the motor 38 through an electrical conduit 49.
• Activation of the motor 38 using the power source 40 spins the mass 34 on an axis including axle first portion 34A and axle second portion 34B but offset from a mass center 34C to vibrate the sub 32 and a tubular (not shown in Fig. 4 — see Fig. 3).
• Fig. 5 is an enlarged section view of the float device 62 of Fig. 3.
• the float device 62 comprises a threaded connection 6OA at which it may be coupled to a casing (see Fig. 3 - float device is illustrated in Fig. 5 decoupled from the casing).
• the float device 62 further comprises a vibration generator comprising a mass 66 rotatably coupled to the float device 62, a motor 68 coupled to the mass 66, and a power source 64 coupled to the motor 68.
• Activation of the motor 68 using the power source 64 spins the mass 66 about an axis including axle first portion 66A and axle second portion 66B but offset from a mass center 66C.
• the float device 62 of Fig. 5 further comprises a module 67 comprising a pressure sensor and a microprocessor.
• the module 67 is in fluid communication with a fluid passage inlet 61 within the threaded connection 6OA through a channel 67A in the float device 62.
• the fluid passage inlet 61 is separated from a fluid passage outlet 63 by a check valve comprising a ball 57 movably captured between a restriction 59 and a spring 58.
• the ball 57 is disposed by the spring 58 against the restriction 59 to prevent flow through the restriction 59 until the pressure in the fluid passage inlet 61 exceeds the pressure in the fluid passage outlet 63 by a differential that is sufficient to overcome the force of the spring 58 against the ball 57, at which time fluid (not shown) will flow from the fluid passage inlet 61, past the ball 57, through the fluid passage outlet 63 and through the exit port 74.
• the float device 62 prevents fluid within the bore 2 (see Fig. 3) from flowing into the fluid passage inlet 61 and entering the casing 30 (see Fig. 3).

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (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)
• Earth Drilling (AREA)
• Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)

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• 2010
  • 2010-02-26 CA CA2753595A patent/CA2753595A1/en not_active Abandoned
  • 2010-02-26 US US12/714,157 patent/US20100212901A1/en not_active Abandoned
  • 2010-02-26 EP EP10706123A patent/EP2401465A2/de not_active Withdrawn
  • 2010-02-26 WO PCT/US2010/025622 patent/WO2010099465A2/en active Application Filing

Non-Patent Citations (1)

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