U.S. patent application number 13/808616 was filed with the patent office on 2013-05-09 for device for laser drilling.
This patent application is currently assigned to FACULDADES CATOLICAS, Associacao sem fins lucrativos, Mantenedora da Pontificia Universidade. The applicant listed for this patent is Arthur Martins Barbosa Braga, Cicero Martelli. Invention is credited to Arthur Martins Barbosa Braga, Cicero Martelli.
Application Number | 20130112478 13/808616 |
Document ID | / |
Family ID | 45440719 |
Filed Date | 2013-05-09 |
United States Patent
Application |
20130112478 |
Kind Code |
A1 |
Braga; Arthur Martins Barbosa ;
et al. |
May 9, 2013 |
DEVICE FOR LASER DRILLING
Abstract
Equipment for laser-drilling having an optical component or feed
module with a set of lasers, the active optical fiber, in the form
of hollow coil, the excitation of the laser active medium made
through the coupling of the light emitted by laser diodes inside
the active fiber, and a mechanical component that is an optic drill
bit with a hollow rigid body and an end of any geometry, the drill
bit having leaky orifices for the optical fibers connection or
bundle of optical fibers with drill bit walls and orifices to allow
the drilling and cooling fluids are released in the surface to be
drilled, the optical fibers being provided from the feed module.
The feed module generates high intensity light generation that
through optical fibers is guided to the optic drill bit. The feed
module and the optic drill bit are coupled to a drill string.
Inventors: |
Braga; Arthur Martins Barbosa;
(Rio de Janeiro, BR) ; Martelli; Cicero; (Ipanema,
BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Braga; Arthur Martins Barbosa
Martelli; Cicero |
Rio de Janeiro
Ipanema |
|
BR
BR |
|
|
Assignee: |
FACULDADES CATOLICAS, Associacao
sem fins lucrativos, Mantenedora da Pontificia Universidade
Rio de Janeiro
BR
|
Family ID: |
45440719 |
Appl. No.: |
13/808616 |
Filed: |
July 8, 2011 |
PCT Filed: |
July 8, 2011 |
PCT NO: |
PCT/BR2011/000211 |
371 Date: |
January 7, 2013 |
Current U.S.
Class: |
175/16 |
Current CPC
Class: |
G02B 6/3624 20130101;
B23K 26/0604 20130101; E21B 7/14 20130101; H01S 3/0407 20130101;
H01S 3/0007 20130101; B23K 26/382 20151001; B23K 26/40 20130101;
H01S 3/094019 20130101; H01S 3/06704 20130101; B23K 26/146
20151001; B23K 2103/50 20180801 |
Class at
Publication: |
175/16 |
International
Class: |
E21B 7/14 20060101
E21B007/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2010 |
BR |
PI 1002337-2 |
Claims
1. A device for laser-drilling, comprising: a) an optical component
or feed module, comprised of a plurality of lasers (200), each one
of the lasers (200) comprising flexible optical fiber (320), wound
in shape of hollow coil (210), and lasers diodes (220)
perpendicularly connected to the coil (210) of active fiber; and b)
a mechanical component or optic drill bit (100), the drill bit
being gifted of: a head (130) with orifices (110) and (120), and of
a body (140), wherein: i) the feed module is responsible for high
intensity light generation that through the optical fibers (320) is
guided to the optic drill bit (100), and ii) the feed module and
the optic drill bit (100) are coupled to a drill string.
2. The device, according to claim 1, wherein the lasers (200) have
a geometry to check the same modular characteristic and assembling
the said lasers above each other in the drill string.
3. The device, according to claim 1, being wherein the device is
able to accept heads (130) of any format.
4. The device, according to claim 1, wherein the optic drill bit
(100) head (130) has a spherical format.
5. The device, according to claim 4, wherein the head (130)
presents an angle that defines the operation maximum angle of the
said optic drill bit (100).
6. The device, according to claim 5, wherein the angle is
determined from a line drawn in the middle of a ball and
perpendicular to a connection direction to the optic drill bit
(100) body connection with the drill string up to the spherical
head (130) intersection with the remaining body (140) of the drill
bit (100).
7. The device, according to claim 5, further comprising providing
direction control in the drilling through the optic drill bit
format (100), wherein the operation angle control enables the said
drill bit drill orifices in the angle said, relative to a middle
line of the same.
8. The device, according to claim 1, further comprising providing,
for each point of laser light interaction with a stone to be
drilled, an optical fiber (320) supplying high intensity laser
light.
9. The device, according to claim 1, wherein each optical fiber
(320) that is associated to a laser (200) or multiple lasers (200)
is combined to produce the light for drilling.
10. The device, according to claim 1, wherein lasers (200) used in
the drilling that are embedded with the optic drill bit (100) in
the device consist of a standard tube employed in the drill
string.
11. The device, according to claim 1, further comprising lasers
individually controlled (200) that feed the points of the light
that interacts with the surface, to determine the drilling
direction turning the said lasers on or off in specific regions of
the drill bit (100) as needed.
12. The device, according to claim 1, wherein the said orifices
(110) are intended to the optical fibers connection (320) or bundle
of optical fibers with the drill bit walls (100), while the
orifices (120) allow drilling and cooling fluids to be released in
the surface to be drilled.
13. The device, according to claim 1, wherein each orifice (110)
wherein optical fibers are fixed to be perpendicular to the optic
drill bit (100) surface tangent in the point of intersection,
ensuring the light incidence perpendicular to the surface to be
drilled in the whole surface of the said optic drill bit.
14. The device, according to claim 1, wherein the number of
orifices (110) is determined from the drilled area by each optical
fiber or bundle of optical fibers such that the whole drill bit
(100) head (130) surface is able to the drilling function.
15. The device, according to claim 1, wherein the optic drill bit
(100) is a mechanical component that supports the optical fibers
(320), and provides geometrical control to the high intensity light
action and promotes the interface of the said drilling device (300)
with the surface to be drilled.
16. The device, according to claim 1, wherein the connection of the
diodes laser (220) to the coil of active fiber (210) is effected
considering the space available and the heat transfer needed to
maintain the operation temperature of the said lasers diodes
(220).
17. The device, according to claim 1, wherein alternatively diodes
laser (220) that are connected directly to optical fibers (320) and
the light generated by the same are used for drilling, dispensing
the coils (210) of fiber-laser.
18. The device, according to claim 1, wherein the operation system
is of the pulse type.
19. The device, according to claim 1, wherein the operation system
is of the ongoing type.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of equipments for
laser-drilling, and more specifically to such equipment comprising
an optical drill bit and a feed module with lasers embedded.
[0003] 2. Prior Art
[0004] A solution for the problems associated to the use of
conventional drilling equipment that employs drilling bits that
comprise one or more cutting mechanical elements was the use of
laser beams as a mean of drilling wells in the ground.
[0005] Thus, U.S. Pat. No. 3,871,485 teaches a drilling process
using a laser beam wherein a laser beam generator connected to a
voltage generator fined by drilling mud or other liquid that passes
through a laser beam slot connected to the drill string is
positioned in the wellbore and a crystal reflector is positioned
inside the laser beam slot to reflect the beam in an elliptical
format through the formation to be entered.
[0006] U.S. Pat. No. 4,066,138 teaches an apparatus to drill the
ground assembled above the ground that drives downward a high power
energy laser ring to drill a cylindrical orifice by fusing the
successive annular regions of the extraction to be entered in a
power level that smashes and ejects the orifice successive
layers.
[0007] U.S. Pat. No. 4,113,036 teaches a laser-drilling method and
system to recover fossil fuels wherein a vertical bore is drilled
in an underground formation; a laser beam is projected through the
vertical bore and reflected horizontally from the orifice through
the formation along an array of bores.
[0008] U.S. Pat. No. 4,090,572 teaches a process and apparatus for
laser-treatment of geological formations where a laser beam is
projected through a guide for the light beam in a wellbore along a
beam guide providing enough energy lasers to melt or vaporize
formations under underground conditions.
[0009] Despite all advantages associated to the use of this
drilling method, it is not based on the physical contact between
the drill bit and the surface to be drilled (among them, the
drilling speed, lack of physical contact between the drilling bit
and the surface to be drilled, energy efficiency, etc.), the lasers
utilization in drilling wells was not developed at trade levels in
function of the lack of lasers with minimal power needed for
efficient and competitive drilling when compared to mechanical
equipments.
[0010] Other problems that limited the practical implementation of
the laser-well drilling were the lasers dimensions that make its
insertion in the orifices (wells) drilled impossible as well as the
nonexistence of efficient (with low losses by constraint, high
transparency and control of susceptibility to nonlinear phenomenon
induction) optical conductors (optical fibers), that allows the
guidance of the laser light to long distances and in places with
small dimensions and difficult access.
[0011] U.S. Pat. No. 5,107,936 teaches a hot-drilling process that
employs laser beams as heat source in which the wellbore profile is
melted by the heat source and the resulting molten stone is pressed
by the neighbor side stone during the drilling process.
[0012] In the late 1990's and early 2000's compact and high power
lasers systems became commercially available and the interest in
its utilization in wells drilling is renewed. Despite the high
power lasers development (based on different types and active
materials, for example, gas, dyes, semiconductor, crystal, optical
fiber doped or not, etc.) the optical fibers development
(mono-mode, multi-mode and with several profiles of the
cross-section index of refraction and materials) with high
transparency, low losses by constraint and control of
non-linearities constitute other motivating factor to use high
intensity laser light for drilling.
[0013] With the use of optical fibers it is possible to guide the
high intensity laser light to long distances (some tens of
kilometers) and keep the laser light quality (temporal and special
intensity and coherencies) in the fiber outlet sufficiently high
ensuring the delivery of high optical densities--condition that
increases the drilling process efficiency.
[0014] In this regard, the patents literature point out the
following recent documents about the subject matter.
[0015] U.S. Pat. No. 6,365,871 relates to a laser-drilling method
through the tool as nozzle (40), in cavity that comprises the
drilling bore (41) through the tool (40) with laser (50), providing
fluid with laser barrier properties in the cavity so, when the bore
(41) is open for the cavity, the laser light passing through the
bore (41) is incident over the fluid whereby the tool (40)
transversal to the cavity from the bore (41) is protected from the
laser light, and causing the fluid does not enter in the drilled
bore (41) by laser during the drilling process. The apparatus to
perform the method is also described.
[0016] U.S. Pat. No. 6,626,249 describes the drilling and recovery
geothermal system that comprises a drilling rig having a riser with
laser and radar perforation assembled in the said elevator,
drilling pipe, rotatory mirror assembled adjacent to the lower end
of the said drilling pipe and devices to establish vacuum adjacent
to the said lower end of the drilling pipe in order to remover and
recover heat and drilling waste.
[0017] U.S. Pat. No. 6,755,262 relates to a well drilling apparatus
that can be at least partially placed in a drilling well. The
apparatus includes a plurality of optical fibers, each one of them
has an end near to the energy inlet and an end far from the energy
outlet of the optical fiber. At least a focus lens is arranged in
the far end from the optical fiber light outlet. The focus lens is
placed to receive energy from the far end from the optical fiber
light outlet corresponding to at least one optical fiber and focus
the same outward the optical fiber light outlet.
[0018] U.S. Pat. No. 6,870,128 describes the well drilling method
with laser beam, the method comprising to guide the laser beam
inside the conduit, where the laser beam is guided through the
conduit by internal reflectivity of the said conduit, and extending
the conduit inside the well, so the laser beam exiting the conduit
is guided over the area in the well to be drilled. A system for
drilling well with laser beam is equally provided, the system
comprising a device to guide the laser beam inside the conduit,
wherein the laser beam is guided through the conduit by internal
reflectivity of the said conduit, and device to extend the conduit
inside the well, so the laser beam exiting the conduit is guided to
an area in the well to be drilled. The invention further provides
an apparatus composed of conduit that can be extended inside the
well, and the surface inside the conduit, where the internal
surface is reflective to the laser beam.
[0019] U.S. Pat. No. 6,888,097 B2 describes an apparatus for
drilling well walls, the apparatus including an optical fiber cable
with an end for laser input and an end for laser output. A source
of laser is connected to the end of the laser input and a laser
head is connected to the end of the laser output. The laser head
includes a laser control component to control at least a feature of
the laser beam. Control elements in the laser head to control the
movement and localization of the laser head are connected to the
optical fiber cable. The laser head is protected in a slot that
protects the optical fiber cable and elements as reflectors and
lens to control the laser beam emitted by optical fiber cable there
arranged, from the aggressive environment found in underground
operations.
[0020] U.S. Pat. No. 7,147,064 describes a drilling apparatus to
drill a well having a drilling bit set that includes a laser
cutting mount and a vacuum mount. The vacuum mount is adapted to
collect steams generated by the laser cutting mount near the
drilling bit set during the drilling apparatus operation. Steams
collected can thus be processed by a chromatographic analyzer to
determine the features of the rock formation being drilled.
[0021] In U.S. Pat. No. 7,487,834 a method for wells drilling with
high power laser is described intended to provide a laser beam to
the well production zone to drill the coating, the cement, and to
form high permeability penetrations in the formation of stone
reservoir to increase the gas flow and/or oil to the well. The
laser beam is provided to a punch laser positioned in the
production zone by an optical fiber-cable, the cable being sloped
around 90 degrees and formatted in the desired beam orientation and
profile. A cutting nozzle in the punch end provides a cleaning flow
to 1) remove from the well droplets of molten metal, and cement and
stone broken fragments that can block the laser beam and 2) create
a free pathway through the well liquids allowing the beam to reach
the target surface during the drilling.
[0022] U.S. Pat. No. 7,416,258 describes the equipment and method
to use lasers in the stones breaking and drilling. A group of laser
beams is handled in a controlled way by an electro-optical key to
locations on the stone surface, creating multiple orifices and
removing a stone layer at the diameter desired. Only a single laser
beam irradiating about 1000 to 5000 W/cm.sup.2 breaks the stone.
The three-dimensional stone removal is performed by breaking the
consecutive layers with the laser head intermittent perpendicular
movement to the stone surface just drilled.
[0023] US Patent Publication US 20100078414 A1 relates to an
apparatus for underground drilling having at least one optical
fiber to transmit light energy from an energy laser source arranged
above the ground towards an underground drilling location and a
mechanical drill bit having at least one cutting surface and
forming at least a light transmission channel aligned to transmit
the light from at least one optical fiber through a mechanical
drill bit using at least one light transmission channel. It is
alleged the equipment developed is especially proper for non
vertical wells.
[0024] Brazilian patent published P10806638-8 (Laser drilling
system and method), of the same authors of the present document,
describes an optical drill bit (104) integrated to a laser-drilling
system. However, this patent application does not describe details
of the said drill bit.
[0025] It is important to highlight that even in the inventions
that propose the use of optical fiber(s) to delivery high intensity
laser light in regions of bottom hole there is no practical
demonstration of this possibility when fiber long passages are
considered (deep wells, i.e. >hundreds of meters). The main
reason for this is the non-linear phenomenon induction during high
intensity laser light propagation for fiber long passages, which is
responsible for mitigate the guided light, degrade fiber
transparencies and, depending on the energy density and/or peak
energy inside the fiber, can damage permanently the optical fiber.
This problem is classic in the optic guided and many research
groups and companies have been making efforts to reduce or
eliminate them. In this respect, see the summary by A. Mendes &
T. F. Morse, "Specialty Optical Fibers Handbook", Chapter 22, pp.
671-696, Elsevier Publisher, 2007.
[0026] Among several lasers technologies, it is important to
highlight the optical fiber-laser development where the high
intensity laser light is generated inside the optical fiber itself.
This laser is compact and in general does not require cooling even
when operating with high intensities (.gtoreq.kW). Furthermore, the
losses by coupling of the light in the laser outlet, with conductor
optical fiber (responsible to guide the high intensity laser light
for long distances up to the interest region) are minimal once it
is the fiber-fiber coupling and not the fiber without free
space.
[0027] Regarding the laser light wavelength, it is noted the
commercial availability of high power lasers systems with
wavelengths varied (from ultraviolet to infrared), depending on the
active element and on the laser cavity design, and lasers with
tunable wavelength. This means that, depending on the surface
material to be drilled, it is possible to use the drilling
wavelength coinciding with the absorption range of this material.
This significantly increases the process efficiency. Thus, during
the drilling it is possible to select in real time the more
appropriate laser light wavelength to the surface. This is other
technological advantage of the laser-drilling regarding a
conventional mechanical system.
[0028] Therefore, it would be advantageous that the art had one
laser-drilling equipment able to generate high intensity light,
such light being guided through optical fibers up to one optical
drill, such drill bit being the mechanical component that supports
optical fibers, provides geometrical control to high intensity
light action and promotes the drilling system interface with the
surface to be drilled.
[0029] Regarding the researched literature, no documents
anticipating or suggesting the teachings of the present invention
were obtained, so the solution here proposed has novelty and
inventive step toward to the state of the art.
BRIEF SUMMARY OF THE INVENTION
[0030] Widely, the laser-drilling equipment according to the
invention comprises:
[0031] a) An optical component or feed module, consisting of a set
of optical fiber-lasers, active, in the shape of hollow coil, the
excitation of the laser active medium being made through the
coupling of the light emitted by lasers diodes inside the active
fiber, the said diodes being connected more efficiently to the
active fiber coil considering the available space and the needed
heat transfer to maintain the diodes operation temperature; and
[0032] b) A mechanical component that is an optical drill bit with
rigid and hollow body and end of any geometry, the said drill bit
being adopted of leaky orifices for optical fibers connection or
bundle of optical fibers with drill bit walls and orifices to allow
the drilling and cooling fluids to be released in the surface to be
drilled, the optical fibers or bundle of optical fibers being
derived from the said feed module, where the feed module is
responsible for high intensity light generation that through
optical fibers is guided up to optical drill bit, the said feed
module and the optical drill bit being coupled to a drill
string.
[0033] For the said drill bit head with spherical geometry, it is
determined an angle .alpha. from the line drawn in the middle of
the ball and perpendicular to the optical drill bit body connection
direction with the drill string up to the ball intersection with
the drill bit remaining body. This angle defines the operation
maximum angle of the optical drill bit and consequently the maximum
slope of the well or drilled bore.
[0034] Thus, the invention provides an equipment for laser-drilling
where the laser system is responsible for high intensity light
generation that through optical fibers is guided up to optical
drill bit, this being the mechanical component that supports the
optical fibers, provides geometrical control to high intensity
light action and promotes the interface of the drilling system with
the surface to be drilled.
[0035] The invention further provides an equipment for
laser-drilling with a reduced number of moveable mechanic parts
present in the drilling system.
[0036] The invention provides an equipment for laser-drilling that
significantly reduces the need of drill string rotation, with large
operational advantage.
[0037] The invention also provides an equipment for laser-drilling
able to monitor the drilling process in situ, with process control
increase.
[0038] The invention further provides an equipment for
laser-drilling able to drill different materials without the need
to substitute the drill bit.
[0039] The invention also provides an equipment for laser-drilling
where depending on the material to be drilled in different
wavelengths of the laser light are triggered to increase the
drilling efficiency.
[0040] The invention further provides an equipment for
laser-drilling where it is possible to use different systems of
operation as ongoing or pulse.
[0041] The invention also provides an equipment for laser-drilling
with reduced maintenance costs.
[0042] The invention further provides an equipment for
laser-drilling where the tectonic movement risks, caused by
drilling are reduced due to the lack of contact between the optical
drill bit and the surface to be drilled.
[0043] The invention also provides an equipment for laser-drilling
where the drilling system dimensions are lower and this is also
lighter than traditional systems.
[0044] The invention further provides an equipment for
laser-drilling where generally it is possible to maintain higher
control of the drilling depth and the drilling direction.
[0045] The invention also provides an equipment for laser-drilling
where due to mechanical strength increase of the drilled well walls
against walls surface vitrification, it is reasonable to speculate
on reducing the need for coating during the drilling.
[0046] The invention further provides an equipment for
laser-drilling that allows the drilling direction control through
the drill bit format, where the angle control a enables the drill
bit drills orifices to a degrees of the drill bit middle line.
[0047] The invention also provides an equipment for laser-drilling
with lasers individual control that feed the light interaction
points with the surface, to determine the drilling direction
turning the lasers on or off in specific regions of the drill bit
as needed.
[0048] These and other objects of the invention are immediately
appreciated by those skilled in the art and by companies with
interests in the segment, and will be described in sufficient
detail to be reproduced in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is an optical drill bit section of the drilling
equipment of the invention showing the head and the body of the
same.
[0050] FIG. 2 is a view of the laser system or feed module of the
drilling equipment of the invention.
[0051] FIG. 3 is a general section of the equipment assembled in a
drill string, with feed module and optical drill bit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0052] The examples herein shown aim only to illustrate one of the
numerous ways of performing the invention, however, without
limiting the scope of the same.
[0053] Thus, the invention relates to an equipment for
laser-drilling where the laser system is responsible for high
intensity light generation that through optical fibers is guided up
to optical drill bit, this being the mechanical component that
supports optical fibers and promotes the interface of the drilling
system with the surface to be drilled.
[0054] The equipment for drilling oil wells according to the
invention, composed of feed module and optical drill bit, can be
directly integrated to drilling conventional systems and can
operate at any depth.
[0055] The feed module is fed by an electricity metal conductor,
the said module consisting of a set of lasers, that generate the
light with high intensity for drilling, and it is coupled between
the drill string and the drill bit, as can be seen in FIG. 3. The
light emitted by lasers is guided up to optical drill bit through
optical fibers.
[0056] The mechanical flexibility in the energy conduction
responsible for drilling up to optical drill bit, provided by
optical fibers allow the idealization of virtually any optical
drill bit format.
[0057] According to the present invention concept, for each point
of laser light interaction with the stone to be drilled there is an
optical fiber providing high intensity laser light. Associated to
each fiber may be a laser or multiple lasers combined producing the
light for drilling. All lasers used in the drilling are embedded
with the drill bit in the cylindrical device consisting of standard
tube employed in the drill string with internal modifications
needed to pack lasers. Thus, lasers with the support cylinder form
the feed module. Therefore, the main function of this module is
generating and supplying high intensity laser light for the optical
drill bit.
[0058] FIG. 3 shows the feed module coupled to optical drill
bit.
[0059] Advantageously, the equipment modular feature of the
invention eases the implementation of the same once each part can
be developed and tested independently. For example, it is possible
to firstly develop a modular laser that can operate inside a
cylinder and in the conditions of pressure and temperature found in
the bottom of a well and that further has conditions to generate
light energy sufficient for drilling a stone. With this laser (that
corresponds to only one point of laser light interaction with the
stone in the optical drill) it is estimated the action effective
area in the stone and consequently it is determined the number of
active points in the optical drill bit, which corresponds directly
to the number of the feed module lasers.
[0060] In addition, it is possible to evaluate constructive details
of the fiber coupling to the laser and the fiber to the optical
drill bit.
[0061] Further advantageously, i) the fact of having the laser
embedded with the optical drill bit significantly reduces the
drilling system complexity; ii) problems with the optical fiber
mechanical fragility, loss of optical properties with the hydrogen
diffusion, in the case of silica fibers, as well as limitation with
the power level transmitted over long distances (responsible for
non linear phenomenon induction), etc. are eliminated.
[0062] On the other hand, it is necessary the lasers, which will be
embedded with the drill bit, to support the operation in
unconventional conditions, high external hydrostatic pressures and
increased temperatures. In addition, they must be packed in reduced
spaces such as the interior of the drilling duct. Obviously, even
thus, lasers must have conditions to generate enough energy to
promote an efficient drilling of stones.
[0063] Based on these premises, involving operation conditions and
needed levels of energy, Applicants researches led to the
development of a laser encapsulated in the shape of ring or coil
that is presented in FIG. 2. It consists of a high power optical
fiber-laser, the laser being pumped by laser light emitting diodes.
The light emitted by many diodes is combined to excite the optical
fiber-laser active medium and then produce laser light with high
intensity and high time consistency and sine qua non spatial
condition to focus the light in the fiber outlet.
[0064] The ring or coil format with pumping diodes positioned over
a half of the ring surface checks the modular feature to the laser
project. This allows the lasers to be assembled on each other
inside the drilling duct forming the feed module, according to FIG.
2 and FIG. 3.
[0065] The ring format also enables the drilling fluid circulation
through lasers in that, besides checking the compatibility with the
remaining of the drilling system, where the fluid circulates inside
the drill string, aids in the lasers cooling.
[0066] The light generated by lasers can be guided up to the
optical drill bit by means of diffractive optical fibers which
properties are ideal to transport high densities of energy. These
fibers have also high damage resistance in its interfaces.
[0067] It is important to highlight the idea of using optical
fiber-laser pumped by diodes is simply motivated by the light
optical quality emitted by this type of lasers. An alternative for
the present invention is to connect the diodes directly to the
fiber and use the light produced by them to drill, without the need
to set up with fiber-laser.
[0068] The optical drill bit, in general, is formed by metal
structure, with specific dimensions and shapes for each drilling
process, where optical fibers that transport the high intensity
laser light are coupled in the internal wall of the said drill bit
and provide high intensity light for drilling.
[0069] The optical drill bit admits to be configured at any
dimension or physical format needed for different drilling scenes.
The end formats of the drill bit will depend on the type of ground
or stone to be drilled, the type of drilling to be performed, the
drilling diameter, the well or bore depth and the resulting
curvature and/or well or bore angle.
[0070] The optical drill bit showed in FIG. 1 is an example of the
drill bit for drilling wells with diameter of 8''. Each channel,
where optical fibers are fixed, is perpendicular to the drill bit
surface tangent in the point of intersection. This ensures that the
light focuses perpendicularly to the surface to be drilled in the
whole drill bit circumferential surface.
[0071] The number of channels to connect the fibers, i.e., points
of interaction of the laser light with the stone to be drilled,
depends on the drill bit superficial area and on the individual
efficiency of each laser in the drilling process.
[0072] The drilling efficiency is given in a simplified manner by
the mass of stone removed divided by the energy embedded in the
drilling process.
[0073] Two features of the present drill bit design allow the
direction control in the drilling. The first is through the drill
bit format. According to what is shown in FIG. 1, the spherical
symmetry of the drill bit allows, against angle control a
(constructive parameter), the drill bit drills bores at a degrees
of the drill bit middle line.
[0074] Other feature that allows the direction control is the
lasers individual control that feed the points of the light
interaction with the surface. It is possible to determine the
direction in which it is desired to drill turning the lasers on or
off in specific regions of the drill bit as needed. Thus, such as
in the perforation operations, this invention can be used to drill
bores perpendicular to the drill bit shaft, through the formation
and passing the coating and the cement region, to allow the oil or
reservoir gas flow to the coated well.
[0075] The drill bit design further foresees channels for drilling
fluid outlet as showed in FIG. 1.
Example 1
Preferred Embodiment
[0076] The invention is described in the following by reference to
the attached Figures, without, however, limiting the same to the
illustrated configurations.
[0077] FIG. 1 illustrates the optical drill bit (100) of the
equipment of the invention. In this Figure, the said drill bit has
a head (130) of any format, herein illustrated as spherical such as
a possible modality among others and a tubular body (140).
[0078] The angle .alpha. mentioned above is measured from the line
drawn in the middle of the ball and perpendicular to the direction
of the optical drill bit (100) body connection with the drill
string up to ball intersection with the drill bit remaining body.
This angle defines the operation maximum angle of the optical drill
bit (100) and consequently the maximum slope of the well or drilled
bore.
[0079] Leaky orifices are present in the drill bit (100) head
(130), being the orifices (110) employed for optical fibers
connection or bundle of optical fibers with drill bit walls and
orifices (120) to allow the drilling and cooling fluids to be
released in the surface to be drilled.
[0080] The number of orifices (110) for optical fibers connection
or bundle of optical fibers is determined from the drilled area by
each optical fiber or bundle of optical fibers so that the whole
head surface (130) in the shape of ball can have conditions to play
the role of perforating.
[0081] The drill bit inner (100) is hollow, enabling the passage of
the optical fibers or bundle of optical fibers (not represented)
conductive of optical energy for drilling and its connection to the
leaky orifices (110) and also drilling and cooling fluids flow
until to be released in the surface to be drilled by leaky orifices
(120).
[0082] FIG. 2 illustrates the lasers used in the equipment of the
invention.
[0083] For lasers (200), that are not high intensity light sources
employed in the laser-drilling, can be integrated to the drill
string, they need to be built with specific format. In addition to
being efficient high power light generation sources, lasers need to
be packed inside the drill string pipes and also allow the drilling
fluid to pass through them. The more appropriate architecture for
this type of need is the optical fiber-lasers. In this type of
lasers, the fiber doped with rare earth ion, constituting the
active medium, is flexible and can be wound forming the hollow coil
(210) as showed in FIG. 2.
[0084] The excitation of the laser active medium, the optical fiber
doped, is made through the coupling of the light emitted by lasers
diodes (220) inside the active fiber. The lasers diodes (220) are
called pumping diodes.
[0085] In the project presented in FIG. 2 the lasers diodes (220)
are perpendicularly connected to the coil (210) of active fiber.
Thus, the laser inner (200) is completely hollow. This format
mainly appreciated the thermal dissipation of the electro-optical
conversion process of the pumping diodes. This configuration uses
its own drilling fluid as control agent and temperature
stabilization.
[0086] It is further possible the specific fluids for cooling being
injected in the drill string inner to ensure the lasers temperature
control.
[0087] The lasers diodes position (220) relatively to the active
optical fiber coil (210) allow two optical fiber-lasers modules
(200) to be coupled as the indicated in FIG. 2 making the system
even more compact.
[0088] The feed module is composed of the plurality of lasers (200)
the optical fiber which the light output is taken up to optical
drill bit (100) by the optical fibers (320) (see FIG. 3).
[0089] Tens of lasers (200) can be stacked along the drill string
pipe as needed, for efficient drilling.
[0090] Each laser (200) is independently controlled enabling
different drilling systems, pulse and ongoing, for example, to be
employed in the drilling.
[0091] FIG. 3 shows the illustration of the equipment (300) concept
of the invention where can be noted: the optical drill bit (100),
the feed module formed by a set of lasers (200) and the optical
fibers (320) connecting each laser (200) to a specific point inside
the drill bit (100). Each point of connection between the drill bit
(100) and the fiber (320) is a communication channel with the drill
bit external surface (100) and is perpendicular to the surface to
be drilled, thus, the optical fiber (320) provides high intensity
light directly over the surface.
[0092] Those skilled in the art will appreciate the teachings
herein presented and will be able to reproduce the invention in the
embodiments presented and in others variants, falling within the
scope in the appended claims.
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