WO2005110020A2

WO2005110020A2 - Apparatus and method for modified horizontal directional drilling assembly

Info

Publication number: WO2005110020A2
Application number: PCT/US2005/014594
Authority: WO
Inventors: William G. Riel
Original assignee: Astec Industries, Inc.
Priority date: 2004-04-30
Filing date: 2005-04-28
Publication date: 2005-11-24
Also published as: EP1751390A4; RU2006142361A; CA2564357C; AU2005244146B2; ATE519919T1; EP1751390A2; CA2564357A1; CN1985066B; CN1985066A; EP1751390B1; WO2005110020A3; ES2371349T3; AU2005244146A1; RU2382165C2

Abstract

An apparatus and method for a modified horizontal directional drilling assembly for drilling pipe into a drilling surface. The drilling assembly comprises a power unit for supplying power to the assembly, a thrust frame adapted to be moved between a position substantially parallel to the drilling surface and a position substantially perpendicular to the drilling surface and a means for moving the thrust frame. The rotary and carriage assembly is adapted to apply rotational, thrust and pull-back forces to the drill pipe. The drilling assembly is adapted to drill pipe into the drilling surface at any angle relative to the drilling surface between substantially parallel to the drilling surface and substantially perpendicular to the drilling surface. The method includes the steps of placing a drill pipe onto the drilling assembly, moving the thrust frame to a desired drilling angle, moving the rotary and carriage assembly into direct contact with the drill pipe, applying rotational, thrust and pull-back forces to the drill pipe, and drilling the pipe into the drilling surface.

Description

APPARATUS AND METHOD FOR MODIFIED HORIZONTAL DIRECTIONAL DRILLING ASSEMBLY

FIELD OF THE INVENTION

This invention relates generally to assemblies and methods for subsurface drilling, and

particularly to assemblies and methods for horizontal directional and vertical subsurface drilling.

BACKGROUND AND DESCRIPTION OF THE PRIOR ART It is known to use a vertical drilling rig in oil, gas and coal bed methane well drilling.

Conventional vertical drilling rigs use heavy drill pipe or drill collars in order to exert downward

force on the drill bit as it enters the earth's surface and begins the well bore. As the drill bit of

the conventional vertical drilling rig drills deeper below the earth's surface, it is sometimes necessary to apply force in the opposite direction of the drilling direction (pull-back force) in order to prevent placing too much weight on the drill bit and causing damage to or failure of the

drill bit.

It is also known to drill oil, gas and methane wells in a vertical direction initially and then

deviate or turn the well bore in increments toward a horizontal direction as the drill bit reaches

the target formation. The bore hole is then continued in the horizontal direction for a distance. This method exposes a greater volume ofthe oil, gas and methane producing formation to the

well bore and produces a higher and longer producing well. In order to covert a vertical drilling

rig to accomplish the combination vertical-horizontal drilling, it is necessary to retrofit the

vertical drilling rig with a top drive adapted to fit into the derrick structure and provide rotational

force to the drill pipe, rather than just a rotary table and Kelly bar. Conventionally, a rotary table is fixed to the drill rig floor or base such that it does not move up and down with the drill pipe.

A heavy fluted round piece of drill pipe called a Kelly bar slides through the rotary table opening

and connects to the drill pipe or casing. The keys that engage with the Kelly bar impart the

torque to the drill pipe string and permit the Kelly bar to raise and lower through the rotary table

opening. The top drive also provides thrust and pull-back forces which are needed while drilling

in the horizontal direction. However, the distances of the horizontal runs produced by

conventional devices and methods are limited by the capability ofthe top drive to apply thrust and pull-back forces to the drill pipe. The diameters of the horizontal runs are also limited by the ability to apply thrust and pull-back forces to the drill pipe.

It is also known to use a variation ofthe vertical-horizontal drilling method described above

which is called slant drilling. In slant drilling, a vertical oil, gas, methane drilling rig is

retrofitted such that the derrick is disposed at an angle, e.g., 45° to 60° from horizontal. A top

drive applies the rotational, thrust and pull-back forces to the drill pipe. It is further known to

use drilling rigs commonly known as super singles for subsurface drilling applications relating to

oil, gas and methane. Super single drilling rigs utilize longer Range III drill pipe lengths which

are 45 feet in length. Super single drilling rigs, therefore, reduce the number of tool joint connections that are required to be made during a subsurface drilling operation. Consequently, the drilling process can be completed more quickly. Super singles utilize a top drive to rotate the

drill pipe, to provide the thrust needed for the drill bit to cut and to control the steering of the cutting assembly. Conventional super singles include top drive units having limited thrust capacity and limited rotary torque capacity. Thus, the horizontal distances and bore hole

diameter that may be achieved using a super single are limited. Still further, conventional drilling rigs include power units that are separate from the drilling

apparatus and therefore require multiple truckloads to transport the drill rig. Conventional oil,

gas and methane drilling assemblies are not anchored to the ground so as to increase

performance specifications. Instead, conventional drilling rigs use their own weight to control

the machine performance specifications. As a result, convention drilling machines are very

heavy and require multiple truckloads to transport. Conventional oil, gas and methane drilling rigs also use heavy weighted drill collars in the drill pipe string in order to provide the thrust

force to the drill pipe and a winch and cable system to provide the pull-back force. Weighted

drill collars, however, are not effective in the horizontal direction. Some conventional oil, gas

and methane drilling rigs use hydraulic cylinders to provide the trust and pull-back forces. Further, conventional oil, gas and methane machines frequently damage the threaded end of a

drill string section when the top drive or rotary table engages the threaded end ofthe drill string

section.

Still further, conventional drilling assemblies do not include a roller drill pipe guide bushing assembly adapted to reduce the wear and damage to the drill pipe string. Conventional drilling

assemblies do not include automated drill pipe slips adapted to reduce the amount of time

required to perform make-up and break-out operations on the drill pipe and/or casing tool joints.

Conventional drilling assemblies do not include pipe handling arms adapted to be pinned to the sub-stmcture for easy removal during transport. Conventional drilling assemblies do not include

a positive rack and pinion carriage (top drive) system which is adapted to provide thrust and pull- back forces to the drill pipe string and eliminate the need for cables, winches, hydraulic cylinders, chain systems and the like to provide such forces. Conventional drilling assemblies

also do not include a slip spindle sub assembly which is incorporated into the top drive system

and adapted to reduce damage and wear to the drill pipe or casing thread.

It would be desirable therefore, if a drilling assembly could be provided that would produce an

increased capacity for drill pipe rotational, thrust and pull-back forces. It would also be desirable if a drilling assembly could be provided that would produce longer well bores and well bores

having a greater diameter than those produced by conventional drilling assemblies. It would also

be desirable if a drilling assembly could be provided that would be capable of entering the earth

and drilling a well bore at an angle steeper than conventional horizontal directional drill assemblies. It would also be desirable if a drilling assembly could be provided that would be

capable of entering the earth and drilling a well bore at an angle closer to horizontal than

conventional vertical drill assemblies. It would also be desirable if a drilling assembly could be

provided that would eliminate the need for heavy drill pipe or drill collars to exert downward

force on the drill bit. It would also be desirable if a drilling assembly could be provided that would be more easily transported. It would also be desirable if a drilling assembly could be provided that is adapted to be anchored to the ground so as to increase performance

specifications. It would also be desirable if a drilling assembly could be provided that would eliminate the need for cables, winches, hydraulic cylinders, chain systems and the like to provide

rotational, thrust and pull-back forces. It would be desirable if a drilling assembly could be provided that would reduce the damage and wear to the threaded end of a drill string section

when the top drive or rotary table engages the threaded end of the drill string section. It would

be desirable if a drilling assembly could be provided that would reduce the amount of time required to perform make-up and break-out operations on the drill pipe and/or casing tool joints. It would be desirable if a drilling assembly could be provided that includes pipe handling arms adapted to be pinned to the sub-structure for easy removal during transport. It would be

desirable if a drilling assembly could be provided that is adapted to perform vertical and horizontal drilling applications with a tube-in-tube drill string. It would also be desirable if a drilling assembly could be provided that would be adapted to continue operations in the event of a power unit failure.

ADVANTAGES OF THE INVENTION

Among the advantages of the invention is to provide a drilling assembly that produces an increased capacity for drill pipe rotational, thrust and pull-back forces. It is also an advantage of the invention to provide a drilling assembly that is capable of producing longer well bores and well bores having a greater diameter than those produced by conventional drilling assemblies. It another advantage ofthe invention to provide a drilling assembly that is capable of entering the earth and drilling a well bore at an angle steeper than conventional horizontal directional drill assemblies. It is still another advantage of the invention to provide a drilling assembly that is capable of entering the earth and drilling a well bore at an angle closer to horizontal than conventional vertical drill assemblies. It is yet another advantage of the invention to provide a drilling assembly that eliminates the need for heavy drill pipe or drill collars to exert downward force on the drill bit. It is a further advantage of the invention to provide a drilling assembly that is more easily transported. It is a still further advantage of the invention to provide a drilling assembly that may be anchored to the ground so as to increase performance specifications. It is also an advantage of the invention to provide a drilling assembly that eliminates the need for cables, winches, hydraulic cylinders, chain systems and the like to provide rotational, thrust and

pull-back forces. It is also an advantage of the invention to provide a drilling assembly that

reduces the damage and wear to the threaded end of a drill string section when the top drive or

rotary table engages the threaded end of the drill string section. It another advantage ofthe

invention to provide a drilling assembly that reduces the amount of time required to perform

make-up and break-out operations on the drill pipe and/or casing tool joints. It is a further

advantage of the invention to provide a drilling assembly that includes pipe handling arms adapted to be pinned to the sub-structure for easy removal during transport. It is a still further

advantage ofthe invention to provide a drilling assembly that is adapted to perform vertical and horizontal drilling applications with a tube-in-tube drill pipe or a tube-in-tube drill pipe string. It

is another advantage ofthe invention to provide a drilling assembly that may be continuously

operated in the event of a power unit failure.

Additional advantages of this invention will become apparent from an examination of the

drawings and the ensuing description.

EXPLANATION OFTECHNICAL TERMS

As used herein, the term "drilling a drill pipe into a drilling surface" includes drilling a bore hole into which a drill pipe or a drill pipe string is pulled. The term "drilling a drill pipe into a

drilling surface" also includes pulling the drill pipe or the drill pipe string out of the bore hole.

As used herein, the term "drilling surface" includes the Earth's subsurface strata and any other

medium into which a bore hole may be drilled. As used herein, the term "hydraulic actuator" includes hydraulic cylinders, hydraulic rotary actuators, pneumatic cylinders and any other device or system in which pressurized fluid is used to impart a mechanical force.

As used herein, the term "tube-in-tube" refers to a type of drill pipe or drill pipe string characterized by an outer drill pipe wall and a substantially axially positioned inner drill pipe wall that is substantially suπounded by the outer drill pipe wall.

SUMMARY OF THE INVENTION

The apparatus claimed herein comprises a modified horizontal directional drilling assembly for

drilling pipe into a drilling surface. The drilling assembly comprises a power unit for supplying power to the assembly, a thrust frame adapted to be moved between a position substantially parallel to the drilling surface and a position substantially perpendicular to the drilling surface

and a means for moving the thrust frame. The drilling assembly further comprises a rotary and

carriage assembly mounted on the thrust frame. The rotary and carriage assembly is adapted to

apply rotational, thrust and pull-back forces to the drill pipe. The drilling assembly is adapted to drill pipe into the drilling surface at any angle relative to the drilling surface between

substantially parallel to the drilling surface and substantially perpendicular to the drilling surface.

The method for drilling pipe into a drilling surface claimed herein comprises providing a

modified horizontal directional drilling assembly. The drilling assembly comprises a power unit

for supplying power to the assembly, a thrust frame adapted to be moved between a position substantially parallel to the drilling surface and a position substantially perpendicular to the

drilling surface, a means for moving the thrust frame, and a rotary and carriage assembly

mounted on the thrust frame. The rotary and carriage assembly is adapted to apply rotational,

thrust and pull-back forces to the drill pipe. The drilling assembly is adapted to drill pipe into

the drilling surface at any angle relative to the drilling surface between substantially parallel to

the drilling surface and substantially perpendicular to the drilling surface. The method further

comprises placing a drill pipe onto the drilling assembly, moving the thrust frame to a desired drilling angle, moving the rotary and carriage assembly into direct contact with the drill pipe,

applying rotational, thrust and pull-back forces to the drill pipe, and drilling the pipe into the

drilling surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The presently preferred embodiments of the invention are illustrated in the accompanying

drawings, in which like reference numerals represent like parts throughout, and in which:

Figure 1 is a side view of a prefeπed embodiment of the modified horizontal directional drilling

assembly in accordance with the present invention illustrating the drilling assembly in a retracted

transport position approaching a drilling site.

Figure 2 is a side view ofthe preferred modified horizontal directional drilling assembly shown

in Figure 1 illustrating the drilling assembly in a retracted transport position on a prefeπed sub¬

structure. Figure 3 is a side view of the prefeπed modified horizontal directional drilling assembly shown in Figures 1-2 illustrating the drilling assembly in a vertical subsurface drilling position with the drill pipe in a horizontal stored position.

Figure 4 is a top view of the prefeπed modified horizontal directional drilling assembly shown in Figure 3.

Figure 5 is a side view ofthe prefeπed modified horizontal directional drilling assembly shown

in Figures 1-4 illustrating the drilling assembly in a vertical subsurface drilling position with the drill pipe in a vertical drilling position and illustrating a prefeπed anchoring system.

Figure 6 is a side view of the prefeπed embodiment of the modified horizontal directional

drilling assembly shown in Figures 1-5 illustrating the drilling assembly in a 45° angle slant subsurface drilling position with the drill pipe in a horizontal stored position.

Figure 7 is a side view of the prefeπed embodiment of the modified horizontal directional

drilling assembly shown in Figures 1-6 illustrating the drilling assembly and the drill pipe in a

45° angle slant subsurface drilling position.

Figure 8 is a side view of the rotary and carriage assembly of the prefeπed embodiment of the

modified horizontal directional drilling assembly shown in Figures 1-7.

Figure 9 is a top view ofthe prefeπed rotary and carriage assembly shown in Figures 1-8. Figure 10 is a partial sectional side view of the telescoping slip spindle sub assembly of the

prefeπed embodiment of the modified horizontal directional drilling assembly shown in Figures 1-9 illustrating the slip spindle sub assembly output spindle in a retracted condition.

Figure 11 is a partial sectional side view of the telescoping slip spindle sub assembly of the

prefeπed embodiment ofthe modified horizontal directional drilling assembly shown in Figures 1-10 illustrating the slip spindle sub assembly output spindle in an extended condition.

Figure 12 is an end view of the telescoping slip spindle sub assembly of the prefeπed

embodiment of the modified horizontal directional drilling assembly shown in Figures 1-11.

Figure 13 is a side view of a first alternative embodiment of the modified horizontal directional

drilling assembly ofthe present invention illustrating the fixed pivot and the wide strut system.

Figure 14 is a top view ofthe first alternative embodiment ofthe modified horizontal directional

drilling assembly illustrated in Figure 13.

Figure 15 is a top view of an alternative embodiment of the rotary and carriage assembly ofthe

prefeπed modified horizontal directional drilling assembly of the present invention.

Figure 15A is an enlarged view of the lower portion of the preferred rotary and carriage

assembly illustrated in Figure 15. Figure 16 is a side view of the alternative embodiment of the rotary and carriage assembly

illustrated in Figures 15 and 15 A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Refeπing now to the drawings, the prefeπed embodiment of the apparatus and method for the modified horizontal directional drilling assembly of the invention is illustrated in Figures 1

through 12. More particularly, as shown in Figures 1 through 12, the prefeπed modified

horizontal directional drilling assembly ("modified HDD assembly") is designated generally by

reference numeral 30. The prefeπed modified HDD assembly 30 is adapted for use in both horizontal directional drilling applications and vertical subsurface drilling applications such as

oil, gas and methane subsurface drilling.

As shown in Figure 1, the prefeπed modified HDD assembly 30 preferably includes a pair of

power units 32 and 34 (not shown). The prefeπed power units are diesel engines, but it is

contemplated within the scope of the invention that any suitable power source such as electric motors, diesel engines and generators and the like may be used. A plurality of power units are

provided so that drilling operations can continue in the event ofthe failure of less than all ofthe power units. More particularly, the prefeπed HDD assembly 30 comprises two independent

power units so that if one of the power units requires repair or maintenance, or if the hydraulic

system connected to one of the power units requires repair or maintenance, the assembly can still be operated at full capacity (at half speed) by the other power unit and the drilling operation can

continue uninterrupted (run-on-one-technology ("ROOT")). Consequently, the risk of bore hole wall collapse is minimized. The power units are preferably attached to the modified HDD

assembly such that they can be transported with the assembly as a single unit. It is contemplated

within the scope of the invention, however, that the power units may be removably attached to

and transported separate from the other components of the drilling assembly.

Still referring to Figure 1, the prefeπed modified HDD assembly 30 also includes rotary and caπiage assembly 40. The prefeπed rotary and carriage assembly 40 is adapted to move along thrust frame 42 and provide thrust force, pull-back force and rotational torque to a drill pipe or

casing. The prefeπed rotary and carriage assembly is a positive rack and pinion carriage system

which eliminates the need for cable, winches, hydraulic cylinders, chain systems and the like.

The prefeπed modified HDD assembly further includes breakout wrench assembly 50 and roller- style anti-friction drill pipe guide bushing assembly 60. The preferred breakout wrench

assembly 50 is adapted to make-up and break-out the drill pipe tool connections. The prefeπed

bushing assembly 60 is adapted to reduce wear on the drill pipe string.

In addition, the prefeπed HDD assembly 30 includes a pair of pivoting hinges 70 (see also Figure 4) which are adapted to permit thrust frame 42 to be pivotally moved between a position

approximately parallel to the drilling surface (as shown in Figure 1) and a position approximately

perpendicular to the drilling surface (as shown in Figure 3). The prefeπed pivoting hinge 70 is a

double hinge arrangement having two pivot points. It is contemplated within the scope of the

invention, however, that the pivoting hinge may have less than or more than two pivot points. It is further contemplated witlun the scope of the invention that less than or more than two pivoting hinges may be used to move thrust frame between a position approximately parallel to the

drilling surface and a position approximately perpendicular to the drilling surface.

Preferably, the rotary and carriage assembly 40 and thrust frame 42 are moved between an

approximately horizontal position and an approximately vertical position by frame hydraulic

cylinders 44 (see also Figure 4). It is contemplated within the scope of the invention, however, that any suitable device or assembly may be used to pivotally move the rotary and carriage

assembly and the thrust frame between an approximately horizontal position and an

approximately vertical position such as a motor and chain assembly, a motor and cable assembly,

a motor and gear assembly and the like. It is further contemplated that less than or more than two hydraulic cylinders may be provided to move the rotary and carriage assembly and the thrust

frame between an approximately horizontal position and an approximately vertical position. It is still further contemplated that the rotary and carriage assembly and the thrust frame may be

moved beyond an approximately vertical position through an approximately 90° arc.

Still referring to Figure 1, the prefeπed modified HDD assembly 30 also includes sub-structure

80 which is adapted to raise the assembly to a sufficient height so as to clear a blow-out

preventer (BOP). In addition, sub-structure 80 is adapted to anchor the assembly to the ground

(as shown in Figure 5) such that thrust forces in excess ofthe weight ofthe assembly and substructure may be applied to the drill pipe or casing. The sub-structure illustrated by Figure 1 is

shown in a disassembled condition for transport. The prefeπed modified HDD assembly 30

further includes remote operated drill pipe or casing slip assembly 85. The prefeπed slip

assembly 85 is adapted to prevent a drill pipe from dropping down into the drill bore. In addition, the prefeπed slip assembly 85 is adapted to reduce the amount of time required to

perform drill pipe and/or casing tool joint make-up and break-out operations. Still further, the

prefeπed slip assembly 85 functions as a safety feature by keeping personnel away from the

moving drill pipe and casing.

Referring still to Figure 1, drill pipe and casing handler 90 is adapted to pick up drill pipe 100 or casing from an approximately horizontal position substantially parallel to the drilling surface

(such as the position in which drill pipes or casings are stored in storage racks). Further, the

prefeπed handler 90 is adapted to pivotally move drill pipe 100 or a casing to an approximately

vertical position substantially perpendicular to the drilling surface for vertical subsurface drilling applications. Still further, the prefeπed handler 90 is adapted to pivotally move drill pipe 100

beyond an approximately vertical position as shown in Figure 7. In addition, the prefeπed

handler 90 is adapted to hold the drill pipe or casing in position until the rotary and carnage assembly is connected to the drill pipe or casing. The preferred handler 90 is adapted to move

the drill pipe or casing into an infinite number of positions from an approximately horizontal stored position to an appropriate position for connection ofthe drill pipe or casing with the rotary

and carriage assembly. The prefeπed handler 90 is removably connected to sub-structure 80 by

one or more pin connections.

Still referring to Figure 1, handler 90 and drill pipe 100 or a casing are preferably moved from the approximately horizontal stored position to an appropriate position for connection ofthe drill

pipe or casing with the rotary and carriage unit by handler hydraulic cylinder 92. It is

contemplated within the scope of the invention, however, that any suitable device or assembly may be used to pivotally move the drill pipe and casing handler between an approximately horizontal stored position and an appropriate position for connection of the drill pipe or casing

with the rotary and caπiage assembly such as a motor and chain assembly, a motor and cable

assembly, a motor and gear assembly, a rotary actuator and the like. It is further contemplated

that a plurality of hydraulic cylinders may be provided to move the drill pipe and casing handler

between an approximately stored horizontal position and an appropriate position for connection

ofthe drill pipe or casing with the rotary and carriage assembly. The prefeπed drill pipe 100 is

shown in the stored horizontal position. The prefeπed handler 90 is shown in a condition ready

for loading and transport.

Still refeπing to Figure 1, the preferred modified HDD assembly 30 further includes a plurality

of leveling jacks 110. Leveling jacks 110 are preferably mounted to the assembly and adapted to

level the assembly. In addition, the prefeπed leveling jacks 110 provide stability to modified HDD assembly 30. Further, the prefeπed leveling jacks 110 are mounted to sub-structure 80 in

order to provide additional anchoring forces to the assembly.

Referring now to Figure 2, a side view of prefeπed modified HDD assembly 30 is illustrated.

More particularly, Figure 2 illustrates prefeπed modified HDD assembly 30 in a retracted

transport position on prefeπed sub-structure 80, As shown in Figure 2, prefeπed modified HDD

assembly 30 includes power unit 32 (power unit 34 not shown), rotary and carriage assembly 40, thrust frame 42, frame hydraulic cylinder 44, breakout wrench assembly 50, bushing assembly

60, pivoting hinge 70, sub-stracture 80, slip assembly 85, drill pipe and casing handler 90,

handler hydraulic cylinder 92, drill pipe 100 and leveling jacks 110. Referring now to Figure 3, a side view of the prefeπed modified HDD assembly 30 is illustrated.

More particularly, Figure 3 shows the prefeπed modified HDD assembly 30 in position for a

vertical subsurface drilling application. The prefeπed drill pipe 100 is shown in a horizontal

stored position. As shown in Figure 3, prefeπed modified HDD assembly 30 includes power

unit 32 (power unit 34 not shown), rotary and carriage assembly 40, thrust frame 42, frame hydraulic cylinder 44, breakout wrench assembly 50, bushing assembly 60, pivoting hinge 70, sub-structure 80, slip assembly 85, drill pipe and casing handler 90, handler hydraulic cylinder

92, drill pipe 100 and leveling jacks 110. Further, as shown in Figure 3, rotary and carriage

assembly 40 and thrust frame 42 of prefeπed modified HDD assembly 30 are adapted to be pivotally rotated from a position approximately parallel to the drilling surface (as shown in

Figures 1 and 2) to a position approximately perpendicular to the drilling surface in order to

perform vertical subsurface drilling applications. Rotary and carriage assembly 40 and thrust

frame 42 are preferably moved between an approximately horizontal position and an

approximately vertical position by frame hydraulic cylinder 44.

Referring now to Figure 4, a top view of the prefeπed modified HDD assembly 30 is illustrated.

More particularly, Figure 4 illustrates prefeπed modified HDD assembly 30 in the position

shown in Figure 3 with the prefeπed pivoting hinges 70 in a lowered position. As shown in

Figure 4, modified HDD assembly 30 includes power unit 32, power unit 34, rotary and caπiage

assembly 40, thrust frame 42, frame hydraulic cylinders 44, pivoting hinges 70, sub-structure 80, drill pipe and casing handler 90, drill pipe 100 and leveling jacks 110. Referring now to Figure 5, a side view of the prefeπed modified HDD assembly 30 is illustrated. More particularly, Figure 5 illustrates preferred modified HDD assembly 30 in a vertical subsurface drilling application with drill pipe and casing handler 90 and drill pipe 100 in a

vertical drilling position. Further, Figure 5 illustrates the prefeπed anchoring system 115. As

shown in Figure 5, prefeπed modified HDD assembly 30 includes power unit 32 (power unit 34

not shown), rotary and carriage assembly 40, thrust frame 42, frame hydraulic cylinder 44,

breakout wrench assembly 50, bushing assembly 60, pivoting hinge 70, sub-stmcture 80, slip

assembly 85, drill pipe and casing handler 90, handler hydraulic cylinder 92, drill pipe 100,

leveling jacks 110 and tipping plate anchors 120. Further, as shown in Figure 5, drill pipe and

casing handler 90 is adapted to releasable retain and pivotally move drill pipe 100 from a position approximately parallel to the drilling surface (as shown in Figures 1-3) to a position

approximately perpendicular to the drilling surface. Preferably, drill pipe and casing handler 90

is moved between a position approximately parallel to the drilling surface and a position approximately perpendicular to the drilling surface by handler hydraulic cylinder 92.

Still referring to Figure 5, the prefeπed anchoring system 115 includes tipping plate anchors 120

which are adapted to be driven into the ground to the required depth. Anchor rod 122 extends

from the tipping plate anchors 120 to the ground surface. Anchor rod 122 may be connected to

sub-structure 80 by anchor hydraulic cylinder 124. The prefeπed anchor hydraulic cylinder 124 is adapted to be set into a socket into the frame of sub-stmcture 80 such that the cylinder may be pivoted for alignment with the anchor rod. The prefeπed anchor hydraulic cylinder is also

adapted to tip the tipping plate anchor and maintain a pre-determined hydraulic pressure such

that the desired anchor rod tensional load will be maintained during drilling operations. In the alternative, anchor rod 122 may be connected to sub-stmcture 80 using a split tapered bushing

which is adapted to lock onto the anchor rod and be inserted into a tapered housing connected to

the sub-stmcture. As the anchor loads are increased, the split tapered bushing fits more tightly in

the tapered housing, thereby increasing the anchor rod grip force.

Referring now to Figure 6, a side view of the prefeπed modified HDD assembly 30 is illustrated.

More particularly, Figure 6 illustrates rotary and carriage assembly 40, thmst frame 42, drill pipe and casing breakout wrench assembly 50, drill pipe guide bushing assembly 60 and slip

assembly 85 of prefeπed modified HDD assembly 30 in a 45° angle slant subsurface drilling position with drill pipe 100 in a horizontal stored position. The prefeπed pivoting hinge 70 is

shown in a lowered position. As shown in Figure 6, modified HDD assembly 30 includes power unit 32 (power unit 34 not shown), rotary and carriage assembly 40, thmst frame 42, frame

hydraulic cylinder 44, breakout wrench assembly 50, bushing assembly 60, pivoting hinge 70,

sub-stmcture 80, slip assembly 85, drill pipe and casing handler 90, handler hydraulic cylinder 92, drill pipe 100 and leveling jacks 110. Further, as shown in Figure 6, rotary and carriage

assembly 40 and thmst frame 42 of prefeπed modified HDD assembly 30 are adapted to be pivotally rotated from a position approximately parallel to the drilling surface (as shown in

Figures 1 and 2) to a position approximately 45° from the horizontal drilling surface in order to perform slant subsurface drilling applications. Rotary and carriage assembly 40 and th st frame 42 are preferably moved between an approximately horizontal position and a position

approximately 45° from the horizontal drilling surface by frame hydraulic cylinder 44. Referring now to Figure 7, a side view ofthe prefeπed modified HDD assembly 30 is illustrated.

More particularly, Figure 7 illustrates prefeπed modified HDD assembly 30, rotary and carriage assembly 40, breakout wrench assembly 50, guide bushing assembly 60, slip assembly 85 and

prefeπed drill pipe 100 in a 45° angle slant subsurface drilling position. The prefeπed pivoting

hinge 70 is shown in a lowered position. As shown in Figure 6, modified HDD assembly 30

includes power unit 32 (power unit 34 not shown), rotary and carriage assembly 40, thmst frame

42, frame hydraulic cylinder 44, breakout wrench assembly 50, bushing assembly 60, pivoting

hinge 70, sub-stmcture 80, slip assembly 85, drill pipe and casing handler 90, handler hydraulic cylinder 92, drill pipe 100 and leveling jacks 110. Further, as shown in Figure 6, drill pipe and

casing handler 90 and drill pipe 100 are adapted to be pivotally rotated from a position

approximately parallel to the drilling surface (as shown in Figures 1, 2, 3 and 6) to a position

approximately 45° from the horizontal drilling surface in order to perform slant subsurface

drilling applications. Drill pipe and casing handler 90 and drill pipe 100 are preferably moved between an approximately horizontal position and a position approximately 135° from the horizontal drilling surface by handler hydraulic cylinder 92.

Referring now to Figure 8, a side view of rotary and carriage assembly 40 ofthe prefeπed embodiment of modified HDD assembly 30 is illustrated. The prefeπed rotary and carriage

assembly 40 is adapted to apply thmst and pull-back forces to a drill pipe or casing or a string of drill pipes or casings through a combination of pinion drive planetary gearboxes and hydraulic

motors. More particularly, as shown in Figure 8, prefeπed rotary and carriage assembly 40

includes caπiage drive planetary gearboxes 140 and carriage drive motors 142. The prefeπed

rotary and carriage assembly further includes rotary gearbox planetary gearboxes 144, rotary gearbox hydraulic motors 146 and rotary gearbox output spindle 148. The prefeπed rotary

gearbox and the prefeπed output spindle applies rotational torque to a drill pipe or a string of

drill pipes. While Figure 8 illustrates hydraulic motors adapted to provide a power source to the

prefeπed rotary and carriage assembly, it is contemplated within the scope of the invention that the rotary and carriage assembly may be powered by and suitable power source such as an

electric motor and the like.

Referring now to Figure 9, a top view of prefeπed rotary and carriage assembly 40 is illustrated.

As shown in Figure 9, prefeπed rotary and carriage assembly 40 includes carriage drive

planetary gearboxes 140 and carriage drive motors 142. The prefeπed rotary and caπiage

assembly further includes rotary gearbox planetary gearboxes 144, rotary gearbox hydraulic

motors 146 and rotary gearbox output spindle 148. In addition, prefeπed rotary and carriage assembly 40 includes telescoping slip spindle sub assembly 150 which is described in more detail below.

Referring now to Figure 10, a partial sectional side view of the prefeπed telescoping slip spindle sub assembly 150 ofthe prefeπed embodiment of modified HDD assembly 30 is illustrated.

More particularly, Figure 10 illustrates preferred slip spindle sub assembly 150 with output

spindle 148 in a retracted condition. As shown in Figure 10, prefeπed slip spindle sub assembly

150 includes output spindle 148, drive sleeve 154 and housing 156. The prefeπed output spindle

148 is adapted to extend and retract in a telescoping manner depending upon the direction of the thmst loading applied to the rotary and carriage assembly. Preferably, the output spindle axially

extends from and axially retracts into housing 156 a distance of approximately four inches. The prefeπed drive sleeve 154 engages prefeπed output spindle 148 so as to transmit rotational

torque from slip spindle input end 158 to slip spindle output end 160. The prefeπed slip spindle

sub assembly reduces damage and wear to the drill pipe and casing thread extends the life of drill

pipe tool joint connections threads as a result of the telescoping action of output spindle 148.

Referring now to Figure 11, a partial sectional side view ofthe prefeπed telescoping slip spindle

sub assembly 150 ofthe prefeπed embodiment of modified HDD assembly 30 is illustrated.

More particularly, Figure 11 illustrates prefeπed slip spindle sub assembly 150 with output

spindle 148 in an extended condition. As shown in Figure 11, prefeπed slip spindle sub

assembly 150 includes output spindle 148, drive sleeve 154, housing 156, input end 158 and

output end 160.

Referring now to Figure 12, a cross-sectional view of the prefeπed telescoping slip spindle sub assembly 150 ofthe prefeπed embodiment of modified HDD assembly 30 is illustrated. More

particularly, as shown in Figure 12, prefeπed slip spindle sub assembly 150 includes output spindle 148, drive sleeve 154 and housing 156.

Referring now to Figure 13, a side view of a first alternative embodiment ofthe modified horizontal directional drilling assembly is illustrated. More particularly, the prefeπed modified

horizontal directional drilling assembly 230 includes fixed pivot 270 and wide stπit system 280. The prefeπed fixed pivot 270 is adapted to permit thrust frame 242 to be pivotally moved

between a position that is substantially parallel to the drilling surface and a position that is substantially perpendicular to the drilling surface. Preferably, fixed pivot 270 is adapted to

peπnit thrust frame 242 to be moved through an approximately 90° angle.

Refeπing now to Figures 13 and 14, the prefeπed wide stmt system 280 is adapted to provide

stability to the drilling assembly. The prefeπed wide stmt system includes a pair of wide st t

system arms 282, each of which have a thmst frame end 283 attached to thmst frame 242 and an

anchoring end 284 adapted to be anchored to sub-stmcture 280. While the wide stmt system

illustrated in Figures 13 and 14 includes a pair of arms, it is contemplated within the scope of the

invention that the wide stmt system may include more or less than two arms. It is also contemplated within the scope of the invention that the anchoring end of the arms may be

anchored to any suitable support structure, including but not limited to, the drilling surface.

Further, although the wide stmt system illustrated in Figures 13 and 14 shows the thrust frame in

a substantially vertical position, it is contemplated within the scope of the invention that the wide stmt system may be adapted for use when the thmst frame is not in a substantially vertical position.

Referring now to Figure 15, a top view of an alternative embodiment of the rotary and carriage

assembly of the prefeπed modified horizontal directional drilling assembly of the present invention is illustrated. The preferred rotary and carriage assembly is designated generally by reference numeral 340. The prefeπed rotary and caπiage assembly 340 is adapted to for use in

connection with tube-in-tube drill pipes and tube-in-tube drill pipe strings. More particularly, the

prefeπed rotary and carriage assembly 340 is adapted to pump fluid (such as bentonite, air, water

and the like) through the annular channel located between the inner tube and the outer tube of a tube-in-tube drill pipe toward t ie cutting tool (such as a percussion hammer) of the drill pipe string. In such a tube-in-tube drill pipe application, the fluid pumped through the annular

channel of the drill pipe actuates the cutting tool, removes cuttings from the face of the cutting

tool, and directs the cuttings into the inner tube for discharge to the drilling surface. Figure 15A

illustrates in detail the flow of fluid and cuttings (represented by aπowed lines 340A and 340B,

respectively) through the lower portion of the rotary and carriage assembly. Figure 15A also

clearly illustrates the prefeπed center cuttings discharge hose 340C which is adapted to convey cuttings from the inner tube of a tube-in-tube drill pipe (or tube-in-tube drill pipe string) to the

cuttings discharge tube 370, which is described below.

As shown in Figures 15 and 16, the prefeπed rotary and caπiage assembly 340 includes caπiage drive planetary gearbox 341, rotary gearbox hydraulic motor 346, rotary gearbox output spindle

348 and telescoping slip spindle sub assembly 350. In addition, the prefeπed rotary and carriage assembly 340 includes plumbing adapted to convey fluid to the annular channel between the

inner tube and the outer tube of a tube-in-tube drill pipe and/or a tube-in-tube drill pipe string.

The preferred rotary and carriage assembly 340 includes plumbing adapted to convey cuttings

from the inner tube ofthe tube-in-tube drill pipe out of the drilling assembly. More particularly,

in the prefeπed rotary and caπiage assembly, fluid inlet tube 360 is connected to below rotary side inlet swivel 362 such that fluid in conveyed to the annular channel between the inner tube and the outer tube of a tube-in-tube drill pipe. Preferably, an inlet hammer union 364 or some

other suitable connection device is located at the upstream end of the fluid inlet tube. Also in the preferced rotary and carriage assembly, cuttings discharge tube 370 is connected to above rotary swivel 372 such that cuttings from the inner tube ofthe tube-in-tube drill pipe may be conveyed out of the assembly. The prefeπed discharge tube 370 also includes discharge hammer union

374 or some other suitable connecting device. While the prefeπed fluid inlet tube 360 and the

prefeπed cuttings discharge tube 370 are illustrated in their prefeπed configuration and

aπangement, it is contemplated within the scope of the invention that the tubes may be any

suitable configuration and they may be located in any suitable aπangement.

In operation, several advantages ofthe apparatus and method ofthe invention are realized. For example, the drilling assembly of the invention produces an increased capacity for drill pipe

rotational, thrust and pull-back forces. The drilling assembly of the invention is capable of

producing longer well bores and well bores having a greater diameter than those produced by

conventional drilling assemblies. The drilling assembly ofthe invention is capable of entering

the earth and drilling a well bore at any angle between approximately parallel to a horizontal drilling surface to a 90° vertical angle. Consequently, the drilling assembly ofthe invention is capable of drilling at an angle steeper than conventional horizontal directional drill assemblies

and at an angle closer to horizontal than conventional vertical drill assemblies. The anchoring

system and rotary and carriage assembly of the prefeπed drilling assembly of the invention eliminate the need for heavy drill pipe or drill collars in order to exert downward force on the

drill bit. The drilling assembly ofthe invention is more easily transported than conventional

drilling assemblies as a result of on-board power units and the reduced weight of the assembly.

The rack and pinion rotary and caπiage assembly of the drilling assembly of the invention

eliminates the need for cables, winches, hydraulic cylinders, chain systems and the like to provide rotational, thmst and pull-back forces. The slip assembly of the prefeπed drilling

assembly of the invention also reduces damage and wear to the threaded end of a drill string section when the top drive or rotary table engages the threaded end of the drill string section.

The drilling assembly of the invention further reduces the amount of time required to perform

make-up and break-out operations on the drill pipe and/or casing tool joints. The arms of the

pipe and casing handler ofthe invention, which are pinned to the sub-stmcture, allow for easy

removal during transport. The drilling assembly of the invention is also adapted to perform

vertical and horizontal directional drilling applications with a tube-in-tube drill pipe and a tube- in-tube drill pip string. In addition, in the event of a power unit failure, the drilling assembly of

the invention may continue to be operated as a result ofthe plurality of power units provided

(run-on-one-technology).

Although this description contains many specifics, these should not be constmed as limiting the scope ofthe invention but as merely providing illustrations of some ofthe presently prefeπed

embodiments thereof, as well as the best mode contemplated by the inventor of carrying out the invention. The invention, as described herein, is susceptible to various modifications and

adaptations, and the same are intended to be comprehended within the meaning and range of equivalence of the appended claims.

What is claimed is:

Claims

1. A modified horizontal directional drilling assembly for drilling pipe into a drilling surface, said drilling assembly comprising: a power unit for supplying power to the drilling assembly; a thmst frame adapted to be moved between a position substantially parallel to the drilling surface and a position substantially perpendicular to the drilling surface; a means for moving the thrust frame; a rotary and carriage assembly mounted on the thmst frame, said rotary and carriage assembly being adapted to apply rotational, thmst and pull-back forces to the drill pipe; wherein the drilling assembly is adapted to drill pipe into the drilling surface at any angle relative to the drilling surface between substantially parallel to the drilling surface and substantially perpendicular to the drilling surface.

2. The drilling assembly of claim 1 wherein the power unit comprises at least two independent power units attached to the assembly.

3. The drilling assembly of claim 2 wherein the drilling assembly is adapted to operate at full capacity at half speed using one of said at least two independent power units in the event that one or more ofthe other of said at least two independent power units is not in operation.

4. The drilling assembly of claim 1 wherein the thmst frame is pivotally connected to the assembly.

5. The drilling assembly of claim 4 wherein the thmst frame is pivotally connected to the assembly by a dual hinge having at least two pivot points.

6. The drilling assembly of claim 1 wherein thmst frame is adapted to be moved tlirough at least approximately 90° relative to the drilling surface.

7. The drilling assembly of claim 1 wherein the means for moving the thmst frame is a frame hydraulic cylinder.

8. The drilling assembly of claim 1 wherein the rotary and carriage assembly is a positive rack and pinion carriage system comprising: a caπiage drive planetary gearbox; a caπiage drive motor; a rotary gearbox planetary gearbox; a rotary gearbox hydraulic motor; and a telescoping slip spindle sub assembly.

9. The drilling assembly of claim 8 wherein the telescoping slip spindle sub assembly comprises: a rotary gearbox output spindle; a drive sleeve; a housing; a slip spindle input end; and a slip spindle output end.

10. The drilling assembly of claim 1 further comprising a break out wrench assembly.

1 1. The drilling assembly of claim 1 further comprising a drill pipe guide bushing assembly.

12. The drilling assembly of claim 1 further comprising a sub-stmcture.

13. The drilling assembly of claim 1 further comprising a leveling jack mounted to the substructure.

14. The drilling assembly of claim 1 further comprising a casing slip assembly.

15. The drilling assembly of claim 1 further comprising a drill pipe and casing handler and a means for moving the drill pipe and casing handler.

16. The drilling assembly of claim 15 wherein the drill pipe and casing handler is removably connected to the sub-stmcture by a pin connection.

17. The drilling assembly of claim 16 wherein the means for moving the drill pipe and casing handler is a hydraulic actuator.

18. The drilling assembly of claim 1 further comprising an anchoring system.

19. The drilling assembly of claim 18 wherein the anchoring system comprises a tipping plate anchor, an anchor rod and an anchor hydraulic cylinder.

20. The drilling assembly of claim 1 further comprising a wide stmt system.

21. A method for drilling pipe into a drilling surface; said method comprising: providing a modified horizontal directional drilling assembly, said drilling assembly comprising: a power unit for supplying power to the drilling assembly; a thrust frame adapted to be moved between a position substantially parallel to the drilling surface and a position substantially perpendicular to the drilling surface; a means for moving the thmst frame; a rotary and carnage assembly mounted on the thmst frame, said rotary and carriage assembly being adapted to apply rotational, thmst and pull-back forces to the drill pipe; wherein the drilling assembly is adapted to drill pipe into the drilling surface at any angle relative to the drilling surface between substantially parallel to the drilling surface and substantially perpendicular to the drilling surface; placing a drill pipe onto the drilling assembly; moving the thmst frame to a desired drilling angle; moving the rotary and carriage assembly into direct contact with the drill pipe; applying rotational, thmst and pull-back forces to the drill pipe; and drilling the pipe into the drilling surface.

22. The method of claim 21 further comprising the step of anchoring the assembly.

23. The method of claim 21 further comprising the step of leveling the assembly.