AU2020102575B4 - Centre bypass mud hammer - Google Patents

Abstract

The present disclosure provides a mud hammer configured to receive a single flow of drilling fluid and deliver a metered portion of the drilling fluid to the drill bit face. The mud hammer operates on the remaining portion of drilling fluid. The metered portion of drilling fluid is delivered to the drill bit face via a bypass tube that passes through the mud hammer. A valving set may determine an amount of drilling fluid that flows through the bypass tube, and in some instances the amount may be adjustable. The provided mud hammer may help limit the drilling fluid's degenerating effects on the mud hammer's internal components by including one or more wear sleeves. The one or more wear sleeves may help prevent contact between a piston and a piston barrel and/or a valving set that generates piston movement and the piston barrel. 22

Description

TITLE CENTRE BYPASS MUD HAMMER BACKGROUND

[0001] As demand for new emission free, renewable, baseload geothermal energy supplies

has increased, operators have been forced to drill deeper to find sufficient heat for thermal energy

production. Much of the higher cost of drilling deeper, especially onshore, is typically associated

with decreased rate of penetration (ROP) caused by both harder rock and higher mud weights

required to counter the harder rock, over-pressured reservoirs, and higher static pressures often

associated with deeper drilling. Typical mud rotary drilling methods may have less than desired

performance metrics in hard rock formations. For instance, typical mud rotary drilling methods

may have a slower drilling rate and shorter drill bit lifetime than is desired, which increases

operational costs in hard rock formations. Percussion drilling systems, combining a fluid or mud

hammer with drill bits, have been developed in an attempt to increase drilling performances in

hard formations.

[0002] Fluid or mud hammer systems convert a portion of the power resident in the drilling

fluid to mechanical force that drives the drill bit into the formation. Percussion forces from the

piston movement striking the drill bit may improve the rate of penetration in hard rock by more

than 500%; however, mud additives in the drilling fluid required for well control and drill cutting

transport to the surface cause a high wear rate on the moving parts of a fluid hammer. This high

wear rate on the working components and the limited amount of fluid that can be pumped through

a typical fluid hammer to clear drilled cuttings from the bottom of the well are significant

drawbacks to typical fluid hammer systems that have been prohibitive to their use for deep well drilling. Accordingly, rotary tricone drilling methods are generally still the only method used.

The low penetration rates and high costs of the typical rotary tricone method, however, are at least

in part preventing the development of geothermal energy production in most countries where deep

hard rock wells are required to reach the required geothermal heat levels for electricity generation,

desalination, heating, cooling and waste water treatment.

[0003] One typical fluid hammer system is a Dual Circulation water or fluid hammer ("DC

fluid hammer"), such as the one disclosed in U.S. Patent Application Publication No.

2018/0044991AL A DC fluid hammer uses a dual circulation drill pipe system to separate drilling

mud from clean water. The clean water, normally injected into the annulus of a drill pipe, is

pumped under pressure to operate the water hammer. This clean water operation may contribute

to longer operation periods between servicing and rebuilding the DC fluid hammer. The drilling

mud is required to have a high viscosity as operators drill deeper wells so that drill cuttings can be

transported to the surface and formation fluids, including high gas pressure, are prevented from

entering the well. The high viscosity drilling mud is typically pumped into an inner tube of a drill

pipe system and delivered through an inner tube passing through the DC fluid hammer to the DC

fluid hammer's drill bit face. This keeps the mud from passing through the DC fluid hammer's

working components, which would wear out the components. Both the clean water and the drilling

mud mix together after exiting the DC fluid hammer and push the drill cuttings to the surface.

[0004] Typical DC fluid hammers, however, have a number of drawbacks. It has been

found that a DC fluid hammer wears out more quickly than desired and fails to perform for required

periods of time when drilling deep wells with drilling muds. For instance, it has been found that

the clean water passing through the DC fluid hammer's working components still wears out the

components.

[0005] Another drawback of a typical DC fluid hammer for drilling deep wells is the high

amount of mud loss. When the total mixed flow exits the well with the drill cuttings, a percentage

of the total fluid has to be cleaned at the surface to between about three and ten microns before it

can be pumped under pressure down the pipe to operate the DC fluid hammer. This is typically

around 20 to 50% of the total fluid volume delivered under pressure down the drill pipe. The mud

and drilling additives that are taken out of this percentage of the total fluid have to be added back

to the drilling mud fluid that is pumped down the DC's hammer's inner tube to be mixed with the

clean water exhausted from the hammer at the bottom of the well. The amount of mud that must

be replaced can be large and may create prohibitively high operational costs for the DC fluid

hammer that may be greater than replacing the entire DC fluid hammer itself every day of

operation.

[0006] A further drawback of the typical DC fluid hammer is that its operation requires a

dual circulation drill pipe so that the DC fluid hammer may receive two separate flows from the

dual circulation drill pipe. One flow is clean water and one flow contains drilling muds and

additives. The clean flow operates the hammer and the drilling mud is channelled to the drill bit

face. A dual circulation drill pipe, however, increases the complexity of operating the drilling

system, at least because a dual circulation drill pipe is not American Petroleum Institute (API)

certified.

[0007] Operating a drilling system using a drill pipe that is not API certified may increase

the risk of injury or damage to equipment, such as to the inner tube that is used to deliver mud to

the bottom of the well, and accordingly such a system does not provide suitable safety levels. For

example, in at least some instances it is mechanically difficult or even impossible to include typical

internal blow out prevention (IBOP) with a drill pipe that is not API certified, such as with a dual circulation drill pipe. As known to one of skill in the art, an IBOP may be a sub that sits below a top drive and may be turned off remotely or by hand in the event of an emergency or blow out.

Without the IBOP, the inner tube that delivers mud to the bottom of the well provides an

unrestricted and unchecked pathway for dangerous gas blow out to the well's surface. In addition,

it is difficult or even impossible to add an internal safety system to the inner tube. Operating a

drilling system without an API certified drill pipe also increases drilling system's operational costs

(e.g., some insurance companies will not provide well insurance unless the driller is using certified

API drilling pipe and safety systems amid the safety concerns of not doing so). Accordingly,

typical operators do not use drill piping that is not API certified, thus decreasing the DC fluid

hammer's utility.

[0008] An additional drawback of at least some typical mud hammers is what may be

termed re-grinding. Re-grinding refers to a drill bit re-drilling, pounding, and grinding the same

rock material over and over unit it is a paste because the rock that is being drilled is not flushed

away from the drill bit face. This is due to the limit on the fluid volume that can be pushed through

the working parts of a typical fluid, water or mud hammer and exhausted through the drill bit ports.

The result is a very slow drilling production or speed and premature failure of the drill bit. For

instance, as an example, re-grinding may cause water, fluid or mud hammer drill bits to fail in just

meters (65.6 feet) when they should last for 400 meters (1312.3 feet) or more.

[0009] By diverting drilling mud to the drill bit face, the typical DC fluid hammer helps

increase flushing and decrease re-grinding. Operation of the typical DC fluid hammer, however,

may result in too much fluid or mud (e.g., 70 to 80% of the total fluid volume) being delivered to

the drill bit face. It has been found that a cushion of high pressure fluid may form under the drill

bit when too much fluid or mud is delivered to the drill bit face, which reduced the typical DC fluid hammer's production levels significantly. It has also been found that reducing mud flow through the typical DC fluid hammer's inner tube in an attempt to solve the high pressure fluid cushion problem resulted in a total drilling fluid volume that was insufficient to lift or transport the drill cuttings to the surface. As a result, it was found that a bypass sub had to be fitted above the DC fluid hammer and above the typical water, fluid or mud hammer in order to deliver sufficient volumes of mud into the well to lift the drill cuttings to the surface. The high volume flowing from the bypass sub above the hammers restricts the flow coming from below that is trying to transport the drill cuttings. In addition, at least some typical fluid, water, mud or DC fluid hammers are limited to flow or operate with only 20% of the total well volume, which is around

200 to 300 gallons per minute on a 12-inch version (30.48 cm) of a DC fluid hammer. This is far

below the total well volume which would be around 1,000 gallons per minute to drill a 12.5-inch

(31.75cm) diameter well below a 5,000 meter (16,404 feet) depth. A 12-inch version of a DC fluid

hammer refers to a typical hole size diameter, 12 inches or 30.48 cm, that the version can drill.

[0010] Accordingly, a mud hammer drilling system that solves at least the above

drawbacks is desired.

SUMMARY

[0011] The present disclosure provides a new and innovative mud hammer, system, and

method for safe and viable percussion drilling in deep wells with improved efficiency over typical

fluid, mud, and water hammers.

[0012] In a first aspect, the invention provides a mud hammer comprising: a piston barrel

including at least one exhaust port configured to receive a single flow of drilling fluid including

drilling mud; a piston positioned within the piston barrel and configured to move in a reciprocating motion operated by a first portion of the drilling fluid; a bypass tube disposed through the piston and in fluid communication with a percussion drill bit; an adjustable valving set configured to divert a second portion of the drilling fluid into the bypass tube; and a wear sleeve positioned to prevent contact between the piston and the piston barrel; wherein the second portion of the drilling fluid diverted into the bypass tube is exhausted from the drill bit and the first portion of drilling fluid is exhausted from the piston barrel via the exhaust port, in a direction away from the drill bit

[0013] In one embodiment, there is provided a mud hammer configured to operate with

drilling fluid that includes drilling mud includes a piston barrel. A piston is positioned within the

piston barrel and is configured to move in a reciprocating motion having a piston stroke length. A

bypass tube is positioned through the piston. A valving set is configured to allow a set amount of

fluid to flow into the bypass tube. A wear sleeve is positioned to prevent contact between the

piston and the piston barrel. A drill bit is in fluid communication with the bypass tube.

[0014] In a second aspect, the invention provides a system comprising: a single flow drill

pipe configured to deliver a single flow of drilling fluid including drilling mud; a mud hammer in

fluid communication with the single flow drill pipe, the mud hammer including: a piston barrel

including at least one exhaust port; a piston positioned within the piston barrel and configured to

move in a reciprocating motion operated by a first portion of the drilling fluid; a bypass tube

disposed through the piston and in fluid communication with a percussion drill bit; an adjustable

valving set configured to divert a second portion of the drilling fluid into the bypass tube; and a

wear sleeve positioned to prevent contact between the piston and the piston barrel, wherein the

second portion of the drilling fluid diverted into the bypass tube is exhausted from the drill bit and

the first portion of drilling fluid is exhausted from the piston barrel via the exhaust ports, in a

direction away from the drill bit.

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[0015] In one embodiment there is provided a system includes a single flow drill pipe

configured to deliver a single flow of drilling fluid including drilling mud. The system may also

include a mud hammer in fluid communication with the single flow drill pipe. The mud hammer

is configured to operate with drilling fluid that includes drilling mud and includes a piston barrel.

A piston is positioned within the piston barrel and is configured to move in a reciprocating motion

having a piston stroke length. A bypass tube is positioned through the piston. A valving set is

configured to allow a set amount of fluid to flow into the bypass tube. A wear sleeve is positioned

to prevent contact between the piston and the piston barrel. A drill bit is in fluid communication

with the bypass tube.

[0016] In a third aspect, the invention provides a method for drilling, comprising:

positioning a mud hammer in a drilling well, the mud hammer including: a piston barrel including

at least one exhaust port; a piston positioned within the piston barrel and configured to move in a

reciprocating motion operated by a first portion of a drilling fluid; a bypass tube disposed through

the piston and in fluid communication with a percussion drill bit, the drill bit having a drill bit face;

an adjustable valving set configured to divert a second portion of the drilling fluid into the bypass

tube; a wear sleeve positioned to prevent contact between the piston and the piston barrel; directing

a single flow of drilling fluid to the mud hammer via a single flow drill pipe, the drilling fluid

including drilling mud; and operating the mud hammer to drill in the drilling well, wherein the

second portion of the drilling fluid diverted into the bypass tube is exhausted from the drill bit at

the drill bit face and the first portion of drilling fluid is exhausted from the piston barrel via the

exhaust port, in a direction away from the drill bit.

[0017] In one embodiment a method includes positioning a mud hammer in a drilling well.

The mud hammer is configured to operate with drilling fluid that includes drilling mud and includes a piston barrel. A piston is positioned within the piston barrel and is configured to move in a reciprocating motion having a piston stroke length. A bypass tube is positioned through the piston. A valving set is configured to allow a set amount of fluid to flow into the bypass tube. The set amount of fluid that flows into the bypass tube includes a first portion of the drilling mud in the drilling fluid. A second portion of the drilling mud in the drilling fluid flows into the mud hammer, exteriorly to the bypass tube, to operate the mud hammer. A wear sleeve is positioned to prevent contact between the piston and the piston barrel. A drill bit is in fluid communication with the bypass tube, the drill bit having a drill bit face. A single flow of drilling fluid is directed to the mud hammer via a single flow drill pipe, the drilling fluid including drilling mud. The mud hammer is operated to drill in the drilling well. The first portion of the drilling mud exits the mud hammer at the drill bit face.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 illustrates a cross section of an example drilling system, according to an

aspect of the present disclosure.

[0019] FIG. 2 illustrates an exploded view of an example mud hammer, according to an

aspect of the present disclosure.

[0020] FIG. 3 illustrates a perspective view of the example mud hammer shown in FIG. 2,

according to an aspect of the present disclosure.

[0021] FIG. 4 illustrates a flow chart of an example drilling method, according to an aspect

of the present disclosure.

DETAILED DESCRIPTION

[0022] The present disclosure provides a new and innovative mud hammer with an

increased lifetime and performance as compared to typical fluid or mud hammers. For example,

the provided mud hammer may have an increased lifetime and performance for deep well drilling

as compared to typical fluid or mud hammers. In another example, the provided mud hammer

may have an increased lifetime and performance for drilling in hard rock formations as compared

to typical fluid or mud hammers. The provided mud hammer is constructed to operate with higher

viscosity fluids (e.g. 50 microns) and is operated by drilling fluid including drilling mud (e.g.,

instead of clean water as in the design of the DC Fluid Hammer). For example, the provided mud

hammer may include greater clearances between its components than at least some typical fluid

hammers to enable the provided mud hammer's operation by drilling fluid. A single flow of

drilling fluid may be delivered to the mud hammer via a standard single flow drill pipe. Typical

single flow drill pipes are API certified, thus increasing the safety and ease ofuse for the provided

mud hammer as compared to a typical mud hammer (e.g., the DC fluid hammer) that is used with

other non-approved types of drill pipes, such as a dual circulation drill pipe, which are not API

certified. For instance, internal blow out prevention (IBOP) may be used with the provided mud

hammer. Additionally, operating the mud hammer with drilling fluid does not result in the high

degree of mud loss experienced with a typical DC fluid hammer since finely filtered water is not

used as it is in a typical DC fluid hammer's operation.

[0023] The provided mud hammer includes a piston that moves in a reciprocating motion

within a piston barrel of the provided mud hammer. A valving set may generate the piston's

movement. In such instances, the valving set that generates the piston's movement also moves in

a reciprocating motion. One drawback of operating a mud hammer with drilling mud is that the drilling mud tends to wear out these moving components more quickly than desired during the mud hammer's operation (e.g., one of the problems that a DC fluid hammer attempts to solve).

[0024] To help combat the durability issues presented by the drilling mud, the mud

hammer may include a wear sleeve that prevents contact between the mud hammer's piston barrel

and the piston. In some instances, the mud hammer may additionally include a wear sleeve that

prevents contact between the mud hammer's piston barrel and the valving set that generates the

piston's movement. The one or more wear sleeves help prevent wear on the mud hammer's

internal components and therefore increase their lifetime before needing to be replaced. Instead,

the one or more wear sleeves are replaced when the one or more wear sleeves are sufficiently

degraded. For instance, the one or more wear sleeves may be designed to last for about the same

amount of the time as the provided mud hammer's drill bit is expected to last, which enables the

wear sleeves and the drill bit to be replaced at the same time.

[0025] Pulling or tripping the mud hammer from the well is a time consuming process, and

thus replacing the one or more wear sleeves at the same time as replacing the drill bit increases the

provided mud hammer's operational efficiency as compared to pulling the mud hammer from the

well at two separates times. Additionally, the operational costs of replacing the one or more wear

sleeves may be much less (e.g., 1/10 of the cost) than the operational costs of drilling mud loss

associated with typical DC fluid hammers. Accordingly, the provided mud hammer is more

efficient and safer to operate than typical DC fluid hammers.

[0026] The provided mud hammer also includes a bypass tube in fluid communication with

its drill bit. Drilling fluid, including drilling mud, delivered to the mud hammer may flow through

the bypass tube and exit at the drill bit's face. The bypass tube thereby increases the flow of drilling mud to the drill bit's face, as compared to some typical mud hammers, so that flushing at the drill bit face is improved and re-grinding is limited.

[0027] A valving set may control how much fluid may flow into and through the bypass

tube. Restricting the amount of drilling fluid that is delivered to the drill bit face may help prevent

the high pressure cushion problem that may result when too much drilling fluid or mud is delivered

to the drill bit face. In various instances, the valving set enables between about 40% to 80% of the

total delivered drilling mud to pass through the bypass tube and be delivered to the drill bit face.

The valving set may be a component of the bypass tube. In at least some aspects, the valving set

may be configured such that the amount of fluid that may flow into and through the bypass tube is

adjustable. In such aspects, the adjustability provides drill operators with the ability to control

how much fluid flows into the bypass tube based on different drilling conditions and geology. The

remainder of the drilling fluid delivered to the mud hammer that does not flow through the bypass

tube is instead pushed under pressure into the mud hammer to operate the mud hammer.

[0028] Compared to a typical 12-inch (30.48cm) version of a water or fluid hammer that

can only flow around 200 to 400 gallons per minute (GPM) (757.1 to 1514.2 liters per minute

(LPM)) in total to the drill face, the inventor has found that a 12-inch (30.48 cm) version of the

provided mud hammer is able to flow in total, around 800 to 1,000 GPM (3028.3 to 3785.4 LPM).

In an example, this total flow may include 300 GPM (1135.6 LPM) forced through the working

components of the provided mud hammer and 700 GPM (2649.8 LPM) through the bypass tube.

This total flow is about 80 to 100% of the total well volume to drill a 12.5-inch (31.75 cm) well

below a 5,000 meter (16,404 feet) depth, which is an increased flow capacity over at least some

typical fluid or mud hammers (e.g., 100 to 150%), as described above. A 12-inch (30.48 cm)

version of the provided mud hammer refers to a size hole in diameter, 12 inches or 30.48 cm, that the version can drill. In other examples, the provided mud hammer may be constructed to drill holes of other suitable diameters (e.g, 17 or 24 inches, which is 43.18 or 60.96 cm).

[0029] Accordingly, the provided mud hammer receives a single flow of drilling fluid,

delivers a metered portion of the drilling fluid to the drill bit face, and operates on the remaining

portion of drilling fluid, while limiting the drilling fluid's degenerating effects on the mud

hammer's internal components. Compared to typical mud rotary drilling methods, the inventor

has found that the provided mud hammer drills at faster rates (e.g., 10 meters/hour or 32.81

feet/hour compared to 300 millimeters per hour or 0.98 feet/hour) in hard rock formations. The

inventor has also found that the provided mud hammer's drill bit has a longer lifetime (e.g., 400

meters or 1312.3 feet compared to 20 meters or 65.62 feet until end of life) than a typical high

grade rotary drill bit when drilling in hard rock formations.

[0030] Turning now to the figures, FIG. 1 illustrates a cross section of an example drilling

system 10. The drilling system 10 includes a single flow drill pipe 12 and an example mud hammer

100. The single flow drill pipe 12 may be any suitable, standard API-certified drill pipe. The

single flow drill pipe 12 may be coupled to the mud hammer. For example, the single flow drill

pipe 12 may include a male threaded portion that couples to a female threaded portion at one end

of the mud hammer 100. A flow 14 of drilling fluid may be delivered to the mud hammer 100

through the single flow drill pipe 12. The drilling fluid includes drilling mud and various additives

as will be appreciated by one having skill in the art.

[0031] Various components may compose the body of the mud hammer 100. Such

components may include one or more of a piston barrel 102, a top sub 126, a drive sub 138, and/or

other suitable components such as one or more components illustrated in the exploded view of

example mud hammer 200 in FIG 2. The mud hammer 100 includes a piston 106. The piston 106 may be positioned within the piston barrel 102. The piston 106 is configured to translate in a reciprocating motion in the direction of the double-side arrow 128. The reciprocating motion of the piston 106 includes a piston stroke length designated by the double-side arrow 114. In various instances, the piston 106 may cycle in the reciprocating motion at a rate of about 10 to 25 cycles per second when a desired fluid or mud pressure for drilling operations is delivered to the mud hammer 100. A cycle is completed when the piston 106 returns to a starting position after translating two piston stroke lengths. In some instances, the piston 106 may cycle at lower rates with a less than desired fluid or mud pressure. In at least some examples, the piston stroke length may be about 40mm (1.57 inches).

[0032] In some aspects, as the piston 106 moves, it strikes a drill bit 108 at the interface

116 on one end of the piston 106. On its other end, the piston 106 may strike a valving set 132, in

some examples, such as the one illustrated. In other examples, the valving set 132 may be

positioned on the opposite end of the piston 106 than is illustrated or may be positioned around

the piston 106. The valving set 132 may be configured to generate movement of the piston 106 as

will be appreciated by one having skill in the art. The valving set 132 may include a single valve

or may include multiple valves or other suitable components, in various instances. In some

instances, the valving set 132 may include one or more check valves and/or plungers. In other

aspects, the piston 106 may include porting 140 instead of or in addition to the valving set 132.

The porting 140 may be configured to generate movement of the piston 106.

[0033] In various aspects, the mud hammer 100 may include a wear sleeve 134 positioned

between the piston 106 and the piston barrel 102. As the piston 106 moves in its reciprocating

motion, friction between the piston 106 and the piston barrel 102 may cause the piston 106 and/or

the piston barrel 102 to degrade. Operating the mud hammer 100 with drilling fluid increases the rate of this degradation. To help prevent this degradation, the wear sleeve 134 helps prevent contact between the piston 106 and the piston barrel 102. As the piston 106 moves, the wear sleeve

134 degrades rather than the (more expensive) piston 106 and/or the piston barrel 102. The wear

sleeve 134 is constructed of a suitable wear resistant material, such as for example, tungsten,

bizaloy, carbon, or diamond impregnated steel. The wear sleeve 134 may be replaceable upon

degrading to its wear limit at which the wear sleeve 134 would begin to be unable to prevent

contact between the piston 106 and the piston barrel 102. In various instances, the wear sleeve

134 is constructed such that it lasts for about as long as the drill bit 108 (e.g., about 40 hours of

continuous operation) during operation of the mud hammer prior to the wear sleeve 134 and the

drill bit 108 reaching their respective wear limits.

[0034] In instances in which the mud hammer 100 includes the valving set 132, the

valving set 132 also moves in a reciprocating motion. In such instances, the mud hammer 100

may include a wear sleeve 136 positioned between the valving set 132 and the piston barrel 102.

To help prevent degradation of the valving set 132 and/or the piston barrel 102, the wear sleeve

136 helps prevent contact between the valving set 132 and the piston barrel 102. The description

of the wear sleeve 134 applies equally to the wear sleeve 136. The wear sleeves 134 and 136

therefore prolong the operational lifetime of the mud hammer 100 in light of the degradation

inducing effects of operating the mud hammer 100 with drilling fluid.

[0035] In some aspects, the mud hammer 100 includes a bypass tube 104. The bypass tube

104 may be positioned through the piston 106. In some instances, the bypass tube 104 may be

positioned through the valving set 132. In some instances, the bypass tube 104 is centered with

respect to (e.g., positioned along a long axis of) the piston 106 and/or the piston barrel 102. In

some aspects, the bypass tube 104 has an inner diameter of between about two and three inches

(about 5.08 to 7.62 centimeters). The bypass tube 104 may be in fluid communication with the

drill bit 108 (e.g., at the interface 118) such that drilling fluid may be delivered to the drill bit 108

through the bypass tube 104. The example mud hammer 100 may be configured such that a

metered portion of drilling fluid delivered to the mud hammer 100 is directed through the bypass

tube 104, while a remaining portion of the delivered drilling fluid is pushed under pressure into

the mud hammer 100 to operate the mud hammer 100. For example, from the flow 14 of drilling

fluid, a portion 16 of the flow 14 flows into the bypass tube 104, while the portion 18A and the

portion 18B flow into the mud hammer 100. Metering the amount of drilling fluid that gets

delivered to the drill bit face 120 through the bypass tube 104 helps prevent the high pressure

cushion problem that may result when too much drilling fluid or mud is delivered to the drill bit

face 120.

[0036] In various aspects, to control the metered flow into the bypass tube 104, the mud

hammer 100 may include a valving set 130. The valving set 130 may be a single valve or adapter

or may be multiple valves and/or adaptors. In some instances, the valving set 130 may be a

component of the bypass tube 104. In other instances, such as the one illustrated, the valving set

130 may be positioned at the receiving end of the bypass tube 104. The valving set 130 may be

configured to allow a set amount (e.g., the flow 16) of fluid delivered to the mud hammer 100

(e.g., the flow 14) to pass into the bypass tube 104. In some instances, the set amount may be an

amount that is less than 80% of the total delivered drilling fluid. In some instances, the set amount

may be an amount between about 50% to 80% of the total delivered drilling fluid. In some aspects,

the valving set 130 may be non-adjustable such that it is configured to allow only a single set

amount. In other aspects, the valving set 130 may be adjustable such that a drill operator may

adjust the set amount of fluid that the valving set 130 is configured to allow to flow into the bypass tube 104. In such other aspects, the adjustability provides drill operators with the ability to alter the amount of drilling fluid delivered to the drill bit face based on different drilling conditions and geology.

[0037] As mentioned, the mud hammer 100 includes a drill bit 108. In some aspects, the

drill bit 108 may be coupled to the body of the mud hammer 100 such that it is removable. The

drill bit 108 includes a drill bit face 120. The drill bit 108 may include one or more exit ports

122A, 122B that enable fluid to exit at the drill bit face 120. The one or more exit ports 122A,

122B are in fluid communication with the bypass tube 104. The flow 16 of drilling fluid that

travels through the bypass tube 104 exits at the drill bit face 120 as one or more flows 124A, 124B.

The one or more flows 124A, 124B help flush cuttings away from the drill bit 108 during operation

of the mud hammer 100.

[0038] In some aspects, the body of the mud hammer 100 may include a drive sub that

includes the drive sub 138 and a shroud 226 (FIG. 2). In such aspects, the drive sub 138 includes

stabilizer wings. In some aspects, the drive sub may also include a suitable bit retention system

for retaining the drill bit 108.

[0039] In at least some instances, the pistonbarrel 102 of the mud hammer 100 may include

one or more exhaust ports 110A, 1OB. Two exhaust ports 110A, 1OB are illustrated in FIG. 1,

though it should be appreciated that the piston barrel 102 may include a single exhaust port or

more than two exhaust ports. The single exhaust port may extend around any suitable portion of

the piston barrel 102, in various instances. After drilling fluid has operated the piston 106, and in

some instances the valving set 132, the drilling fluid may exit the piston barrel 102 through the

one or more exhaust ports 110A, 1OB. The exhaust from the exhaust ports1OA, 1OB is directed

in a direction (e.g., upwards during operation) away from the drill bit 108, as indicated by the exhaust flows 112A and 112B. Directing the exhaust flows 112A, 112B away from the drill bit

108 may help assist in flushing cuttings away from the drill bit 108.

[0040] FIG. 2 illustrates an exploded view of an example mud hammer 200. In various

instances, the mud hammer 100 may include any of the components of the mud hammer 200, and

vice versa. It should also be appreciated that the components illustrated in FIGS. 1 and 2 are not

necessarily shown to scale. The example mud hammer 200 may include a top sub 126. In some

instances, the mud hammer 200 may include a bypass tube 104. A valving set 130 may be

positioned at a receiving end of the bypass tube 104. In some instances, one or more o-rings 202

may be positioned between the bypass tube 104 and the valving set 130. The mud hammer 200

may include a piston 106. In some instances, the mud hammer 200 may include a wear sleeve

134. The mud hammer 200 may include a piston barrel 102. In some instances, the mud hammer

200 may include a drive sub 138. The mud hammer 200 may include a drill bit 108.

[0041] In various instances, the mud hammer 200 may include any suitable combination

of the following components: one or more o-rings 204, a cirlip 206, a distributor 208, a top barrel

or sub 210, a check valve or plunger 211, a y-ring or check valve 212, a spring 214, a compression

buffer 216, a bypass tube mount 218, a bearing bush 220, one or more bit stop rings 222 and 224,

and a shroud 226. In some instances, the compression buffer 216 may be a ring, such as a steel

ring. The check valve or plunger 211, the y-ring or check valve 212, the spring 214, and/or the

compression buffer 216 may compose a valving set 132. In some instances, the bearing bush 220

may be cold pressed. In some instances, the bit stop ring 222 may be an o-ring. FIG. 3 illustrates

a perspective view of the example mud hammer 200 shown exploded in FIG. 2.

[0042] FIG. 4 illustrates a flow chart of an example drilling method, according to an aspect

of the present disclosure. Although the example method 400 is described with reference to the flowchart illustrated in FIG. 4, it will be appreciated that many other methods of performing the acts associated with the method 400 may be used. For example, the order of some of the blocks may be changed, certain blocks may be combined with other blocks, and some of the blocks described are optional.

[0043] A mud hammer may be positioned in a drilling well (block 402). For example, the

mud hammer may be any of the described embodiments of the mud hammer 100. In another

example, the mud hammer may be any of the described embodiments of the mud hammer 200. A

single flow of drilling fluid may be directed to the mud hammer via a single flow drill pipe (block

404). The drilling fluid includes drilling mud. The single flow drill pipe may be any suitable,

standard API-certified drill pipe. In an example, the mud hammer 100 positioned in the drilling

well is constructed to operate on drilling fluid, which enables directing a single flow of drilling

fluid to the mud hammer. This is in comparison to at least some typical DC fluid hammers, which

require a dual circulation drill pipe system to separate drilling mud from clean water. At least

some of such typical DC fluid hammers are unable to operate via a single flow drill pipe. Some

typical DC fluid hammers may be adapted to operate via a single flow drill pipe, but such adaption

results in an inefficient mud or fluid hammer as compared to the provided mud hammer 100 or

200.

[0044] The mud hammer may then be operated to drill in the drilling well (block 406). In

an example, of the single flow of drilling fluid that is directed to the mud hammer 100, a set amount

(e.g., between 50% and 80%) of drilling fluid flows into the bypass tube (e.g., the bypass tube 104)

of the mud hammer 100 during operation. In various instances, the drilling fluid that flows into

the bypass tube 104 exits the mud hammer 104 at a drill bit face (e.g., the drill bit face 120) of the

mud hammer 100. A remaining portion of the single flow of drilling fluid may flow into the mud hammer 100, exteriorly to the bypass tube 104, to operate the mud hammer 100. In some aspects, the method 400 may further include replacing one or more wear sleeves (e.g., the wear sleeve 134 and/or the wear sleeve 136) of the mud hammer. In an example, the wear sleeve 134 and/or the wear sleeve 136 are replaced once they reach a respective wear limit. In an example, the wear sleeve and/or the wear sleeve 136 are constructed such that their respective wear limits take about the same amount of time to reach as a wear limit of the drill bit 108 during operation of the mud hammer 100.

[0045] As used herein, "about," "approximately" and "substantially" are understood to

refer to numbers in a range of numerals, for example the range of -10% to +10% of the referenced

number, preferably -5% to +5% of the referenced number, more preferably -1% to +1% of the

referenced number, most preferably -0.1% to +0.1% of the referenced number.

[0046] Furthermore, all numerical ranges herein should be understood to include all

integers, whole or fractions, within the range. Moreover, these numerical ranges should be

construed as providing support for a claim directed to any number or subset of numbers in that

range. For example, a disclosure of from I to 10 should be construed as supporting a range of from

I to 8, from 3 to 7, from I to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.

[0047] The terms "comprise", "comprises", "comprised" or "comprising", "including" or

"having" and the like in the present specification and claims are used in an inclusive sense, that is

to specify the presence of the stated features but not preclude the presence of additional or further

features.

[0048] The examples and aspects disclosed herein are to be construed as merely illustrative

and not a limitation of the scope of the present disclosure in any way. It will be apparent to those

having skill in the art that changes may be made to the details of the above-described examples without departing from the underlying principles discussed. In other words, various modifications and improvements of the examples specifically disclosed in the description above are within the scope of the appended claims. For instance, any suitable combination of features of the various examples described is contemplated.

Claims (5)

niuiiik-Y L-JUj~s-LK INUk. /UVUI'-t/t.UUUU't CLAIMS The invention is claimed as follows:

1. A mud hammer comprising:

a piston barrel including at least one exhaust port configured to receive a single flow of

drilling fluid including drilling mud;

a piston positioned within the piston barrel and configured to move in a reciprocating

motion operated by a first portion of the drilling fluid;

a bypass tube disposed through the piston and in fluid communication with a percussion

drill bit;

an adjustable valving set configured to divert a second portion of the drilling fluid into

the bypass tube; and

a wear sleeve positioned to prevent contact between the piston and the piston barrel,

wherein the second portion of the drilling fluid diverted into the bypass tube is exhausted

from the drill bit and the first portion of drilling fluid is exhausted from the piston barrel via the

exhaust port, in a direction away from the drill bit.

2. The mud hammer of claim 1, wherein the adjustable valving set is positioned at a

receiving end of the bypass tube.

3. The mud hammer of claim 1, wherein the adjustable valving set is a first valving set, the

mud hammer further comprising a second valving set configured to generate the reciprocating

motion of the piston, and niuiiik-Y L-JUj~s-LK INUk. /UVUI'-t/t.UUUU't wherein the wear sleeve is a first wear sleeve, the mud hammer further comprising a second wear sleeve positioned to prevent contact between the second valving set and the piston barrel.

4. A system comprising:

a single flow drill pipe configured to deliver a single flow of drilling fluid including

drilling mud;

a mud hammer in fluid communication with the single flow drill pipe, the mud hammer

comprising:

a piston barrel including at least one exhaust port;

a piston positioned within the piston barrel and configured to move in a

reciprocating motion operated by a first portion of the drilling fluid;

a bypass tube disposed through the piston and in fluid communication with a

percussion drill bit;

an adjustable valving set configured to divert a second portion of the drilling fluid

into the bypass tube; and

a wear sleeve positioned to prevent contact between the piston and the piston

barrel,

wherein the second portion of the drilling fluid diverted into the bypass tube is exhausted

from the drill bit and the first portion of drilling fluid is exhausted from the piston barrel via the

exhaust ports, in a direction away from the drill bit.

5. A method for drilling comprising:

positioning a mud hammer in a drilling well, the mud hammer comprising: niuiiik-Y L-JUj~s-LK INUk. /UVUI'-t/t.UUUU't a piston barrel including at least one exhaust port; a piston positioned within the piston barrel and configured to move in a reciprocating motion operated by a first portion of a drilling fluid; a bypass tube disposed through the piston and in fluid communication with a percussion drill bit, the drill bit having a drill bit face; an adjustable valving set configured to divert a second portion of the drilling fluid into the bypass tube; a wear sleeve positioned to prevent contact between the piston and the piston barrel; directing a single flow of the drilling fluid to the mud hammer via a single flow drill pipe, the drilling fluid including drilling mud; and operating the mud hammer to drill in the drilling well, wherein the second portion of the drilling fluid diverted into the bypass tube is exhausted from the drill bit at the drill bit face and the first portion of drilling fluid is exhausted from the piston barrel via the exhaust port, in a direction away from the drill bit.