1. Maxing Jars

2. Deployment of Maxing Jars
Drill Pipe
Maxing Jar
Other Down hole
Elements (Drill Collars
Etc.)
Maxing Double Hydraulic Jar
-Delay times constant with respect to
temp. and viscosity.
-Adjusting pull during delay adjusts
impact

3. MAXING DRILLING JARS
(Hydraulic Two-way)
O.D. I.D.
4 3/4” 121 mm 2 1/4” 57 mm
6 1/2” 165 mm 2 3/4” 70 mm
8” 203 mm 3” 76 mm
Deployment of Maxing Jars

4. Quality
The Max Jar is designed and constructed to withstand high
temperatures, high torques, H2S, CO2 and other corrosive
environments.
• Tool joints and API body connections are stress-relieved using a
modified API relief groove on pin connections and a modified bore back
on box connections.
• Wear areas are hard-surfaced for prolonged seal life.
• The use of Computer-Aided Design (CAD), Finite Element Analysis
(FEA) and Computer-Aided Manufacturing (CAM) enhances the
performance of the Maxing Energy Jars
.
Deployment of Maxing Jars

5. Features
• Hitting power adjustable at rig floor.
• Firing times are not affected by oil temperature or viscosity.
• Insensitive to right or left-hand torque.
• Standard operating temperatures up to 400°F (250°C?.) Special seals are
available upon request for higher operating temperatures.
• Can be run in an open or closed position.
• Spline end can be run in an up or down position
Deployment of Maxing Jars

6. Deployment of Maxing Jar

7. Jar Theory
“Jarring provides a method for
dynamically transferring strain energy
from the drill string above the Jar to
the stuck point below the Jar.”
A jar is used to free a “stuck pipe” by
generating an amplified force at the
stuck point using the energy from the
force applied at the surface.

8. Drill String acts like a spring
Hammer Weight
Anvil
Piston Provides Delay
Then release
Hammer Weight – all BHA tubulars
Above the jar
Anvil – the surface area where the
piston collides
Piston – moving part inside the detent
chamber
Jar Theory – Jar - Terms
Drill Pipe – the length of tubulars
Connected from the rig floor to top
Of the BHA

9. The energy of the jar comes
From the force applied on
Surface, this applied force is
Used to:
---Overcome the string weight
(if jarring up) and
---Overcome the drag
(resistance due to friction)
---- Fire the jar
Jar Theory – Storing energy

10. Jar Theory – Detent Mechanism
Detent System
A system that is used to restrict the
movement of a mechanical part (piston)
momentarily before releasing it.
------- Hydraulic Detent------
restriction created by metering
a hydraulic fluid
across an orifice
------- Restriction allow the drill
pipe to store energy by
stopping it from moving at one
point so the drill pipe
stretches/compresses
Detent
Area
Valve

11. Jar Theory – Up Jarring - Cocking the
Jar
--Drill String is lowered
-- Piston moves down into the detent cylinder
Jar is cocked
Lower drill pipe
To cock jar
HDWP – the
Hammer
weight
Detent system –
Piston moves down
and jar cocks
Stuck Point

12. Jar Theory – Up Jarring – Pulling Up
-Drill String is picked up with an
applied force (FAPP)
-The applied force first overcomes
the string weight (SW) and the drag
(friction due to motion)
-The force exceeding the SW and the
Drag the Over Pull (OP) then
stretches the drill pipe
OP = FAPP – SW – Drag
-The over-pull energy is stored in the
drill pipe as stretch
OP force stretches the
Drill pipe it acts as a
Spring – stores
energy
HWDP – the
Hammer weight
and the piston
free travel
U
P
F
O
R
C
E
J
A
R
Detent System restricts
Up movement as
Piston moves through
Detent cycle

13. Jar Theory – Up Jarring – Free Travel
-Jar Fires
-Piston moves pass restriction
in detent chamber. Fluid by passes
metering valve.
-Drill Pipe contracts at a recoil
velocity VC
-Piston and hammer weight above the jar
goes into free travel moving with
the same velocity VC
VC = FO VA / AC E
VC = free contraction speed of collar
FO = over pull
AC = cross-section of collar
VA = acoustic velocity of steel
E = constant for modulus of elasticity
of steel
OP force stretches the
Drill pipe it acts as a
Spring – stores
energy
HWDP – the
Hammer weight
and the piston
free travel
U
P
F
O
R
C
E
J
A
R
Stuck Point

14. Jar Theory – Up Jarring – Collision
-After free travel the piston
collides with the anvil
- Shock waves are generated
Equivalent to the final energy
Gained from moving the
Hammer weight at the
increased velocity VN
Amplified Energy
= ½ MVN 2
Drill pipe stretches
Acts as a spring –
Stores energy
HWDP – the
Hammer weight
Detent system
Restricts up
Movement as piston
Moves through
Detent cycle
Stuck Point

15. Jar Theory – Up Jarring – Collision
-Shock waves propagate
-Towards the stuck point
-Each wave releases a certain
amount of energy peaks which
creates a tensile force that
attempts to move the stuck
point up
Drill pipe stretches
Acts as a spring –
Stores energy
HWDP – the
Hammer weight
Stuck Point
Detent system
Restricts up
Movement as piston
Moves through
Detent cycle

16. Jarring Up
In order to fire the jar upwards, the operator must determine the force or pull
required to unlatch the jar to begin metering.
Formula:
Force required = lock setting + buoyed drill string weight above the jar + hole
drag – pump open force.
(Pump open force = pump open area x pressure drop across the bit)
Once this pull force is exceeded and applied to the jar, it will unlatch and begin
the metering sequence. During metering, the jar can be pulled with more/less
force to increase/decrease the jarring impact. The force or pull used will
determine the delay time of the jar until impact.
Jarring Down
To fire the jar down, the drill string is lowered applying weight to the latch that
exceeds the preset mechanical latch setting. At this point, the latch will release
allowing the jar to meter downwards until the jar fires, creating a downward
blow.
Formula:
Force required = lock setting + pump open force + hole drag.
Once the latch is released, the applied load should not exceed the maximum
allowable for pre-firing. If the jar is required to fire again, lift and reset the jar to
repeat the process. To return to drilling, the operator must lift up until off
bottom, and then continue drilling.

17. How to calculate the Buoyancy Factor.
The formulas below demonstrates how to determine this factor.
Buoyancy Factor (BF) = (65.5 - mud weight density in pound per gallon (ppg))
÷ 65.5
For example, if the drilling fluid weight is 13.0 pound per gallon
(ppg), as per the equation above, the factor can be calculated by
simply inputting mud weight density into the equation.
BF = (65.5 - 13.0) ÷ 65.5
BF = 0.8015
How to use the Buoyancy Factor.
In order to figure out the actual weight of drilling string in mud,
the air weight of drilling string times the buoyancy factor equal to
actual drill string weight, called buoyed weight, in drilling fluid.
The simple equation shows the relationship of actual weight in
drilling fluid.
Actual Weight = Air Weight of Drill String x BF