FIELD OF THE INVENTION
The present invention relates to a novel wire line winch. More particularly, the
invention relates to a winch assembly having accelerated jarring effect. The invention
5 further relates to an improved hydraulic control circuit thus enabling fast acceleration
and stoppage with excellent running, pulling and jarring capability as and when
required.
BACKGROUND TO THE INVENTION
10
A winch is a mechanical device which finds utility in winding up or out or otherwise
while adjusting the tension of wire cable. The simplest forms consist of a reel or coil and
attached hand crank. In more complex forms, winches stand installed at the centre of
machines like tow trucks and elevators. The reel or coil, also known as the winch drum,
15 is the main component in winch devices. Modern designs have gear assemblies and are
powered by electric, hydraulic, pneumatic or internal combustion drives. Some further
include a solenoid brake and/or a mechanical brake or ratchet and pawl device that
prevents it from unwinding unless the pawl is retracted.
20 Winch assemblies are widely applicable in the oil and gas industry, for example down
hole operations involve installing, actuating, and removing various types of well
equipment and removing tools, for deploying objects or the like into wellbores on a rollable
medium. The roll-able means may include wireline, coiled tubing or the like.
Normally, winches are installed at surface level, such as on a platform, and the wireline
25 extends into a wellbore through special surface equipment such as 'Blow Out
Preventers', injectors, stuffing boxes etc. which maintain a seal between the wellbore
and the environment.
Surface mounted winches are based on a common basic design and include a rotatable
drum for supporting the wireline, a drive source, such as a motor, for rotating the drum,
and a transmission assembly, such as a gear box for transmitting drive to the drum. As
the winch is mounted within ambient conditions, conventional components and
5 equipment may be readily utilized. Some of these well wireline services utilize tools
connected to a long length of steel wireline necessary to reach the work area in the
well.
Coiled tubing is used to control downhole valves, manifolds and other well tools. In
10 addition, electric logging may be performed by means of wires run within the coiled
tubing. Yet another operation that may be performed with coiled tubing is well cleaning,
washing or swabbing by means of fluids or gases run through the tubing.
A great deal of force, acceleration, and speed is needed to operate tools in the well.
15 Powerful mechanical rotational means such as diesel engine driven wireline reels have
been used to achieve the necessary pulling force. Both powerful torque and jarring
actions are required of a wireline reel system. The wireline service industry usually
achieves the requirement by various methods of gears, drive couplings, chains,
sprockets, levers, dog clutches, etc. connected to a large horsepower prime mover such
20 as a diesel engine.
During the jarring operation a well tool is set, activated, deactivated, stuck, or being
removed. Jarring normally requires some tension be maintained on the wireline so that
the wireline doesn't entangle on the wireline reel. In general, pneumatic brake may be
25 used in jarring operations to build up more acceleration power before rotation
commences. Basically, the jarring tool is able to apply an impact force that amplifies
tension applied to the carrier structure. The amplified impact force is transmitted to
other tools in the tool string to which the jarring tool is coupled so that the tool string
can be freed.
Due to complex and cumbersome protocols of operating the wireline winches, the
5 management of winding up of the wireline becomes even trickier. -
Conventional jarring tools rely exclusively on application of tension over the carrier
structure to initiate and control the intensity and timing of the jarringforce. A right
combination of tension in the wireline and the torque during operations for the purpose
of improving the jarring effect is yet to be achieved. The state of the art winches have
10 problems of frequent breakdown, increased down-time and ineffective jarring action
which leads to frequent entanglements and mismanagement of wireline.
OBJECT OF THE INVENTION
15 The main object of the invention is to provide a wireline winch assembly with improved
and accelerated jarring effect.
Another object of the invention is to provide a wireline winch assembly which is easy
and quick to operate.
20
Yet another object of the invention is to address the requirement of hassle free
functioning of wireline winch especially at the stage of winding in of the wireline.
Yet another object of the invention is to provide an improved hydraulic control circuit
2 5 for the winch assembly.
Yet another object of the invention is to increase the pulling and jarring capability of
wireline winches.
Yet another object of the invention is to save the down time in repairing and performing
various downhole operations.
Still another object of the invention is to obviate the drawbacks of presently available
5 winch assemblies.
SUMMARY OF THE INVENTION
The present invention relates to a novel wire line winch. More particularly, the
10 invention relates to a winch assembly having accelerated jarring effect. The invention
further relates to an improved hydraulic control circuit thus enabling fast acceleration
and stoppage with excellent running, pulling and jarring capability as and when
required.
15 In one aspect, the present invention aims at improving the wire line operations while
doing work-over services in producing oil wells. The disclosed invention relates to
advantageous and significant improvement on the existing jarring process. The purpose
of the invention is to provide accelerated jarring action through wire line tools on tubing
accessories, such as Gas lift Valves, while doing the work-over in oil wells.
20
In another aspect, the present invention provides an improved and modified hydraulic
control circuit for fast acceleration and stopping action with excellent running, pulling
and jarring capability as and when required. The present invention provides an
assembly with utilizing Hydraulic displacement control in axial piston pump where
2 5 hydraulic input signal operates a four way servo valve. This arrangement ports provide
hydraulic pressure to either side of a double acting servo piston which in turn tilts the
cradle swash plate, thus varying the pump's displacement from full displacement in one
direction to full displacement in the opposite direction.
In another aspect, the present invention provides an improved calibration in the size of
orifice of the hydraulic pump to achieve the required rate of swash plate response for
acceleration and deceleration. Swash plate response time is the time required for the
pump output flow to change from zero to full flow (acceleration) or full flow to zero
(deceleration). This hydraulic signal pressure can be regulated by control flow process.
Thus the size of orifice incorporated in the passage of control flow can control the
desired hydraulic signal pressure and match the rate of swash plate response to the
acceleration and deceleration requirements of the application. The improved calibration
results into a significant improvement of 20% in response time.
In another aspect, the present invention provides a modification and adjustment of the
mechanical tension of the spring of the servo valve. The modified spring of the servo
valve provides an excellent and smooth acceleration and deceleration of the pump
delivery over the entire movement of the joystick control.
Moderating the size of the orifice in the pump to an optimum level and adjustment of
the mechanical tension of the spring are resulted in control flow of an appropriate
quantity of oil to the pump control and thus achieve maximum jarring effect according
to the invention.
In general, higher acceleration of wire line tools in minimum time, results into more
effective jarring. Better jarring is achieved in the set up of gas lift valves which results
into less down time. This saves time in repairing completion equipment while doing
work-over and repair-work in oil wells. This further saves lot of down time in producing
oil.
The present invention aims at determining the optimum size of orifice which will do
most effective jarring in oil wells. The results were achieved after a lot of simulation of
the hydraulic pump in relation to jarring effect on wire line tools.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be more completely .understood in consideration of the following
detailed description of various embodiments of the invention in connection with the
accompanying drawings.
FIG.l is a block diagram of the wireline winch system in accordance with the present
invention;
FlG.2 is a schematic diagram of engine-pump assembly;
FlG.3 is a closed loop system circuit diagram;
FIG.4 is a schematic diagram of pump in accordance with the present invention;
FIG.5 is a graph showing relation between the pump displacement and signal pressure;
FIG.6 & FIG.7 show diagrams of different stresses in a helical spring.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to exemplary embodiments of the present
invention, examples of which are illustrated in the accompanying drawings. It is to be
understood that other embodiments may be utilized and structural and functional
changes may be made without departing from the respective scope of the present
invention.
Referring to Fig.1, the wireline winch system is illustrated in a block diagram. The
system of the present invention comprises a wireline, a diesel engine driven variable
displacement hydraulic pump assembly 10, hydraulic communication hoses 11, a
wireline winch assembly 12, ,hydraulic hoses 13, a operator control panel 14 and
electrical instrumentation control wires 15.
5 The operator control console 14 provides controls for the operator to run the system
from an operating position advantageous to the wireline work performed. The operator
control console 14 is in communication with control and monitoring system of winch
assembly 12 by means of hydraulic hoses 13. In the same way the control console 14 is
in communication with hydraulic pump assembly 10 by means of electrical
10 instrumentation control wires 15. Hydraulic communication hoses 11 allow passage of
hydraulic fluid power to release winch assembly 12 and for the return of used power
fluid back to hydraulic pump assembly 10 in a closed loop hydraulic system.
Referring to Fig.-2, the engine-pump assembly comprises a diesel engine 16 af sufficient
15 horse power capacity to meet the requirement of the system, a variable displacement
and flow direction controllable hydraulic pump 17, a diesel tank 19, and a hydraulic oil
tank 20. The hydraulic pump 17 is controlled by hydraulic displacement control (HDC)
18.
Referring to Fig.-3, a closed loop hydraulic system is illustrated in a circuit diagram. The
closed loop hydraulic system comprises a reversible variable displacement pump 17 and
a variable displacement motor 32. The hydraulic lines 35 connect the main ports of the
pump 17 to the main ports of the motor 32. Fluid flows in the direction from the pump
17 to the motor 32 and then back to the pump in 17 this closed circuit. Either of the
hydraulic lines 35 can be under high pressure. Here the position of pump swash plate 22
determines which line has high pressure as well as the direction of fluid flow.
The reversible variable displacement pump 17 comprises of an input shaft 21, pump
swash plate 22, and servo control cylinders 23. The multifunction valve 24 is used to
control the fluid flow in hydraulic lines 35. The hydraulic displacement control valve 18,
charge pump 25, charge pressure relief valve 26, servo-pressure relief valve 27, heat
exchanger 28, hydraulic oil reservoir 29, suction stainer 30, and hydraulic remote
control (Joystick) 31 are connected in a closed loop hydraulic system.
The charge pump 25 is necessary to supply cool fluid to the system to maintain the
positive pressure in the main system loop. It also provides pressure to operate the
control system and to control the internal leakage. The charge pump 25 is a fixed
displacement gerotor type pump driven off the main pump shaft. The Charge pressure
relief valve 26 on the pump maintains charge pressure at a designated level. A directacting
poppet valve relieves fluid when charge pressure reaches a certain level.
The multifunction valve 24 comprises of a system check valve, a pressure limiter valve, a
high pressure relief valve, and a bypass valve in a replaceable cartridge. There are two
multifunction valve cartridges in each pump 17 to handle functions in either direction.
This pump has a sequenced pressure limiting system and high pressure relief valve.
When the system pressure reaches a preset value, the pressure limiter rapidly de-stroke
the pump to limit system pressure. For unusually rapid load application, the high
pressure relief valve immediately limits pressure by cross-porting system flow. The
pressure limiter valve acts as a pilot for the high pressure relief valve spool. The high
pressure relief valve is sequenced to operate at approximately 35 bar (500 Psi) above
the level that initiates the pressure limiter value.
Referring to Fig.4, a pump is illustrated in a schematic diagram which comprises a
reversible variable displacement pump 17, a charge pump 25, a charge pressure relief
valve 26, multifunction valves 24, a hydraulic remote control (joystick) 31, a hydraulic
displacement control valve 18 and a servo-piston 40.
The hydraulic displacement control valve 18 uses a hydraulic input signal to operate a
spring centered four way servo valve. This valve ports hydraulic pressure to either side
of a dual-acting servo piston 40. The servo piston 40 rotates the cradle swash plate 22
through an angular rotation of It 17', thus varying the pumps displacement from full
displacement in one direction to full displacement in the opposite direction. The angular
position of the pump swash plate 22 is proportional to input pressure. The angle of
swash plate 22 controls the volume of fluid displaced into the system. The servo piston
40 forces the swash plate 22 into the inclined position.
The hydraulic displacement control is a high gain control. A small change of input signal
moves the servo valve into a full open position which permits maximum flow to servo
cylinder resulting in full displacement of pump. The response time that is the time
required for the pump output flow to change from zero to full flow (acceleration) or full
flow to zero (deceleration) is a function of hydraulic signal pressure and which can be
regulated by control flow passage. The control flow may be controlled by size of orifice
incorporated in passage of control flow.
Referring to Fig.5, a graph is illustrated showing the relation between the pump
displacement and signal pressure. The present invention results into a significant
improvement of 20 % in response time by incorporating the following:
1. The improved calibration in the size of orifice achieves the required rate of
swash plate response to the acceleration and deceleration.
2. The modification and adjustment in the mechanical tension of the spring of the
servo valve responding to input signal pressure for achieving the smooth
acceleration and deceleration of the pump delivery over the entire movement
of the joystick control.
Orifice is a small opening of any cross-section to control the flow of fluid resulting in
5 speed regulation in a hydraulic system. The present invention controls the speed of
servo piston by regulating the flow rate. The improved calibration in the orifice size 0.81
mm to 2.34 mm results the best jarring effect.
EXAMPLE 1
10 Based on Formula:-
Area (Sq. In) = 0.3208 X GPM
Velocity (ft/Sec.)
GPM = Area (Sq.in) X Velocity (ft1Sec.l
0.3208
= T[ r2 (Sq.in) x Velocity (ft1Sec.l
0.3208
- 20 Initially the orifice size was 0.81mm (0.032")
-- 0.0160/0.3208
-- 0.050 Gallons per min
-- 0.225 Liters per min.
We have modified the orifice size to 2.34 mm (0.092")
= 0.13288 ( r= 0.09212 = 0.046)
0.3208
= 0.414 gallons per min.
= 1.864 litres per min.
Thus by changing the orifice diameter from 0.81 mm to 2.34 mm the output flow from
the orifice has increased from 0.225 LPM to 1.864 LPM. This increased flow increases
the servo piston's actuation and resulting in tilting the swash plate more quickly means
better jarring effect say 20% improvement.
The modifications and adjustments in the mechanical tension of the spring of servo
valve responding to input signal pressure and achieving the smooth operation of pump
over the entire movement of joystick control. The helical springs are made from hard
drawn carbon steel wire containing 0.60 to 0.70 percent Carbon and 0.60 to 1.0 percent
manganese. The wire of spring with greater strength and less ductility has been used in
the present invention. The modified wire of spring has following properties:
i) Modulus of Shear Stress (r) around 483 Mpa.
ii) Modulus of Rigidity(G) around 80 ~ ~ / m m ~
iii) Modulus of Elasticity(E) around 210 ~ ~ / m m *
Referring to Fig.6 & Fig.7, diagrams of different stresses in a helical spring are
illustrated.
EXAMPLE 2
Considering a helical compression spring made of circular wire and subjected to an axial
load W.
D = Mean Diameter of Spring Coil
d = Diameter of the Spring Wire
n = Number of Active Coils
G = Modulus of Rigidity for the Spring Material
W = Axial Load on the Spring.
TI = Maximum Shear stress inducted in the wire
C = Spring Index = D/d
As per Fig.6 (b) the load W tends to rotate the wire due to twisting moment (T) set up in
the wire. This torsional shear stress is indicated in the wire,
T=WXD/2
= n/16 X rl X d3
rl =8 W.D/ (nxd3)
In addition to the torsional shear stress (rl) indicated in the wire, Direct Shear stress due
to load W also acts.
Direct Shear Stress due to Load W,
r2 = Load/ Cross sectional Area of the wire
= W/ (n/4 x d2)
= 4w/nd2
Now Maximum shear stress inducted in wire
= Torsional Shear stress + Direct Shear Stress
Where C = D/d
Data of the spring modified are as below:-
Spring Free Length - 57.4 mm
Spring Solid Height - 39.4 mm
Diameter of Wire - 2.3 mm
5 Spring 0.D - 14.2 mm
Spring I.D - 9.68 mm
Min. Load to start to move Compression - 2 N
TABLE-1: LOAD TEST
Deflection (mm) I Load (N)
Maximum Shear Stress inducted in Spring wire
-- Torsional Shear Stress + Direct Shear stress
484.86 Mpa (Matching with desired value)
Higher acceleration of wireline tools in minimum time results into more effective
jarring.
It should be understood that the embodiments described above are merely exemplary
and that modifications may be made thereto without departing from the scope of the
present invention.
It is to be understood that the present invention is not to be limited to just the
preferred embodiment disclosed, but that the invention described herein is capable of
numerous rearrangements, modifications and substitutions without departing from the
scope of the claims hereafter.

We Claim:
1. A wireline winch system having accelerated jarring effect comprising:
a winch housing; a diesel engine driven variable displacement hydraulic pump
assembly (lo), hydraulic communication hoses (ll), a wireline winch assembly (12),
hydraulic hoses (13), an operator control panel (14) and electrical instrumentation
control wires (15);
Wherein:
a reversible variable displacement pump (17) is defined within the hydraulic pump
assembly (10) and an orifice is calibrated to permit fluid communication to achieve the
required rate of swash plate (22) response and the desired hydraulic signal pressure;
and
an adapted spring of the servo valve within the housing of a hydraulic displacement
control valve (18) is used for excellent and smooth acceleration and deceleration of
the pump delivery over the entire movement of the joystick control (31).
2. The wireline winch system as claimed in claim 1, wherein the said diesel engine driven
variable displacement hydraulic pump assembly (10) further comprises of a reversible
variable displacement pump (17) and a variable displacement motor (32).
3. The wireline winch system as claimed in claim 2, wherein the said diesel engine driven
variable displacement hydraulic pump assembly (10) is in a closed loop circuit.
4. The wireline winch system as claimed in claim 2, wherein a reversible variable
displacement pump (17) is defined within the hydraulic pump assembly (10) and an orifice
is calibrated to permit fluid communication.
5. ' The wireline winch system as. claimed in claim 4, wherein the size of said orifice is
calibrated in the range of 0.81 mm to 2.34 mm.
6. The wireline winch system as claimed in claim 2, wherein a hydraulic displacement control
valve (18) is defined within the hydraulic pump assembly (10) and an adapted spring of
the servo valve is used for excellent and smooth acceleration and deceleration of the
pump delivery over the entire movement of the joystick control (31).
7. The wireline winch system as claimed in claim 6, wherein the said adapted spring having
Modulus of Shear Stress, T value of 483 Mpa, Modulus of Rigidity, G of 80 K ~ / m man~d
Modulus of Elasticity, E of 210 K~/rnm~.