Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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STIMULATION AND INJECTION SYSTEM
FIELD OF THE INVENTION
The invention relates to a system for injection of a vapor-containing stream
and chemicals into underground formations, pumps, conduits or tanks.
BACKGROUND OF THE INVENTION
Previous technologies have attempted to recover oil by injecting hydrogen
peroxide into the fornzation and allowing uncontrolled decomposition and
heating.
This often resulted in down hole fires and damage to equipment.
One improvement to the direct injection of hydrogen peroxide was made by
utilizing an in line vertical steam generator that could be used to cap the
well head.
The decomposition of hydrogen peroxide and silver mesh generated steam and
oxygen, which were directly injected into the formation. Problems with this
system
occurred due to an inability to precisely control temperature and pressure,
which
resulted in damage to formations and well heads.
BRIEF SUMMARY OF THE INVENTION
This invention is an improvement over the prior art. It utilizes a
configuration which can allow generated vapor-containing stream to bypass the
well
and be released to the atmosphere. An injection system for injection of water
is
included to moderate the temperature at the injection site or in the injected
sites.
The strength (%) of the hydrogen peroxide solution can be used to control or
vary
pressure and heat. Increased efficiency is obtained by pre-heating the
catalyst screen
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and using, for example, a silver screen coated with samarium oxide. The system
also allows injection of treatment chemicals along with the vapor-containing
stream.
The system has many applications and capabilities, due to its unique creation
of a heated vapor-containing stream at various temperatures and pressure, it
becomes an ideal injection system for paraffin problems in heavy crude and gas
depleted formations as well as in pumps, conduits or tanks which contain or
have
contained heavy crude, hydrocarbons and gas. The vapor-containing stream
generator may have a preheater some electric and some chemical and is capable
of
decomposing various percentages of HZOZ. It has variable pressure injection
pump,
as well as a throttle valve to start or stop as needed. It can be operated on
automatic
by presetting an operating temperature and sensing the controlled temperature
at
various locations on the well and the injection equipment. It has two heat
exchangers one for HZO and one for various chemicals including KIi30 or other
compositions to soften or liquefy paraffms. The heat exchangers are
temperature
controlled at various temperatures for specific need of certain chemicals.
They are
also used at variable pressures controlled by the injection pumps and there
drive
units.
The systems pumps may be driven by 12 volts DC, 120 volts AC, direct
drive gas engines and hydrostatic drives. If any of the systems fail there is
a back up
pump with a different drive. The system is fail-safe and cannot be operated
until the
gas generator has reached temperatures 350°F and above.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows one embodiment of the system as a schematic.
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DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a system utilizing at least one vapor-
containing stream generator to produce and inject a vapor-containing stream
which
can comprise steam, heated water, heated gas, and/or chemicals into
underground
formations, pumps, conduits or tanks. The system uses a vapor-containing
stream
drive with variable pressure a~.zd temperature, a steam drive with variable
pressure
and temperature, and chemical injection at variable pressures and temperature,
which allows custom tailored cyclic drives.
The injection system has many applications due to the ability to inject heated
vapor-containing streams at various temperatures and pressures. The injection
system is ideal for solving paraffin problems as well as a heavy crude and gas
depleted formations as well as in pumps, conduits or tanks. In addition the
system is
environmentally clean and easy to operate.
The pumps and vapor-containing stream generator and generator are present
in a single location, e.g., a truck. Thus, the system may be completely
mobile.
Each pump has a drive unit and each is capable of injecting various
chemicals and/or water or steam into the underground formations. Some of the
pumps operate at high pressure and some operate at low pressure.
The system generates heat from at least one hydrogen peroxide fueled vapor-
containing stream generator. The temperatures created are from ambient up to
1,300°F (704 °C) and the pressures are from zero to 2,500 psi.
The generator can
have a series of pre-heaters, some electric and some chemical, and is capable
of
decomposing various percentages of H202. The vapor-containing stream
generators
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have a variable pressure injection pump for injection of the H202, as well as
a
throttle valve to start or stop as needed.
The generators can be operated on automatic by presetting an operating
temperature and sensing the controlled temperature at various locations on the
well,
such as with temperature sensors clamped to the well seals, and on the
injection
equipment. The generators have heat exchangers, one for water to regulate
temperature and one for various chemicals, such as KH30. The heat exchangers
are
temperature controlled at various temperatures and are selected based on the
chemicals used. They are also used at variable pressures controlled by the inj
ection
pumps and their drive units.
The pumps may be driven by any suitable means such as 12 volts DC, 120
volts AC, direct drive gas engines and hydrostatic drivers. The pumps have
automated drive units. Preferably there is a backup pump with a different
drive in
case any of the pumps fail.
The system also has monitors for formation back pressure. The system is
fail-safe and cannot be operated until the gas generator has reached
temperatures of
350°F and above. The system provides short injection times and is
capable of
producing large amounts of ceded gas.
Generally the system is hooked up to a well and the water and/or chemicals
are injected into the well at various intervals. For example, heated gas is
injected
into the well for about 1 minute to about 60 minutes. The temperature of the
heated
gas generally ranges from 15°C to about 700°C at the well head
and at a pressure of
about 1 psi to about 3000 psi above the backpressure. Then a chemical such as
KH30 is injected into the well followed by additional heated gas at an
increased
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backpressure of about 1 psi to about 3000 psi above the well backpressure. The
process may be repeated and varied as needed to clean the well.
The apparatus for introducing a vapor-containing stream into underground
geological formations, pumps, conduits or tanks of this invention comprises:
at least one vapor-containing stream generator having a liquid hydrogen
peroxide fuel introduction zone, a catalyst zone and a zone for creating a
backpressure of a vapor-containing stream formed by the generator;
a conduit for introducing the liquid hydrogen peroxide fuel with said liquid
hydrogen peroxide having a concentration of from 70-98 weight percent into the
vapor-containing stream generator; means for directing the vapor-containing
stream
into the formation, pump, conduit or tank and means for introducing a fluid
into the
formations, pumps, conduits or tanks.
The apparatus can further comprise means for introducing a water-containing
fluid into the formation, pump, conduit or tank downstream of the means for
directing the vapor-containing stream into the formation, pump, conduit or
tank.
The vapor-containing stream is at a temperature of at least about 212°
F. The
apparatus can further include means for flushing the conduit as well as the
formation, conduit, pipe or tank prior to introducing the vapor-containing
stream
into the formation, conduit, pipe or tank as well as valve-means in the
conduit for
venting to atmosphere said vapor-containing stream. The apparatus can also
have a
second valve-means for cooperating with the valve-means to effect flow of the
vapor-containing stream into the conduit, pipe, conduit or tank with
concomitant
discontinuance of venting flow.
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The present invention also is directed to a process for introducing a vapor-
containing stream into a geological formation, a pump, a conduit or a tank for
effecting stimulation of flow of material in the formation, pump, conduit or
tank
wherein the process comprises:
(a) introducing hydrogen peroxide having a concentration of from
70 to 98% into at least one vapor-containing stream generator;
(b) passing the hydrogen peroxide into a catalyst zone of at least
one generator to generate a vapor-containing stream;
(c) introducing the vapor-containing stream from at least one
generator and a fluid to enhance the flow of material from said formation,
pump,
conduit or tank; and
(d) enhancing the flow of material in the formation, pump,
conduit or tank. In the present process, the vapor-containing stream is at a
temperature of at least about 212° F.
Description of Figures
The diagram illustrated in figure 1 depicts a vapor-containing steam
generator assembly that employs two thermal pressure generators (16+32) that
can
be used simultaneously with each other or individually to each other. The
thermal
pressure generators (TPG) are comprised of a catalyst metered injection plate
(12), a
catalyst (not labeled), anti-channel baffles (14), a catalyst retainer plate
(15), and a
venturi .067 - .500 (17). Each thermal pressure generator will be equipped
with an
H202 heating band (11) and a catalyst heating band (13) to be used before the
initial
activation of the generators, this start up temperature will ensure H202
decomposition when introduced into each catalyst bed of the two generators.
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These two generators are connected to the TPG tree assembly (19) by flow
directors (18) which consists of heavy wall stainless steel. Between both
generators
are high temperature/high pressure check valves (21), which protect the
generators
from over pressurization and catalyst contamination. Upon thermal pressure
generator activation the vapor-containing stream is released to atmosphere
through a
normally open electric/pneumatic activated (EPA) vent valve (33), until the
desired
temperatures and system's ok are met. At that moment the normally open EPA
vent
valve then closes in harmony with the opening of the normally closed EPA main
injection valve (20) to introduce the vapor-containing stream to another high
temperature/high pressure check valve (21). This check valve initially
prevents the
TPG tree assembly from over pressurization and catalyst contamination.
Finally, the
vapor-containing stream exists through the quick connect coupling (22).
There are three injection lines located on the TPG assembly tree, one
between both generators, which is incorrectly labeled as (38), this injection
line is a
secondary H20 injection line. The next being the H2,0 primary injection line
(35),
which is located right below the EPA vent valve these two injection lines
provide
temperature control and saturation content within the vapor-containing stream.
Both
injection lines can be actuated simultaneously or independent of each other
The final
injection line can be found below the EPA main injection valve, this line
delivers
I~H30 downstream in an atomized flow (38).
The vapor-containing stream generator assembly is not only comprised of the
TPG tree assembly but also a fluid, air and fuel supply system. These systems
begin
with the fuel supply, consisting of a H202 tank reservoir (3), which would
contain
hydrogen peroxide that would be filled and properly vented through the
reservoir's
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fill and vent (2). Under the control of the EPA H202 supply valve (4), the EPA
H202 injection valve (8), and the EPA H202 injection valve (30) the fuel can
be
directed to either or both thermal pressure generators by means of the H202
pump
(7). The fuel supply is then coupled right before the TPG units by check
valves
(9+31) to protect the fuel supply system. In the case of H202 pump failure,
pump
cavitation or any system failure, there is an EPA bypass valve (5) and a
safety relief
(6) surrounding the H202 pump.
The fluid systems seen in figure 1 consist of an H20 delivery and a I~H30
delivery. The I~H30 fluid system will be explained lastly after the air system
since
the H20 and air system somewhat coincide with one another. The H20 supply
depicted in figure 1 is comprised of a H20 tank reservoir (50) with a H20 tank
fill/vent (51). The system routes in multiple paths to provide a failsafe for
essentially any mechanical failure in the H20 delivery to the TPG tree
assembly.
The first path is controlled by the EPA primary H20 injection supply valve
(49),
which opens to introduce H20 to two independent H20 injection lines under the
control of two different EPA H20 injection valves (37+24), both lines are
coupled
with a check valve (36+23) before the injection line to provide no back flow.
This
H20 injection path is powered by the primary H20 pump (46), and outfitted with
a
safety relief (47) surrounding the pump. Both H20 injection lines can be
actuated
simultaneously or independently.
The secondary path is bifold because its serves two purposes; one of which is
a secondary pump back up and the other purpose deals with post TPG activation
in
which I like to call the "cleaning" cycle or the flush system. The secondary
backup
system is powered by an H20 pump (48) which delivers H20 under the control of
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the EPA H20 injection secondary pump backup valve (25) to the two independent
EPA H20 injection valves (again 24+37) in case of H20 primary pump (again 46)
failure. This provides a failsafe for the temperature control and saturation
content.
The flush system is under the controls of the EPA H20 flush injection valve
(26),
the EPA bypass valve (again 5), and the EPA H202 injection valves (again
8+30).
It is primarily powered by the secondary H20 pump (again 48), but in the case
of
the secondary H20 pump failing the flush system can be rerouted. This
alternate
route is under the control of the EPA primary H20 injection supply valve
(again 49),
the EPA H20 injection secondary pump backup valve (again 25), the EPA H20
flush injection valve (again 26), the EPA bypass valve (again 5), and the EPA
H2.02
injection valves (again 8+30). The secondary routing is powered by the primary
H20 pump (again 46). The flush system can only be actuated after post
activation
of the thermal pressure generators. This flush system initially begins with
the
deactivation of the H202 pump (again 7), the closing of EPA H202 supply valve
(again 4), and then the disconnection of H202 fuel delivery lines at the
primary
coupler directly before both thermal pressure generators. After disconnection
the
injection of H2~ "cleanses" the H202 fuel delivery line of any excess H202
left
within the line. The flush system also coincides with the air system, which is
the
second part of the flush system. It is comprised of an air purge supply (29),
and
under the control of the EPA air purge injection valve (28), the EPA bypass
valve
(again 5), and the EPA H202 injection valves (again8+30), which when opened
forces air through the previously flushed H202 fuel delivery lines. The
purpose is
to then force outward and dry any H20 left in the H202 delivery line, making
it safe
and ready for transport. The air system also has its own safety feature
involving an
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inline air purge check valve (27) to ensure nothing overcomes the air purge
supply
or valve.
The final fluid system, which will conclude the overview of figure l, is the
chemical injection system. This system is comprised of a KH30 tank reservoir
(44),
which is constructed with a fill/vent (45). The system is order control of the
I~HH30
EPA injection supply valve (43) and the KH30 EPA injection valve (40), the
system
itself is powered by the KH30 injection pump (42). It is located between the
two
valves. This pump is also surrounded by a safety relief (41) to ensure the
pump
itself will be in a looped cycle when the KH30 injection supply valve (again
43) is
open and the KH30 EPA injection valve (again 40) is closed. It also has a
check
valve between the KH30 EPA injection valve (again 40) and the KH30 injection
line
(again 38) to provide assurance that nothing will overcome the I~H30 fluid
system.
The safety relief found on pumps 7, 42 and 46 are there because the pumps
are constantly running upon there primary valve actuation to provide a
constant loop
system for pumps when primary supply valves are open and injection valves are
closed.
While the present invention has been described with reference to the specific
embodiments thereof, it should be understood by those skilled in the art that
various
changes may be made and equivalents may be substituted without departing from
the true spirit and scope of the Invention. In addition, many modifications
may be
made to adapt a particular situation, material, composition of matter,
process,
process step or steps, to the objective, spirit and scope of the present
invention. All
such modifications are intended to be within the scope of the claims appended
hereto.
