Note: Descriptions are shown in the official language in which they were submitted.
CA 02822235 2013-07-29
Gas-type combined thermal carrier generation system
Field of the invention
The present invention relates generally to an area of oil recovery technology,
and more
specifically to a gas-type combined thermal carrier generation system.
Background of the invention
Injecting saturated steam into oil formation for heavy oil extraction is one
of the extensively
applied methods worldwide. At present, injecting carbon dioxide and nitrogen
individually into oil
formation become a significant breakthrough in terms of new technology
application for high crude oil
production and enhanced oil recovery at various countries all over the world,
which have shown their
effects on oil production and economic benefits.
The combined thermal carrier containing high temperature nitrogen, carbon
dioxide, water vapor
as well as combustion heat carried is generated under the condition of closed
burning environment with
the help of both high temperature and high pressure combined thermal carrier
generator. In the
combined thermal carrier, carbon dioxide can play a role to dissolve crude oil
while nitrogen plays a
role of elastically flooding for crude oil, and steam plays a thermal role for
crude oil. The combined
thermal carrier is all injected through thermal injection pipeline into oil
formation so as to enhance oil
recovery and single-well productivity. Once injection is in process, it is
required to adjust the combined
thermal carrier based on injection parameters in terms of its temperature,
flow rate and total amount of
carrier injected thereby increasing the enhanced oil recovery and single-well
productivity. Meanwhile,
reliable control for temperature, pressure, and flow rate of the combined
thermal carrier becomes a
reliable technology for effectively compensating stratum energy for oilfields
with low permeability.
At present, the combined thermal carrier generator operates relying generally
on diesel as main
fuel. Though it has shown excellent cost performance in terms of enhanced oil
recovery and
comprehensive benefits in comparison to conventional oil recovery techniques,
diesel as fuel is still
costly. If natural gas supply is available in the oil reservoir, the cost of
natural gas is obviously lower
than that of diesel. In such an oil reservoir most of associated gas is
directly exhausted by either
discharging it into air or burning it out, such that it wastes useful fuel
material and pollutes the
CA 02822235 2013-07-29
environment as well.
Therefore, by considering to lower the running cost using natural/associated
gases as fuel, if
natural gas or associated gas is available or provided in oil reservoir area
the gas-type combined
thermal carrier generator using these gases as burning gas can reduce
production cost with the
combined thermal carrier.
Summary of the invention
In order to overcome the shortcomings mentioned above, it is an object of the
present invention to
provide a gas-type combined thermal carrier generation system in which the
natural gas or associated
gas as fuel generated along with the oil production in oil reservoir, it can
effectively reduce running
cost and realize carbon natural by reducing its emissions to zero as well as
energy saving and emission
reduction if oil reservoirs are available with these conditions mentioned
above in the light of
technology used to enhance the oil recovery and single-well productivity with
gas-type combined
thermal carrier comprehensive application.
The objective of the present invention is realized in such a way that it
applies a gas-type combined
thermal carrier generation system, which it comprises a combined thermal
carrier generator, air
pipeline, fuel pipeline and water pipeline, and an input end of the gas-type
combined thermal carrier
generator is connected with the air pipeline, gas pipeline and water pipeline,
respectively.
An air regulating valve, an air mass flow meter, an air pressure transmitter,
and an air check valve
are successively arranged on the air pipeline. A first gas pressure
transmitter, a gas stop valve, a gas
constant temperature control system, a gas flow regulating valve, a gas mass
flow meter, a second gas
stop valve, a second gas pressure transmitter, and a gas check valve are
successively arranged on the
gas pipeline. The gas flow regulating valve is connected in parallel with a
gas compensation regulating
valve. A feed water control valve, a high frequency pressure varying pump, a
first water pressure
transmitter, a water filter, a water mass flow meter, a second water pressure
transmitter, and a water
check valve are successively arranged on the water pipeline. An output end of
the combined thermal
carrier generator is connected with oil formation through a delivery pipework
of the combined thermal
carrier. The delivery pipework of the combined thermal carrier comprises a
thermal carrier pressure
transmitter, an output temperature transmitter, a first output safety valve, a
first electric blowoff valve,
an output check valve, and an output stop valve, connected one another
successively with pipelines.
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In a first aspect, the combined thermal carrier generator is further arranged
with a cooling water
temperature transmitter.
In another aspect, an output end of the combined thermal carrier generator is
further connected
with a pipeline for recovering waste liquor, which comprises a second output
safety valve and a second
electric blowoff valve connected one another with pipelines, and the second
output safety valve is
connected in such a way that it is arranged between the first output safety
valve and the first electric
blowoff valve.
In further another aspect, a compressed air bypass is arranged on the gas
pipeline, and the
compressed air bypass includes a bypass pressure transmitter and three safety
overflow valves
connected one another in parallel. The three safety overflow valves are
respectively connected with the
first gas stop valve, gas flow regulating valve and second gas stop valve in
series.
Compared with the prior-art technique, the gas-type combined thermal carrier
generation system
of the present invention uses natural gas or associated gas as fuel generated
in the process of oil
production in the oilfield, it can effectively reduce the running cost and
realize carbon natural by
reducing its emissions to zero as well as energy saving and emission reduction
if oil reservoir area is
available with these conditions mentioned above in the light of technology
used to enhance the oil
recovery and single-well productivity with gas-type combined thermal carrier
comprehensive
application.
Brief description of the drawings
These and other features, aspects, and performances of the present invention
will become better
understood when the following detailed description is read with reference to
the embodiments and
accompanying drawings herein below.
Figure 1 is a schematic of gas-type combined thermal carrier generation system
of one
embodiment of the present invention.
Figure 2 is a schematic to describe the principle of gas flow regulating
system of one embodiment
of the present invention.
Figure 3 is a schematic to describe the principles of gas flow regulation and
safety control system
of one embodiment of the present invention.
Figure 4 is a schematic to describe the principle of temperature control
system of one embodiment
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of the present invention.
Figure 5 is a schematic to describe the principle of safety control system of
one embodiment of
the present invention.
Description of numbers marked in the figures:
Combined thermal carrier generator
11 Cooling water temperature transmitter
12 Thermal carrier pressure transmitter
13 Output temperature transmitter
14 First output safety valve
First electric blowoff valve
16 Output check valve
17 Output stop valve
18 Second output safety valve
19 Second electric blowoff valve
Air pipeline
21 Air regulating valve
22 Air mass flow meter
23 Air pressure transmitter
24 Air check valve
Gas pipeline
31 First gas pressure transmitter
32 First gas stop valve
33 Gas constant temperature control system
34 Gas flow regulating valve
Gas compensation regulating valve
36 Gas mass flow meter
37 Second gas stop valve
38 Second gas pressure transmitter
39 Gas check valve
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40 Water pipeline
41 Feed water regulating valve
42 High frequency pressure varying pump
43 First water pressure transmitter
44 Water filter
45 Water mass flow meter
46 Second water pressure transmitter
47 Water check valve
51 Bypass pressure transmitter
52 Safety overflow valve
Detailed description of the embodiments
Referring to Fig. 1, gas-type combined thermal carrier generation system 100
of one embodiment
of the present invention may comprise a combined thermal carrier generator 10,
a air pipeline 20, a gas
pipeline 30, and a water pipeline 40. Combined thermal carrier generator 10
has three input ends and
one output end. These input ends are connected with the air pipeline 20, gas
pipeline 30, and water
pipeline 40, respectively, thereby introducing air, gas and water,
accordingly. In one embodiment, the
gas can be natural gas. In another embodiment, the gas can be associated gas
of oil reservoir. The
combined thermal carrier generator 10 can output the combined thermal carriers
comprising nitrogen,
carbon dioxide and water vapor as required.
An air regulating valve 21, an air mass flow meter 22, an air pressure
transmitter 23, and an air
check valve 24 are successively arranged on air pipeline 20.
A first gas pressure transmitter 31, a first gas stop valve 32, a gas constant
temperature control
system 33, a gas flow regulating valve 34, a gas mass flow meter 36, a second
gas stop valve 37, a
second gas pressure transmitter 38, and a gas check valve 39 are successively
arranged on gas pipeline
30. The gas flow regulating valve 34 is connected in parallel with a gas
compensation regulating valve
35.
A feed water regulating valve 41, a high frequency pressure varying pump 42, a
first water
pressure transmitter 43, a water filter 44, a water mass flow meter 45, a
second water pressure
transmitter 46, and a water check valve 47 are successively arranged on water
pipeline 40.
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The output end of combined thermal carrier generator 10 is connected with oil
formation through
a delivery pipework. The delivery pipework of the combined thermal carrier
comprises a thermal
carrier pressure transmitter 12, an output temperature transmitter 13, a first
output safety valve 14, a
first electric blowoff valve15, a output check valve 16, and an output stop
valve 17 connected one
another in order. The combined thermal carrier generator 10 is arranged with a
cooling water
temperature transmitter 11. The output end of the combined thermal carrier
generator 10 is further
connected with a pipeline for recovering waste liquor, which comprises a
second output safety valve 18
and a second electric blowoff valve 19 via pipelines connected one another.
The second output safety
valve 18 is connected in such a way that it is arranged between the first
output safety valve 14 and the
first electric blowoff valve 15.
A compressed air bypass 50 is arranged on gas pipeline 30. The compressed air
bypass 50
includes a bypass pressure transmitter 51 and three safety overflow valves 52
connected one another in
parallel. The three safety overflow valves 52 are respectively connected with
the first gas stop valve 32,
the gas flow regulating valve 34, and the second gas stop valve 37 in series.
In the combined thermal carrier generation system of one embodiment of the
present invention, air
is input through air regulating valve 21 and air mass flow meter 22, and gas
fuel mass is regulated with
gas stop valves 32 and 37 and gas mass flow meter 36, and vaporized water mass
is controlled by high
frequency pressure varying pump 42 and water mass flow meter 45, and output
temperature transmitter
13 is used to monitor and measure in situ output thermal carrier temperature,
to realize temperature
regulation for high temperature high pressure gas combined thermal carrier,
and flow rate control for
high temperature high pressure combined thermal carrier. The high temperature
high pressure
combined thermal carrier generated by combined thermal carrier generator 10
contains carbon dioxide,
nitrogen and water vapor, in which the temperature of the output thermal
carrier is controlled with
mixing the vaporized water such that nitrogen, carbon dioxide, and combustion
heat carried are
comprehensively utilized to enhance the oil recovery and single-well
productivity with this new
thermal extraction technology.
The high temperature high pressure combined thermal carrier generated by
combined thermal
carrier generator 10 contains carbon dioxide, nitrogen and water vapor, in
which the temperature of
output thermal carrier is controlled with mixing the vaporized water. In order
to secure safety in the
process of injection, the combustion is controlled in accordance to
coefficient of residual oxygen
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strictly within the range between 1.00-1.05, such that oxygen content of the
output thermal carrier is
much lower than 5% as required for safety sake. Finally, based on the
requirements of geological
technology concerning injection of thermal carrier to oil formation output
stop valve 17 is connected to
pipeline on ground to inject to the oil formation via Christmas tree under the
conditions of certain
temperature and pressure so as to satisfy the process requirements on
increasing single-well
productivity and enhanced oil recovery for oil reservoir. At the same time, in
order to satisfy the
different conditions of oil reservoirs, the injection flow rate in the process
of injecting high temperature
high pressure combined thermal carrier is controlled based on the air flow,
once the air flow is
confirmed the gas flow rate is automatically regulated such that the thermal
carrier is completely
combusted in high temperature and high pressure environment to output carbon
dioxide, nitrogen and
water vapor; Gas can be secured to be accurately combusted under the condition
of high pressure
through an automatic control system for gas flow rate in accordance to the
given proportion of
corresponding air mass; with accurate flow rate regulation by an automatic
regulating system for gas
flow and system compensation circulation control, it is realized to ignite the
fire smoothly with both
low flow rate high pressure and high flow rate high pressure to accurately
control the combustion in a
continuously stable and safety manner. A flow rate control system for high
pressure deionized water
can ensure the gas combined thermal carrier generator to be operated in safety
and thermal carrier
temperature to be controlled on the basis of process requirements as well.
Figure 2 is a schematic to describe the principle of gas flow regulating
system of one
embodiment of the present invention. Referring to Fig. 2, the gas-type
combined thermal carrier
generation system of one embodiment of the present invention controls the flow
rate by gas flow
regulating valve 34 of the gas flow regulating system, and a compensation
system is formed with gas
compensation regulating valve 35, and instantly blocking gas supply when power
off is realized with
gas stop valves 32 and 37, and gas constant temperature control system 33 is
used to ensure that both
high flow and low flow rates can satisfy the requirements on ignition for gas
combined thermal carrier
generator and temperature in operation, such that the flow control for high
pressure combustion is
stabilized.
Figure 3 is a schematic to describe the principles of gas flow regulation and
safety control system
of one embodiment of the present invention. Referring to Fig. 3, the gas-type
combined thermal carrier
generation system of one embodiment of the present invention is realized that
both the output gas can
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be ignited at low flow rate at preset temperature and the stable control for
high gas flow at high
pressure by gas constant temperature control system 33 through gas flow
regulating valve 34, gas
compensation regulating valve 35 and gas mass flow meter 36, such that the gas
flow can be input
stably into the combined thermal carrier generator, thereby avoiding sudden
stop of gas supply caused
by unstable gas flow as well as realizing the safety control.
Figure 4 is a schematic to describe the principle of temperature control
system of one embodiment
of the present invention. Refer to Fig. 4, the gas-type combined thermal
carrier generation system of
one embodiment of the present invention controls the water flow with high
frequency pressure varying
pump 42 such that the temperature of the output thermal carrier can satisfy
requirements on the process,
meanwhile the water flow control can ensure cooling water temperature to
satisfy equipment run in
safety, and the core of gas-type combined thermal carrier generator can be
firmly secured.
Figure 5 is a schematic to describe the principle of safety control system of
one embodiment of
the present invention. Refer to Fig. 5, the gas-type combined thermal carrier
generation system of one
embodiment of the present invention is realized with air pressure transmitter
23 at high pressure to
detect the air pressure, air check valve 24 to prevent the combined thermal
carrier to flow back thereby
damaging components on the pipeline, air mass flow meter 22 to inject
quantitatively the air flow mass,
so as to monitor the pressure and flow rate in real time. Flow rate control
for gas supply system and
safety protection are realized through safety overflow valve 52, gas stop
valves 32 and 37, gas mass
flow meter 36, gas check valve 39, gas pressure transmitters 31 and 38 on the
pipeline. The water
quantity of water supply system and safety protection can be realized through
water mass flow meter
45, water check valve 47, water filter 44, and water pressure transmitters 43
and 46 on the water
pipeline. Alarm for stoppage and evacuation as well as pressure release due to
feed back, extremely
high temperature and pressure during the process of injection can be realized
through output
temperature transmitter 13, output safety valve 14, electric blowoff valve 19,
output check valve 16,
and output stop valve 17 on the output pipelines such that high temperature,
high pressure, high
efficiency injection technique can be satisfied.
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