Disclosure of Invention
The application aims to solve the technical problems of the prior art, and provides a drilling outlet flow monitoring and well control overflow leakage early warning system and method.
The technical scheme adopted by the application is as follows: the utility model provides a drilling outlet flow monitoring and well control overflow early warning system, includes cell body and drilling fluid measurement management system, cell body wherein one end be equipped with the inside entry that communicates of cell body, cell body keep away from the one end of entry be equipped with the inside export that communicates of cell body, be equipped with the baffle subassembly in the cell body, form drilling fluid rectification district in the one end that is close to the entry between baffle subassembly and the cell body inside wall, form drilling fluid reflux zone in the one end that is close to the export between baffle subassembly and the cell body inside wall, form the drilling fluid passageway that can supply drilling fluid to pass through and communicate drilling fluid rectification district and drilling fluid reflux zone between baffle subassembly and the cell body inside wall, the position that corresponds with drilling fluid rectification district on the cell body is equipped with flow measurement appearance, the position that corresponds with drilling fluid rectification district and drilling fluid reflux district on the cell body is equipped with entry level measurement appearance and export level measurement appearance respectively, be equipped with the sampling pipeline that communicates with it on the entry, the sampling pipeline is equipped with the sampling flowmeter on the sampling pipeline, the sampling pipeline other end that is close to the export inside the cell body, flow measurement appearance, entry level measurement appearance, export level measurement appearance and sampling tube are all electrically connected with the measurement system.
In one embodiment, the drilling fluid measurement management system comprises a control module, a data operation module, a data acquisition module, a data conversion module, a communication module, a data storage module and a display screen, wherein the data acquisition module is electrically connected with the flow measuring instrument, the inlet liquid level measuring instrument, the outlet liquid level measuring instrument and the sampling flowmeter respectively, the data acquisition module is electrically connected with the data operation module through the data conversion module, and the data operation module, the communication module, the data storage module and the display screen are electrically connected with the control module respectively.
In one embodiment, the baffle assembly comprises a fixed baffle connected with the tank body and a movable baffle arranged on the fixed baffle, a drilling fluid channel which is communicated with the drilling fluid rectifying area and the drilling fluid reflux area and can be used for fluid to pass through is formed between the fixed baffle and the inner side wall of the tank body, and a filtering rectifying hole which is communicated with the drilling fluid rectifying area and the drilling fluid reflux area is arranged on the movable baffle.
In one embodiment, a measuring area is arranged at a position, close to the movable partition plate, inside the tank body, and the flow measuring instrument is arranged in the measuring area.
In one embodiment, the flow measuring instrument comprises a transmitter and two antennas arranged below the transmitter, wherein one antenna is internally provided with a guided wave radar sensor and a conductive sensor negative electrode loop, the other antenna is internally provided with a conductive sensor and a guided wave radar sensor echo loop, and the antenna and the guided wave radar sensor are respectively and electrically connected with the data acquisition module.
In one embodiment, the bottom of the tank body is provided with a deflector inclined along the outlet direction.
In one embodiment, the deflector comprises a first deflector segment arranged at one end of the drilling fluid rectifying area and a second deflector segment arranged in the drilling fluid reflux area, wherein the first deflector segment and the second deflector segment are inclined along the outlet direction.
In one embodiment, the side of the tank body opposite to the inlet is provided with an anti-overflow port.
In one embodiment, the sampling pipe is provided with a cleaning port communicated with the inside of the sampling flowmeter.
The application also discloses a method for monitoring the flow of the drilling outlet and early warning the well control overflow and leakage, which is realized by a system for monitoring the flow of the drilling outlet and early warning the well control overflow and leakage, and comprises the following steps:
step 10, returning drilling fluid enters a tank body and a sampling pipeline from an inlet, a flow measuring instrument measures returning drilling fluid main flow, returning drilling fluid main flow conductivity and returning drilling fluid main flow solid phase content, a sampling flowmeter measures returning drilling fluid sampling flow, returning drilling fluid density, returning drilling fluid temperature and returning drilling fluid gas content, an inlet liquid level measuring instrument and an outlet liquid level measuring instrument respectively measure returning drilling fluid liquid levels of an inlet and an outlet, if the returning drilling fluid flow measurement is carried out, the step 20 is carried out, if the returning drilling fluid main flow measurement is carried out, the step 30 is carried out, if the returning drilling fluid sampling flow measurement is carried out, the step 40 is carried out, if the returning drilling fluid solid phase content measurement is carried out, the step 50 is carried out, if abnormal early warning is carried out, and the step 60 is carried out;
step 20, calculating the flow of the returned drilling fluid, wherein the calculation formula is as follows:, wherein ,for returning the drilling fluid flow>For returning the main flow of the drilling fluid,/for>For the sampling flow of the return drilling fluid, x is the solid phase content of the return drilling fluid;
step 30, calculating the main flow of the returned drilling fluid, wherein the calculation formula is as follows:, wherein />For returning the main flow of the drilling fluid, C is the structural coefficient of the tank body, A is the cross-sectional area of a flow passage, R is the hydraulic radius, S is the fluid gradient, K is the sectional correction coefficient of the real-flow calibration flow, and the flow passage is a drilling fluid passage formed between the fixed partition plate and the tank body; the hydraulic radius is the ratio of the wet circumference of the cross section of the flow channel to the cross section area; the gradient of the fluid is the ratio of the variation of the liquid level height of the flow channel to the length of the flow channel;
step 40, calculating the sampling flow of the returning drilling fluid, wherein the calculation formula is as follows:, wherein ,/>Sample mass flow for returning drilling fluid, +.>Is the density;
step 50, calculating the solid phase content of the returning drilling fluid, wherein the calculation formula is as follows:wherein x is the solid phase content of the return drilling fluid, K1 is a correction database, G is the conductivity of the injected drilling fluid, G1 is the conductivity of the return drilling fluid, and G2 is the conductivity of the solid phase in the return drilling fluid;
wherein ,，/>，/>，/>for the distance between the two antennas, +.>For injection into the downhole drilling fluid conductivity, +.>The conductivity of the downhole return drilling fluid detected by the flow meter,/->Is solid phase conductivity;
step 60, if the well is in a drilling state, proceeding to step 70, if the well is in a drilling stop state, proceeding to step 80;
step 70, comparing the data collected by the flow measuring instrument, the inlet liquid level measuring instrument and the outlet liquid level measuring instrument with drilling state and pump stroke data in a logging system in real time, when two or three parameters of main flow of return drilling fluid measured by the flow measuring instrument, inlet liquid level of a tank body measured by the inlet liquid level measuring instrument and outlet liquid level of the tank body measured by the outlet liquid level measuring instrument suddenly rise or fall, and the pump stroke data are exceeded, determining whether drilling is in a drilling state or not, if drilling is in the drilling state and the pump stroke data are stable, and meanwhile, if drilling has no abnormal operation, judging that overflow or leakage risk exists in the drilling, and the drilling fluid measurement management system makes corresponding abnormal prompts;
and 80, comparing the data acquired by the sampling flowmeter with drilling state and pump stroke data in the logging system in real time, when the density of the returned drilling fluid or the sampling flow of the returned drilling fluid acquired by the sampling flowmeter suddenly rises or continuously rises, determining whether the drilling is in a drilling stop state, if the drilling is in a drilling stop state and the pump stroke data is 0, meanwhile, if the drilling is not abnormally operated, judging that the drilling has overflow risk, and making corresponding abnormal prompt by the drilling fluid measurement management system, wherein when the density of the returned drilling fluid or the sampling flow of the returned drilling fluid acquired by the sampling flowmeter continuously rises or abnormally, the drilling fluid measurement management system can be combined with the temperature of the returned drilling fluid, the inlet liquid level and the outlet liquid level to carry out overflow monitoring and early warning.
The application has the beneficial effects that:
1. the drilling fluid entering the tank body is guided and arranged through the baffle plate assembly, and the measurement effect of the flow measuring instrument is combined, so that the flow can be directly measured under the condition of no full pipe, and the measurement result is not influenced by mud cakes attached to the inner wall;
2. the sand settling problem of the tank body is solved by the action of the baffle plate assembly and the guide plate, and the operation intensity of field personnel is reduced;
3. by monitoring abnormal data and fluids in different states, the method can realize quick response when abnormal conditions (overflow or leakage) occur, prevent misjudgment and misreport, accurately monitor incoming fluid signals when overflow occurs in the drilling stopping process, and quickly feed back abnormal signals;
4. the measurement element and the drilling fluid measurement management system arranged in the system can be integrated into the existing logging system, and are linked with the drilling state and the pump path data, so that the early warning and linkage functions are realized;
5. the flow measuring instrument adopts a top-loading structure, is convenient to install and maintain, can monitor various types of liquid flows, comprises single liquid, gas-liquid two-phase fluid and liquid-solid two-phase fluid, corrects the influence of the gas-liquid two-phase flow or the liquid-solid two-phase flow on the total flow by setting different influence coefficients, and improves the accuracy and stability of measurement;
6. the flow measuring instrument, the sampling flowmeter, the inlet liquid level measuring instrument, the outlet liquid level measuring instrument and other sensors are highly integrated, so that the installation and use faults of the sensors are reduced, the accuracy and the reliability of data are improved, and data guarantee is provided for efficient, quick and accurate overflow leakage early warning and monitoring.
Detailed Description
The application will be described in further detail with reference to the accompanying drawings and specific examples.
As shown in fig. 1-8, a drilling outlet flow monitoring and well control overflow leakage early warning system comprises a tank body 1 and a drilling fluid measurement management system 2, wherein one end of the tank body 1 is provided with an inlet 3 communicated with the inside of the tank body 1, one end of the tank body 1 far away from the inlet 3 is provided with an outlet 4 communicated with the inside of the tank body 1, a partition plate assembly 5 is arranged in the tank body 1, a drilling fluid rectifying area 6 is formed between the partition plate assembly 5 and the inner side wall of the tank body 1 at one end close to the inlet 3, a drilling fluid reflux area 13 is formed between the partition plate assembly 5 and the inner side wall of the tank body 1 at one end close to the outlet 4, a drilling fluid channel 14 which is used for drilling fluid to pass through and is communicated with the drilling fluid rectifying area 6 and the drilling fluid reflux area 13 is formed between the partition plate assembly 5 and the inner side wall of the tank body 1, a flow meter 7 is arranged at a position on the tank body 1 corresponding to the drilling fluid rectifying area 6, an inlet liquid level measuring instrument 10 and an outlet liquid level measuring instrument 11 are respectively arranged at positions on the tank body 1 corresponding to the drilling fluid rectifying area 6 and the drilling fluid reflux area 13, a sampling pipeline 8 is arranged on the inlet 3 and is communicated with the sampling pipeline 8, and the sampling pipeline 8 is connected with the sampling pipeline 10 and the sampling pipeline 10 at one end of the sampling pipeline is communicated with the sampling pipeline 10.
In this embodiment, the drilling fluid measurement management system 2 includes a control module 201, a data operation module 202, a data acquisition module 203, a data conversion module 204, a communication module 205, a data storage module 206 and a display screen 207, where the data acquisition module 203 is electrically connected with the flow meter 7, the inlet 3 liquid level meter, the outlet 4 liquid level meter and the sampling flowmeter 9 respectively, the data acquisition module 203 is electrically connected with the data operation module 202 through the data conversion module 204, and the data operation module 202, the communication module 205, the data storage module 206 and the display screen 207 are electrically connected with the control module 201 respectively.
In this embodiment, the partition board assembly 5 includes a fixed partition board 501 connected to the tank body 1 and a movable partition board 502 disposed on the fixed partition board 501, a drilling fluid channel 14 communicating the drilling fluid rectifying area 6 and the drilling fluid reflux area 13 and allowing fluid to pass through is formed between the fixed partition board 501 and the inner side wall of the tank body 1, and a filtering rectifying hole 503 communicating the drilling fluid rectifying area 6 and the drilling fluid reflux area 13 is disposed on the movable partition board 502.
In this embodiment, a measuring area 15 is disposed in the tank 1 near the movable partition 502, and the flow meter 7 is disposed in the measuring area 15.
In this embodiment, the flow meter 7 includes a transmitter 701 and two antennas 702 disposed below the transmitter 701, wherein one of the antennas 702 is provided with a guided wave radar sensor and a negative electrode loop of the conductivity sensor, the other antenna 702 is provided with a return loop of the conductivity sensor and a return loop of the guided wave radar sensor, and the antennas 702 and the guided wave radar sensor are respectively electrically connected with the data acquisition module 203.
In this embodiment, a deflector 12 inclined along the direction of the outlet 4 is disposed at the bottom of the tank body 1.
In this embodiment, the deflector 12 includes a first deflector segment 1201 disposed at one end of the drilling fluid rectifying area 6 and a second deflector segment 1202 disposed in the drilling fluid reflux area 13, where the first deflector segment 1201 and the second deflector segment 1202 are both inclined along the direction of the outlet 4.
In this embodiment, the side of the tank body 1 opposite to the inlet 3 is provided with an anti-overflow port 16.
In this embodiment, the sampling pipe 8 is provided with a cleaning port 17 which is communicated with the inside of the sampling flowmeter 9.
The application also discloses a method for monitoring the flow of the drilling outlet and early warning the well control overflow and leakage, which is realized by a system for monitoring the flow of the drilling outlet and early warning the well control overflow and leakage, and comprises the following steps:
step 10, the return drilling fluid enters the tank body 1 and the sampling pipeline 8 from the inlet 3, the flow meter 7 measures the main flow of the return drilling fluid, the conductivity of the main flow of the return drilling fluid and the solid phase content of the main flow of the return drilling fluid, the sampling flow meter 9 measures the sampling flow of the return drilling fluid, the density of the return drilling fluid, the temperature of the return drilling fluid and the air content of the return drilling fluid, the inlet liquid level meter 10 and the outlet liquid level meter 11 respectively measure the liquid level of the return drilling fluid at the inlet 3 and the outlet 4, such as the flow measurement of the return drilling fluid, and the step 20 is entered, such as the main flow measurement of the return drilling fluid, the step 30 is entered, such as the sampling flow measurement of the return drilling fluid, the step 40 is entered, such as the solid phase content measurement of the return drilling fluid, the step 50 is entered, such as the abnormal early warning is entered, and the step 60 is entered;
step 20, calculating the flow of the returned drilling fluid, wherein the calculation formula is as follows:, wherein ,for returning the drilling fluid flow>For returning the main flow of the drilling fluid,/for>For the sampling flow of the return drilling fluid, x is the solid phase content of the return drilling fluid;
step 30, calculating the main flow of the returned drilling fluid, wherein the calculation formula is as follows:, wherein />For returning the main flow of the drilling fluid, C is the structural coefficient of the tank body, A is the cross-sectional area of a flow passage, R is the hydraulic radius, S is the fluid gradient, K is the sectional correction coefficient of the real-flow calibration flow, and the flow passage is a drilling fluid passage 14 formed between the fixed partition plate 501 and the tank body 1; the hydraulic radius is the ratio of the wet circumference of the cross section of the flow channel to the cross section area; the gradient of the fluid is the ratio of the variation of the liquid level height of the flow channel to the length of the flow channel;
step 40, calculating returnsThe back drilling fluid sampling flow is calculated according to the following formula:, wherein ,/>Sample mass flow for returning drilling fluid, +.>Is the density;
step 50, calculating the solid phase content of the returning drilling fluid, wherein the calculation formula is as follows:wherein x is the solid phase content of the return drilling fluid, K1 is a correction database, G is the conductivity of the injected drilling fluid, G1 is the conductivity of the return drilling fluid, and G2 is the conductivity of the solid phase in the return drilling fluid;
wherein ,，/>，/>，/>for the distance between the two antennas, +.>For injection into the downhole drilling fluid conductivity, +.>The conductivity of the downhole return drilling fluid detected by the flow meter,/->Is solid phase conductivity;
step 60, if the well is in a drilling state, proceeding to step 70, if the well is in a drilling stop state, proceeding to step 80;
step 70, comparing the data collected by the flow measuring instrument 7, the inlet liquid level measuring instrument 10 and the outlet liquid level measuring instrument 11 with the drilling state and pump stroke data in the logging system in real time, when the main flow of the drilling fluid measured by the flow measuring instrument 7, the inlet liquid level of the tank body 1 measured by the inlet liquid level measuring instrument 10 and the outlet liquid level of the tank body 1 measured by the outlet liquid level measuring instrument 11 suddenly rise or fall, and the pump stroke data are exceeded to set the early warning fluctuation rate, determining whether the drilling is in the drilling state, if the drilling is in the drilling state and the pump stroke data are stable, and meanwhile, judging that the drilling has overflow or leakage risk if the drilling has no abnormal operation, and the drilling fluid measurement management system 2 makes corresponding abnormal prompt;
and step 80, comparing the data acquired by the sampling flowmeter 9 with the drilling state and the pump stroke data in the logging system in real time, when the density of the returned drilling fluid or the sampling flow of the returned drilling fluid acquired by the sampling flowmeter 9 suddenly rises or continuously rises, determining whether the drilling is in a drilling stop state, if the drilling is in the drilling stop state and the pump stroke data is 0, meanwhile, determining that the drilling has overflow risk if the drilling has no abnormal operation, and making a corresponding abnormal prompt by the drilling fluid measurement management system, wherein when the density of the returned drilling fluid or the sampling flow of the returned drilling fluid acquired by the sampling flowmeter 9 continuously rises or is abnormal, the drilling fluid measurement management system 2 can perform overflow monitoring and early warning by combining the temperature of the returned drilling fluid, the inlet liquid level and the outlet liquid level.
When the drilling outlet mud measurement and overflow leakage early warning system works, drilling fluid enters the tank body 1 and the sampling pipeline 8 through the inlet 3. The drilling fluid entering the tank body 1 firstly enters the drilling fluid rectifying area 6, and the drilling fluid can smoothly flow in the drilling fluid rectifying area 6 because the drilling fluid rectifying area 6 in the tank body 1 is formed by the fixed partition plate 501 so as to be beneficial to the circulation of the drilling fluid according to a specific path. During this process, a substantial portion of the drilling fluid enters the drilling fluid recirculation zone 13 through the drilling fluid passage 14. A small part of drilling fluid is subjected to secondary rectification through a filtering rectifying hole 503 of the movable partition plate 502, large-particle rock debris interference is isolated under the action of the filtering rectifying hole 503, and then the main flow, the conductivity and the solid phase content of the drilling fluid are measured by a flow meter 7. To ensure a better measurement result, a separate measuring zone 15 may be provided for the measurement. After the measurement is completed, the drilling fluid re-enters the drilling fluid recirculation zone 13. During the circulation of drilling fluid, the inlet level gauge 10 and the outlet level gauge 11 measure the drilling fluid level at the inlet 3 and the outlet 4, respectively. The sampling flowmeter 9 arranged on the sampling pipeline 8 is used for measuring the sampling flow, density, temperature and gas content of the drilling fluid; the sampled drilling fluid after the measurement is further fed into the drilling fluid recirculation zone 13. Drilling fluid entering the drilling fluid recirculation zone 13 exits the tank 1 through the outlet 4. In order to prevent sand from settling, a guide plate 12 is arranged in the tank body 1, and the guide plate 12 is divided into a first guide section 1201 and a second guide section 1202; both the first flow guiding section 1201 and the second flow guiding section 1202 are inclined towards the outlet 4 so that the outlet 4 is the lowest point of the whole tank 1, thereby preventing sand settling.
The specific functions of the control module 201, the data operation module 202, the data acquisition module 203, the data conversion module 204, the communication module 205, the data storage module 206 and the display screen 207 of the drilling outlet mud measurement and overflow leakage early warning system are as follows:
the control module 201: the neural center of the system realizes the functions of scheduling data functions of all modules, acquiring data at the site end, processing algorithm logic related to the system, calling a database and the like, and is interacted with the data communication of a remote logging system, so that the functions of drilling fluid measurement and accurate overflow and leakage early warning are finally realized;
the data operation module 202: the method is used for data deep processing and database learning, runs before matching with a control module and communicates with the control module to realize data internal interaction;
the data acquisition module 203: the system is communicated with a field end sensor, so that physical isolation between the acquisition end and the field end is realized, data acquisition, screening and filtering are carried out, and preparation work is carried out for data conversion;
the data conversion module 204: the data format conversion and the data interaction are carried out with the data acquisition module and the data operation module, so that the functions of going up and down are played;
the communication module 205: the method mainly provides data communication isolation and interaction functions for the digital communication sensor at the site end, and ensures the safety of the internal modules of the system;
the data storage module 206: all production operation parameters, early warning information and other event record information are stored, the power failure is stored for a long period, and the data black box provides backup data for a logging system, so that later review is facilitated;
display screen 207: the method is used for displaying the operation parameters, and inquiring, operating and modifying information such as operation curves, event records, setting parameters, system internal parameters and the like.
The overflow preventing port 16 arranged in the drilling outlet mud measuring and overflow warning system can recover drilling fluid and prevent the drilling fluid from losing under the condition that a large amount of drilling fluid enters the tank body 1 and cannot smoothly enter the drilling fluid backflow region 13 from the drilling fluid rectifying region 6. The cleaning port 17 is provided for cleaning the sampling flow meter 9 when the well is in a stopped state to ensure the accuracy of measurement.
According to the drilling outlet mud measurement and overflow leakage early warning system, according to actual requirements, a conductivity meter 18, a degasser 19 and a well cementation mud interface 20 can be arranged on the tank body 1 so as to increase the functionality of the system.
The fixed baffle 501 is used for forming a drilling fluid rectifying area 6 in the tank body 1 so as to facilitate the drilling fluid to circulate along a specific path, thereby facilitating the smooth flow of the drilling fluid, reducing dead zone formation, avoiding local sand settling and meeting the measurement requirement. The movable partition 502 is matched with the filtering rectifying hole 503 arranged on the movable partition 502 to be used for filtering the secondary rectification of drilling fluid and isolating the interference of large-particle rock debris, and provides better measurement and adjustment effects for flow measurement.
The inlet liquid level measuring instrument 10 and the outlet liquid level measuring instrument 11 are non-invasive radio frequency radar liquid level meters. The inlet liquid level measuring instrument 10 and the outlet liquid level measuring instrument 11 adopt high-frequency radio frequency radar liquid level meters, are not in contact with media, are not influenced by temperature, water vapor and local micro pressure, are provided with protective covers, prevent the influence of mud splashing, are high in reaction speed and low in failure rate, and improve the accuracy and stability of liquid level measurement. The sampling flowmeter 9 is a gas-liquid two-phase mass flowmeter. The sampling flowmeter 9 adopts a resonance technology and a gas-liquid two-phase gas-containing management system to measure the medium density, so that accurate measurement of the medium density from empty pipe to full pipe can be realized, drilling fluid density monitoring from stopping drilling to normal drilling is realized, and the influence of factors such as liquid level height, temperature, pressure, solid phase content change, gas-containing state and the like is avoided; the sampling flowmeter 9 adopts a nitrogen-filled isolation technology to realize temperature monitoring, a patch thermal resistor is used outside the measuring tube, the nitrogen is filled in an isolation area between the measuring tube and the protective housing, and the medium temperature measurement is not influenced by the external environment temperature, the drilling state, the liquid level and other factors.
The guide plate 12 is arranged in the application, so that drilling fluid flows from the inlet 3 to the outlet 4 (from high to low) according to a designed path, dead angle areas are filled in an early pre-buried mode, the drilling fluid is prevented from settling sand in the tank body 1, and maintenance difficulty and cost are reduced.
In step 50, the correction database is obtained through indoor and on-site data collection, arrangement and learning; the conductivity of drilling fluid injected into the well is a known technical parameter index in a logging system; the solid phase conductivity comprises rock scraps and soil, a stable fluid conductivity monitoring area is arranged at the edge of the double antennae 702 of the flowmeter 7, and the resistivity of the solid phase is far greater than that of drilling fluid for water-based mud, so thatFar less than->The method can directly measure the approximate solid phase content, and can also be used for testing and correcting the rock debris component in the drilling fluid by returning, so that as for oil-based mud, a small-range high-precision conductivity sensor needs to be configured and the solid phase component is accurately detected, and the accurate detection of the solid phase content is ensured.
In step 70, for more accurate abnormality pre-warning, the flow meter 7, the inlet level meter 10 and the outlet level meter 11 are designed in redundancy; when the drilling state is determined to be in drilling, pump stroke data are stable, if the monitored main flow, inlet liquid level and outlet liquid level parameters of the drilling liquid drop out of standard, judging that leakage risk exists; if the monitored main flow, inlet liquid level and liquid level parameters of the drilling fluid rise to exceed the standard, judging that overflow risks exist, and making a corresponding early warning prompt by the drilling fluid measurement management system 2; in the judging process, the current well drilling start-stop pump state change and the interference of the starting and stopping column on the measuring result are combined, so that accurate and rapid overflow abnormal early warning is realized, and false alarm and false judgment are avoided or reduced.
The foregoing examples merely illustrate specific embodiments of the application, which are described in greater detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application.