The present invention relates to a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system. Particularly, the present invention relates to a submersible water lifting system for automatic fire fighting at unmanned platform having said system, that is efficient yet simple to install, energy saving, noise free, and economical.
Mineral oil and Natural gas are most valuable products in terms of economy. There are two main sectors in this Industry:
In upstream sector, there are two main departments: Drilling Department and Production Department. The function of drilling department is, to explore the area on land (onshore) and offshore (in sea) with higher possibility of Oil/Gas existence and then drill wells in those area for exploitation of these products. After drilling wells, the task is taken over by the production department; whereby the content is extracted to obtain fluid containing oil, gas, water and earth materials like dirt/sand etc. These components are then separated to make these products (oil and gas) compatible for further processing (say refining).
Now this separation process of oil, gas and water needs equipment and vessels like, separators, Knock Out Drums (KODs), storage vessels, power generators, pumps and motor, pipe lines etc. Thus, a complete plant is required in place for carrying out separation process; which requires large space. There are onshore plants (on land) as well as offshore (in sea) plants for the mentioned purpose.
The offshore plants have marine structures known as platforms with various deck levels (say it, floors of building) to accommodate living quarters for human being as well as process plant for oil and gas separation. The Marine Structure, having living quarters, are called manned Platforms (or process complex) and the marine structure without living quarters for human being are called unmanned platforms. (Unmanned platform is also known as Well Head Platform)
It is pertinent to note that the oil rich area, under earth surface (called Reservoir) is spread over large area in square kilometers. So, numbers of wells are required to be drilled over this area and offshore platforms are built on groups of such wells to maximize production of oil. Amongst said offshore platforms, one of the platforms is usually a processing platform; where the contents from all wells can be collected and processed under the supervision of men. Rest of the platforms work on automated mode and generally do not require continuous supervision and hence remain unmanned. All unmanned platforms are inter connected with said manned platform through subsea pipe lines (generally at Sea bed level), like, well fluid lines, water injection lines, gas injection lines, etc. Wherein, said Water injection line is high pressure water line to inject water into wells for recovery of oil. Said unmanned platforms are occasionally visited by men for operational/maintenance jobs. Generally, it is remotely operated from manned platform.
Water injection systems are used for oil recovery extraction from oil reservoir (underground in the earth) by injecting high pressure water in some wells and extracting oil from other wells. This is called secondary oil recovery. The wells, in which, pressurized water is injected, are called water injection wells, whereas the wells, from which, oil extracted, are called Oil producing wells. Wells at sea bed; wherein pressurized water is injected in to the water injection wells to pressurize oil in the reservoir and to recover oil from the nearby oil wells, drilled by the drilling department of the oil and gas industry. The water has such high pressure that it limits the application to the above mentioned purpose and it is risky to use for any other purposes at such pressure. The pressure is so high that it can damage material and men if it use directly for fire fighting purpose; and is manually difficult to control or at times it is uncontrollable in given situation and with given resources
Since Oil and natural gas are highly flammable, there is a high risk of fire associated with such platforms; which results in huge destruction and losses of assets and manpower. So the fire fighting system has vital role in productivity by safeguarding assets and human lives. Existing fire-fighting systems generally uses one or more of the below technologies depending upon complexity of plant, means, nature of fire, types of area like open area or enclosed area etc:
But there are places in offshore platforms where compatible firefighting systems are either not available or if available then it is difficult to operate in automatic mode. Also, all existing systems are not compatible for unmanned platform at offshore, either by water flow quantity or by timely action to extinguish fire.
Moreover, while certain systems require maintenance at regular intervals; during which the platform is rendered disconnected with the firefighting system. Accidents leading to fire at this point may run the risk of complete destruction and human loss. Certain systems tend to chock and fail to operate when actually required; leading to the failure to serve the purpose. Additionally, manual operation or starting of firefighting system operation is not adequate at unmanned offshore platforms; as men do not reside there. Certain systems also fail to operate in open area while others fail to serve the purpose at closed areas. Their reliability for total, efficient and all types of fire extinction at Oil and Gas platforms is questionable.
Certain incidences have been recorded, when such platforms caught fire; due to gas leakage and the installed fire-fighting system did not work or support at that moment; leading to huge losses and emergency; calling for requirement of external help. At said platforms, which are far away from land; and between water on all the sides limited external help could be provided; when such incidences take place. With the available technology for this purpose; said external help includes firefighting ships that uses high power diesel based pumps to lift water and pours on the fire caught areas or Army/Navy helicopters for transfer of manpower and strategic planning. Thus, existing system were proven insufficient or inefficient to safeguard the offshore platforms when fire took place. This was specifically worst when the offshore platforms were unmanned platforms.
Major letdowns were due to failure of water-lifting system to start lifting water for fire-fighting system to work; wherein said water lifting systems were heavy and bulky fire engine and pump. This lifting system needs regular maintenance which is difficult at unmanned platform as man is not residing there. Alternative water lifting systems face problems of chocking with marine growth and failure of operations when in need.
Thus, there is an unmet need to provide a water lifting system for automatic firefighting, in oil and gas industry to be used at said platforms; especially such systems that are feasible and useful at offshore platforms. Particularly, there is a need to provide such system that is efficient yet simple to install and economical.
Disadvantages of the Prior Arts:
Existing water lifting system for automatic fire fighting, suffer from at least one of the following disadvantages:
Objects of Invention:
The main object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that is efficient yet simple to install, energy saving, noise free, and economical.
Another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system wherein installation is possible by simple modification in existing offshore platform arrangement. This eliminates installation of additional multi-part arrangements thereby reduces the complexity in construction and operation.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that is self-cleaning and hence auto-maintenance.
Yet another objective of the present invention is to eliminate risk of fire, on main body of water lifting system itself, by locating it into water body.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that requires minimum space for installation.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that eliminates bulky and uneconomical installations; thereby making present invention simple and easy to install and economical.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire-fighting system for unmanned platforms having said system that ensures safeguard from fire; particularly to the unmanned platform and reduces the premium of insurance.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that requires almost no maintenance.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that is simple and safe to operate. It assures for valuable function of fire-fighting system.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that utilizes internal energy available in the flow of water injection line and eliminates the requirement of external energy sources like fuel; thereby saving said energy sources.
Yet another object of the present invention is to provide a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system that also ensures to facilitate the utility requirements such as wash down pump.
Meaning of Reference Numerals of Said Component Parts of Present Invention:
Water injection systems described herein above is used by the applicant for the purpose of the present invention; in such a manner that overcomes the risks associated with high pressure. The applicant of the present invention has utilized the available high pressure water flow, in system, for its use in emergency situation of major fire. The system is developed such that the emergency as well as the purpose of fire extinguishing is served using the available water supply arrangement.
Said water injection system has main water supply line known as Water injection Header (22) from which, water can be distributed to different wells through sub-sea pipes; a water inlet line (3) is directed from said water injection header (22) at a platform to the present invented system (1) to act as a water inlet for the present invented system (1).
The applicant has developed the present invention to utilize the pressurized water for present invented system (1) such that the system controls the pressure; making it utilizable for the purpose as well as it provides a mechanism of utilizing water from the water body (20) (sea) along with it; so as to get maximum benefit of the available pressurized water placed there for oil extraction.
The present invention relates to a submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said system (1) that is efficient yet simple to install, energy saving, noise free and economical.
More particularly, the present submersible water lifting assembly and automatic fire fighting system for unmanned platforms having said water lifting system for automatic fire-fighting [shown diagrammatically in
Present submersible water lifting assembly; for the purpose of present invention; is a High Pressure Recovery Turbine Pump (7) [referred herein after as HPRTP] that utilizes under water arrangements of unmanned platform and enables the fire-fighting system to efficiently lift water from the sea water; using the force of existing water injection system; eliminating the requirement of fuel engine driven pump, for lifting the water. Thus, said High Pressure Recovery Turbine Pump (7)/HPRTP (7A) enables fire safety without use of bulky engine driven fire water pump; unlike that of the prior art.
Referring to
Wherein said HPRTP (7) is provided to receive high pressure water from the water inlet line (3) through its primary inlet (7a) to utilize the energy of the same and create the suction within the HPRTP (7) to suck more water from the water body (20) within which the present invented system (1) is used through its secondary inlet (7b) and thereby reduce the pressure of the water and increase the amount of the water to be flown within the present invented system (1); without use of any external source of energy. The water with reduced pressure and increased amount discharges from the HPRTP (7) to the discharge water line (8) through discharge outlet (7c). A suction strainer (7d) is provided on the secondary inlet (7b) to avoid the entry of marine substances. The water, which is a mixture of initially received water from water injection system and the water received from water body (20) (sea); both together discharges from the HPRTP (7) to the discharge water line (8). It is pertinent to note that the water suction from the water body (20) (sea) is as high as enabling suction of multiple times of water flow as compared to the originally received pressurised water flow; resulting into utilization of maximum water from the abundant and free water source and eliminating wastage energy, stored in the pressurized water. It also minimise the use of high pressure water which is required for other important purposes (oil extraction). The turbine wheel (7u), comprised of turbine runner (7h) and plurality of turbine bucket (7m), is used as prime mover; run by velocity of water jet through nozzle (7v), provided at primary inlet (7a). This turbine wheel (7u), is protected and supported by turbine wheel housing (7e) and partition wall (7f). The partition wall (7l) supports central hub bushing or bearing (7g), and separates turbine wheel (7u) and impeller (7q). The shaft-1 (′7p) is supported at turbine end bushing or bearing (7k) fixed into turbine wheel housing (7e) at one end and at the central hub bushing or bearing (7g), fixed in the partition wall (7l), as a second end. The impeller end bush washer (7s), between impeller housing (7o) and impeller (7q), is provided to minimise water recycling from pump volute-1 (7x) to secondary inlet (7b) and also provides stability to impeller (7q). The discharged water from impeller volute-1 (7x) enter into diffuser (7w) through Oval shape aperture (7t) in partition wall (7l), between turbine wheel (7u) and impeller (7q) of HPRTP (7). The plurality of turbine bucket (7m) is fixed with turbine runner (7h) by tightening plurality of bolts and nuts with Plurality of runner hole (7l). Similarly, turbine wheel housing (7e), partition wall (7l) and impeller housing (7o) are boxed up by the help of bolts and nuts with plurality of housing hole (7n) as shown in the
Referring to
Wherein; the turbine wheel (7u) and impeller (7q) are coupled together in a shaft-2 (7p′) with the help of shaft key-2 (7j′). The components, plurality of propeller (7z) and stator wheel (7y) are engaged with impeller housing (7o) and shaft-2 (7p′). The one end of the shaft-2 (7p′) is supported at the turbine wheel housing (7e) and other end of shaft-2 (7p′) is supported at stator wheel (7y) (refer to
Referring to
Wherein; the water inlet line (3) is connected, with water injection header (22) same way as plurality of water injection wells (23) is connected with said water injection header (22); for operation of present invented system (1) where water injection header (22) is part of platform. The fire signal transmission line-1 (2a) transmit fire signal from fire detection system (2) to control panel (4) where fire detection system (2) is part of platform (fire detection system is a part of oil & gas process, for well closer and process shut down).
The blow down valve (5), Pressure Regulating Valve (6), deluge valve-1 (16A), deluge valve-2 (16B), isolation valves (13), isolation valve-2 (14), and plurality of sprinklers (18) are shown symbolically in the drawing.
The exploded pictorial view of component HPRTP (7) is shown with indication of primary inlet (7a), secondary inlet (7b), discharge outlet (7c), nozzle (7v), diffuser (7w) and suction strainer (7d). The drawings shown are conceptual view of entire system.
Fire detection system (2); which is part of oil and gas operation, at platforms is utilized for obtaining fire signal though fire signal transmission line-1 (2a), to activate the present invented system (1) for fire fighting.
Water inlet line (3) tapped from Water injection header (22) provides pressurized water to the present invented system (1). The inflow of water from the water inlet line (3) and is controlled by pressure regulating valve (6) Said water has a high pressure and cannot be used for the purposes of extinguishing the fire. Thus, a mechanism of pressure control is provided in the said system (1) to best utilize the available source of water for fire extinguishing through present invented system (1). The fire signal received by Control Panel (4) though fire signal transmission line-1 (2a), from fire detection system (2); activates blow down valve (5), through instrument control line (5a), and allows pressurised water to enter the said system (1), through water inlet line (3). Simultaneously control panel (4) send fire signal to open plurality of deluge valve (16) [deluge valve-1 (16A) or deluge valve-2 (16B) or both or more] though fire signal transmission line-2 (11). A Pressure Regulator Valve (6) regulates pressure of the water flow; which is in turn facilitated by the Pressure taping (12). A submersible water lifting system is provided to receive high pressure water from the water inlet line (3) through its primary inlet (7a) to utilize the energy of the same and create the suction within the HPRTP (7)/(7A) to suck more water from the water body (20) (sea), within which the present invented system (1) is used, through its secondary inlet (7b) and thereby reduce the pressure of the water and increase the amount of the water to be flown within the system; without use of any external source of energy. The water with reduced pressure and increased amount discharges from the HPRTP (7) or HPRTP (7A), to the discharge water line (8) through discharge outlet (7c). A suction strainer (7d) is provided on the secondary inlet (7b) to avoid the entry of marine substances. The water, which is a mixture of initially received water from water injection system and the water received from water body (20) (sea); both together discharges from the HPRTP (7) or HPRTP (7A), to the discharge water line (8). It is pertinent to note that the water suction from the water body (20) is as high as enabling suction of multiple times of water flow as compared to the originally received pressurised water flow; resulting into utilization of maximum water from the abundant and free water source and eliminating wastage energy, stored in the pressurized water. It also minimise the use of high pressure water which is required for other important purposes. The water from discharged water line (8), reaches to plurality of water sprinkler header (10), through non return valve (9a) & fire water header (9); to spray water, over fire caught area, through plurality of Sprinklers (18). Plurality of water sprinkler headers (10) are provided to sprinkle water on fire caught area; amongst which, a First Water Sprinkler Header (10a) is provided to sprinkle water in upper deck and a Second Water sprinkler header (10b) is provided to sprinkle water in lower deck. There are Non-Return Valve (9a) provided in the system to facilitate single side flow of water for fire-fighting.
Plurality of deluge valve (16) is provided to allow passing of water to said First Water Sprinkler Header (10a) or Second Water sprinkler header (10b) or both or more; depending upon the area in which fire has taken place. This directs the water to the fire affected area only; and avoids wastage of water by blocking passage of water in other areas. Further, depending on the number of water sprinkler headers, arranged in different regions of the platform; plurality of deluge valve (16) is provided to facilitate in directing the water flow in area where fire is existing.
The control panel (4) is preferably powered by water pressure taken from water inlet line (3) through supply pressure line (21); or otherwise it can also be powered by pneumatic/electric power as per location where system is used.
The submersible water lifting assembly of present automatic fire-fighting system is placed below Water surface level (19) of water body (20) (see
Present invented system (1) also has provisions to allow the water to be used for other purposes including cleaning. Fire Water Header Isolation Valve (13) is thus provided; which can be closed and Utility Water isolation Valve (14) can be opened so as to allow said resultant water to pass through Utility water header (15) for said purposes.
Additionally, Fire Water Header Isolation Valve (13) and Utility/service Water isolation Valve (14); both can be closed to ensure water discharge from secondary inlet (7b) into the water body (20) (sea), for cleaning of the suction strainer (7d). This ensures there is no blockage and allows ready infusion of water through secondary inlet (7b). This makes the maintenance simple and efficient. Also, there is no requirement of rendering the platform at risk of fire, during maintenance of fire-fighting system unlike the prior arts.
Wherein modifications in the present invented system (1) for accommodating present water lifting assembly i.e. HPRTP (7) or HPRTP (7A), involves the modifications in terms elimination of complex arrangements of air/gas start up vessel, diesel storage vessel, diesel tank, diesel engine, gear box, multi stage centrifugal pump, vertical column casing, 40 meter length heavy duty shaft and related arrangements of its supply and usage during operation of said prior art system. The elimination of said parts results in simplified rearrangement of remaining parts to provide a simple yet efficient said system (1) as shown in
Further, herein before disclosed are the preferred embodiments of the present invented systems (1) with reference to accompanying drawings.
Here, it is to be noted that the present invention is not limited thereto and can be used for varied applications including fire fighting systems for onshore and water transport systems for transporting water from lower level to higher levels. The components like flow meters, drain line tapings with drain valves, pressure gauges, blinds, plugs, isolation valves etc are not shown in the Figure & not described is understood 86 still in the scope of the intervention Furthermore, the component parts described are not meant there to limit its operating, and any rearrangement of the component parts for achieving the same functionality is still within the spirit and scope of the present invention. It is to be understood that the drawings are not drawn to scale and are only for illustration purposes.
Working of the Invention:
Referring to
Referring to
Inlet water flow from water inlet line (3) to the HPRTP (7) or HPRTP (7A), is known as primary flow and inlet water flow from water body (20) to HPRTP (7) or HPRTP (7A), is known as secondary flow. Whereas these both the flows mix together and travel towards fire water header (9) is known as generated flow or discharged flow. These generated flow depends upon parameters, inlet flow rate Qp, pressure of inlet flow Pp, flow ratio M (secondary flow rate to primary flow rate). Secondary pressure Ps, discharge pressure (needed pressure) Pd, nozzle diameter An, efficiency η etc.
In High Pressure Recovery Turbine Pump (HPRTP), applied parameters, 16 mm diameter of nozzle (7v), primary water supply flow pressure 100 kg/cm2, secondary water inlet suction pressure 2 kg/cm2 and required desired pressure 10 kg/cm2, the efficiency observed is 0.6, with the resultant discharged flow rate 600 m3/hr.
Given below table 1 provides information of discharge flow rate with respect to provided other parameters of the system.
Table 1 provides information of discharge flow rate with respect to provided other parameters of the system.
Illustration:
From the table 1, it is observed that keeping primary pressure head constant, as discharged head increases, the total discharged flow rate (Qd) decreases and similarly, keeping discharged pressure head constant, it is observed that the total discharged flow rate (Qd) increases with rising of primary pressure head. So the HPRTP (7) can be use for wide range of capacity by adjusting parameters of the pump.
In High Pressure Recovery Turbine Pump (HPRTP) (7A), applied parameters, 16 mm diameter of nozzle (7v), primary water supply flow pressure 100 kg/cm2, secondary water inlet suction pressure 2 kg/cm2 and required desired pressure 15 kg/cm2, the efficiency observed is 0.6, with the resultant discharged flow rate 500 m3/hr.
Given below table 2 provides information of discharge flow rate with respect to provided other parameters of the system.
Table 2 provides information of discharge flow rate with respect to provided other parameters of the system
Illustration:
From the table, it is observed that discharge flow rates are comparatively lower then example 1. That is because the discharge pressure head increased at the cost of flow rates. Similarly as in example 1, keeping primary pressure head constant, as discharged head increases the total discharged flow rate (Qd) decreases and similarly, keeping discharged pressure head constant it is observed that the total discharged flow rate (Qd) is increased with raising of primary pressure head. So the pump can be use for wide range of capacity by adjusting parameters of the HPRTP (7A).
Comparison of Prior Art and Present Invention
The typical prior art (or traditional arts) and the present invention are hereby compared in the below table to clearly bring out the technical differences between the prior art and the present invention.
A comparison is done between the prior art (or traditional) turbine pumps and the submersible water lifting assembly (HPRTP) of the present invention through the values of various parameters and its impact. This clearly depicts the disadvantages of the prior arts (or traditional) systems; thereby establishing the need for the present invention.
A further comparison is done between an existing fire fighting system and the present automatic fire fighting system having a submersible water lifting assembly (HPRTP). Table 4 herein below shows a component wise distinction between the prior art and the present invention.
Applicability of Present Invention:
The Submersible water lifting system and the automatic Fire Fighting System having the same assembly, has its main applicability in Oil and Gas Industry at offshore platforms particularly at unmanned platforms where electricity, fire engines and regular human presence are not available but high pressure water flow is available.
It can also be used at onshore to lift water for fire fighting, from low level ponds provided that high pressure water flow is available by any means like water injection lines, tanker having high pressure pump.
Though present invented system (1) is mainly designed for emergency fire fighting operations, it can also use as a utility or service water pump in all onshore and offshore installations where high pressure water flow is available. It can also be used in marine applications like stripping of blast tanks and sewage treatment plants etc. in ships.
There are varies applications of the present invented system (1); which includes, but not limited to the applications listed herein below. The system as a whole or part of system can also be used in below mentioned industries.
Number | Date | Country | Kind |
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201821018583 | May 2018 | IN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IN2019/050381 | 5/13/2019 | WO | 00 |