Ventilation apparatus of a drillship

Abstract

Provided is a ventilating apparatus for a drill ship, which allows a drill ship sailing around an arctic region to maintain appropriate temperature and pressure. The ventilating apparatus for the drill ship includes: a derrick forming an enclosed space blocked from the exterior; a moonpool formed under the derrick; an air supply device supplying outside air to the moonpool or the derrick; and an air exhaust device exhausting the supplied outside air out of the top of the derrick.

Claims

1. An arctic drill ship, comprising: a propulsion system to sail the artic drill ship about the sea; a ship deck; a derrick installed on the ship deck; a moonpool formed under the derrick which is in contact with seawater and exposed to sea waves, and wherein the derrick and the moonpool collectively form a compartment within the artic drill ship that extends from the derrick to a surface of the sea and defines an enclosed space blocked from an exterior environment, the enclosed space of the compartment being susceptible to air pressure fluctuations arising from interaction of the sea waves with the moonpool throughout drilling operations; and a ventilation apparatus, the ventilation apparatus including: an air supply device arranged to supply outside air to the enclosed space of the compartment collectively formed by the derrick and the moonpool, the air supply device coupled to a moonpool area defined by the moonpool at a lower end of the enclosed space; an air exhaust device arranged to exhaust the supplied outside air out of the enclosed space through a top end of the derrick opposite the moonpool area; and a pressure regulating damper provided in a side of the derrick between the top end and the moonpool area which supplies air to or exhausts air from the enclosed space to prevent rapid pressure variation such that the internal air pressure within the compartment collectively formed by the derrick and the moonpool is constantly maintained despite the interaction of the sea waves with the moonpool throughout drilling operations.

2. The artic drill ship according to claim 1, wherein the air supply device comprises a heater to heat the outside air.

3. The artic drill ship according to claim 1, wherein the air supply device comprises a shut-off damper to shut off an air flow when an emergency situation occurs while the artic drill ship is sailing.

4. The artic drill ship according to claim 1, wherein the air supply device comprises a supply louver to prevent an inflow of particles other than air.

5. The artic drill ship according to claim 1, wherein the derrick comprises an openable or closable air supply port through which the outside air is supplied.

6. The artic drill ship according to claim 1, further comprising a heat blower provided inside the derrick to heat air for effective ventilation.

7. The artic drill ship according to claim 1, wherein the air exhaust device comprises an exhaust louver.

8. The artic drill ship according to claim 1, wherein, a supply fan is installed in the air supply device, an exhaust fan is installed in the air exhaust device, and the operating speeds of the supply fan and the exhaust fan are changed depending on temperature of the outside air.

9. The artic drill ship according to claim 1, wherein the air supply device supplies the outside air to at least one of the moonpool and the derrick through a duct, and wherein a wire mesh is provided at an end of the duct which is coupled to the at least one of the moonpool and the derrick.

10. An arctic drill ship, comprising: a ship deck; a derrick installed on the ship deck; a moonpool formed under the derrick which is in contact with seawater and exposed to sea waves, and wherein the derrick and the moonpool collectively form a compartment within the artic drill ship that extends from the derrick to a surface of the sea and defines an enclosed space blocked from an exterior environment, the enclosed space of the compartment being susceptible to air pressure fluctuations arising from interaction of the sea waves with the moonpool throughout drilling operations; and a ventilation apparatus, the ventilation apparatus including: an air supply device arranged to supply outside air to the enclosed space of the compartment collectively formed by the derrick and the moonpool, the air supply device coupled to a moonpool area defined by the moonpool at a lower end of the enclosed space; an air exhaust device arranged to exhaust the supplied outside air out of the enclosed space through a top end of the derrick opposite the moonpool area; and a pressure regulating damper provided in a side of the derrick between the top end and the moonpool area which supplies air to or exhausts air from the enclosed space to prevent rapid pressure variation such that the internal air pressure within the compartment collectively formed by the derrick and the moonpool is constantly maintained despite the interaction of the sea waves with the moonpool throughout drilling operations.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a side view illustrating a conventional drill ship which performs a drilling operation on the sea.

(2) FIG. 2 is a conceptual diagram illustrating a situation in which a ventilating apparatus for a drill ship sailing around an arctic region is operating in a hot season.

(3) FIG. 3 is a conceptual diagram illustrating a situation in which a ventilating apparatus for a drill ship sailing around an arctic region is operating in a cold season.

DETAILED DESCRIPTION

(4) Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

(5) FIG. 2 illustrates a situation in which a ventilating apparatus for a drill ship sailing around an arctic region is operating in the hot season.

(6) A derrick 110 and a moonpool 120 are ventilated through a ventilating apparatus according to the present invention. The derrick 110 is fixedly installed on a deck (not shown) of a drill ship 100 and the moonpool 120 is formed under the derrick 110, such that drills for a drilling operation or the like move downwardly through the derrick 100 and the moonpool 120. Since this is well known in the shipbuilding industry, detailed description thereof will be omitted for conciseness.

(7) Since the drill ship 100 to which the present invention is applied sails around the arctic region, the derrick 110 has an enclosed structure blocked from the exterior so as to prevent air having a temperature below zero from being directly contacted with a variety of drilling equipment inside the derrick 110.

(8) Although the terms hot season and cold season are used in this specification, they represent the conditions of the arctic region and thus it should be noted that a temperature does not exceed 10 C. even in a hot season.

(9) Even when the drill ship 100 sails around the arctic region, the ventilating apparatus according to the embodiment of the present invention can prevent the internal temperature of the drill ship 100 from dropping rapidly and can constantly maintain temperature and pressure suitable for sailing and drilling.

(10) To this end, an air supply device 130 installed outside the derrick 110 supplies fresh outside air through a supply fan 131. However, in the case where the ventilating apparatus according to the present invention operates in a hot season, air is not separately heated through a heater 134 of the air supply device 130, considering the temperature of the outside air. The outside air supplied through the air supply device 130 may flow through a duct 136 to a space where the moonpool 120 is formed.

(11) The end of the duct 136 may be coupled to the derrick 110. However, in terms of circulation of outside air, it is more advantageous to couple the end of the duct 136 to the moonpool 120 disposed under the derrick 110, because air can be ventilated through the whole derrick 110.

(12) A wire mesh 137 is formed at the end of the duct 136 coupled to the moonpool 120, whereby air can be effectively supplied to the moonpool 120.

(13) The air supply device 130 includes a supply louver 132 which can allow the inflow of outside air and prevent the inflow of large particles or rainwater. In addition, the air supply device 130 includes a shut-off damper 133 which can shut off an air flow in the event of a fire or other emergency.

(14) An air supply port 150 is formed on the side of the derrick 110. The air supply port 150 may be opened in a hot season. Accordingly, outside air may flow into the derrick 110 through the air supply port 150 as well as the air supply device 130.

(15) In the case where the drill ship 100 according to the present invention sails around the arctic region in a hot season, the supply fan 131 and an exhaust fan 141 may be operated at high speed to supply and exhaust air at high speed. To be specific, since a temperature in a hot season is relatively high as compared to a cold season, it is less likely that the derrick 110 and the moonpool 120 will be frozen. Therefore, the outside air need not stay in a space formed by the derrick 110 and the moonpool 120 for a long time. In a hot season, outside air also flow into the derrick 110 through the air supply port 150, as described above. Therefore, an amount of air for ventilation is sufficient.

(16) The outside air supplied to the moonpool 120 flows upwardly, passes through the derrick 110, and is exhausted out of the derrick 110 through the exhaust fan 141 installed in an air exhaust device 140, as indicated by the arrows in FIG. 2. In such a manner, fresh air is continuously supplied to the moonpool 120 and the derrick 110. Accordingly, even though gas or the like is generated during a drilling operation, it is exhausted immediately to the exterior, thereby ensuring the safety of operations in spite of the use of the derrick 110 having the enclosed structure.

(17) As illustrated in FIG. 2, an exhaust louver 142 may be provided in the air exhaust device 140. The exhaust louver 142 can allow the exhaust of air and prevent the inflow of large particles or rainwater from the exterior.

(18) Since the derrick 110 has the enclosed structure, the internal pressure of a compartment formed by the moonpool 120 and the derrick 110 may rise or drop excessively if waves hit the opened space under the moonpool 120 which is in contact with seawater. To prevent such a rapid pressure variation and maintain the internal pressures of the derrick 110 and the moonpool 120 at constant levels, a pressure regulating damper 111 may be installed on the side of the derrick 110 as illustrated in FIG. 2. The pressure regulating damper 111 suctions or exhausts air according to a variation in the internal pressures of the derrick 110 and the moonpool 120.

(19) FIG. 3 illustrates a situation in which a ventilating apparatus for a drill ship sailing around an arctic region is operating in a cold season.

(20) Since the operation of the ventilating apparatus of the present invention in the cold season is almost identical to the operation in the hot season, the following description will be focused on differences therebetween.

(21) In the cold season of the arctic region, air temperature outside the drill ship 100 is below zero and it is extremely cold. Therefore, cold outside air flowing into the air supply device 130 is heated to an appropriate temperature by the heater 134 and is supplied to the moonpool 120 and the derrick 110.

(22) In addition, considering below zero temperatures outside the drill ship 100, air heated by the heater 134 needs to stay in the space formed by the derrick 110 and the moonpool 120 for a long time. Therefore, the supply fan 131 and the exhaust fan 141 may be operated more slowly than in the hot season.

(23) It is preferable to close the air supply port 150 formed on the side of the derrick 110. Since outside air temperature is extremely low, a variety of drilling equipment may be frozen if air is supplied to the derrick 110 without being heated by the heater 134 or the like.

(24) A plurality of heat blowers 160 may be installed inside the derrick 110 to heat air and forcibly circulate the heated air. Although the air heated by the heater 134 is supplied to the moonpool 120 and the derrick 110, a more effective air ventilation may be achieved by installing an additional heat source, separately from the heater 134, in the inside of the derrick 110, considering the cold season.

(25) According to the ventilating apparatus for the drill ship of embodiments of the present invention, ventilation of warm air into the drill ship makes it possible to meet a temperature maintenance condition required when the drill ship sails around the arctic region. In addition, it is possible to minimize the rapid pressure change due to the influence of waves generated in the moonpool.

(26) In addition, energy can be efficiently used by partially changing the method for operating the ventilating apparatus of the drill ship, depending on the cold season and the hot season of the arctic region.

(27) According to the embodiments of the present invention, the ventilating apparatus for the drill ship can maintain temperatures and pressures of the moonpool and the derrick at appropriate levels, considering the influence of temperature and waves, such that the drill ship is efficiently operating in an arctic region.

(28) Since the derrick and the moonpool have the enclosed spaces blocked from the exterior in order for preventing freezing, it is possible to minimize the influence of the temperature and pressure of the space formed by the derrick and the moonpool according to the external temperature and waves.

(29) Moreover, since the pressure regulating damper prevents the excessive pressure change in the derrick and the moonpool, it is possible to prevent the generation of excessive positive pressure and negative pressure even though waves hit in the moonpool.

(30) While the ventilating apparatus for the drill ship according to the present invention has been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.