KR20170023802A - Drillship - Google Patents

Abstract

The invention relates to a drill ship comprising a hull (2) extending along a longitudinal axis (X) between a bow (3) and a stern (4). The drill flow (6) is located above the main deck, and each of the drilling towers is provided with at least one gate (7), at least one drill Extends over the drill flow 6 close to the pools 8 'and 8 ", and the door pulls the hull 2 from the drill flow 6 to the bottom 9 of the hull itself 2 It traverses vertically. Each of the one or more drilling towers has a box-like structure and supports the lifting devices 70 from outside thereof. The drill flow 6 extends completely beyond the flow dimensions of the one or more drilling towers 7 ', 7 "in order to utilize the readily available space.

Description

DRILLSHIP {DRILLSHIP}

Field of the Invention [0002] The present invention relates to a drill ship, and more particularly to a drill ship for locating, exploring and utilizing buried layers of hydrocarbons or other energy and mineral resources.

For the same reasons, the drill ship according to the invention is particularly intended to operate at deep water (over 450 m) and intrinsic (over 1,500 m).

Drill ships are a type of coastal units specialized in drilling oil wells at depths above 3000 meters below sea level. These units are typically operated to locate and prepare for future use by other coastal units specialized in the production of natural gas and crude oil.

The drillships generally include an operating area for drilling rigs located in the midship of the ship.

As is known, in the current drill ships, the drilling rigs include at least one drilling tower constructed by a structural lattice characterized by a structure of transversal rods bolted to each other derrick). Almost all drill rigs, including hooks that pull up drill strings, are contained within the lattice structure.

From a structural point of view, the lattice structure A is located on a so-called drill floor B. In turn, the drill flow B is supported in a terminology by a scaffold (C) referred to as a "sub-structure ", and then the scaffold is located on the main deck D easily. The entire structure described above extends over a central drilling well E (the term "door pool"), wherein the central drilling passage extends from the main deck to the bottom and directly through the bottom to the water Approach.

This solution has been extensively tested for 20 years on various coastal floating vessels.

One limitation of this structural solution is related to the fact that the lattice derrick limits the expansion of the drilled flow surface into the perimeter of its base because the main suspension and drilling machine are contained within the lattice case. As a result, the possible increase in the deck's operating area substantially collides with the physical and structural limits of derrick.

For the reasons mentioned above, it is impossible to create new operating spaces on the drill flow while being limited by conventional derrick.

As a result, it is an object of the present invention to eliminate or at least reduce the drawbacks of the prior art mentioned above by implementing an available drill ship with a more elongated drill flow, without requiring an increase in the flow dimensions of the drilling towers It is on.

It is a further object of the present invention to make available drill shafts that have a more elongated drill flow and at the same time ensure the overall operation of the drilling rigs.

Technical features of the present invention in accordance with the above-mentioned objects can be seen clearly in the following claims, which can be understood by those skilled in the art with reference to the accompanying drawings, which show one or more embodiments by non-limiting examples, , In which: < RTI ID = 0.0 >
1 shows a schematic isometric view of an associated support structure and a lattice tower of a conventional type and of a drill flow on a main deck;
2 shows a perspective view of a drill ship according to a preferred embodiment of the present invention;
Figures 3 and 4 show two isometric side views of each of the right side and left side of the joint shown in Figure 2;
5 is a plan view of the easy drill flow shown in FIG. 2; FIG.
- Figure 6 shows a plan view of the easy main decay shown in Figure 2, located under the drill flow; And
7 is a view of the simple hull shown in Fig. 2. Fig.

Referring to the attached drawings, reference numeral 1 generally denotes drillshows according to the present invention.

Hereinafter and in the description of the invention and in the claims hereinafter, the reference will be made in conjunction with the simplification (1) according to the conditions of use. Therefore, the criteria for top or bottom position or horizontal or vertical orientation should be understood in this sense.

According to a general embodiment of the invention, the drill ship 1 comprises a hull 2 extending between a bow 3 and a stern 4 along a longitudinal axis X.

The shoe 1 comprises a main deck 5 where the drill flow 6 is located above the main deck and one or more drilling towers 7 ' Extends over the drill flow (6) in close proximity to at least one door pool (8 ', 8 ") that transversely transverses the hull (2) to the bottom (9) of the hull itself.

"Drill flow" means, as will be appreciated, the space on which drill rigs are placed and which are called to operate directly by a technician who operates the above-mentioned leagues. In particular, this is the space where the drill strings sink and operate on the door.

According to the present invention, each of the one or more drilling towers 7, 7 'has a box-like structure and supports the lifting devices 70 externally by themselves.

In particular, each of the one or more towers 7 ', 7 "referred to above has a columnar shape and a base (generally circular) of any shape. The lifting devices are, in particular, And a lifting hook 70 of drill strings cantilevered with respect to the vertical stretch axis Y.

This type of drilling tower has a compressive load of pulls originating from external loads suspended from the lifting hooks and lifting winch cables 71 on opposite sides of the vertically and symmetrically perfectly aligned drilling towers compression load. 2, 3 and 4, the lifting cables of the hooks go to a pair of pulleys 72 and 73 located on top of the towers 7 ', 7 " 70 to the symmetrical winch 71. The geometry as described above ensures a perfect vertical and symmetrical alignment of the lifting cables, thereby ensuring a static load on the drilling tower of the compression only.

In accordance with the present invention, the drill flow 6, in particular as shown in Fig. 2, has a flow dimension of the above-mentioned one or more drilling towers 7 ', 7 " It extends completely outside.

Thus, due to the present invention, the shoe 1 can have a more elongated drill flow without requiring an increase in the flow dimension of the drilling towers. The limits of the stretching and declining of the drill flow are fundamentally influenced only by the size of the hull.

This is made possible by the use of drilling towers with box structures and with external lifting devices instead of grid structure towers with internal lifting devices.

The box-structure tower is a structural solution that provides a number of advantages when compared to conventional lattice solutions.

In particular, an important advantage derives from the previously mentioned external positioning of the suspension line of the drill strings. In fact, considering that the suspension line is generally cantilevered from the tower, it is basically exposed and there are no obstructions on a large part of the horizon. This can create the entire area of the deck surrounding the available towers, and the suspension lines facilitate the distribution of heavy and bulky equipment through lifting means on the board. This operation may not be possible if a closed cage structure of a conventional lattice drilling tower is present. In a conventional lattice solution, the drill flow is divided into two distinct operating zones. The first operating zone is confined (covered) within the perimeter of the base of the derrick and is thereby blocked by the structure. In this first zone, the handling of any equipment by external lifting means such as a crane on the deck is prevented. The second operating zone is located outside the derrick (uncovered). In this second operating zone, the equipment supporting the various operations can be moved including the support of the lifting means on the deck. Variously, by using towers with a box structure, the entire surface expansion of the drill flow is uncovered and available for lifting and steer operations, including, but not limited to, the help of lifting means on the deck. This increases the safety and operation of the entire zone.

Another advantage is that it is associated with lowering the level of drill flow of some activity that can occur significantly with the resulting increase in operational and safety difficulties in conventional grid configurations. Particularly large winches are placed at the drill flow level. This brings significant advantages related to the efficiency and safety of operation on decks.

Preferably, the sheath 1 comprises at least two drilling towers 7 ', 7 "having boxed structures and external lifting devices.

Advantageously, each of said at least two towers 7 ', 7 "is dedicated to a single drilling line. In other words, such towers 7', 7" As a result, when dual drilling lines for dual drilling activities to be carried out in parallel are installed in the vessel 1, using independent towers 7 ', 7 "with single drilling lines, The physical constraints imposed by conventional derrick towers with two drilling lines are eliminated (considering that they are supported by the same tower). The structural and functional independence of the two or more towers 7 'and 7 " The whole enables positioning them to the most convenient mutual positions, reducing the risk of mutual interference and thereby improving movement of people and objects on the drill flow. This results in a configuration with an extended drill flow that provides all of the benefits associated with the extended and unobstructed workspace.

Even if not shown in the accompanying drawings, a single drilling tower is installed in the ship 1, and such a single tower can be structured to serve as a single drilling line.

According to a preferred embodiment shown in the attached drawings, the shoe 1 comprises the above-mentioned drilling towers 7 ', 7 ", having a box-like structure and external lifting devices. Extends continuously between the two drilling towers 7 ', 7 "to form a single, extended drill flow.

Advantageously, the two towers 7 'and 7 "can be placed at a greatest distance from each other, and the distance is easily compatible with the available dimensions of the platform.

In this way it is possible to maximize the surface of the drill flow 6.

As shown in Figure 2, the shoe 1 includes an operating zone 20 dedicated to drilling activities. Advantageously, two drilling towers 7 ', 7 "are arranged in the working drilling zone 20 (in the direction parallel to the longitudinal axis X) to maximize the available surface area of the extending single drill flow 6 ) In the distal positions.

The expression "located at distant positions" means that the two towers 7 'and 7 "are positioned as opposed to each other in a direction parallel to the longitudinal axis X, It is used to mean far apart.

Preferably, as shown in Figures 2, 5 and 6, the above-mentioned operating zone 20 dedicated to drilling activities preferably comprises a first operating zone 10 of easy management located in the bow, , Preferably in the middle of the ship between the third operating zone 30 of power generation for easy propulsion located at the stern.

The distribution of the three operating zones as provided in the embodiment shown in the accompanying drawings is representative of the existing vessels to be drilled and in particular provides:

A housing tower (10) at the forward end;

A main exposure deck 5 extending from the housing tower to the stern end;

- a lower deck (below the main deck) which contains the operating support areas of the sheer platform and most of the drilling machine and whose aft end houses the engine room and the power generating machine;

- a highly positioned drill flow (6) in which steering is performed using drill strings, and hooks that lift and rotate said strings.

However, the present invention can also be applied to handles having different configurations of operating zones.

Advantageously, the single extended drill flow 6 referred to above extends substantially through the longitudinal extent of the second operating zone 20 from the first operating zone 10 to the third operating zone 30 .

According to the embodiment shown in the attached drawings, the shoe 1 is connected to the riser 2, one of the two drilling towers 7 ', 7 "in the second operating zone 20, a hold 23 for the riser and a cementer 24. The maximum longitudinal distance between the two drilling towers 7 ', 7' 'is the distance between the hold 23 and the cementer 24, Lt; / RTI >

Preferably, the drill flow 6 with the main part 6 'extends to the zone in which the drilling towers 7', 7 "are located, and the first appendix portion < (6 "') on the cymenter (24), and on the bow having the second portion (6' ').

Preferably, as shown in the accompanying drawings, the single extended drill flow 6 referred to above extends from the bow to the stern, and in the extended zone, the area of the cymterer 24 at the stern, Incorporates both the hold 23 for storing the risers, and expands them equally above. A single extended stream 6 as described above is located in the bow on the housing tower 10.

Advantageously, the use of a single elongated drill flow 6 makes it easier to implement a solution with two or more separate and independent door pools. In fact, the extending drill flow 6 provides greater operational flexibility for drilling activities. This makes it possible to increase the distance between drilling towers and thereby technically enable to provide independent door pools for each drilling tower.

Preferably, the easy includes two or more separate and mutually independent door pools 8 ', 8 "each dedicated to a single drilling tower 7', 7 ". This technical solution is particularly structurally feasible when the drilling towers are independent of each other and thus can be spaced apart without any limitation of the type of operation involved in drilling activities.

The presence of several small door pools rather than a large size single door pool has a number of advantages listed below:

- increase in the hydrostatic thrust volume of the underwater part of the hull;

- an increase in the internal space which is easy to use as compartments for consumable liquids (larger autonomy) and technical spaces (warehouses, workshops, subsidiaries, etc.);

- a probable reduction of the waves inside the small door pools;

- a substantially definite reduction in resistance to movement due to a reduced open surface on the bottom of the can;

- improvement of structural continuity and therefore local stress reduction;

- large free surface area available on major decks; And

- almost certainly simplification of possible complete and / or partial closure systems of door pools.

The presence of a single large door pool in which all of the drilling towers operate can be provided as an alternative. However, this solution is undesirable because it imposes restrictions on the maximum distance between the towers. In fact, to avoid hydrodynamic problems, there is a tendency not to make gate-pools that exceed a certain size.

In particular, the two or more independent door pools 8 ', 8 "mentioned above are arranged along the longitudinal axis of the easy central line X. [

Unlike lattice towers, towers with boxed structures and external lifting devices can not be located in the center on the axis of the door pool, but in a manner eccentric to this axis to have a lifting hook of the tower perpendicular to the door pool in a decentralized manner.

Preferably, the two or more towers 7 ', 7 "referred to above, as shown particularly in Figures 5, 6 and 7, are oriented towards the first side 2' ) Are arranged asymmetrically with respect to the longitudinal axis of the shifted center line X. In particular, the two towers are both moved toward the same side.

According to an alternative embodiment not shown in the accompanying drawings, the two or more towers mentioned above may be symmetrically positioned with respect to the longitudinal axis X of the easy center line, i.e. on the longitudinal center axis X .

The off-axis or on-axis placement of the centerline can also be used if it also has a single drilling tower.

In accordance with the embodiment shown in the accompanying drawings, within the drilling operating zone 20, the shoe 1 is used to store drill strings made in close proximity to the two or more drilling towers 7 ', 7 " The storage area 40 as described above is moved to the second side 2 ", which is easier with respect to the longitudinal center axis X, opposite to the side where the two towers are moved . 2, the storage compartment 40 is delimited by a vertical wall 60 extending beyond the drill flow 6 from the main deck 5, on the outwardly facing side. This wall serves as a vertical support element for the drill strings.

The storage and assembly areas of the drill strings are referred to in the jargon as "set back ". These zones, which are integral with the drill flow or which are in any case next to the drill flow, generally have three strings of one side screwed to the other side to form a single string of about 41 m length It is used to store pre-prepared drill strings in groups. This often makes it possible to reduce the time required to lower and raise the total string, which is several kilometers in length and has the right diameter and which has the type of string for the specific drilling operation planned. In operation, the pre-assembled drill strings using the main lifting hooks can thus be used as special racks, called fingerboards, which cut the strings vertically at two points (one at the bottom and one at the top) (One-sided drilling campaign and other-sided drilling campaigns). In particular, such fingerboards can be made in the above-mentioned wall 30, which is used as a vertical support element of the drill flow. At this stage, the strings are prevented from flexing by their own weight, and claws previously clipped pre-strings under the main hook and by a machine known as a rough neck, Are always handled in a vertical position to prevent damage by special machines, called smartrackers, which move the string to the end of the string. From this moment the strings are prepared to start the cycle of introduction and oil well extraction and moved by the smart racker from the center of the drill flow to the lifting hooks from the pinker board and vice versa. At the end of the drilling operation the strings are unscrewed by the rough knuckles and in the opposite manner as described above, using a special dedicated horizontal chute, called a catwalk, . According to the embodiment shown in the accompanying drawings, the drill strings can be stored one by one on an easy side, so that they are inclined towards the center of the ship, while when the upper end is vertically below the lift for the lift, Until the upper end is stored vertically below the lifting hook until it is in the center of the door pool; The string is then lifted, inserted into a central hole on the drill flow, and down into the hole of the well below the sea bed.

Preferably, the drill flow 6 also extends into the storage zone 40 as described above. In particular, as shown in FIG. 5, on the drill flow 6 in the storage zone 40, one or more openings are implemented to move the strings between towers and setbacks.

The positioning of the set bag in the body of the shoe is done by a person who visually checks the string's exact catch to avoid the risk of falling and damage caused by incorrect control, directly above the drill flow and no more than 40 meters high The presence at such height also makes it possible to attach pre-assembled strings to the tower's lifting hook (Topdrive), as in the case of conventional lattice towers generally required.

Preferably, each drilling tower 7 ", 7 "is directly supported by a support structure 50 structurally integrated with the hull 2. The support structure 50 and / or the towers 7 ', 7 "traverse the drill flow 6. The latter is structurally supported by the support structure 50 and / or by the drilling tower itself.

In particular, as shown in FIG. 4, the support structure 50 of the towers 7 ', 7' 'extends vertically into the hull 2.

Preferably, the support structure is structurally integrated with the main deck 5 located, or the auxiliary deck under the main deck located, or the bottom 9 of the hull 2 on which it is located.

Advantageously, as shown in the accompanying drawings, the drill flow 6 is structurally integral with the snug and results in an easy fastening structure.

As discussed above, the drilling towers 7 'and 7 "are integral with the hull structural body in view of considerable weight and structural dimensions which are influenced by the large loads required to support and steer. As a result, In addition, one or more door pools made in the hull must be installed to permit the initiation of the necessary equipment for diving operations.

Due to the dimensions and weight of the structures of the towers and the associated lifting equipment, it is technically impossible to assemble them on mobile drill flows suitable for moving towers off-board. This solution (beyond the present invention) will prevent the problem of penetrating the bottom easily for the passage of the instruments necessary for the diving operation, but can only be used for light equipment. In this case, unlike the provision of the present invention, the drilling towers can be supported by a movable drill flow and can not be integrated with the ship hull.

The use of fixed and immovable drill flows in the sense specified above has the benefit of increasing the free zones available on the deck below the drill flow. In the case of a mobile drill flow, the area of the deck below which is necessary for the movement of the movable deck must be kept free and unavailable for other purposes. Instead, with a fixed drill flow, the area under the drill flow is a free zone that can be advantageously utilized for diving operations.

Advantageously, the drill flow 6 can also be carried out by dedicated pillars, or other vertical structure (also by the towers 7 ', 7 ") and / or by the support structure of the tower, In particular, the drill flow 6 is supported by at least one structural support element 60, and the structural support element is connected to the one (1) mentioned above with respect to the longitudinal central axis X of the joint 1, Extends vertically from the main deck 5 in proximity to the second side 2 "at the side facing the drilling towers 7 ', 7" And a wall defining the limits of the storage and assembly area 40 of the drill strings.

The present invention allows for a number of advantages that can be achieved, which are already described in part.

The drill ship according to the present invention has a drill flow that is more elongated compared to the conventional solution, without requiring an increase in the flow dimension of the drilling towers.

The drill ship according to the invention has a more elongated drill flow and at the same time ensures full operation of the drill rigs.

Due to the present invention, the ease of installation of several independent door pools of small dimensions, due to the use of drilling towers not related to one another, is structurally reasonable and feasible, with an excellent hydrodynamic performance and a And has benefits associated with distribution.

Thus, the present invention has been devised to achieve the intended object.

Obviously, the actual embodiments thereof are capable of other forms and configurations than those described and still remain within the scope of the invention.

Furthermore, all parts can be replaced with technically equivalent parts, and the dimensions, shape and materials used can be changed as needed.

Claims (13)

Includes a hull 2, a main deck 5 and one or more drilling towers 7 ', 7 "extending along a longitudinal axis X between a bow 3 and a stern 4 On which a drill floor (6) is located and each of the drilling towls extends over the drill flow (6) in proximity to at least one door pool (8 ', 8 " The door pool is a drill ship (1) which traverses the hull (2) vertically from the drill flow (6) to the bottom (9) of the hull itself (2)
Each of the one or more drilling towers 7 ', 7 "has a box-like structure and supports lifting devices 70 on its own outside,
The drill flow (6) completely extends outside the flow dimension of the one or more drilling towers (7 ', 7'') to utilize the readily available space. The method according to claim 1,
Wherein each drilling tower comprises at least two of the drilling towers (7 ', 7 "), each drilling tower dedicated to a single drilling line. The method of claim 2,
Said drill flow 6 comprising two of said drilling towers 7 ', 7 ", said drill flow 6 extending continuously between two drilling towers 7', 7 " Forming, drill-in. The method of claim 3,
Comprising a motion zone (20) dedicated to drilling activities,
The two drilling towers 7 ', 7 "are arranged in a direction parallel to the longitudinal axis X of the simple drill flow 6 to maximize the available surface area of the extending drill flow 6, 20) located at distal positions. The method according to any one of claims 2 to 4,
(8 ', 8 "), each of which is dedicated to a single drilling tower (7 ', 7"). The method of claim 5,
Wherein the two or more door pools 8 ', 8 "are along the longitudinal center axis X of the easy and the two or more drilling towers 7', 7" , And the towers are moved towards the first side (2 ') of the can. The method of claim 6,
The storage and assembly areas of the drill strings which are made close to the two or more drilling towers 7 ', 7 "and which are moved towards the second side 2" And preferably the drill flow (6) extends into the storage zone (40). The method according to any one of claims 1 to 7,
Characterized in that each of said at least one drilling tower or said at least two drilling towers (7 ', 7 ") is directly supported by a support structure (50) structurally integrated with the hull (2) The support structure 50 of the drilling tower 7 ', 7''and / or the drilling tower itself 7', 7 '' traverses the drill flow 6, (50) and / or by the drilling tower itself. The method of claim 6 or claim 8,
Characterized in that the drill flow (6) has a second side (2 ") at a location facing the longitudinal axis (X) of the ship (1) , Supported by at least one structural support element (60) extending vertically from the main deck (5). The method according to claim 7 or 9,
Wherein the structural support element (60) is constituted by a wall delimiting the storage and assembly section (40) of the drill strings. The method of claim 4,
The operating zone 20 dedicated to the drilling activity is preferably provided with a first operating zone 10 of easy control located in the bow and a second operating zone 10 preferably having a power for propulsion, Is located at the center of the ship between the third operating zone (30) of generation. The method of claim 11,
The single drill flow (6) extends substantially through the longitudinal extent of the second operating zone (20) from the first operating zone (10) to the third operating zone (30). The method according to claim 12 or 13,
One of the two drilling towers 7 ', 7 "in the second operating zone 20 is located at the stern and the other is a hold 23 and a cementer 24, , Wherein the distance in the maximum longitudinal direction between the two drilling towers (7 ', 7'') is limited by the distance between the hold (23) and the cementor (24).

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