KR20110061872A - Drilling working method in a seabed drilling facility - Google Patents

Abstract

PURPOSE: A drilling method of submarine drilling machine is provided to reduce the time and cost required for boring work by proceeding a casing assembly work during drilling work in an oil drilling ship. CONSTITUTION: A drilling method of submarine drilling machine comprises the steps of drilling to form a hole in a submarine stratum using a drill bit, assembling a casing(100) at one side of a derrick(130), and descending the assembled casing into the submarine stratum and installing the casing.

Description

Drilling working method in a seabed drilling facility

The present invention relates to a drilling operation method in a subsea drilling facility that can reduce the time required for drilling operations to reduce the charter rate.

As the international rapid industrialization and industry develop, the use of resources such as petroleum is gradually increasing. Therefore, stable production and supply of oil is becoming a very important problem at the global level.

For this reason, the development of marginal fields and deep-field oil fields, which have been neglected in recent years due to lack of economic feasibility, has become economic. Therefore, along with the development of seabed mining technology, a drilling vessel equipped with drilling equipment suitable for the development of such an oil field has been developed.

Conventional subsea drilling is mainly used for rig ship or fixed platform dedicated to subsea drilling, which can be sailed only by other tugboats and anchored at one point of the sea using mooring devices. Recently, so-called drill ships, which are manufactured in the same form as general ships so that they can be sailed by their own power and equipped with advanced drilling equipment, have been developed and used for subsea drilling.

In the center of a rig ship or a drilling ship (hereinafter referred to as a drilling ship) equipped with various drilling equipments to drill oil or gas existing in the basement of the seabed, a riser for drilling oil or gas existing in the basement of the seabed Or a moonpool is formed so that a drill pipe can be moved up and down.

1 is a side view showing a conventional drilling vessel performing drilling operation at sea level.

The operator uses a top dirve installed on the derrick 2 to advance the riser 4 and the tubular member 5 downward through the door pool 3 formed in the center of the drilling line 1, thereby to the sea bed. (6) Drilling seabed resources stored in well 13 located in reservoir 12 below.

The riser 4 provides a passage through which the mud returns as a member that is advanced to the bottom of the sea floor 6 before advancing the tube member 5 to the well 13. When the riser 4 is installed, the tube member 5 is advanced downwardly into the well 13 through the sea bed 11.

As described above, when the riser 4 is advanced downward to the sea bottom 6 or the tube member 5 is advanced to the oil well 13, the long riser 4 or the tube member 5 is advanced downward. Rather, the short risers 4 and the tubular members 5 are connected to each other and advanced downward. The blowout preventer (BOP) 7 is provided in the sea bottom 6 to prevent abnormal high pressure from rising up the pipe member 5. In the subsea layer 11, the casing 8 is fixed by cement, and then the seawater resources are drilled by inserting a pipe member 5 equipped with a drill bit 10 into the casing. The mud 9 is inserted into the tubular member 5 to prevent the drill bit 10 from overheating by the heat generated when the drill bit 10 drills the ground and to lubricate to make drilling easier. do. This mud exits through the drill bit 10 and returns back through the casing 8 and the riser 4. When the drilling operation is completed, the pipe member 5 is transported to the drill floor through the door pool 3, separated, and then transported to the loading site.

2 is a view showing the structure of a conventional general derrick.

The derrick 2 is provided with a traveling block 14, a top drive 15, a rotary table 16, and the like. Pipe members such as drill pipes and casings are gripped by the top drive 15 and advanced to the seabed through the rotary table 16. The traveling block 14 is a means for elevating the tubular member held by the top drive 15.

A large part of the drilling work involves joining pipe members to advance to the sea floor, or separating and disassembling the joined pipe members one by one. Since this work is based on one traveling block 14 and the top drive 15, the drilling work, the installation of the casing on the sea bed in the early stage of the drilling work, for example You have to work, and two jobs cannot be done at the same time.

3A to 3E are diagrams illustrating a process of installing a casing at the beginning of a conventional drilling operation.

First, start drilling a subsea bottom 6 using a 36 "drill bit 10 to dig a hole, for example about 100 m (see FIG. 2A). On the top of the drill bit 10 is a drill collar (drill collars; 18) are connected, on top of which a number of drill pipes (5) are connected in turn, leading to the drilling line 1. In modern oil well drilling, the distance from the drilling line (1) to the bottom of the seabed (6) is thousands m is about.

Next, the drill bit 10, the drill collar 18, and the drill pipe 5 are placed on the drilling line 1 and separated one by one. Next, the 30 "casings 19 are connected one by one through the rotary table of the drilling vessel 1 until they are about 100 m. A casing string such as a drill pipe 5 is connected to the upper part of the 30" casing 19. ) To the bottom of the seabed (6) and to insert the 30 "casing (19) into the hole. Next, cementing through the 30" casing (19) inside, the 30 "casing (19) and strata Fully cemented (see Figure 2b) cementing inserts the cement into the casing, pressurizes the cement and places the cement in the space between the strata and the casing to cure. This ensures stable drilling of subsequent drilling operations.

Next, the drill pipe 5 is separated from the 30 "casing 19, and then a plurality of connected drill pipes 5 are lifted up onto the drilling line 1 and separated one by one. ", Then connect the drill collar 18 and the drill pipe 5 to the drill bit 10 to continue drilling to drill holes deeply about 1000 m (see Figure 2c).

Next, remove the drill bit 10 by raising the drill pipe 5 to the drilling line and insert the 20 "casing 20 into the hole and cementing to completely bond the 20" casing 20 to the ground layer. (See FIG. 2D).

Next, the drill bit 10 is replaced by 18 ", and then drilling continues to dig more deeply (see FIG. 2E).

As described above, the drilling operation takes a lot of work to connect the pipe members one by one from the drilling line 1, or to install the casing in the hole. In recent oil well drilling, the distance from the drilling vessel 1 to the sea bottom 6 is about several thousand m, and the distance from the sea bottom 6 to the well is often 1000 m or more.

Since the daily usage fee of drilling equipment such as drilling ships is about $ 500,000, the reduction of working time in drilling work is a very important problem directly related to the reduction of oil production cost. In the drilling line 1 conventionally having one derrick 2, since work such as drilling or casing installation is performed based on one traveling block 14 and top drive 15 installed in the derrick 2, When one job is done, the next one must be done, and two jobs cannot be done at the same time. This is inefficient for drilling rigs where the daily fee is very high.

Therefore, the present invention has been invented in view of the above circumstances, and in the drilling operation such as drilling and casing installation, by carrying out the casing assembly work while the drilling operation is in progress on the drilling vessel, the drilling time can be reduced and the drilling cost can be reduced. The purpose is to provide drilling methods that can be used.

Drilling operation method in a subsea drilling equipment having a single derrick according to an aspect of the present invention, the drilling step for forming a hole in the sea bed by a drill bit; A casing assembly step of assembling the casing on one side of the derrick during the drilling step; A casing installation step of installing the casing by lowering the assembled casing to the seabed after completion of the drilling step; Characterized in that it comprises a.

In addition, in the casing assembly step, the casing is characterized in that assembled outside of the derrick.

In the casing installation step, the assembled casing is transported to a well center and then lowered to the sea bed by lifting means.

In addition, the assembled casing is characterized in that it is transferred to the well center by the Christmas tree trolley.

In addition, in the casing assembly step, the casing is a casing vertical transfer device located outside of the derrick; A guide device positioned outside the derrick to guide the casing which is vertically lifted and lowered; It is characterized in that it comprises a vertical lift by the assembly.

In addition, the casing vertical transfer device is characterized in that supported by the derrick.

Subsea drilling equipment having a single derrick according to an aspect of the present invention, the casing vertical transfer device located outside of the derrick; A guide device positioned outside the derrick to guide the casing which is vertically lifted and lowered; Transfer means for transferring a plurality of assembled casings outside the derrick to a well center in the derrick; Characterized in that it comprises a.

In addition, the casing vertical transfer device is characterized in that supported by the derrick.

In addition, the guide device is characterized by having an arm capable of gripping the casing.

According to the present invention, while the drilling operation is carried out in the drilling vessel having a single derrick, since the casing is connected to the outside of the derrick at the same time, it is possible to shorten the time required for the casing installation. Therefore, it is possible to reduce the molten material of the drilling rig by a shortened time.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. The same reference numerals in the drawings denote like elements throughout the drawings.

4A to 4L are views illustrating a process of assembling a casing outside the derrick in a subsea drilling facility according to the present invention and transferring the casing to a well center in the derrick.

In the present invention, the subsea drilling equipment is meant to include all of the facilities that can drill the resources of the seabed equipped with a derrick, such as drillships, rig ships, semi-submersible drilling ships, tension leg platform.

In general, at the beginning of drilling operations, casings are installed on the seabed. The casing is installed to solidify the wells so that subsequent drilling operations can be performed stably. Casing installation work is performed by drilling the bottom of the seabed using a drill bit to dig a hole, then lowering the casing in the hole and fixing the casing by cementing. The deeper the hole is drilled into the seabed, the smaller the diameter of the casing.

In recent oil well drilling, the distance from the drilling rig to the bottom of the seabed is thousands of meters, and the distance from the bottom of the oil well to the well is often 1000 m or more.

In drilling vessels with conventional single derricks, operations such as drilling or casing installation are based on one traveling block and top drive installed in the derrick. Therefore, when the drilling work is completed at the drilling line, the drill bit should be pulled up to the drilling line, and then the casing installation work should be performed by connecting a plurality of casings in turn by the traveling block and the top drive to the sea floor.

Since the daily charter cost of drilling equipment such as drilling ships is about $ 500,000, the saving of working time in drilling work is a very important problem directly related to the reduction of oil production cost.

For example, if a 20 "casing is installed about 1,000 meters long on the seabed, about 100 feet of 45 feet (45 feet) of length should be connected, which takes about 65 hours. The charter price is about $ 1.3 million.

In the present invention, during the drilling step by the top drive in the drilling ship having a single derrick, the casing is connected to the outside of the derrick. The drilling step refers to a step in which drilling related operations are performed, in addition to drilling a seabed strata by a drill bit, pulling a drill bit to a drilling line. When working in this way, the time required to connect the casings one by one by the top drive in the derrick can be shortened, which saves about $ 1.3 million in charter charges when the casing is connected at about 1000 m. Result. Since casings of different diameters are installed in various types, the time for installing the entire casing can be further shortened, thereby further reducing the amount of charter fee.

Typically, the casing is connected using a traveling drive and a top drive installed inside of the derrick, so an additional device for this is required to perform the task of connecting the casing outside of the derrick. Additional devices include a casing horizontal feeder 120, a casing vertical feeder 140, and a guide device.

Referring to FIG. 4A, a casing horizontal conveying device 120, a casing vertical conveying device 140, a guide device, and an X-mas tree trolley 160 are illustrated.

When the crane 110 lifts the casing 100 loaded at the casing loading place 101 and places it on the casing horizontal conveying device 120 on the catwalk, the casing horizontal conveying device 120 places the casing 100 on the derrick 130. The outer casing vertical transfer device 140 is transported horizontally to the installed place.

The casing vertical conveying device 140 is a device for lifting vertically by lifting the casing 100 conveyed by the casing horizontal conveying device 120. The casing vertical transfer device 140 is configured by installing the rail 141 on the outside of the derrick 130 and installing a lifting device 142 that can be elevated on the rail 141. Preferably, the rail 141 is supported by the derrick 130.

The guide device is a device for guiding the casing 100 to prevent shaking in the vertical lifting process. The guide device includes an upper casing arm 151 and a lower casing arm 152 (see FIG. 4C). Preferably, the guide device has an arm capable of gripping the casing 100.

The Christmas tree trolley 160 is positioned under the derrick 130. The drilling line is provided with a rail 161 along the door pool 3, and is configured to move the Christmas tree trolley 160 along the rail. The Christmas tree trolley 160 is a device that is generally installed on the drilling ship, the main purpose is to manipulate the Christmas tree, but in the present system is used to transfer the assembled casing 100 to a well center (well center). A Christmas tree is a structure made up of several valves to regulate the flow of oil in an oil well. The well center refers to a part where the main drilling operation is performed by the equipment such as the top drive in the derrick 130.

The power tree 170 is installed in the Christmas tree trolley 160. The power slip 170 is hydraulically operated and serves to prevent free fall of the casing by holding the casing.

Referring to FIG. 4B, the casing vertical transfer device 140 lifts the transferred casing 100.

Referring to FIG. 4C, the casing vertical transfer device 140 lowers the casing 100 through the power slip 170. The casing is guided by the upper casing arm 151 and the lower casing arm 152 as it descends. When the lower end of the casing 100 reaches the power slip 170, the power slip 170 locks the slip part to prevent the casing from falling freely.

Referring to FIG. 4D, the casing vertical transfer device 140 moves up and returns, and the Christmas tree crane 180 moves to grip the casing 100. The Christmas tree crane 180 is a device that is generally installed on the drilling ship, the main purpose is to operate the Christmas tree, but in the present system is used for the operation of the casing. The holding of the casing 100 by the Christmas tree crane 180 in place of the casing vertical transport device 140 has a limit on the height and weight of the casing vertical transport device 140, which can lower the casing 100. Because there is.

Referring to FIG. 4E, the Christmas tree crane 180 lowers the casing 100 using the lifting device, and the power slip 170 grips the upper end of the casing.

Referring to FIG. 4F, the Christmas tree crane 180 raises the elevator and returns to its original position.

Next, when the crane 110 lifts another casing 100 loaded at the casing loading place 101 and places it on the casing horizontal conveying device 120, the casing horizontal conveying device 120 conveys the casing 100 vertically to the casing. Transfer towards device 140 (see FIG. 4A).

Next, the casing vertical transfer device 140 lifts the casing 100 transferred (see FIG. 4B).

Referring to FIG. 4G, the casing vertical transfer device 140 lowers the casing to a position where the power slip 170 may be connected to the casing previously grasped. At this time, the upper casing arm 151 closes the arm and grips the casing 100, and the lower casing arm 152 pushes the casing to align the two casings.

Referring to FIG. 4H, the casing vertical transfer device 140 returns, and a casing tong 190 connects the two casings 100 into one.

Referring to FIG. 4I, when the Christmas tree crane 180 moves to grasp the casing 100 and then lowers the casing using the lifting device, the upper end of the casing to which the power slip 170 is assembled is gripped.

Referring to FIG. 4J, the Christmas tree crane 180 raises the elevator apparatus and returns to its original position.

By repeating this process, the casing 100 is connected by a desired length, for example 1000 m.

Referring to FIG. 4K, the Christmas tree trolley 160 holding the casing 100 assembled to the desired length moves to the well center along rails installed on both sides of the door pool. When the Christmas tree trolley 160 moves to the well center, the drilling operation ends and the drill bit is pulled up to the drilling line. At this time, the top drive 200 grips the casing string 102 for connecting to the upper portion of the assembled casing (100). The casing string 102 serves as a string for lowering the casing 100 to the seabed. The assembled casing 100 is connected to the casing string 102 and lowered to the seabed.

Referring to FIG. 4L, when the top drive 200 lowers the casing string 102 through the rotary table 210, the casing barrel 190 connects the assembled casing 100 to the casing string 102.

When the casing string 102 is connected to the casing 100, the casing string 102 is continuously connected with a string such as a drill pipe to move the assembled casing to the sea floor by lifting means (traveling block, top drive, etc.) to proceed with the casing installation. do.

As described above, in the present invention, while drilling is performed by the top drive 200 in the drilling vessel having a single derrick 130, the casing 100 is connected to the outside of the derrick 130. When the drilling operation is completed in the well center, the assembled casing can be moved directly to the well center and lowered to the seabed. In this case, after the drilling operation is completed, the time required to connect the casing can be shortened by the casing by lowering the seabed by connecting the casings one by one by the top drive 200 in the derrick 130. In the above-described example, when casings are connected by about 1000 m by connecting 100 casings having a length of about 45 ft, the present invention can shorten about 65 hours in the present invention, which results in a charter cost of about 1.3 million dollars. . Since casings of different diameters are installed in the sea bed, the entire casing installation time can be further shortened, thereby further reducing the charter rate.

However, in the present invention, an additional device is installed to proceed with the operation of connecting the casing 100 from the outside of the derrick 130. Such additional devices include a casing horizontal conveying device 120, a casing vertical conveying device 140, and a guide device.

Even though a separate device cost is added to connect the casing 100 outside the derrick 130 in the present invention, this cost is considerably compared with the chartering cost, considering that drilling is carried out for several decades with one drilling vessel. It is less. Therefore, by using the drilling operation method of the present invention, it is possible to shorten the time required for the drilling operation to reduce the charter fee.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention will be.

1 is a side view showing a conventional drilling ship performing drilling operation at sea level.

2 is a diagram showing the structure of a conventional general derrick.

3A to 3E are views illustrating a process of installing a casing at the beginning of a conventional drilling operation.

Figures 4a to 4l is a view showing a process of assembling the casing from the outside of the derrick in the offshore drilling equipment according to the present invention to transfer to the well center in the derrick.

<Explanation of symbols for the main parts of the drawings>

100 casing

101: casing loading place

102: casing string

110: crane

120: casing horizontal feed device

130: Derrick

140: casing vertical feed device

151: upper guide arm

152: lower guide arm

160: Christmas Tree Trolley

170: power sleep

180: Christmas Tree Crane

190: Casing Bucket

200: top drive

210: rotary table

Claims (9)

In the method of drilling work in a subsea drilling equipment having a single derrick, Drilling for forming a hole in the sea bed by means of a drill bit; A casing assembly step of assembling the casing on one side of the derrick during the drilling step; A casing installation step of installing the casing by lowering the assembled casing to the seabed after completion of the drilling step; Drilling operation method comprising a. The method according to claim 1, In the casing assembly step, the casing is a drilling operation method, characterized in that assembled outside of the derrick. The method according to claim 1, In the casing installation step, the assembled casing is transported to the well center and is drilled, characterized in that lowered by the lifting means to the sea bed. The method of claim 3, The assembled casing is transported to a well center by a Christmas tree trolley. The method according to claim 1, In the casing assembly step, The casing includes a casing vertical conveying device located outside of the derrick; A guide device positioned outside the derrick to guide the casing which is vertically lifted and lowered; Drilling operation method comprising the step of lifting and assembling vertically by. The method according to claim 5, And said casing vertical conveying device is supported by said derrick. In an offshore drilling rig with a single derrick, A casing vertical conveying device located outside of the derrick; A guide device positioned outside the derrick to guide the casing which is vertically lifted and lowered; Transfer means for transferring a plurality of assembled casings outside the derrick to a well center in the derrick; Subsea drilling equipment comprising a. The method of claim 7, The casing vertical transfer device is an offshore drilling facility, characterized in that supported by the derrick. The method of claim 7, The guide device has a subsea drilling facility, characterized in that it has an arm that can hold the casing.

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