KR20100008587A - Drill bit for drillship - Google Patents

Abstract

PURPOSE: A drill bit for drilling is provided to make successive drilling work regardless of the drilling depth by automatically changing the diameter of the drill bit. CONSTITUTION: A drill bit for drilling comprises a divisional blade(104) and a supporting member(110). The divisional blade is installed on the cut-back end side of a cylindrical body(102) of the drill bit according to the columnar direction. The divisional blade can be stretched and shrunk to and from the cylindrical body. The diameter of the supporting member can be changed according to the mud pressure delivered through a drill pipe according to the stretch or shrink of the divisional blade. The supporting member comprises a spring One end of the spring is connected to the divisional blade. The other end is connected to the inner side of the drill pipe.

Description

Drill Bits for Drilling {DRILL BIT FOR DRILLSHIP}

The present invention relates to a drill bit for drilling, and more particularly, according to various drilling depths in a drill bit device for performing offshore exploration drilling, equipped with a single derrick or double derrick. It relates to a drill bit for drilling so that the diameter of the drill bit can be automatically varied.

In general, drilling is the drilling of small diameter holes in the earth's crust to understand the structure and characteristics of the strata, and to obtain knowledge of the interior of the earth's crust, or to obtain oil, natural gas, hot springs, and groundwater. To be taken.

Depending on the purpose of use, there are various sizes, ranging from several meters to thousands of meters in length and several millimeters to tens of centimeters in diameter. Today, large-scale drilling of up to several meters in diameter is carried out for use as a vertical tunnel.

According to the excavation method, there are a shock type that impacts the drill bit and breaks the rock and drills it, and a rotary type that drills by rotating the bit in which the diamond and cemented carbide is inserted into the end of the steel pipe (pipe) against the rock surface. The deepest drilling hole in the world is 8,000 meters perforated in the American oil field.

Conventionally, when drilling is performed offshore for oil field development and exploration, offshore exploration drilling is mostly performed using a drillship vessel equipped with a single derrick. Since 1998, drilling has been carried out offshore using single derricks and offshore exploration drilling using a drillship vessel equipped with a double derrick capable of simultaneously performing primary and secondary exploration drilling operations.

 A single derrick or multiple derrick device generally drills several holes while decreasing the diameter of the drill bit in turn, where the depth and diameter of these drilling holes are determined by the rock layer and depth in which the deposits are located.

1 is a cross-sectional view schematically showing a conventional general drilling drilling process.

Drillers, that is, risers (10), casings (20), and drilling strings of various diameters are used for drilling from a crude oil drilling vessel (1) suspended at sea.

The bore line 1 and the seabed are connected by a riser 10, and when the drill bit 40 accidentally touches a gas field in the ground at the end of the drill pipe 30, the BOP 12 prevents the gas from rising and exploding. ) Is installed. The BOP 12 blocks the inlet of the borehole when gas is ejected from the seabed, thereby preventing human injury on the bore.

 And the drill pipe 30 which is located in order from the casing 20 with a large diameter inside in the seabed, and is connected from the drilling line 1 to the inside of the casing 20 is installed.

At the end of the drill pipe 30 is provided a drill bit 40 mounted to different diameters according to the drilling depth, the drill motor 32 for transmitting rotational power to the drill bit 40 is drill pipe 30 Installed on the

And the drilling line (1) is to supply the rock or mud after drilling through the casing 20 and the outside of the drill pipe 30, the feed pump (2) for transferring the mud to the drill pipe 30 at a pressure suitable for the drilling depth Is installed.

Therefore, the drilling process, the drill bit 40 through the hydraulic power transmitted by the mud pressure through the feed pump (2) is moved along the inside of the drill pipe 30 with a straightness, and by the drill motor 32 Will proceed with drilling. And the rock and mud during the drilling process is transferred through the outside of the casing 20 and the drill pipe 30, while the drilling is adjusted so that the formation (formation) is not collapsed while maintaining the pressure of the drilling hole properly.

However, in order to replace the diameter of the drill bit suitable for the drilling depth during drilling in the conventional drilling process as described above, the drill bit at the end of the drill pipe end by collecting all of the drill pipe and the drill bit down to the drilling line and down the drilling in progress After replacing, drill again by re-joining the drill pipe to the position where drilling was stopped again. This process had a problem that the deeper the drilling depth, the greater the time required for collection and fastening. Moreover, the depth of drilling continues to deepen, and this process is very wasteful as the location of oil reserves expands into the deep sea.

Therefore, in the present invention, the diameter of the drill bit is appropriately changed according to the mud pressure transmitted through the drill pipe, thereby providing a drill bit for drilling which can be continuously drilled without replacement according to the drilling depth as the drill bit is variable in diameter For that purpose.

In order to achieve the above object, the present invention, in the drilling drill bit installed at the end of the drill pipe, at least one is installed along the circumferential direction on the end side of the cylindrical body of the drill bit, so that it can be unfolded or retracted from the body Drill bits for drilling, each of which includes a rotatable dividing blade, and a support member for varying the diameter of the dividing blade to expand or retract according to the mud pressure transmitted through the drill pipe, such as supporting the dividing blade. to provide.

And preferably the dividing blades are retracted with greater mud pressure to reduce the overall diameter of the drill bit.

In addition, the support member is characterized in that the one end is connected to the splitting blade, the other end is made of a spring connected to the inner surface of the drill pipe.

As described above, according to the drill bit for drilling in the present invention, as the drill bit having a variable diameter according to the mud pressure, the drilling operation can be performed continuously without replacement according to the drilling depth, thereby collecting and coupling the drill pipe and The replacement time is reduced, thereby improving productivity.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Figure 2 is a plan view of a drill bit for drilling according to an embodiment of the present invention, Figures 3a to 3b is a cross-sectional view of the state of use of the drill bit for drilling according to an embodiment of the present invention.

The drill bit 100 for drilling shown in FIG. 2 is installed at the end of the drill pipe 30 (shown in FIG. 3), and is divided into a cylindrical body 102 and a split blade rotatably installed in the body 102. It consists of 104.

The body 102 is connected from the end of the drill pipe 30 (shown in FIG. 3) and is installed with a hollow interior.

And at the end side of the body 102, at least one or more divided blades 104 which are divided in the circumferential direction and are rotatable, respectively. The splitting blade 104 has a screw-shaped blade as a portion that drills a drilling hole substantially.

The support member 110 is installed so that the dividing blade 104 is rotated in an operation of expanding or contracting from the body 102.

Support member 110 may be an elastic material having a restoring force, preferably a spring is installed. One end of the support member 110 is connected to the dividing blade 104, the other end is connected to the inner surface of the drill pipe 30 so that the support member 110 is fixed to the drill pipe 30. ) The diameter of the drill bit 100 becomes smaller as the respective splitting blades 104 are retracted according to the degree of expansion of the supporting member 110, and conversely, as the expansion force is restored, the unfolding operation of each splitting blade 104 is performed. As a result, the diameter of the drill bit 100 is increased.

Accordingly, the supporting member 110 supports the splitting blades 104 such that the splitting blades 104 can be unfolded or retracted in accordance with the mud pressure transmitted through the drill pipe 30. It has a configuration to change the diameter through.

The drilling drill bit is constructed as follows.

Referring to FIGS. 3A to 3B, the oil drilling rig 1 floating on the sea is connected to the sea bottom as a riser 10, and the drill bit 100 is connected to the sea bottom at the end of the riser 10. If touched incorrectly, the BOP (12) is installed to prevent the gas rises and explodes.

And the drill pipe 30 which is located in order from the casing 20 with a large diameter inside in the seabed, and is connected from the drilling line 1 to the inside of the casing 20 is installed.

An end of the drill pipe 30 is equipped with a drill bit 100 provided with a split blade 104 on the body 102 so that the diameter can be varied.

In addition, a drill motor 32 for transmitting rotational power to the drill bit 100 is installed on the drill pipe 30.

On the other hand, the drilling line (1) is a supply pump (2) for transferring the rock or mud after the drilling through the outside of the casing 20 and the drill pipe 30, the mud to the drill pipe 30 at a pressure suitable for the drilling depth ) Is installed.

Thus, in the drilling process, when the mud is supplied through the supply pump 2 at a pressure corresponding to the depth to be drilled, the mud pressure exerts pressure on the upper surfaces of the splitting blades 104 located inside the drill pipe 30. In addition, the divided blades 104 to which pressure is applied are rotated while expanding the support member 110, and are retracted from the body 102 when the overall view thereof is reduced in diameter.

Accordingly, the drill bit 100 rotated by the drill motor 32 has a drilling diameter while the diameter of the drill bit is reduced by the revolving rotation of the splitting blades 104 according to the mud pressure that increases as the drilling depth increases. do.

In the drilling process, rocks and muds are transferred through the outside of the casing 20 and the drill pipe 30, and the formation of the drilling holes is controlled so that the formation is not collapsed. The pressure applied to the) is released and returned to the restoring force of the support member 110.

Therefore, in the present invention, since the drilling operation is performed only when the mud of a constant pressure suitable for the drilling depth is supplied, the diameter of the drill bit 100 may be changed through the dividing blade 104 by using this, thereby continuously drilling operation. This is a useful invention that can proceed simultaneously with drilling and casing 20 work.

What has been described above is only one preferred embodiment of the drill bit for drilling according to the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, the gist of the present invention Without departing from the scope of the present invention, any person having ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

1 is a cross-sectional view schematically showing a conventional general drilling drilling process,

2 is a plan view of a drill bit for drilling according to an embodiment of the present invention,

3A to 3B are cross-sectional views of the state of use of the drill bit for drilling in accordance with one embodiment of the present invention.

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

100: drill bit 102: body

104: dividing blade 110: support member

Claims (3)

In the drill bit for drilling installed at the end of the drill pipe, At least one end portion of the cylindrical body of the drill bit is installed along the circumferential direction, and each of the rotatable split blades can be expanded or retracted from the body; Support member for varying the diameter by the operation of expanding or retracting the splitting blade in accordance with the mud pressure transmitted through the drill pipe, such as supporting the splitting blade Drill bit for drilling comprising. The method of claim 1, The dividing blade is a drill bit for drilling, the overall diameter of the drill bit is reduced by the operation of retracting the greater the mud pressure. The method of claim 1, One end of the support member is connected to the dividing blade, and the other end of the drilling drill bit consisting of a spring connected to the inner surface of the drill pipe.

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