RU2382927C1 - Method for laying of pipeline under water obstacle - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is related to construction, namely to technologies of trenchless laying of pipelines. In method for laying of pipeline under water obstacle, including connection of boring head of microtunneling complex with the first section of pipeline, drilling of well with boring head by length of boring head hydraulic cylinders travel, pushing of pipeline by hydraulic cylinders of microtunneling complex by length of boring head hydraulic cylinders travel, further serial growth of pipeline by sections, drilling of well and pushing of pipeline each time by length of boring head hydraulic cylinders travel till exit of boring head to design point, according to invention, pipeline is laid, axis of which represents a parabola, made of sections bent along axis by angle of up to 6 degrees, at the same time drilling of well is carried out along radius of pipeline with the help of drilling head made of two parts, every of which has possibility of rotation by axis by the angle of up to 3 degrees.

EFFECT: reduced costs and time for laying of pipeline.

2 cl, 2 dwg

Description

The invention relates to construction, and in particular to technologies for trenchless pipe laying, and can be used in the oil and gas industry for laying or repairing trunk pipelines with a diameter of 630 mm or more under a water obstacle.

The horizontal directional drilling method described on the Internet is widely known (http://www.polimer-resurs.ru/razdel_gnb/info_gnb.htm, http://www.gnbrt.ru/index-m-56-p-63. htm, http://vis-mos.ru/index.php?section=11, http://www.ingestrov.ru/view/document/gnb-technology, http://www.podzem.ru/drilling/ )

The method includes: drilling a pilot well, which is carried out using a rock cutting tool - a drill head with a bevel in the front and an integrated emitter. The construction of the pilot well is completed by the exit of the drill head at a point specified by the project. After the completion of the pilot drilling, the well is expanded. In this case, the drill head is disconnected from the drill rods and a reverse action reamer is attached instead. By applying traction with simultaneous rotation, the rimmer extends through the borehole in the direction of the drilling rig, expanding the pilot borehole to the diameter required for pulling the pipeline. Next is the pulling of the pipeline. On the side of the well opposite the rig, ready to pull the whip of the pipeline. A head is attached to the front end of the lash with a swivel and a rimmer receiving traction and at the same time does not transmit rotational motion to the pipeline. Thus, the drilling rig draws into the well a whip of the stretched pipeline along the project path.

The disadvantage of this method is that the laying of a steel pipeline under an obstacle and drilling is carried out along the radius of the natural bend of this pipeline, the length of the transition is at least 700 meters. In addition, this method makes it difficult to lay the pipeline in complex soils - rocks, permafrost, boulder-pebble soils with a high degree of water cut.

A known method of microtunnelling, widely described on the Internet fhttp: //www.bamts.ru/technic/tehnology/microtunnel.php. http://krep.mccinet.ru/s33.htm, http://www.ingestrov.ru/view/document/mikrotunnelirovanie, http://www.sibdom.ru/article.php?id:=122). The microtunneling method is as follows. Initially, preparations are made for the start and receiving shafts, the minimum dimensions of which depend on the size of the micro-shield of the tunnel complex, and the depth is determined by the depth of the pipeline. A jack installation is lowered into the launch shaft, onto which a microboard and a platform with hydraulic cylinders for crushing the microboard are mounted. The well is drilled to the length of the microboard, then a separate pipe section is attached to it, which is caught in the formed well by a jack station. Next, the pipeline is built up by the next pipe section. The direction of penetration is controlled by a laser. When the microboard enters the receiving shaft, the installation is dismantled.

The disadvantages of the method is the need to prepare start and receiving shafts, which is extremely difficult in drilling in soils with a high degree of water cut, and also provides for laying the pipeline only in a straight line or curve within the natural bend of the pipe.

The closest analogue of the proposed method is the technology of laying the pipeline "Direct Pipe", developed by Herrenknecht AG (official journal of the Russian society of trenchless technologies "ROBT" No. 2, March 2008, p.40-42; http: //www.herrenknecht. com / process-technology / research-development / direct-pipe.html), which combines the advantages of horizontal directional drilling and microtunneling. The method is as follows. The microtunnel tunnel complex Herrenknecht is installed directly on the ground, without the need for special mines. The pipeline is a whip from separately welded pipe sections, which are subsequently phased welded into a single thread. The first section of the pipe is connected to the drill head microtunnel tunnel complex. Through the pipe mill, the feed force necessary for sinking is applied to the drill head, the hole is drilled to the stroke length of the drill head hydraulic cylinders, then the pipeline is pushed by the microtunnel tunnel complex hydraulic cylinders to the stroke length of the drill bit hydraulic cylinders. From the starting pit, a well is drilled and a pipe is pushed each time along the stroke length of the drill head hydraulic cylinders until the drill head exits to the design point. In this case, the pipe is laid in a straight line or along the radius of the natural bend of the pipe. The described method is selected by the applicant as a prototype.

The disadvantage of the prototype is that the laying of a steel pipeline under the river bottom and, accordingly, drilling is carried out either horizontally or along the radius of the natural bend of this pipeline, which is 1200 of its diameters, that is, the length of the replacement or laying pipe should be at least 700 meters, however, in most cases, the terrain does not allow this. An obvious drawback is the fact that the maximum capacity of the jack installation (microtunneling complex) does not allow to stretch a pipeline longer than 800 meters.

The technical task is to create a more economical and universal way of laying pipelines.

The technical result is to reduce costs by reducing the length of the transition and the time of its implementation, expanding the scope of this method, namely the possibility of its application when laying a pipeline under a water body in difficult terrain, in particular when crossing small rivers, as well as in difficult soil - rocks, permafrost, in soils of varying degrees of water cut.

To achieve the task in a method of laying a pipeline under a water obstacle, which includes connecting the drill head of the microtunnel tunnel complex to the first section of the pipeline, drilling the well with the drill head for the stroke length of the drill’s hydraulic cylinders, pushing the pipeline with the hydraulic cylinders of the microtunnel tunnel for the stroke length of the drill’s hydraulic cylinders, and further sequential building up sections, drilling and pushing the pipeline each time for according to the invention, a pipeline is laid, the axis of which is a parabola composed of sections bent along the axis by an angle of up to 6 degrees, while drilling the well is carried out along the bend radius of the pipeline using the drill head, composed of two parts, each of which has the ability to rotate on an axis at an angle of up to 3 degrees. In the process of laying the pipeline ballast water.

Laying a pipeline, the axis of which is a parabola composed of sections bent along the axis at an angle of up to 6 degrees, and drilling a well along the bending radius of the pipeline can significantly reduce the transition length and, accordingly, reduce financial and labor costs for penetration, and also expand the scope This method, in particular, allows you to use it in difficult terrain, for example, when crossing small rivers, and also allows you to use this method in conditions of difficult soil.

The use of a drill head, made up of two parts, each of which has the ability to rotate along the axis by an angle of up to 3 degrees, allows drilling along the bending radius of the laid pipeline.

Pulling the pipeline with its ballasting with water allows you to create zero buoyancy of the pipeline and to ensure its stabilization in the lower extreme position of the well when laying the pipeline in conditions of heavily flooded soils.

In addition, laying a pipeline composed of sections bent along the axis at an angle of up to 6 degrees, and ballasting the pipeline with water allows increasing the friction force of the bent pipe against the well during the laying of the pipeline at the time of operation of the hydraulic cylinders, which significantly reduces the load on the jacking station of the microtunnel tunnel complex.

Patent studies have not identified methods characterized by the claimed combination of features, therefore, we can assume that this method meets the criterion of "novelty."

The use of a combination of distinctive features is also not known, which indicates compliance with the criterion of "inventive step".

In addition, the proposed method can be used on an industrial scale and will find application, in particular, when laying or replacing large-diameter pipelines in the oil and gas industry, i.e. characterized by the criterion of "industrial applicability".

The essence of the proposed technical solution is illustrated by drawings, where figure 1 shows a diagram of the pipeline; figure 2 - diagram of the bending segment of the pipe.

The inventive method of laying a pipeline under a water obstacle is as follows.

Equipment is installed on the surface of the construction site - a microtunneling complex, which includes a main punching hydraulic cylinder with a capacity of up to 500 tons, a pipe crimping mechanism with a surface that preserves insulation, a bentonite preparation and supply unit, a hydraulic station and a control unit. The pipeline being laid 1, having a bend along the axis of up to 6 degrees, is welded in place by sequentially joining the sections during the process of pulling the pipeline, while building the pipeline, the joint is examined, degreased and waterproofed. For tunneling, a microtunnel drill bit 2 is used, which has the ability to change the direction of movement up to 6 degrees along the axis, composed of two parts, each of which has the ability to rotate along the axis by an angle of up to 3 degrees. The drill head is equipped with a rotary cutting tool 3, as well as hydraulic cylinders 4, providing the feed force of the drill head during the drilling of the well.

The first section of the pipeline 1 is welded to the drill head 2, which is fed to the drilling point. Then, the first section of the well is drilled for the stroke length of the drill head hydraulic cylinders. During the drilling process, bentonite is fed into the drilling zone, which is then transported to the surface together with the soil. After drilling the head of the borehole section, the main hydraulic cylinder of the microtunneling complex pushes the section of the pipeline into the well. Next, the next section of the pipeline is welded, the well is drilled with a drill head for the stroke length of its hydraulic cylinders, and the section is pushed into the well. The described sequence of actions is carried out until the drill head reaches the design point. To ensure zero buoyancy of the pipeline and its stabilization in the well, as the length of the well increases, the pipeline is ballasted with water.

The length of the sections of the pipeline is about 11.4 m, the stroke length of the hydraulic cylinder of the drill head is 1.1 m.

Under the influence of the main hydraulic cylinder of the microtunnel tunnel complex, during the laying of a pipeline curved along the axis, the forces exert on it:

F ₁ - reaction force of the support (drill head),

F ₂ - the reaction force of the pipe,

F ₃ - the resulting force that increases the friction force of the pipeline against the well walls at the time of operation of the hydraulic heads of the drill head.

The influence of the force F ₃ at the time of operation of the hydraulic cylinders of the drill head contributes to reliable stabilization of the position of the pipeline in the well.

To track and adjust the trajectory of the drill head, a navigation system is used.

For various types of soils, drill heads with different cutting parts can be used.

Currently, a project is underway to lay the Gryazovets-Leningrad 1 gas pipeline, km 455.0-480.0, through the Valya river (34 m wide) and the Syasya river (42 m wide) of the Leningrad region of the Tikhvin region. The rivers have a complex relief - steep banks. When calculating the transition length, the following data were obtained:

- when laying a pipeline with a diameter of 1220 mm along the natural bend radius of the pipe at a depth of 3.5 m from the bottom of the river, the length of the transition will be at least 700 m, taking into account the terrain;

- when laying a pipeline with a diameter of 1220 mm according to the claimed method, the transition length will be no more than 120 m.

The bending radius of one pipe segment is calculated by the following formula:

R = L 360 ° / 2πα,

Where

R is the bending radius

L is the length of the pipe segment,

π is a constant,

α is the angle of the tap.

It is obvious that the laying of the pipeline by the claimed method will give a high economic effect due to a significant reduction in the length of the transition, and will also allow, in accordance with the studies, to perform the transition in conditions of difficult terrain.

Thus, the inventive method allows to minimize the length of the transition, and therefore, reduce the time and cost of construction. The method allows for one passage of the drill head to lay the pipe of the desired diameter. At a cost of work, the method is comparable to an open method of laying pipelines. It is most economically feasible to use this method in the construction of crossings under small and medium rivers, ravines, railways.

Claims (2)

1. A method of laying a pipeline under a water obstacle, including connecting the drill head of the microtunnel tunnel complex to the first section of the pipeline, drilling the well with the drill head for the stroke length of the drill’s hydraulic cylinders, pushing the pipeline with the hydraulic cylinders of the microtunnel tunnel for the stroke length of the drill’s hydraulic cylinders, further sequential extension of the pipeline in sections, tunneling wells and pushing the pipeline each time over the stroke length of the hydraulic cylinders of the drill head drilling until the drill head exits to the design point, characterized in that a pipeline is laid, the axis of which is a parabola composed of sections bent along the axis at an angle of up to 6 degrees, while the well is drilled along the bend radius of the pipeline using a drill head composed of two parts, each of which has the ability to rotate along the axis at an angle of up to 3 °. 2. The method according to claim 1, characterized in that in the process of laying the pipeline is ballasted with water.

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