RU2778870C1 - Device for directional expansion of a pilot well - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the field of construction, in particular to the means of horizontal directional drilling (HDD) or directional drilling with the expansion of engineering wells, for example, by drilling and to tools used in trenchless construction of pipelines in the ground. The device for directional expansion of the pilot well includes an asymmetric expander (2) with a canister (3) attached to it to accommodate the measuring probe (4) of the HDD location system. In this case, the case (3) with the measuring probe (4) is installed longitudinally, rigidly fixed directly behind the asymmetrical cutting expander (2) and connected to the tightened pipeline (7) through the swivel (5). The asymmetric expander (2) is made in the form of a combination of halves of two symmetrical cutting expanders of different designs.

EFFECT: implementation of an asymmetric cutting reamer in the form of a combination of halves of two symmetrical cutting reamers of different design makes it possible to create non-equilibrium shear forces in the form of transverse shear forces when pulling the drill string, and the rigid attachment of the canister with the measuring probe immediately behind the asymmetric reamer makes it possible, when using a swivel, to avoid impact on of torsional loads with unhindered display of the position of the asymmetric expander according to the readings of the measuring probe, providing together an increase in the reliability of the device.

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Description

The invention relates to the field of construction, in particular to tools for horizontal directional drilling or directional drilling (HDD, HDD) with the expansion of engineering wells, for example, by drilling, and to tools used in trenchless construction of pipelines in the ground.

The problem is this.

The main method of producing an engineer well includes directional drilling of a pilot well and formation of an engineer wellbore by reaming the pilot well. The stages of the implementation of an engineering well consist of developing a project for a future well, drilling a pilot well, the position accuracy of which is controlled by the HDD location system according to the position of the measuring probe placed in the drill head, the drill string exiting to the earth's surface, replacing the drill head with an expander of the required diameter attached to it through the swivel by the pipeline, pulling the drill string back with the expansion of the well for free tightening of the pipeline, and trimming the pipeline in technological pits after the pipeline is completely pulled into the well. At the same time, the required accuracy of drilling a pilot well is ensured by the use of a location system with a measuring probe placed in the drill head, and directional controllability is ensured by the asymmetry of the drilling tool attached to the drill head.

When rotating the drill head with the cutting tool and pressing on the drill string from the side of the drilling rig, approximately straight-line drilling of the pilot hole occurs. Any heterogeneity of the soil causes the drill string with the drill head to deviate from the desired direction. Correction of the drilling direction is achieved by turning the drill head to the required position and pushing the stationary drill string a certain distance. Due to the asymmetric fastening of the cutting tool of the drill head, the drill head shifts in the right direction. After that, drilling continues until the next correction.

To pull a pipeline of the required diameter into the well, the pilot well is expanded with a special tool - an expander, which is attached to the drill string instead of the drill head. To avoid rotation of the pipeline in the resulting well, the latter is connected to the expander through a swivel containing a bearing connection and cardan eyes on both sides, in order to create mainly longitudinal forces on the pipeline when pulled into the well. At present, almost all designs of expanders have an axisymmetric shape.

When performing particularly critical work when laying engineering wells, for example, for arranging storm sewers, a minimum deviation from the design route is required. And if, when drilling a pilot well, they are guided by the indications of the HDD location system and can control the position and direction of the drill head, then when expanding the well, it is initially considered that the route will pass through the pilot well. At the same time, when laying a well in soft soils belonging to the class of dispersed according to GOST 25100-2011 (clayey, silt, sapropels, etc.), there is a deviation (subsidence) of the pilot well route from the design values due to the own weight of the drilling rig. and instead of a round hole, the section of the pilot well in the middle of the route is an elongated ellipse, as a result of which the drill string, together with the expander, “breaks” the weak soil of the pilot well and passes along its lower part, while the finished well will no longer correspond to the design route. With a large deflection, the well becomes inoperable due to the appearance of negative slopes. Thus, we can talk about "blind" (not controlled) expansion of the pilot well.

When expanding a pilot well with a standard reamer in soft soil, the pressure forces on the reamer are approximately symmetrical, the weight of the drill string with the reamer is not compensated in any way, and due to the elongated (slit-like) cross section of the pilot well, the reamer, together with the drill string and the tightened pipeline, gradually goes down the route pilot well.

Known methods and devices for creating an engineering well, including directional drilling of a well and one or multiple expansion of a pilot well by means of an expander on a string of drill rods with the possibility of simultaneously pulling a pipeline into the well, for example, are described in US patents 7389829 B2, 2008/06/24, " Method and apparatus for forming a bored hole", US 7730969 B2, 2010/06/08, "Reamer and method for directional drilling", CA 2815739 A1. 2012/05/03, "Method for the underground installation of a pipe", but none of them offers a solution for high-precision engineering well laying.

From the point of view of logic, to create a high-precision engineering well, it is necessary to know the position of the expander underground at the expansion stage and have a mechanism for adjusting the latter in order to compensate for deviations of the working well from the planned route. In this case, the purposes of the controlled reaming of the well can be the measuring probe of the location system, located in close proximity to the reamer and used to measure the depth, inclination and position of the reamer, as well as the asymmetric shape of the reamer, which, when pulled, allows to correct the position of the formed engineering well within a small range.

Thus, a method for high-precision laying of an engineering wellbore is known, presented in US patent 2006/0269361 A1, 2006/11/30, "Apparatus for on-grade boring" and a device that implements it, selected as a prototype.

The method for producing an underground pipeline includes the initial stage of drilling a pilot well through the ground at a given angle of inclination by extending the drill string with a steerable drill head attached to it through the ground.

After completion of the pilot drilling, the drill head is replaced with a reamer having a diameter larger than the pilot hole and attached to the drill string, the reamer being provided with a percussion device, such as an air hammer, including a hammer that provides repeated strikes against the reamer. The reamer is pushed back (towards the rig) through the pilot hole at an angle while the impactor is actuated to help the reamer move along the ground and pull the tubing connected to the reamer into the larger diameter hole formed behind the reamer.

According to the patent, as one of the embodiments, the reamer consists of two parts, where the first part is an asymmetrical cutting reamer for controlling the position underground, in front of which is mounted a socket for the HDD navigation system probe with a probe fixed in it to indicate the orientation to the drilling rig operator steering surface on the front of the extender.

The implementation of the well production method according to US 20060269361 A1 is very complex. In addition, the use of only a percussion mechanism to advance the expander with a pipeline attached to it is possible only in relatively soft soils with compaction of the borehole walls. The front asymmetric part of the expander with the attached navigation system probe plays an auxiliary role here and practically does not participate in the expansion of the engineering well.

The above method in different versions uses a tandem scheme of an asymmetrical cutting expander and an impact sealing expander. To control the position of the asymmetric cutting reamer, a drilling rod with a socket for the measuring probe of the HDD location system is installed in front of the latter, in which the measuring probe is rigidly fixed, giving the operator of the drilling rig information about the position of the asymmetric cutting reamer.

One of the options for implementing the method according to US 2006/0269361 A1 is based on the use of only an asymmetrical cutting expander (rimmer) with a rod with a measuring probe fixed in front of it (section 0044 of the patent), which is a prototype for the claimed technical solution. Below is a translation of section 0044 of US 2006/0269361 A1 with reference to the drawings to the description of this patent.

The cutting rimmer according to the known invention can also be used alone, without the aid of the impact rimmer, to perform sloped drilling. As shown in FIG. 11 and 12, the retractable flange 65 of the rimmer 51 is connected by a U-bracket 66 to a conventional pipe puller, such as an expanded conical pipe puller 67. Bracket 66 is inserted through lug 68 in flange 65 and secured with bolt 69 through lug 71 into the forward flange 72 of pipe puller 67. Bracket 66 can be replaced with a cable or any similar industrial pull connector. In addition, it is desirable to supply the cutting rimmer 51 with a drilling fluid (such as bentonite) through a hollow drill string. The drilling fluid is injected from a series of holes 74 on the outer surface of the rimmer 51 in a manner well known in the art, with the holes communicating with the central channel 31 through the drill head. The cutting rimmer 51 may also have teeth and/or helical grooves (76, FIG. 11) that are effective in improving the cutting action.)

According to this solution, the cutting rimmer destroys the soil during the rotation and pulling of the drill string, and the drilling fluid contributes to the removal of soil from the well and strengthens its walls. To correct the direction when the drill string is stationary, the asymmetric cutting rimmer, together with the measuring probe, is rotated so that when pulled, the drill string, together with the asymmetric cutting rimmer and the attached pipeline, moves in the direction of reducing the deviation error of the engineering well from the design route. Then the rotation begins again with the destruction of the soil by the cutting rimmer. The adjustment procedure can be repeated many times until the completion of the laying of an engineering well.

Fully functional implementation of the well production method according to US 20060269361 A1 is very complex. In addition, the use of only the percussion mechanism to advance the expander with the pipeline attached to it is only possible in relatively soft soils with compaction of the borehole walls. The front asymmetric part of the expander with the attached navigation system probe plays an auxiliary role here and practically does not participate in the expansion of the engineering well.

A significant disadvantage of this solution is the placement of the measuring probe in the seat of the drill rod in front of the asymmetrical cutting rimmer. A drill rod with a probe socket or (or the same, a drill head with a probe socket) is the weakest point of the drill string both when drilling a pilot hole and when reaming it by reaming due to the obligatory presence of long longitudinal slots on the socket body for the unhindered exit of an alternating magnetic field, carrying all the necessary information, from the measuring probe. Even when drilling a pilot hole, the drill head with the measuring probe placed in it experiences strong torsional twisting. If we are talking about expanding a pilot well by drilling out, the twisting forces increase in proportion to the diameter of the cutting rimmer, which requires a cardinal increase in the strength of the drill rod closest to the rimmer with a measurement probe socket. Therefore, the progressive method of drilling an engineering well with a large-diameter reamer with the removal of rock along with drilling fluid, which allows laying pipelines in all categories of soils, is not applicable here or is applicable with great limitations due to the appearance of excessive torsional loads on the socket (case) of the probe, which can lead to its destruction and the failure of the entire mechanism. Thus, the known device is unreliable in operation.

The task is to increase the reliability of the device by providing the possibility of laying a pipeline without exposure to excessive torsional loads on the socket (case) of the probe.

The problem is solved by the fact that in the device for directional expansion of a pilot well, which includes an asymmetric expander with a canister rigidly attached to it for accommodating the measuring probe of the HDD location system, ACCORDING TO THE INVENTION, the canister with the measuring probe is installed longitudinally, rigidly fixed directly behind the asymmetric cutting expander and is connected to the pipeline to be pulled through a swivel, while the asymmetric expander is made in the form of a combination of halves of two symmetrical cutting expanders of different designs to create non-equilibrium shear forces in the transverse direction when pulling the drill string.

The implementation of an asymmetric cutting reamer in the form of a combination of halves of two symmetrical cutting reamers of different design makes it possible to create non-equilibrium shear forces in the form of transverse shear forces when pulling the drill string, and the rigid fastening of the canister with the measuring probe immediately behind the asymmetric reamer makes it possible, when using a swivel, to avoid impact on of torsional loads with unobstructed display of the position of the asymmetric expander according to the readings of the measuring probe, providing together an increase in the reliability of the device.

The claimed device is novel in comparison with the prototype, differing from it in such essential features as the implementation of an asymmetric cutting expander in the form of a combination of halves of two symmetrical cutting expanders of different designs, a longitudinal arrangement of the canister with a measuring probe, its rigid fastening immediately behind the asymmetrical cutting expander and its connection with a tightened pipeline through a swivel, which together ensure the achievement of the desired result.

The Applicant is not aware of technical solutions that have these distinctive features, which would ensure the achievement of the desired result in the aggregate, therefore, he believes that the claimed device meets the criterion of "inventive step".

The claimed device can be used in horizontal / directional drilling (HDD, HDD) with the expansion of engineering wells, for example, by drilling, and in the trenchless construction of pipelines in the ground, therefore, it meets the criterion of "industrial applicability".

The invention is illustrated by drawings, which are presented in:

- fig. 1 - the process of expanding the pilot well by rotating and pulling the drill string;

- fig. 2 - design of an asymmetric expander;

- fig. 3a - 3c - symmetrical expanders used for the manufacture of an asymmetric expander;

- fig. 4 is a diagram of a directionally corrected expansion, which makes it possible to obtain minimal errors when laying an engineering well.

In FIG. 1a, b schematically shows the process of expanding a pilot well by rotating and pulling the drill string. Here 1 is the first drill rod in front of the expander, 2 is an asymmetric cutting expander, 3 is a canister where the measuring probe 4 of the HDD location system is located. The swivel 5 serves to prevent the rotation of the head 6 with the end of the pipeline 7 being pulled into the well fixed in it.

Here, the device for directional expansion of the pilot well includes an asymmetric expander 2 with a canister 3 attached to it to accommodate the measuring probe 4 of the HDD location system. At the same time, the canister 3 with the measuring probe 4 is installed longitudinally, rigidly fixed directly behind the asymmetric cutting expander 2 and connected to the tightened pipeline 7 through the swivel 5. In this case, the asymmetric cutting expander 2 (Fig. 2) is made from a half of the "carrot" expander (Fig. 3a) and a hollow cutting reamer (fig. 3c) to create non-equilibrium shear forces in the transverse direction when pulling the drill string. It can also be made from a combination of the dilator halves shown in FIG. 3c and 3d.

Correction of the position of expander 2 (rimmer) with a string of drill rods in a pilot well is carried out due to non-equilibrium forces of compression of the body of asymmetric expander 2 during its short-term pulling with a stationary drill string (in the process of drilling out). The correction can be multiple with constant control of the position of the expander 2 to the readings of the HDD location system using the signals of the measuring probe 4 fixed in the canister 3 rigidly connected to the asymmetric expander 2. At the same time, the high accuracy of determining the depth to the probe, which avoids the error of deviation of the created well from the project , is achieved by using solutions according to the applicant's patent RU 2717360, G01V 3/12, 06/25/2019 for the invention "Method for improving the accuracy of measuring the depth of the position of an electronic probe underground for the HDD location system".

The figure 4 shows a diagram of a pilot well expansion corrected in the direction, which allows to obtain minimal errors when laying an engineering well.

In comparison with the prototype, the proposed device is more reliable in operation.

Claims (1)

A device for directional expansion of a pilot well, including an asymmetric reamer with a canister attached to it for placing a measuring probe of a horizontal directional drilling locating system, characterized in that the canister with a measuring probe is installed longitudinally, rigidly fixed directly behind the asymmetric cutting reamer and connected to a tightened pipeline through the swivel, while the asymmetric expander is made in the form of a combination of halves of two symmetrical cutting expanders of different designs to create non-equilibrium shear forces in the transverse direction when pulling the pipeline.

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