SU1148390A1 - Signalling device for setting core receiver - Google Patents

Abstract

SIGNALING INSTALLATION OF A REMOVABLE CORNER RECEIVER, comprising a housing with an annular outer lug, a cooperating end surface with a shoulder of the core pipe, radial holes located on both sides of the annular outer lug and communicating with an axial channel in which the signaling element is placed, the discharge zone with a cavity. This is so that, in order to increase the reliability of operation, an annular groove and an additional annular ridge are made under the annular outer ledge n, wherein on the cylindrical surface of the latter has channels connecting the bore to the cavity koltsevzlo drain. (L 4 00 co; o

Description

BACKGROUND OF THE INVENTION The invention relates to a technique for drilling wells using core kits with removable core receivers.

A known set of cylinders contains a detector for installing a removable core receiver in the form of a reverse spring-loaded ball valve that overlaps the central channel of the removable core receiver, and the valve body is provided with an annular seal that interacts with the annular protrusion of the core tube.

However, with increasing depth of the well, the flow rate of flushing fluid during the descent of a known core receiver decreases and, consequently, the pressure drop decreases with the flow through the non-return valve. Therefore, to obtain a clear signal, the valve opening force must be increased by pressing in the special adjusting screw. This circumstance creates a constant hydraulic resistance in the valve area during flushing during the entire drilling time. Because of this, the value of unproductive pressure drop at a well depth of 1500 m reaches 10-15% of the pressure of the mud pump.

Also known is the detector of a removable core receiver, which includes a housing with an annular outer lug, an interacting end surface with a KOLONKO scaffold.

a radial hole located on both sides of the annular outer protrusion and communicating via an axial channel in which the signaling element is located, a pressure zone with a drain cavity.

A disadvantage of the known construction is the possibility of false triggering of the detector when the core receiver is not fixed because of the large hydraulic resistance to the fluid flow around the latter, for example, when the annular projection of the core receiver is 10-15 mm from the landing stage of the core receiver and the downward movement of the core receiver is limited to core remains. or sludge.

The aim of the invention is to increase the reliability of operation of the detector.

The goal is achieved by the fact that in the detector a removable core receiver includes a housing with an annular outer protrusion, a cooperating end surface with a shoulder of the core pipe, radial holes located on both sides of the annular outer protrusion and communicating with an axial channel in which the signal element is placed , a pressure zone with a drain cavity, an annular groove and an additional annular protrusion are made under the annular outer ledge, and the surface of the last issue (lnen channels that connect the annular groove with the cavity drain.

Figure 1 shows the moment of fixation of the device when mounted on the landing step of the core pipe; figure 2 is a cross section through the through channels of the additional annular protrusion; in FIG. 3, the indicator when the core receiver is installed; and in figure 4 - in the position with an unspecified core receiver.

Removable installation alarm

The 0 core receiver contains a housing 1 with an annular protrusion 2, the upper 3 and lower 4 radial openings connected by a channel 5. A calibrated channel is installed in channel 5

2 sleeve 6 with a conical seat 7 for accommodating a signaling element in the form of a ball 8 of elastic material. The inner diameter of the sleeve 6 and the diameters of the radial

0 holes 3 and 4, somewhat smaller than the diameter of the ball 8. The body 1 is connected via thread 9 to adapter 10, which has a bore 11 for accommodating the ball

5 8 while drilling. In the housing 1 under the annular protrusion 2 there is an annular groove 12, and under it there is an additional annular protrusion with C1 with a channel 13 for flow

0 flushing fluid from the pressure zone (upper holes 3) into the drain cavity (lower holes A).

During the operation of the detector before the descent of the removable core receiver ball

5 8 is forced through one of the radial holes 3 into the channel 5 of the housing 1, is placed on the conical seat 7 of the sleeve 6 and is there throughout the entire descent. At the time of installation of the core receiver (Fig. 1), the end face 14 of the annular protrusion 2 mates with the annular shoulder 15 of the core pipe 16, thereby eliminating the possibility of flow of flushing fluid outside the core receiver into the annular gap 17 between the body 1 and the core pipe 16. This cleansing agent 3 is pumped into the central channel 5 and, interacting with the ball 8, forces it through the calibrated sleeve 6 into the bore 11 of the adapter 10 (FIG. 3). After pressing the ball 8, the washing liquid flows out through the radial holes 4 in the annular gap 17, where it comes to the bottom of the well.

When a ball is pushed through a sleeve, a pressure drop is created, its size is determined by the size of the hole in the sleeve and the size of the ball and the properties of the elastic material from which the ball is made. This pressure drop is recorded by the operator of the manometer of the mud pump, as well as the temporary cessation of the release of flushing fluid from the well. The duration of the signal also depends on the flow rate of the flushing fluid and the inner diameter of the sleeve 6. Therefore, the sleeve is designed as a replaceable element of the detector and can be selected based on the flushing mode, which is determined by the depth of the well.

The cross-section of the through channels 13 of the housing 1 is chosen so that with any replaceable sleeve 6, corresponding to a specific flush flow rate

fluid, the hydraulic resistance when it passes around the core receiver outside the core is greater than the pressure drop for pushing the ball 8 through the sleeve 6, only when the removable core receiver is installed (fixed) in the core screen with fasteners, and the annular protrusion 2 with the end 14 of the landing ledge 15 (fig.Z). With an unsecured core receiver (Fig. 4), the cleaning agent flows through the annular groove 12 and through channels 13 around the core receiver outside and enters the annular gap 17 without creating a pressure drop sufficient to force the ball 8 through the sleeve 6. The annular groove 12 allows during the landing process core receiver to minimize the hydraulic resistance at the entrance to the annular gap between the housing 1 and the annular ledge 15 of the coring tube.

The use of a signaling device will allow to exclude the device operation when the core receiver is not fixed and to ensure the receipt of a reliable installation signal. In addition, the use of the invention will prevent the loss of the core that is destroyed when an uncooled core receiver, i.e., improves the quality of the test. The latter is particularly important when drilling for minerals, such as coal, where the wells have a depth of 1000-2000 m. The time required for unproductive drill string lifting is significantly reduced.

Claims (1)

REMOVABLE CORE RECEPTION INSTALLATION SIGNALING SYSTEM, comprising a housing with an annular external protrusion, an interacting end surface with a ledge of a core pipe, radial holes located on both sides of the annular external protrusion and communicating by means of an axial channel in which the signaling element is located, the pressure zone with a drain cavity characterized in that, in order to increase the reliability of operation, an annular groove and an additional annular protrusion are made under the annular outer protrusion, wherein cylindrical surface of the latter has channels connecting the annular groove g having a cavity discharge. ZHG ^{, P} 'P§