SU855186A1 - Core barrel reducer - Google Patents

Description

(54) COLUMN PIPE ADAPTER

one

The invention relates to the fastening of a string of drill pipes with core pipes during exploration drilling.

When drilling wells, the drill bit, in particular, the adapter from the drill pipe to the core pipe, must have sufficient strength, transmit the rotation, the axial force to the bottom necessary to destroy the rocks, and be the guide fluid to the bottom hole for cooling the drill bit and removing cuttings (sludge) from the well.

A drain adapter is known, consisting of a body with radial holes and an inner core with the same holes, connected to the stop coupling by its upper end, and the lower end of the core is provided with slots in contact with the corresponding slotted body casing, face bead and radial ones tapering outwardly inclined windows located between the slots and designed to pass the ballfix when lifting the core.

The disadvantage of this adapter is its limited focus on the performance of certain functions and the inability to influence the drilling regimes depending on the strength of the drilled rocks.

A core tube adapter is also known, comprising a coupling with a shank having radial holes, and a nipple mounted concentrically with a shank, made with radial holes fQ and spring-loaded relative to the coupling, with the nipple fixed by a shear element relative to the coupling 2J.

The disadvantage of this adapter is that it cannot regulate the amount of flushing fluid supplied to the bottomhole during the drilling process, as well as the axial load, depending on the rocks being traversed.

The purpose of the invention is to automatically control the axial load on the bottomhole and the amount of washing liquid M to the bottomhole during the drilling process.

This goal is achieved by the fact that the nipple is mounted with the possibility of limited axial movement.

the couplings are in the process of eupenia and alignment of the holes at its extreme upper position And also by the fact that the holes are made in several rows.

FIG. I depicts a general view of the adapter; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one; in fig. 4, view B in FIG. one.

The adapter includes (for connecting to the drill string) a coupling 1 with a shank 2, made (lower part) of the jECTHrjiaHHoro section and having a series of holes 3. on which nipple 4 is freely fitted with the same number of holes 5 (for connection to the core pipe) and secured by a nut 6, which serves to limit the movement from the action of axial force and the spring 7 of the nipple 4 to the shank 2 of the coupling 1.

The adapter works as follows.

The total deformation of the springs 7 is calculated from the maximum possible axial force on the crown, which also determines the amount of movement of the nipple 4 on the shank 2 of the coupling 1. It is known that when drilling hard rocks a small amount of sludge forms at the bottom of the well, and when drilling weak rocks a large amount sludge Therefore, to remove the sludge from under the crown, in each case a different amount of flushing fluid is needed, and the speed of the upward flow of flushing fluid in the annulus must be constant, ensuring the normal operation of the borehole system. And it is also known that when drilling hard rocks, it is necessary to increase the axial force on the crown, and when drilling weak rocks - to reduce. Hence, when drilling rocks of different strengths, it is necessary to observe drilling patterns. When drilling intermittent rocks, holding drilling regimes is difficult, and under these conditions various complications and accidents often occur. Excessive amount of washing fluid supplied under the crown, as well as an excessive increase in axial force on the crown, reduce the mechanical speed of drilling, which is highly undesirable. JB adapter for adjusting the axial force on the crown set the spring 7. Analytically, the axial force on the crown, taking into account the action of the spring 7 is expressed by the following relationship

RC (ft-Pmax.) + Pl, (i)

where is the axial force on the crown, kgf.

Pt - the total force on the bottom of the weight of the projectile and the hydraulic system of the machine, kgf;

 Maximum compressive force of the Spring, kgf;

PI-force compression of the spring, depending on the rocks drilled, kgf.

As the axial force increases, nipple 4 moves along the shank 2 of clutch 1 and

Through a series of holes 3 and 5, a common SLC hole is formed, through which the flushing fluid from the projectile is poured into the annulus: With the full alignment of the rows of holes 3 and 5, the flushing fluid is completely drained. When the axial force decreases, and this happens during the drilling of weak rocks, the rows of holes 3 and 5 sec. Are displaced by the action of the spring 7 to drain the washing liquid, all the washing liquid goes under the end of the crown.

The amount of washing fluid supplied under the crown is determined by the following expression

QK QH - Qs.n. (2)

 -the amount of washing liquid entering under the crown, l / min;

QM - the amount of flushing fluid supplied by the pump to the drill pipe, l / min; p5p.- the amount of flushing fluid drained from the drill into the annulus, l / min.

When the adapter operates, the correspondence between dependences (1) and (2) is fulfilled, i.e. the axial force and the amount of washing liquid are automatically controlled.

0 The use of this adapter in the drill string layout makes it possible to rationally resolve the issue of well drilling technology in moving sills, regardless of the skill level and experience of the drillers. This adapter allows you to get the best effort on the rock cutting tool, depending on the strength of the drilled rocks, helps to automatically supply the required amount of flushing fluid to cool the crown and remove the sludge from under the crown, while ensuring complete and timely removal of sludge from the well to create a constant upstream flow rates in a difficult space, which significantly contributes to preserving the 5 walls of the well. The use of this adapter when drilling over intermittent geographies significantly reduces the cost of drilling.

Claims (1)

Invention Formula 50 1. A core tube adapter containing a sleeve with a shank having radial holes, and a nipple mounted concentrically with a shank, made with radial holes and spring-loaded relative to the sleeve, characterized in that in order to automatically control the axial load on the bottom and the amount supplied to bottom hole flushing, nipple