RU2181828C2 - Core barrel - Google Patents

Abstract

FIELD: core drilling of wells; applicable in geological prospecting and mining industry. SUBSTANCE: core barrel includes outer barrel, crown bit and anvil with centering band in lower part and movable connected with outer barrel. Core receiver is located between crown bit and anvil. Core receiver is installed in outer barrel movably with possibility of interaction with crown bit and anvil. Made in zone of interaction of core receiver and anvil, on anvil centering band are recesses overlapped by core receiver in its extreme upper position relative to anvil. EFFECT: higher efficiency of core drilling due to improved quality of produced core attained by differential washing of bottom hole. 3 dwg

Description

 The technical solution relates to a device for drilling wells with coring and can find application in exploration and mining.

 Known core projectile by.with. USSR 713982, class E 21 V 25/00, publ. BI 5, 1980, in which the inner core receiver pipe is connected to the drill bit using a threaded connection and transmits torque, and shock pulses are transmitted to the drill bit through the outer pipe.

 The disadvantage of this projectile is its low reliability, because shock waves reflected from the bottom, acting on the threaded joint, destroy it.

 Known double-core projectile according to the patent of the Russian Federation 2098595, class. E 21 V 25/00, publ. BI 34, 1997, containing an outer pipe, a core receiver pipe placed therein, a drill bit with a central hole, movably connected to the bottom of the outer pipe, and an adapter.

 The disadvantages of this projectile are, firstly, the large loss of energy during its transfer to the drill bit due to the large mass of pipes and, secondly, the poor quality of the core due to poor flushing of the face before drilling.

 The closest in technical essence and the achieved effect to the proposed core set is a drill on A. with. USSR 1127967, class E 21 B 10/04, publ. BI 45, 1984, containing a combined crown with percussion and support elements connected respectively to the core receiver and outer pipes of the double core pipe, and a hammer, the body of which is connected to the outer pipe, and the hammer is installed with the possibility of interaction with the core receiver pipe, while supporting the elements of the combined crown are equipped with diamonds, and its percussion elements are made in the form of conical shaped inserts.

 The disadvantage of this projectile is the low quality of the obtained core material due to the inevitable loss of its part during pumping of the flushing fluid during all technological operations through the core receiving pipe.

 When cleaning the bottom of the well from deposited sludge before drilling, this flushing path gives a positive result - a more effective cleaning of the bottom, and when selecting core material (drilling), pumping fluid through the core pipe and, therefore, through core material leads to the removal of part of the core material into annular space, and its output inevitably decreases, which worsens the normative indicator of drilling quality.

 The technical problem solved by this invention is to improve the quality of the obtained core by differentiating flushing of the bottom of the well.

 The problem is solved in that in the proposed core set comprising an outer pipe, a drill bit, an anvil with a centering belt in the lower part, movably connected to the outer pipe, and an inner core receiver mounted in the outer pipe movably with the possibility of constant interaction with the drill crown and anvil, according to the proposed solution, in the zone of interaction between the inner core receiver pipe and the anvil, grooves are made on the centering belt of the anvil, overlapping the inner core emnoy pipe in its uppermost position relative to the anvil.

 This ensures effective cleaning of the bottom of the well from the deposited cuttings before drilling, as part of the flushing fluid is pumped through open grooves on the centering belt of the anvil and then through the inner core pipe and bottom of the well. During drilling (coring), all flushing fluid is pumped only through the annular gap between the inner core receiver and the outer pipe, thereby preserving the core material. Drilling quality is improving.

 The essence of the technical solution is illustrated by an example of the design and drawings, where Fig. 1 shows a longitudinal section of a core set, general view; figure 2 - node I in figure 1, the connection of the drill bit with the outer pipe (on an enlarged scale) before starting drilling; figure 3 - node II in figure 1, the interaction zone of the inner core-receiving pipe and the anvil, when the core-receiving pipe is in its lowest position, before drilling (on an enlarged scale).

 The core set (Fig. 1-3) consists of an outer pipe 1, anvil 2, a drill bit 3, which are movably connected to the outer pipe 1 by means of splined joints 4 and 5, and an inner core receiver 6. In the lower part of the anvil 2 on the centering grooves are made in the girdle 7, which are inclined with openings 8 in the lower position of the inner core receiving pipe 6 communicated with the central channel 9 of the anvil 2. In the upper part of the set, the anvil 2 is connected movably to the outer pipe 1 using a nut 10 and a spline connection 4. In the lower part of the set the bottom pipe 1 is movably connected to the drill bit 3 by means of a threaded sleeve 11 having splines 5. The drill bit 3 is kept in the set from falling out by a split ring 12 and a nut 13. An annular gap 14 is formed between the inner surface of the outer pipe 1 and the outer surface of the inner core-receiving pipe 6. .

 Column set works as follows. A projectile consisting of a percussion machine (not shown) and a core set is lowered into the well. Before starting work, in order to obtain high-quality core, the face is flushed. In this case, the projectile is kept in weight without the support of the drill bit 3 to the bottom. At this time, the inner core receiving pipe 6 (Fig. 3) is in the lower position and the grooves 7 are fully open. The flushing fluid through the central channel 9 and inclined holes 8 passes through the grooves 7 into the inner core receiver pipe 6 and then through the drill bit 3 to the bottom of the well, washing it intensively (Fig. 2). At the same time, some part of the flushing fluid along the annular gap 14 and the spline grooves 5 passes into the annulus, cleaning the well. After cleaning the bottom and well, the projectile is lowered to the stop of the drill bit 3 in the bottom of the well. Anvil 2 moves downward and the inner surface of the core-receiving pipe 6 overlaps the grooves 7 of the anvil 3 (Fig. 3).

 Then the drum machine is turned on. The flushing fluid passes to the face only along the annular gap 14 between the pipes 1 and 6. The hammer of the machine strikes the anvil 2. The shock pulses are transmitted to the drill bit 3 through the inner core pipe 6. The torque from the rod stand is transmitted to the drill bit 3 through the outer pipe 1 and splined joints 4 and 5. The drilled core enters the inner core receiving pipe 6, and the shock pulses traveling through this pipe contribute to more efficient core advancement.

Claims (1)

 A core set comprising an outer pipe, a drill bit, an anvil with a centering belt in the lower part, movably connected to the outer pipe, and an inner core receiver mounted in the outer pipe movably with the possibility of constant interaction with the drill bit and anvil, characterized in that in the zone interactions of the inner core-receiving pipe and the anvil, grooves are made on the centering belt of the anvil, overlapping by the internal core-receiving pipe in its extreme upper position relative to the anvil flax.

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