DE102016125916A1 - drilling - Google Patents

Abstract

Drilling device for hard rock by means of a fluid, comprising at least one drill head with antechamber and mixing chamber, on which at least one forward nozzle and at least one rearward nozzle is present, wherein fluid in the mixing chamber is mixed with abrasives and the fluid escapes with the abrasives from the forward nozzle in which a division of the fluid flow takes place in the region of the antechamber, abrasive-free fluid emerges from the backward nozzles, mixing of abrasives and abrasive-free fluid takes place in the mixing chamber and the fluid added with the abrasives escapes from the forward-directed nozzles.

Description

The invention relates to a drilling device for hard rock by means of a fluid, comprising at least one drill head with antechamber and mixing chamber, at least one forward nozzle and at least one rearward nozzle.

In general, it is known that abrasives can be mixed with a rinsing fluid for water jet-based drilling methods in order to increase the drilling rate of progress. This can also be done in radial jet drilling (RJD) drilling to improve the process. With the current use of pure water as the cutting and rinsing fluid alone, extremely hard rock layers can not or only with difficulty be drilled through. The addition of abrasives into the rinsing fluid, however, can penetrate harder rocks or rock layers. However, this procedure in the drill head can lead to damage to the inner geometry of the drill head and the water supply to the drill head and slow down the propulsion speed.

So is in the US 6,932,285 B1 discloses the principle of the supply of abrasives to a mixing chamber acted upon with water, wherein the supply of the abrasive takes place radially via a lateral feed line. Furthermore, in the US 6,932,285 B1 a device shown as a water jet drilling device, in which water is mixed with abrasives in a mixing chamber and can escape from an outlet nozzle.

The US 6,263,984 A1 describes the use of a device as a water jet drilling device, are arranged in the backward nozzles from which water can escape with abrasives. In addition, water with abrasives impinges on a rotation body, causing it to rotate, whereby the water with the abrasives can subsequently escape from the outlet nozzles.

In the CN 104033106 A a drilling head for a water jet drilling device is shown, which has over rearward spooling nozzles, a mixing chamber and a rotary body, wherein via rotating outlet nozzles, a fluid can escape from the drill head.

Furthermore, an external supply of abrasives near the drill head by magnetically induced force fields is known. Due to the locally very high flow velocities of the fluid and the particles, the particles have a very high momentum, which in addition to the attacking fluid forces must be overcome by the magnetic field in order to force it to another "fluid path". In addition, the magnetic fields must direct the small particles into extremely small openings in the drill head, which can not be reliably guaranteed in practice without considerable effort. In addition, the pierced rock layer can affect the acting magnetic field as unfavorably as ambient temperatures of up to 200 ° C as they are present in geothermal reservoirs.

A problem with the known state of the art is that it can lead to increased wear in the supply line and the drill head when promoting a mixture of abrasives and rinsing liquid to the drill head. Thus, the drill head can be damaged by the escape of abrasives on the optional side nozzles and the leads that are not based on plastics, all or part of the drilling device.

The object of the invention is to provide a fluid-based drilling device for hard rocks and / or rock layers, which on the one hand ensures protection of the drill head and the Bohrzuleitungen from major damage and increased wear and / or allows fluid-based drilling using a rotating, pulsating fluid jet.

The object is achieved by the features of the independent claim 1 solved.

The development of geothermal reservoirs and oil / gas deposits located in extremely hard rock strata can often not be accomplished without the use of hydraulic or chemical stimulation. Alternatively, the RJD drilling method can produce thin, long holes underground from a main well. In order to allow drilling in the hard rock with this method, abrasives can be passed through an abrasive-containing supply line in a mixing chamber in the drill head, wherein a mixing of abrasive and an abrasive-free fluid in the mixing chamber and escapes with the abrasive fluid escaped from a forward nozzle and allows a drilling operation, wherein at least one rearward nozzle is arranged in the region of the drill head, from which fluid escapes without abrasives in order to ensure a continuous, slippery Bohrvortrieb.

The drilling device and the drilling process can be seen as an environmentally friendly alternative to "fraying". By means of RJD drilling, it is possible to introduce long, thin holes into the hard rock instead of hydraulic crack generation, which makes the development of deposits equally possible. The drilling device and the method is also suitable as an independent Drilling method for coiled tubing applications (CT drilling) as well as for bringing small single holes into the formation from an existing hole, also using CT drilling.

By adding abrasives into the fluid in the mixing chamber to the at least one forward nozzle extremely hard rocks and / or rock strata can be pierced or cut and deposits behind it can be developed. As abrasives disperse solids such as metal salts such as iron oxides, silicates such as silica or other ionic, amorphous or metallic solids are used according to the invention, which can be externally supplied to the drilling device via a supply line. The supply of the abrasives in the drill head according to the invention takes place via an abrasive-containing feed line into a mixing chamber. In this mixing chamber, the abrasives are mixed with an abrasive-free fluid. The fluid without abrasives passes through an abrasive-free supply line into the drill head in the antechamber and is passed via leads and / or focusing nozzles in the mixing chamber and added only in a mixing chamber with abrasives.

In a particular embodiment of the subject invention is also provided that the abrasives are generated only in the drilling device, for example, metal strips or other strand-like solids are passed over the abradant-containing feed line into the drill head and there are crushed into abrasives or there the disperse abrasives in situ be generated, for example, by rotating removal of the metal strip or the strand-like solid in the region of the drill head.

The pre-mixing chamber and the invention are spatially separated from each other. In the region of the drill head, one or more rear-facing nozzles are arranged, by means of which the fluid can be introduced without abrasives into the borehole and / or used as a propulsion medium and / or lubricant for the drill. The number of backward nozzles depends on the particular structure of the drill head and the purpose of the drilling device. In addition, flushing outlets may also be arranged in the region of the drill head in order to flush removed drill rock out of the drill hole and to ensure uniform propulsion of the drilling device.

In the mixing chamber, the fluid, for example, a liquid, in particular water, mixed with abrasives to serve as an additive, with the help of the forward-facing nozzles on the drill head, a material removal of the substrate done and a hole can be made. The fluid used usually has a viscosity of η = 1 to 20 at 20 ° C, but may also contain mixtures or dispersions of water with other compounds such as ethylene glycol. The choice of fluid depends on the particular application and the type of drill bit.

According to the invention, it is therefore intended to divide a fluid flow for the backward nozzles and flushing outlets without abrasives and a fluid stream with abrasives for the forward nozzles. The fluid typically has the same composition for the backward nozzles and the rinsing throat as for the forward nozzles, with the restriction that the fluid for the forward nozzles in the mixing chamber is additionally supplemented with abrasives. However, it is also alternatively provided that the abrasives are supplied with a fluid of the mixing chamber, in which the abrasives are at least dispersively distributed. It can then take place in the mixing chamber to a thorough mixing of the abrasive material-free fluid with the abrasivesubststoffhaltigen fluid, wherein the composition of the fluids may differ with and without abrasives.

The supply of abrasives can be made possible by external or internal leads into the drill head. For this purpose, it is provided in a particular embodiment of the subject invention that the leads extend coaxially to the drill head, which has the advantage that the fluid entry of the rinsing fluid and / or the abrasives is uniform and the propulsion is not hindered by the coaxial arrangement of the leads. It is also provided in a particular embodiment that the leads extend both within and / or coaxially in the drilling device to the drill head. The drilling device according to the invention can have a plurality of backward-pointing and several forward-directed nozzles, as well as a plurality of flushing outlets.

Advantage of the drilling device according to the invention is that damage to the drill head by the use of the abrasive-free fluid in the backward nozzles and / or scavenging outlets is avoided. The drilling procedure thus provides an alternative to conventional drilling methods and, in contrast to hydraulic stimulation, it is possible to predetermine the length of the borehole and the extent of the contact area between the borehole and the reservoir. In addition, the introduction of a bore takes only a few minutes. In addition, no seismicities are induced in the rock by dispensing with the breaking up of the subsoil. In particular, that water or other non-toxic compounds are used as fluid In contrast to the use of other fluids, the subsoil is not contaminated in other prior art drilling devices and methods.

According to the invention, an effective removal of material can be ensured by the fact that in the region of the prechamber at the drill head also backward nozzles and / or scavenging outlets are arranged in order to drill further or deeper at the same power can. This represents a particular advantage of the drilling device according to the invention and the method, since, according to the current state of research, the pumping power is a limiting factor in the length of the bore. From the backward nozzles and / or scavenging exits an abrasive-free fluid flow exits, which minimizes the frictional forces acting on the drill head and the leads. The drill head may be pushed further towards the rocks and / or rock strata via the fluid of the backward nozzles than without their presence based on the assumption that the rock properties are approximately constant in the horizontal direction.

In a particular embodiment, the drill head on a rotating inner part, which is mounted on an axis on the housing of the drill head. The fluid mixed with the abrasives can emerge from the region of the rotating inner part via at least one forward-rotating nozzle. Essentially, presently means that the forward nozzles have an orientation or inclination of less than 90 ° with respect to the bit, and the relative angle of inclination may vary with the nature of the substrate.

Advantage of the rotating inner part is that a uniform material removal is given to the borehole wall. For conventional RJD drilling heads, the orientation of the forward nozzles is static. Thus, only selectively removed material. The rotation of the entire surface of the borehole wall is processed evenly.

In the case of the special embodiment with a rotating inner part, the drill head comprises at least one focusing nozzle on the rotating inner part and at least one bore on the static area (stator) of the drill head for regulating the water supply. For this purpose, the drilling device according to the invention in the case of the particular embodiment with rotating inner part comprises at least one mixing chamber, at least one prechamber, at least one rearward nozzle and / or flushing outlet, at least one transition for the abrasive and at least one forward nozzle. In a particularly advantageous embodiment, the rotating inner part has three and the stator has four holes for regulating the water supply, so that at least one or none of the holes can be superimposed on the focusing nozzle during rotation of the inner part. Due to the overlapping of the bores of the stator occurring periodically with the focusing nozzle of the rotating inner part, a pulsation of the fluid flow can take place, the frequency of the pulsation being made possible by different rotational speeds of the inner part. When the bores overlap with the focusing nozzle, the abrasive is forced into the forward nozzle so that when the bores overlap with the focusing nozzle, the fluid abruptly forces the abrasives out of the forward nozzles to produce a pulsatile fluid flow. Such generation of a pulsating fluid flow must occur in or just before the drill bit. A generation in the pump has the result that the pulsating movement is damped by the dynamic properties of a long hydraulic line (fluid inertia and line compressibility) and, if necessary, completely compensated to the drill head.

The backward nozzles and / or flushing outlets are acted upon during the rotation of the inner part in the absence of overlap of the bores of the stator and the rotating inner part with abrasive-free fluid, the fluid serves as a lubricant within the borehole and on the other hand as a driving medium for the drilling operation. According to the invention, the backward-pointing nozzles run obliquely to the longitudinal central axis of the drill head, so that the oblique arrangement of the backward nozzles and / or scavenging outlets facilitates propulsion of the drill head and removal of removed rock or subsurface from the borehole. In addition, the fluid such as water or mixtures of water with hydrocarbons acts as a lubricant between the rotating inner part, the pre-chamber and the drill head housing.

The rotation of the inner part can be achieved by the rotating inner part enclosing an acute angle in the range of 1 ° to 11 ° with respect to the housing of the drill head. By the circuit of the focusing nozzles on the rotor and the bores on the stator, the drill head is subjected to fluid, whereby a rotation of the inner part is induced. In the area of the rotating inner part there is an annular gap between the housing of the drill head and the rotating inner part, which can vary in size and width depending on the intended use of the drilling device. Likewise, a lubricating gap between the rotating inner part and the static portion of the drill head may be present, in the abrasive-free fluid can enter and the sliding of the rotating inner part along the surface of the static portion of the drill head easier.

The SMC drilling apparatus according to the invention finds particular application in the development of geothermal reservoirs, oil / gas deposits, anchor bores, exploration wells, stimulation wells, and / or use for CT drilling.

The invention will be described again in detail with reference to the following figures:

1 shows a simplified principle of the drilling device according to the invention 1 for hard rock in a vertical cross-sectional section of the drill head 2 , Inside the drill head 2 runs a supply line 6a for the supply of abrasive-free fluids into the prechamber 8th and a supply line 6b for the supply of abrasives 5 (not shown) in a mixing chamber 3 , antechamber 8th and mixing chamber 3 are in the direction of the forward nozzle 4 separated and arranged one behind the other, so that the abrasive-free fluid through the antechamber 8th and a focusing nozzle 14 into the mixing chamber 3 enters and there with the abrasives 5 (not shown) can be mixed. The abrasive-free fluid passes through a backward nozzle 7 from the drill head 2 into a borehole. The backward nozzle 7 is present obliquely to the longitudinal central axis of the drill head 2 arranged and allows the use of the abrasive-free fluid as a propulsion medium and / or lubricant for the drilling device 1 , In contrast, the abrasive-containing fluid with the abrasive-free fluid, which from the mixing chamber 3 via a Fokussierdüse 14 in the mixing chamber 3 enters as a cutting jet, which from the forward nozzle 4 from the drill head 2 can escape continuously.

In the 2 is a drilling device according to the invention 1 shown with rotating inner part 9 in a vertical cross-section. The drill head 2 includes the housing of the drill head 2 , which is a static area of the housing as a stator 11 includes and a rotating inner part 9 , One recognizes the abrasive-free supply line 6a about the a fluid in the antechamber 8th of the drill head 2 can occur. From the antechamber 8th outgoing is a backward nozzle 7 arranged obliquely to the longitudinal central axis, by means of which abrasive-free fluid can escape into the wellbore. About a transition 12 Abflussstoffstoffhaltiges fluid from an abrasive-containing supply line passes 6b into the mixing chamber 3 , in which about an abrasive-containing transfer line 12 the abrasive-free fluid with abrasives 5 (not shown) is mixed. The rotating inner part 9 has a focusing nozzle 14 on that towards the antechamber 8th or drilling 13 the static area of the drill head 2 point. This constructive arrangement of the holes 13 , Transfer 12 and focusing nozzle 14 is shown in sections AA and BB. The inner part 9 is over an annular gap 10 from the housing of the drill head 2 spaced. During rotation of the inner part 9 each overlaps a part of the holes 13 the antechamber 8th with the focusing nozzle 14 of the rotating inner part. At congruence of the holes 13 the antechamber 8th with the focusing nozzle 14 Abrasive-free fluid enters the mixing chamber 3 one. Via the forward nozzle 4 can then mixed with the Abrasivstoffstoffen fluid from the drill head 2 emerge and act as a cutting jet. The rotation of the inner part 9 is produced by the continuous application of abrasive-free fluid at least one existing Fokussierdüse 14 that is not congruent with the hole 13 of the static part of the drill head 2 with the abrasive-free fluid, wherein the position of the focusing nozzle 14 an acute angle to the drill head 2 of the inner part 9 includes

3 shows a structural design of the drilling device 1 with analog structure too 2 , Abrasivstofffreies fluid is via an abrasive-free supply line 6a to the prechamber 8th passed, which partially in the rotating inner part 9 located. The backward nozzles 7 are in the rotating inner part 9 at the antechamber 8th arranged. The rotating inner part 9 consists in the present case of two parts pressed into one another, wherein via an abrasive-containing feed line 6b a supply of abrasives 5 (not shown) in the mixing chamber 3 is possible, which in the rotating inner part 9 is arranged. A special feature of this design is the branch of the abrasive-free fluid on the supply line 6a , The lubrication column 15 in which a rotational movement of the rotating inner part 9 to the housing of the drill head 2 occurs relative to each other, is applied with abrasive-free fluid. Since the pressure of the abrasive-free fluid compared to the abrasive-containing fluid is substantially higher, the lubrication gaps 15 flows through the abrasive-free fluid and prevents penetration of the abrasives 5 (not shown) in the lubrication column 15 ,

While the high pressures of the abrasive-free fluid, the rotating inner part 9 Depending on the design, but especially in this embodiment, generate a force that the rotating part 9 Press out axially, is in the annular gap 10 built a pressure that generates an axial force that counteracts. The annular gap 10 is designed so that the projected area of the annular gap 10 is greater than the hydraulically effective area, the pressing out of the rotating inner part 9 from the drill head 2 would cause. The supply of abrasive-free fluid to this annular surface of the annular gap 10 takes place through a pipe 17 in which a pressure drop is generated depending on the flow. Would the rotating inner part abut the cone, so No fluid could flow and in the pipe 17 There was no pressure. The force is due to the larger area of the annular gap 10 now bigger and pushes the rotating inner part 9 into the drill head. This can be done by opening the annular gap 10 Fluid flow, the pressure drop of the line 17 rises with flowing fluid until an equilibrium of forces and pressure is established, which is the rotating inner part 9 axial zentiert and represents an axial plain bearing. The fluid which allows this centering, can from the flushing outlets 16 from the drilling device 1 escape.

4 shows a variation of 2 with the abrasive feed line 6b in the middle of the drilling device 1 through the antechamber 8th therethrough. The holes 13 to generate the pulsation are characterized by an overlap as in 2 are described around this supply line 6b arranged around. The backward nozzles 7 are in the static part of the drill head 2 arranged. The central supply allows the supply of a strand-shaped abrasive, by the rotation of the rotating inner part 9 in the mixing chamber 3 is crushed.

LIST OF REFERENCE NUMBERS

1

drilling

2

wellhead

3

mixing chamber

4

Forward nozzle

5

abrasives

6a

Abrasive-free supply line

6b

Abrasive-containing supply line

7

Backward nozzle

8th

antechamber

9

Rotating inner part

10

annular gap

11

stator

12

Transition management

13

drilling

14

focusing nozzle

15

lubricating gap

16

purge outlet

17

management

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US Pat. No. 6,932,285 B1 [0003]
• US 6263984 A1 [0004]
• CN 104033106 A [0005]

Claims (10)

Drilling device (1) for hard rock by means of a fluid, comprising at least one drill head (2) with prechamber (8) and mixing chamber (3), at least one forward nozzle (4) and at least one rearward nozzle (7), characterized in that abrasive material fluid via an abrasive-free feed line (6a) into the antechamber (8) and into at least one rearwardly directed nozzle (7) passes and abrasives (5) via an abrasive-containing feed line (6b) into the mixing chamber (3) and the with the abrasives (5) staggered fluid from the at least one forward nozzle (4) emerges. Drilling device (1) after Claim 1 , characterized in that the pre-chamber (8) and the mixing chamber (3) spatially separated from each other in the drill head (2) are arranged. Drilling device (1) after Claim 1 or 2 , characterized in that the supply lines (6a, 6b) run together or independently within or outside the drilling device (1). Drilling device (1) according to one of the preceding claims, characterized in that the supply lines (6a, 6b) extend coaxially to the drill head (2). Drilling device (1) according to one of the preceding claims, characterized in that the rearwardly directed nozzles (7) and / or flushing outlets (16) are arranged obliquely to the longitudinal center axis of the drill head (2). Drilling device (1) according to one of the preceding claims, characterized in that the drill head (2) has a rotating inner part (9). Drilling device (1) according to one of the preceding claims, characterized in that the rotating inner part (9) has at least one focusing nozzle (14) and a transfer line (12). Drilling device (1) according to one of the preceding claims, characterized in that an annular gap (10) and / or lubrication gap (16) in the region of the drill head (2) is present. Drilling device (1) according to one of the preceding claims, characterized in that over the feed line (6b) metal strip or strand-like solid in the drill head (2) out and the abrasives (5) are generated in situ. Use of a drilling device (1) according to Claim 1 to 9 for use in geothermal reservoir development, oil / gas deposits, anchor drilling, exploration drilling, stimulation drilling and / or CT drilling.

Images