DE2401790A1 - METHOD OF JOINING THE BOTTOM ENDS OF DRILL HOLES - Google Patents

Description

The invention relates to a method for connecting the lower ends of two or more boreholes which are drilled in a rock salt layer, the due to geological anomalies, a connection of the boreholes using the well-known hydraulic breaking method does not allow.

When salt deposits are dismantled using the leaching process, one or more boreholes are usually drilled through the overlying geological formations into the

409829/0396

earthly degradation layer brought down. By suitable means are then generated in this layer open cavities or passages or Strömungssyste "ne, so that the mineral in a simple ^T \ else can thereby be reduced, that is circulated through these holes or flow systems a suitable solvent. The solvents used are mainly water, acids, steam or other liquid or gaseous solvents that are not saturated with regard to the mineral to be degraded.

It is known that the efficiency of the lye degradation process in the cave systems can be improved, the longer you can design the flow path of the solvent in the storage system. Such flow courses are usually It is much cheaper if you open a cave or cave as early as possible at the beginning of the lye decomposition. creates a space that is essentially horizontal, and in some cases vertical, between the point of the Depression of the solvent and the point of exit of the alkali extends. These are usually laid out horizontally Caves or flow passages tend to become to enlarge vertically by itself.

In such caves, which are in communication with a single double-lined borehole, the operation is first of all on the vertical distance between the solvent injection and the vent openings in the drill casing limited. For this reason, in practice it is preferable to proceed in such a way that several boreholes are drilled into the roan Brings down bearings and connects them to one another using conventional hydraulic mining methods in such a way that between them flow systems or caves for the fluid flow of solvents are formed. Processes of this type are described, for example, in US Pat. No. 3,064,957 and in US Pat. Reissue Patent 25,682.

409829/0396

ORIGINAL

These procedures are either aar nicat or ieiocb only under gross te.i Aut '/ ana ci'iroh. tangible, venn r ^ ri s chen zv / ei or several drill holes, a gsolouisc'ie /.no.-iialie, for example a fraction In, lic; t.

The invention is based on the object of creating a method for quick and easy connection of the lower formation of boreholes in bearing layers, which prevent geological anomalies between the ends of the boreholes and prevent the boreholes from being connected according to the known methods. To solve this problem, a method is proposed according to the invention, which is characterized in that boreholes are drilled into the La3er on both sides and at some distance from the anomaly, that one of the new ¹ , the boreholes from the bearing as far as practicable on the anomaly, thereby creating a first elongated passage for the fluid flow, and then from one of the wells on the other side of the anomaly using the leaching method to make a second elongated passage through the salt layer and through the anomaly to the junction creates with the first pass.

The Utrü -.unr-adur-chaanofe obtained by the process between the nuts of the drill holes on either side of the The anomaly run essentially horizontally and thus enable an advantageous flow guidance during the subsequent Leach mining process.

Also by the method according to the invention the actual dismantling of dismantling was not only taken up more favorably, but also more carefully in the further course being controlled.

When performing the method according to the invention

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ORK3INAL INSPEGTED

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a flexible solvent feed pipe is inserted through one of the boreholes slid down into the camp. It is ensured that the actual outlet opening or outlet nozzle for the solvent at the end of the flexible down pipe horizontally along the due phase interface between the mixture of the introduced solvent and scanned by density differences and the lye obtained and an overlying layer of a buffering preventing dissolution of the bearing or shielding, for example of oil, any other suitable hydrocarbon gas or air or an equivalent Material. Through this measure, the otherwise usually upwardly directed progress becomes; the degradation by leaching in favor of the horizontal Progress towards the anomaly and that of the first Well conveyed from guided passage too. During this time, the outlet nozzle is for the solvent precisely controlled with regard to their direction. This type of control is also compared to the known Procedure represents a significant improvement.

The invention is described below on the basis of preferred exemplary embodiments described in more detail in connection with the drawings. Us show:

Fig. 1 is a section through a bearing

a transfer with a thematic representation of the third stage the method according to the invention;

FIG. 2 shows a section along Z- * 2 in FIG. 1;

FIG. 3 is a section of that shown in FIG

Type after the connection of the

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ORiQiNAL

lower aohrlochenden through the? momalie;

Pig. 4 correspond to the ü "'i-: for 1 and .1

chenden 'cut, of the progressive Leach degradation stages the interconnected ears seigt;

i ^? icj. .ο one in their feed direction

controllable nozzle for carrying out the method according to the invention; and

-Ti-Cj. 6 another controllable nozzle for

Carrying out the method according to the invention,

In figures 1 and 2, drill holes IC and 11 are shown, which are deposited in the bearing 14 of a mineral layer. The boreholes are preferably up to the range the lower limit of the stratum to be mined 'By such. Boreholes are then known per se '.ieise by hydraulic breaking (U.S. Patent 3,064 and U3-l * eissue patent 25,682) the flow passages driven to connect the lower ends of the boreholes with each other.

In the example shown in Figures 1 and 2 drips the circular around the foot of the borehole 12 herua elaborated hydraulic fracture zone IS, however, to one geological. Displacement 16, The connection of the boreholes IC and Lü sauntered, however, despite trying one supported termination. For example, geological anomalies of this type often occur in the Appalachian Salt Basin

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2AÜ1790

aiii ", a storage system in the east of the United States. Solcüe and xa other i.ao-ials can occur, for example, in the form of open or closed dislocations, sharp folds or in the form of cracks that are filled with insoluble gangue The method according to the iSrfindurv-i. can also be established by anonals of the kind described between the borehole feet, which create flow paths for the fluid used in the process. This improves and facilitates the decomposition of leach and can be carried out with a higher degree of efficiency.

So if, when trying to connect two boreholes, the hydraulic fracture on the bottom of the bearing layer hydraulic demolition supported by j.jeira also came to a halt at a geological anomaly 16, In the context of the invention, the borehole 10 is lined with a jacket 20, the lower end of which is slightly has laterally curved opening sleeve 22. In this lining a flexible pipe 25 is sunk through that the solvent is pressed into the bearing. Under the guidance of the curved output sleeve 22, the flexible jioar introduced into the warehouse in a horizontal position. The liquid solvent is then pressed in through this nozzle 25 and radiates horizontally against the opposite one Surface of the bearing layer, which makes the bearing mineral the opposite surface is solved. The lye thus obtained flows through the outside surrounding the supply line 25 Cylinder ring to the surface of the earth.

üra that radiates out of the nozzle at the end of the Solvent supply line 25 escaping solvent horizontally to escape "in order to move the leaching process horizontally towards the anomaly 16 ensure and connect the connection with the passage 15 previously created by hydraulic demolition,

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to floatation devices, for example one or .aehrere flotation collar 26,2o, in the range eggs nozzle oü to the feed line 25 is fixed, üiese floats are arranged at a certain distance from each other in the ^T .eise that the nozzle 30 horizontally on the above surface, or at least at least in the area of the surface of the mixture of the solvent and the lye produced by dissolving the lacjerminerals floats in the washed-out cave. By applying floats of the type described, a downward diving or an upward bending of the nozzle and thus a deflection of the progressive "dissolving process in the warehouse from the horizontal direction in an upward or downward direction and missing the broken area 15 around the shaft around safely avoided will.

With a preferred development of the Lrfindu.iq, an undesired migration of the advancing leach degradation front from the intended horizontal can also be avoided by introducing a substance into the leaching drive that forms an insulating cushion outside the solvent / solution mixture phase that a port stepping of the solution upwards, the preferred direction of movement, is avoided. To produce such an insulating cushion or such an insulating layer, oil, air, other gases or corresponding substances can be brought through the shaft 10 into the cavity formed by the leaching. This insulating material can be selected and applied in such a way that it floats in the desired strength on the solvent / solution mixture during the entire advance and thus controls the advance direction. For this purpose, the insulating material, for example the Ul _1, can simply be added to the dissolving liquid in appropriate proportions and together with it

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down through the borehole 10.

The tSciiwi.nmer 26.2 to 3 are calculated so that the density of the combination of the feed end portion, the nozzle and the ochwiinmern something than the density of the material is just large, which is used for the insulating pads. At the same time, the density of the combination is lower than the density of the mixture of solvent and construction solution at the bottom of the cave.

The ochv; i; rrrner can be made of suitable solid materials consist, for example, of wood, foamed plastic, Glass or the like, but they can preferably also be inflatable.

A particularly useful special design of the nozzle head 30 can be used in cases where the soluble Mineral existing bearings to be mined are relatively smooth and level with the formation of a flat and clean Separating layer rests on an underlying base made of insoluble material. In this case it can the nozzle head 30 is provided with a self-propelled traction device of the type shown in FIG be. According to a preferred embodiment of such In the drive, the nozzle head is provided with slots 32 into which the paddle wheels 34 protrude. These paddle wheels are between baffles on the outer wall of the Housing of the nozzle head 3O are attached, rotatably mounted. When the solvent is pressed through the nozzle head, the paddle wheels are hydrodynamic entrained or driven in the manner shown by the arrows in FIG. "If he is so trained The nozzle head reaches the sole of the tunnel driven forward by the outlet, it is through the over the baffles 36 protruding blades of the paddle wheels

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34 in the direction of the solvent jet emerging from the nozzle pulled forward.

Instead of this hydrodynamic feed drive can however, any other drive, for example a.-lofcor drive, controlled by suitable means from the surface of the earth.

Course directional control within those in the foregoing ..is observed horizontal lioene can be different devices are used. In the simplest way, the direction of advance lying in the horizontal direction can be used of the nozzle head 30 can be controlled, for example, by the fact that the upper end of the flexible Zulextungsroiires 25 rotated about its central axis. As a result, an effective and usually sufficient directional control of the nozzle head can be achieved can be achieved.

Liac'h a somewhat more agile, but also more precise control method The nozzle head 30 can contain laterally arranged control nozzles 38 (Fxct. 5), the control function of which is controlled automatically or from above ground v / can earth.

Finally, the nozzle head can also be equipped with an automatic electronic control can be provided, which the nozzle head always on a for example in the borehole 12 Aligned target mark. In either case, the direction control mechanism is used in the horizontal plane, however, it is either remotely controlled from the surface or with an automatic one Control system that can be monitored from the surface if necessary. One such Control device 40 monitored from the borehole is scary shown in FIG.

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4 shows the manner in which the leachate degradation of the soluble bearing is then preferably carried out after the lower ends of the two boreholes 10 and 12 have been connected in the method described above. The floats 20, 20 are changed in such a way that the end of the feed pipe 25 with the nozzle head 30 no longer works horizontally, but upwards. The jet of solvent emerging from the nozzle breaks down the soluble bearing in an upward direction. This erection of the nozzle head can take place according to various methods. For example, the _3chwi: Nmer be further inflated 23, the float 26 can be moved towards the nozzle head v / earth, the flexible tube 25 are pulled out for replacement of the Schwirnmer meantime from the wellbore IC, wherein the float 28 replaced with a floating more capable swimmer can be.

The nozzle, which is directed upwards from the horizontal in the manner described above, then dismantles the bearing down to the ceiling. As the mining progresses, the flexible pipe 25 can then be gradually and progressively withdrawn from the borehole 10, the mining then being able to be carried out in the manner shown in FIG .

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Claims (9)

F a t e η t a η s ο r ü c h e 1. Method sura connecting the lower and s of i; vei or more boreholes, which are drilled in a rock layer, which due to aeoloois heranor.alien a connection of the boreholes aa ^ i what is called hydraulic fracturing method, characterized in that one to drill holes into the bearing on both sides and at some distance from the anomaly, so that from one of the boreholes the bearing can be broken as far as practicable towards the anomaly, thereby creating a first elongated passage for the fluid flow, and then from one of the boreholes on the other side of the anomaly creates a second elongated passage through the salt bed and through the anomaly to junction with the first passage after the leaching process. 2. The method according to claim 1, characterized in that the leach degradation with the aid of a liquid solvent carried out, which is carried out through a flexible pipe or a hose is fed, which is brought down through the corresponding borehole and at the front The lower end is provided with a nozzle which contains means with which it is applied to the first Durchganci can be led to. 3. The method according to claim 2, characterized in that the nozzle head with the help of laterally attached Control nozzles, which are operated optionally, controls. 4. The method according to any one of claims 2 or 3, characterized in that a target marker in the broken first passage and that one 4098 2-9 / U 39b -! 2- 2 4 U! 790 the nozzle head sunk in the other borehole for Auslaugeahbau with an electronically controlled one Targeting mechanism equips the propulsion of leach degradation leads to the target marker. 5. The method according to claim 2, characterized in that that you can adjust the nozzle head using a horizontally and vertically responding direction indicator controls. o. Verfanren according to any one of claims 1 to 5, characterized marked that one is driving the passage after the leaching process, the upper ceiling of the lacjers protects against dissolution by introducing an insulating pad. 7. The method according to claim 6, characterized in that as IJmaterial for the dissolution of the camp after ooen preventing cushion a liquid verv / endat whose density is less than the density of the storage liquor, and that this protective liquid in the by the leach degradation created tunnels as an additive to the deposited solvent. β. Method according to one of Claims 6 or 7, characterized characterized in that the nozzle head is located in the area of the phase interface between the protective or insulating pad and the one consisting of lukewarm and solvent Mixture in the lower part of the passage or tunnel leads. 9. Use of the method according to any one of claims 1 to 3 for the degradation of leaching from a soluble mineral Storage layer in such a way that the leach degradation begins in the area of the first pass and gradually counter to the propulsion direction of the second 40982 ^ / 0390 The passage continues in the direction of the borehole r-2u, through which the solvent supply line is brought down. 409823 / U39b ORIGINAL INSPECTED L e r s e i ΐ e Cf; .