Union of Oberröblingen
| Oberröblingen shaft | |||
|---|---|---|---|
| General information about the mine | |||
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| other names | Union of Oberröblingen | ||
| Information about the mining company | |||
| Start of operation | 1909 | ||
| End of operation | abandoned in 1913 | ||
| Successor use | no | ||
| Funded raw materials | |||
| Degradation of | |||
| Greatest depth | 642 m | ||
| Geographical location | |||
| Coordinates | 51 ° 27 '16 " N , 11 ° 40' 27" E | ||
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| Location | Oberröblingen | ||
| local community | Mansfelder Land lake area | ||
| District ( NUTS3 ) | Mansfeld-Südharz | ||
| country | State of Saxony-Anhalt | ||
| Country | Germany | ||
| District | Saale-Unstrut | ||
Schacht was a Oberröblingen in sinking begriffener bay on potassium salts of the former union Oberröblingen district sea area Mansfeld in Saxony-Anhalt . The shaft had to be abandoned due to the uncontrollable inflow of saline solution.
Geological and hydrogeological reservoir conditions
Geological and reservoir economic situation
The shaft lies on the SW flank of the saddle running from Delitz am Berge via Teutschenthal towards Eisleben ; the SW flank of this anticline also represents the NE flank of the Querfurt Mulde. North of the shaft, the Zechstein - Salinar at the Teutschenthaler Sattel has been largely depleted as a result of the elevation of the saddle axis towards the northwest. The km in 1.7 from the shaft standing drilling sub Röblingen has, in addition Auslaugungsrückständen the All-formation and the line formation until the Staßfurt lineup as intact horizon from.
In the Oberröblingen IV borehole further to the west, the Aller formation was also attacked, while the Zechstein is still completely present in the Oberröblingen II, III and IV boreholes to the south and in the Oberröblingen shaft.
After the deepest of the trough (boreholes Stedten 1 and 2, Schrapplau 1,3,4 and 5) the thickness of the overburden increases continuously (presence of shell limestone and increasing thickness of the red sandstone ). The occurrence of a brine source in the Stedten 2 borehole, around 1.5 km south of the Oberröblingen shaft, is remarkable . According to the shaft profile and the results of the shaft pre-drilling, the overburden and the sunken Zechstein layers show the normal profile (thickness / rock formation) usual for the Mansfeld Mulde. Because the shaft was drowned, rock salt or potash salts were not extracted, and no information is available on the quality or chemical composition of the rock and potash salts drilled through with the pre-drilling of the shaft.
For the Oberröblingen I and II wells in the vicinity of the shaft, the following quality specifications were made for the area of the potash store (details of the maximum and minimum values in%):
| OT hole | K 2 O | NaCl | MgCl 2 | MgSO 4 | CaSO 4 | Insoluble | MgBr 2 |
|---|---|---|---|---|---|---|---|
| Oberröblingen I | 10.44-12.56. Average 7.98 | 15.04-60.34 | 4.62-23.93 | 5.23-16.18 | 0.38-3.80 | 0.38-3.80 | Average 0.196 |
| Oberröblingen II | 10.44-12.56. Average 10.51 | 12.99-21.02 | 20.72-28.88 | 3.05-11.43 | 1.96-2.79 | 1.22-4.02 | Average 0.245 |
According to these analyzes , the potash salt deposit in the area of the Oberröblingen shaft is definitely comparable with the deposit in the Staßfurt seam of the Teutschenthal mine (currently the backfill mine of " GTS Grube Teutschenthal Safety GmbH & Co. KG ").
Hydrogeological conditions
The natural hydrogeological conditions in the area of the Oberröblingen shaft are essentially influenced by the immediate leaching of the salinar in the vicinity . The effects of the lignite opencast mine east of the shaft (see map above) were insignificant at the time. The area around the Oberröblingen shaft is only a little south of the extensive subrosion depression of the Eisleben lowlands . As the salt water inflows during the shaft sinking showed, it is hydrogeologically influenced from this area. Within the large Eislebener lowlands that are stored in the wider area of the shaft are Subrosionssenken of Erdeborn and Unterröblingen particularly noteworthy. Locally usable water resources are rarely found in the subrosion areas. Most of the time, the hanging wall is largely drained, while the lying wall is too salty. As aquifers is medium red sandstone to look at. The Lower Buntsandstein , which is mainly designed as a groundwater barrier, is of very little importance . Here, water only flows in the area of the roe stone banks . As a result of the neighboring leaching, these waters are mostly saline and also have high carbonate hardness .
Also worth mentioning are the subsidence of the surface associated with subrosion , such as the subrosion sinks of Erdeborn and Unterröblingen in the wider area as well as the sinkholes that occur particularly in the course of the Hornburg Deep Fault (e.g. "Teufe" near Oberröblingen). In the immediate vicinity of the Oberröblingen shaft, however, such phenomena are not known.
The financial and business situation
Representative : Adolf Soa, mine director, Oberröblingen am See (he was also a board member of Adler-Kaliwerke AG).
Authorized representative: Mine director Möller.
Operations manager : Graduate mining engineer Schaper.
Workforce: an average of 90 men.
Foundation: 1909.
Number of Kuxe : 1000; the Adler potash works owned 995 of them.
Relations with the Eagle potash plants AG: In connection with the financial restructuring of the Group's eagle Kaliwerke A.-G. The Kuxe of the union passed into the ownership of the Adler-Kaliwerke except for a few. According to the achieved thereby economic unity of the two companies have replaced the eagle Kaliwerke in 1916, the bank debt of Oberröblingen and the senior mortgage taken (about 1.5 million. Mark from 1 January 1912).
Lawful : 10 Prussian maximum fields, located in the boundaries in the Bergfrei of the Oberbergamtsviertel Halle-Saale . In 5 of these fields - acquired in autumn 1910 by the "International Drilling Company" for 0.8 million marks - hard salt deposits were detectedby OT drilling.
Drilling: The whole area is 10 OT through holes open , were geteuft 8 to the salt deposit of those. Two of them were found in potash: Borehole Oberröblingen I (final depth 690.95 m; carnallite from 603.25 - 613.65 m T.) and borehole Stedten 2 (final depth 1003.0 m; carnallite and sylvin from 925.80 - 955, 30 m T.).
Closure: Since there was no reliable guarantee that the shaft would be lowered due to the inflow of solution , the necessary financial resources of up to RM 2 million could not be obtained at the time, as well as due to the fact that the potash deposit to be developed was only available was a carnallite deposit, the General Assembly decided on October 29, 1925 to close it down. After submitting the closure declaration, the Oberröblingen union received a closure rate of 0.7555 thousandths.
In 1936 the assets of the four companies forming the Adler Group (Adler-Kaliwerke AG, Bergwerksgesellschaft Hope mbH, Kaliwerke Adolfs Glück AG and Oberröblingen Union) were transferred to the main shareholder, Kaliwerke Aschersleben AG.
Shaft sinking / shaft lining
The construction of the shaft began at the end of December 1909 in the former field Oberröblingen I. The planned breakthrough from the mine field with that of the neighboring Adler potash works was approved by the mining authorities. This would have solved the so-called "two-shaft question" (second shaft as escape or weather shaft) for both potash plants. The lowering of the shaft to a depth of 21.25 m went smoothly. The first water inflows of up to 0.7 m³ / min were evident here. At the end of 1910 the shaft was 48.30 m deep. In 1911 the inflows increased up to 3.2 m³ / min. By reaching a depth of 82 m and installing the first wedge ring to set down the cast iron tubbings to be introduced , the inflow was initially reduced to around 100 l / min. At the end of 1912 a depth of 463 m was reached. The lining of the segments reached down to a depth of 375.5 m; Exceptions are two brick sections between 0 and 19 m and from 150 to 159 m depth.
On May 13, 1913, the first major salt water ingress occurred at a depth of 642 m, which led to the shaft being drowned. For a closer examination, a pre-drilling of the shaft was then made from the hanging bench . The bore ended in the older rock salt (6 m), the total depth was 875.4 m. The borehole was then cemented . After the restart of the work and swamps of the shaft, gravel concrete, brick gravel and a concrete plug with standpipes for investigations or the cementing of the boreholes were introduced. After the supposedly good completion of the consolidation work, the removal of the concrete plug began. There was again strong solution inflows. As the new dewatering system was not fully installed, it was unavoidable that the shaft would sink again .
Below the shaft depth of 376.5 m, the shaft was secured in masonry (presumably 2 stones thick). This ends at the foot of the wall at a depth of 608 m. The clear diameter of the shaft is 6 m. Below the base of the wall, the mountain is free, then remains of the standpipe concrete plug will probably follow from 616 to 626 m depth. The embankment below with brick gravel and the introduced gravel concrete then probably fill the shaft up to the final depth (642 m).
The salt water breakthrough in the shaft
The "Union of Oberröblingen" shaft reached a depth of 642 m on May 13, 1913 and was located in the Lower Buntsandstein. When the bottom of the shaft was bored , there was still no inflow in the boreholes, so blasting was carried out in the usual way. After the blast, an approximately 24% NaCl brine broke through with an influx of 4-5 m³ / min. The brine rose to the hanging lawn bench in six days . Since it threatened to overflow, the shaft was walled 5 m high. Even at this level the inflow was up to 400 l / min and had to be pumped out continuously. The brine breakthrough came completely unexpected. The last tributaries were at a depth of around 350 m in the Middle Buntsandstein - just above the border with the Lower Buntsandstein - at a rate of 500 l / min. The lower red sandstone itself was completely dry. The bottom of the shaft was some 40 m above the younger rock salt when the brine broke through.
Of the various conjectures about the origin of the brine, the most likely one is that it came from a closed and pressurized cavity. Above days, at the location of the former Salty Lake , which is about 2 km north of the shaft, a saddle made of red sandstone used to stretch from southeast to northeast, and the salt store immediately below it. The salt head under the red sandstone saddle was only approx. 50 m below the level surface of the earth and so day water could easily penetrate through crevices up to the salt and leach it out. After cavities had formed in this way, the red sandstone ceiling gradually collapsed and the former saddle became a subsidence area, the " salty lake ". The trapped brine penetrated the cracks of the falling red sandstone into the area of the shaft and the weight of the collapsed red sandstone ceiling pressed the lye with force up to days when approaching such a crack . To investigate the breakthrough point and the mountains below, a deep borehole was then sunk in the drowned shaft. The installation of the drilling equipment turned out to be very difficult, as it had to be carried out at the height of the suspended bank due to the walling of the shaft. The drill rods were secured in such a way that several nested drill pipelines were guided by means of clamps on tension ropes. Nevertheless, there were frequent pipe breaks and the pipelines had to be pulled and re-installed more often. The hole was sunk to a depth of 875.4 meters; of which the last 6 m in the older rock salt. The drilling revealed that there was a fragile zone about six meters thick beneath the bottom of the shaft . The mountains below were completely intact. The carnallite deposit was drilled from 836 to 867.5 m. The borehole was then cemented and the pipelines removed.
Current condition (status 2004)
Since the GDR's safekeeping order of October 10, 1971 (GDR GBl. II No. 73), the council of the Halle district has been responsible for a large number of old potash pits, so-called “pits of old mining without legal successors”. With the accession of the GDR to the scope of the Basic Law, the abandoned Abteufschacht Oberröblingen was also considered to be a "decommissioned facility of a mining operation for which a legal successor does not exist or can no longer be determined". In place of the councils of the districts, the respective state governments acted until the relevant regulatory authority regulations were issued (for the state of Saxony-Anhalt: Law on Public Safety and Order of the State of Saxony-Anhalt (SOG LSA) in the version published on 23 September 2003 ( GVBl. LSA p. 214), last amended on May 18, 2010 (GVBl. LSA p. 340)). Thus, the Oberröblingen shaft has been the responsibility of the municipality in terms of regulatory law with regard to the duty of care for the purpose of averting danger. To ensure public safety, the shaft tube is secured with a cover (see above images). The manhole cover is fenced in with a chain link fence.
Manhole closure i. J. 2004
Manhole closure i. J. 2004
Manhole closure i. J. 2004
swell
- Fuchs, Götze: Analysis of mining damage for the "Union Oberröblingen" shaft in Oberröblingen am See. Teutschenthal, May 1970, archive of the LAGB Saxony-Anhalt.
- J. Mossner (Hrsg.): Handbook of the potash mines, salt pans and deep drilling companies. Finanz-Verlag, Berlin 1936.
- G. Pinzke: Expert opinion on the assessment of the mining and public safety of selected potash pits without legal successors on the territory of the Halle district. Council of the District of Schwerin, Dept. Geology 1979, Archives of the LAGB Saxony-Anhalt.
- Yearbooks of the German lignite, hard coal and potash industries. Wilhelm Knapp publisher in Halle / Saale.
- Schaper: The brine breakthrough in the "Union Oberröblingen" shaft. In: The Kalibote. No. 25/1934.
literature
- Blei, Jung: About the anomalous Zechstein profiles in the area of the Mansfeld Mulde. Freiberg Research Booklet C 133, Bergakademie Freiberg, 1962.
- Löffler: The Zechstein potash and rock salt deposits in the GDR. Part III: Saxony-Anhalt. Freiberg research booklet C 97 / III, Bergakademie Freiberg, 1962.
- v. Hoyningen: Salt tectonics and leaching in the area of the Mansfeld Lakes. Freiberg research booklet C 56, Bergakademie Freiberg, 1959.
- Schroeder: The ingress of salt water in the Oberröblingen shaft. Geological State Institute Berlin, 1921.