EP1112437A1 - Method for the in-situ extraction of gas from coal seams - Google Patents
Method for the in-situ extraction of gas from coal seamsInfo
- Publication number
- EP1112437A1 EP1112437A1 EP99953624A EP99953624A EP1112437A1 EP 1112437 A1 EP1112437 A1 EP 1112437A1 EP 99953624 A EP99953624 A EP 99953624A EP 99953624 A EP99953624 A EP 99953624A EP 1112437 A1 EP1112437 A1 EP 1112437A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- gas
- borehole
- coal
- pressure
- pressurization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003245 coal Substances 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims abstract description 18
- 238000011065 in-situ storage Methods 0.000 title claims abstract 3
- 238000000605 extraction Methods 0.000 title abstract description 4
- 239000007789 gas Substances 0.000 claims description 34
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 238000003795 desorption Methods 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 230000029087 digestion Effects 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims 1
- 230000002035 prolonged effect Effects 0.000 abstract description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 10
- 239000011148 porous material Substances 0.000 description 7
- 230000035699 permeability Effects 0.000 description 5
- 230000000638 stimulation Effects 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 230000029058 respiratory gaseous exchange Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005923 long-lasting effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/006—Production of coal-bed methane
Definitions
- the invention relates to a method for the m-situ demand of gas from coal beds, the structure of the gas-containing coal being broken down by means of gases and / or liquids introduced into the coal bed by means of pressurized gases and / or liquids and then for the flow paths in the coal Gas demand a pressure smaller than the respective desorption pressure is applied to the bore.
- the possibility of extracting methane from m coal seams from mined coal mines by means of an m-situ demand from m the borehole in question is determined by the parameters gas content, permeability and Porosity of the coal as well as the desorption pressure of methane, which depends on the gas content of the coal.
- stimulation techniques have been used within the framework of previously known methods which are known per se from oil production, in that the borehole drilled into the coal seam used for the production of gas is brief, that is to say over a period of less than one hour to a few hours, by means of injection of water or a suitable gas under a uniformly high pressure, for example from 300 to 350 bar.
- This pressurization leads to the formation of a so-called fracture, by means of which the macrostructure of the coal is broken up at its natural mechanical weak points such as bad, fissures, etc.
- the pressurization takes place with the simultaneous introduction of a suitable material, such as, for example, a rolling sand, by means of which the open macrostructure is kept open and at the same time a gas flow path is established along the broken mechanical weak points.
- a suitable material such as, for example, a rolling sand
- the known stimulation method has the disadvantage that it is only possible to achieve satisfactory gas production rates in coal seams with a low permeability if the coal is highly saturated with methane and the desorption pressure is consequently relatively close to the application pressure. Is a low permeable coal on the other hand, if the frac introduced in each case results in only a small depth of penetration of the pressure funnel which arises when the pressure is reduced for the gas demand.
- the supply pressure to be set below the desorption pressure at the borehole therefore only acts on a comparatively small coal volume, namely that which is directly perpendicular to the respective fracture.
- the known stimulation technique thus only influences comparatively small floz sections; there is no volumetric flux influence, at least for a short time, and the rate of migration of the pressure drop in the seam during operation is too low.
- the invention is therefore based on the object of specifying a method of the type mentioned at the outset by means of which the gas demand rate can be increased.
- the solution to this problem arises, including advantageous refinements and developments of the invention, from the content of the claims, which follow this description.
- the basic idea of the invention is that for the exploration of the coal, a pressure is applied to the borehole which is effective over a longer period of time and which is less than the smallest main stress determined in the respective seam horizon used for gas production, the loading of the borehole during of the digestion period with a cyclically changing pressure.
- the invention is associated with the advantage that the application of pressure to the coal seam to be used for gas production that is less than the smallest main stress determined in the corresponding seam opens the complex crack system in the pore area from macropores to microporous structures, without opening or opening new cracks in the area of the macro structure.
- the microcracks do not return to their dense starting position, since the prolonged pressurization with a pressure in the region of the main stress means that there is little dislocation of the microcrack surfaces and, because of the associated detachment of fine particles, a permanent gap of the respective crack surface is generated, so that the use of proppants such as sands etc. can advantageously be dispensed with.
- the opening of the crack system in the pore area is further supported by the fact that the application according to the invention the borehole takes place during the digestion period with a cyclically changing pressure, so that this leads to a kind of breathing in the pore area of the coal to be digested, which is why once opened pore structures cannot close again.
- This also supports the displacement of the microcrack surfaces against each other and the transport of detached fine particles within the opened microporous structures.
- the permeability of the coal is increased permanently and over a larger surface area without a larger coal volume having to be pumped to a pressure level below the desorption pressure during the subsequent conveying operation, so that this larger coal volume with the permeability increased by the measure according to the invention gas production is available.
- the lowest main stress prevailing in the coal seam to be used for gas production is measured in order to determine the pressure to be set in the individual case, and the application pressure is set lower than the main stress determined; the pressure is applied over a longer period of time, which can be specified as one day to several days or weeks.
- This long-lasting pressurization with the pressure designed for the given main stress leads to the desired disintegration of the pore structure of the coal without changes in the mechanical structure of the coal seam.
- the pressure can be applied to the borehole by injecting water or gas.
- water used to pressurize the borehole
- reservoir water present in the deposit can also be pressed into the borehole or the pore structure breathing can be generated by cyclically applied pressure via the pressure excitation of the reservoir water.
- the gas flowing to the borehole and to be conveyed can be pressed back into the borehole for pressurizing it; alternatively the injection of C0 2 is provided may be what the advantageous effect is that of reducing to be conveyed methane (CH 4) to the coal on admission of C0 2 binding, so that the relied on for pressurizing C0 2 gas also acts as a subsidy.
- CH 4 methane
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
- Artificial Fish Reefs (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
According to the inventive method for the in-situ extraction of gas from coal seams, the gas extraction rate should be increased. To this end, the invention provides that a pressurization of the borehole which is effective over a prolonged period of time is employed in order to open up the coal. The pressure is lower than the lowest amount of principal stress determined in the respective seam horizon from which gas is to be extracted. The pressurization of the borehole is carried out using a cyclically fluctuating pressure during the opening-up time period.
Description
Verfahren zur m-Situ-Forderung von Gas aus Kohleflozen Process for m-situ gas demand from coal beds
B e s c h r e i b u n gDescription
Die Erfindung betrifft ein Verfahren zur m-Situ-Forderung von Gas aus Kohleflozen, wobei zur Schaffung von Fließwegen in der Kohle die Struktur der gashaltigen Kohle mittels unter Druck m ein m das Kohlefloz niedergebrachtes Bohrloch eingebrachten Gasen und/oder Flüssigkeiten aufgeschlossen und anschließend für die Gasforderung ein kleiner als der jeweilige Desorptionsdruck bemessener Druck an der Bohrung angelegt wird.The invention relates to a method for the m-situ demand of gas from coal beds, the structure of the gas-containing coal being broken down by means of gases and / or liquids introduced into the coal bed by means of pressurized gases and / or liquids and then for the flow paths in the coal Gas demand a pressure smaller than the respective desorption pressure is applied to the bore.
Die Gewmnungsmoglichkeit von m Kohleflozen anstehendem Methan aus bergmannisch nicht aufgeschlossenen Flozhoπzonten mittels einer m-Situ-Forderung aus m das betreffende Kohlefloz niedergebrachten Bohrlochern wird bestimmt durch die Parameter Gasinhalt, Permeabilität und
Porosität der Kohle sowie durch den im einzelnen vom Gasinhalt der Kohle abhängigen Desorptionsdruck des Methans. Zur Förderung des Methans hat man im Rahmen von bisher bekannten Verfahren Stimulationstechniken angewendet, die aus der Erdölförderung an sich bekannt sind, indem das in das zur Gasförderung herangezogene Kohleflöz niedergebrachte Bohrloch kurzzeitig, d. h. über einen Zeitraum von weniger als einer Stunde bis zu wenigen Stunden, mittels Injektion von Wasser oder eines geeigneten Gases unter einen gleichmäßig hohen Druck, beispielsweise von 300 bis 350 bar, gesetzt wird.The possibility of extracting methane from m coal seams from mined coal mines by means of an m-situ demand from m the borehole in question is determined by the parameters gas content, permeability and Porosity of the coal as well as the desorption pressure of methane, which depends on the gas content of the coal. For the extraction of methane, stimulation techniques have been used within the framework of previously known methods which are known per se from oil production, in that the borehole drilled into the coal seam used for the production of gas is brief, that is to say over a period of less than one hour to a few hours, by means of injection of water or a suitable gas under a uniformly high pressure, for example from 300 to 350 bar.
Diese Druckbeaufschlagung führt zur Ausbildung eines sogenannten Fracs, mittels dessen die Makrostruktur der Kohle an ihren natürlichen mechanischen Schwachstellen wie Schlechten, Klüfte etc. aufgebrochen wird. Die Druckbeaufschlagung geschieht unter gleichzeitiger Einbringung eines geeigneten Materials, wie beispielsweise eines rolligen Sandes, mittels dessen die aufgeschlossene Makrostruktur offengehalten und gleichzeitig ein Gasströmungsweg entlang der aufgebrochenen mechanischen Schwachstellen hergestellt wird. Mit dem bekannten Verfahren wird insoweit lediglich die Zutrittsfläche in das Förderbohrloch vergrößert.This pressurization leads to the formation of a so-called fracture, by means of which the macrostructure of the coal is broken up at its natural mechanical weak points such as bad, fissures, etc. The pressurization takes place with the simultaneous introduction of a suitable material, such as, for example, a rolling sand, by means of which the open macrostructure is kept open and at the same time a gas flow path is established along the broken mechanical weak points. In this respect, the known method merely increases the access area into the production borehole.
Mit dem bekannten Stimulationsverfahren ist der Nachteil verbunden, daß damit in Kohleflözen mit einer geringen Permeabilität nur dann befriedigende Gasförderraten erzielbar sind, wenn die Kohle hochgesättigt an Methan ist und demzufolge der Desorptionsdruck relativ nahe an dem Beaufschlagungsdruck liegt. Ist eine geringpermeable Kohle
dagegen untersattigt, so ergibt sich ausgehend von dem jeweils eingebrachten Frac nur eine geringe Eindringtiefe des bei Absenkung des Drucks für die Gasforderung sich einstellenden Drucktrichters. Der unterhalb des Desorptionsdrucks am Bohrloch einzustellende Forderdruck wirkt daher nur auf ein vergleichsweise kleines Kohlevolumen, nämlich dasjenige, welches unmittelbar senkrecht zum jeweiligen Frac ansteht. Damit beeinflußt die bekannte Stimulationstechnik nur vergleichsweise geringe Flozabschnitte; es findet zumindest kurzfristig keine volumetπsche Flozbeemflussung statt, und die Wanderungsgeschwindigkeit der Druckabsenkung im Flöz beim Forderbetrieb ist zu gering.The known stimulation method has the disadvantage that it is only possible to achieve satisfactory gas production rates in coal seams with a low permeability if the coal is highly saturated with methane and the desorption pressure is consequently relatively close to the application pressure. Is a low permeable coal on the other hand, if the frac introduced in each case results in only a small depth of penetration of the pressure funnel which arises when the pressure is reduced for the gas demand. The supply pressure to be set below the desorption pressure at the borehole therefore only acts on a comparatively small coal volume, namely that which is directly perpendicular to the respective fracture. The known stimulation technique thus only influences comparatively small floz sections; there is no volumetric flux influence, at least for a short time, and the rate of migration of the pressure drop in the seam during operation is too low.
Infolgedessen ist bei einer geringen Permeabilität und einem geringen Desorptionsdruck der zur Gasforderung herangezogenen Kohle der zur Unterschreitung des Desorptionsdruckes m einem wirtschaftlich interessanten Kohlevolumen benotigte Zeitraum entsprechend lang; die erzielbaren Gasforderraten können dann so gering sein, daß eine wirtschaftliche Gasforderung nicht gegeben ist.As a result, with a low permeability and a low desorption pressure of the coal used for the gas demand, the period of time required to fall below the desorption pressure m is an economically interesting coal volume; the achievable gas demand rates can then be so low that there is no economical gas demand.
Der Erfindung liegt daher die Aufgabe zugrunde, ein Verfahren der eingangs genannten Art anzugeben, mittels dessen die Gasforderrate gesteigert werden kann.The invention is therefore based on the object of specifying a method of the type mentioned at the outset by means of which the gas demand rate can be increased.
Die Losung dieser Aufgabe ergibt sich einschließlich vorteilhafter Ausgestaltungen und Weiterbildungen der Erfindung aus dem Inhalt der Patentansprüche, welche dieser Beschreibung nachgestellt sind.
Die Erfindung sieht in ihrem Grundgedanken vor, daß zum Aufschluß der Kohle eine über einen längeren Zeitraum wirksame Beaufschlagung des Bohrloches mit einem Druck eingestellt wird, der kleiner als die kleinste in dem jeweiligen zur Gasförderung herangezogenen Flözhorizont ermittelte Hauptspannung ist, wobei die Beaufschlagung des Bohrloches während des AufSchlußzeitraumes mit einem zyklisch wechselnden Druck erfolgt.The solution to this problem arises, including advantageous refinements and developments of the invention, from the content of the claims, which follow this description. The basic idea of the invention is that for the exploration of the coal, a pressure is applied to the borehole which is effective over a longer period of time and which is less than the smallest main stress determined in the respective seam horizon used for gas production, the loading of the borehole during of the digestion period with a cyclically changing pressure.
Mit der Erfindung ist der Vorteil verbunden, daß die Beaufschlagung des zur Gasförderung heranzuziehenden Kohleflözes mit einem Druck, der kleiner als die kleinste in dem entsprechenden Flöz ermittelte Hauptspannung ist, das in der Kohle vorhandene komplexe Rißsystem im Porenbereich von Makroporen bis hin zu Mikroporenstrukturen öffnet, ohne daß sich neue Risse im Bereich der Makrostruktur öffnen oder öffnen müßten. Im Anschluß an das Aufbrechen der Porenstruktur gehen die Mikrorisse nicht wieder in ihre dichte Ausgangslage zurück, da durch die länger andauernde Druckbeaufschlagung mit einem im Bereich der Hauptspannung liegenden Druck eine geringe Disloziierung der Mikrorißflachen gegeneinander und wegen der damit verbundenen Ablösung von Feinstpartikelchen ein bleibender Spalt auf der jeweiligen Rißfläche erzeugt wird, so daß in vorteilhafter Weise auch auf den Einsatz von Stützmitteln wie Sanden etc. verzichtet werden kann.The invention is associated with the advantage that the application of pressure to the coal seam to be used for gas production that is less than the smallest main stress determined in the corresponding seam opens the complex crack system in the pore area from macropores to microporous structures, without opening or opening new cracks in the area of the macro structure. After the pore structure has been broken open, the microcracks do not return to their dense starting position, since the prolonged pressurization with a pressure in the region of the main stress means that there is little dislocation of the microcrack surfaces and, because of the associated detachment of fine particles, a permanent gap of the respective crack surface is generated, so that the use of proppants such as sands etc. can advantageously be dispensed with.
Die Öffnung des Rißsystems im Porenbereich wird weiterhin dadurch unterstützt, daß erfindungsgemäß die Beaufschlagung
des Bohrlochs während des AufSchlußzeitraumes mit einem zyklisch wechselnden Druck erfolgt, so daß es hierdurch zu einer Art Atmung im Porenbereich der aufzuschließenden Kohle kommt, weshalb sich einmal geöffnete Porenstrukturen nicht wieder schließen können. Hierdurch werden auch die Verschiebung der Mikrorißflachen gegeneinander und der Transport von abgelösten Feinstpartikelchen innerhalb der geöffneten Mikroporenstrukturen unterstützt.The opening of the crack system in the pore area is further supported by the fact that the application according to the invention the borehole takes place during the digestion period with a cyclically changing pressure, so that this leads to a kind of breathing in the pore area of the coal to be digested, which is why once opened pore structures cannot close again. This also supports the displacement of the microcrack surfaces against each other and the transport of detached fine particles within the opened microporous structures.
Somit wird mit dem erfindungsgemäßen Verfahren die Permeabilität der Kohle dauerhaft und über einen größeren Flächenbereich erhöht, ohne daß beim anschließenden Förderbetrieb ein größeres Kohlevolumen auf ein Druckniveau unterhalb des Desorptionsdruckes gepumpt werden müßte, so daß dieses größere Kohlevolumen mit der durch die erfindungsgemäße Maßnahme erhöhten Permeabilität für eine Gasförderung zur Verfügung steht.Thus, with the method according to the invention, the permeability of the coal is increased permanently and over a larger surface area without a larger coal volume having to be pumped to a pressure level below the desorption pressure during the subsequent conveying operation, so that this larger coal volume with the permeability increased by the measure according to the invention gas production is available.
Im einzelnen wird zur Bestimmung des im Einzelfall einzustellenden Druckes die in dem für die Gasförderung heranzuziehenden Kohleflöz herrschende niedrigste Hauptspannung gemessen, und es wird der Beaufschlagungsdruck niedriger als die ermittelte Hauptspannung eingestellt; die Druckbeaufschlagung erstreckt sich über einen längeren Zeitraum, der mit einem Tag bis mehreren Tagen oder Wochen angegeben werden kann. Diese lang andauernde Druckbeaufschlagung mit dem auf die gegebene Hauptspannung ausgelegten Druck führt zum erwünschten Aufschluß der Porenstruktur der Kohle, ohne daß sich Veränderungen in dem mechanischen Gefüge des Kohleflözes einstellen.
Nach einem Ausführungsbeispiel der Erfindung kann vorgesehen sein, daß während des AufSchlußzeitraumes Perioden der Druckbeaufschlagung des Bohrloches und Perioden der Gasförderung zyklisch wechseln.In particular, the lowest main stress prevailing in the coal seam to be used for gas production is measured in order to determine the pressure to be set in the individual case, and the application pressure is set lower than the main stress determined; the pressure is applied over a longer period of time, which can be specified as one day to several days or weeks. This long-lasting pressurization with the pressure designed for the given main stress leads to the desired disintegration of the pore structure of the coal without changes in the mechanical structure of the coal seam. According to one embodiment of the invention, it can be provided that periods of pressurization of the borehole and periods of gas production alternate cyclically during the disintegration period.
Nach Ausführungsbeispielen der Erfindung kann die Druckbeaufschiagung des Bohrloches mittels Einpressen von Wasser oder von Gas ausgeübt werden. Soweit Wasser für die Druckbeaufschlagung des Bohrloches herangezogen wird, kann auch in der Lagerstätte anstehendes Lagerstättenwasser in das Bohrloch eingepreßt bzw. durch zyklisch aufgebrachten Druck die Atmung der Porenstruktur über die Druckanregung des Lagerstättenwassers erzeugt werden. In gleicher Weise kann nach einem Ausführungsbeispiel der Erfindung das dem Bohrloch zuströmende und zu fördernde Gas für die Druckbeaufschlagung des Bohrloches in dieses rückgepreßt werden; alternativ kann auch das Einpressen von C02 vorgesehen sein, was die vorteilhafte Wirkung hat, daß bei Zutritt von C02 die Bindung des zu fördernden Methans (CH4) an die Kohle verringert wird, so daß das für die Druckbeaufschlagung herangezogene C02-Gas gleichzeitig als Förderhilfe wirkt.According to embodiments of the invention, the pressure can be applied to the borehole by injecting water or gas. Insofar as water is used to pressurize the borehole, reservoir water present in the deposit can also be pressed into the borehole or the pore structure breathing can be generated by cyclically applied pressure via the pressure excitation of the reservoir water. In the same way, according to one exemplary embodiment of the invention, the gas flowing to the borehole and to be conveyed can be pressed back into the borehole for pressurizing it; alternatively the injection of C0 2 is provided may be what the advantageous effect is that of reducing to be conveyed methane (CH 4) to the coal on admission of C0 2 binding, so that the relied on for pressurizing C0 2 gas also acts as a subsidy.
Die in der vorstehenden Beschreibung, den Patentansprüchen und der Zusammenfassung offenbarten Merkmale des Gegenstandes dieser Unterlagen können einzeln als auch in beliebigen Kombinationen untereinander für die Verwirklichung der Erfindung in ihren verschiedenen Ausführungsformen wesentlich sein.
The features of the subject matter of these documents disclosed in the above description, the patent claims and the abstract can be essential individually or in any combination with one another for realizing the invention in its various embodiments.
Claims
P a t e n t a n s p r ü c h e P a t e n t a n s r u c h e
Verfahren zur in-Situ-Förderung von Gas aus Kohleflözen, wobei zur Schaffung von Fließwegen in der Kohle die Struktur der gashaltigen Kohle mittels unter Druck in ein in das Kohleflöz niedergebrachtes Bohrloch eingebrachten Gasen und/oder Flüssigkeiten aufgeschlossen und anschließend für die Gasförderung ein kleiner als der jeweilige Desorptionsdruck bemessener Druck an der Bohrung angelegt wird, dadurch gekennzeichnet, daß zum Aufschluß der Kohle eine über einen längeren Zeitraum wirksame Beaufschlagung des Bohrloches mit einem Druck eingestellt wird, der kleiner als die kleinste in dem jeweiligen zur Gasförderung herangezogenen Flözhorizont ermittelte
Hauptspannung ist, wobei die Beaufschlagung des Bohrloches während des AufSchlußzeitraumes mit einem zyklisch wechselnden Druck erfolgt.Process for the in-situ production of gas from coal seams, whereby to create flow paths in the coal, the structure of the gas-containing coal is digested by means of gases and / or liquids brought into the borehole under pressure and then a smaller than for the gas production the respective desorption pressure is applied to the borehole, characterized in that for the exploration of the coal an effective exposure to the borehole over a longer period of time is set at a pressure which is smaller than the smallest determined in the respective seam horizon used for gas production The main stress is, whereby the borehole is exposed to a cyclically changing pressure during the digestion period.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß während des AufSchlußzeitraumes Perioden der Druckbeaufschlagung des Bohrloches und Perioden der Gasförderung zyklisch wechseln.2. The method according to claim 1, characterized in that periods of pressurization of the borehole and periods of gas production alternate cyclically during the digestion period.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Druckbeaufschlagung des Bohrloches mittels Einpressen von Wasser ausgeübt wird.3. The method according to claim 1 or 2, characterized in that the pressurization of the borehole is applied by pressing water.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß als Wasser in der Lagerstätte anstehendes Lagerstättenwasser eingepreßt wird.4. The method according to claim 3, characterized in that pending deposit water is injected as water in the deposit.
5. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Druckbeaufschlagung des Bohrloches mittels Einpressen von Gas ausgeübt wird.5. The method according to claim 1 or 2, characterized in that the pressurization of the borehole is exerted by injecting gas.
6. Verfahren nach Anspruch 5, dadurch gekennzeichnet, daß das dem Bohrloch zuströmende und zu fördernde Gas für die Druckbeaufschlagung des Bohrloches benutzt und in das Bohrloch rückgepreßt wird.6. The method according to claim 5, characterized in that the gas flowing to the well and to be promoted gas is used for pressurizing the well and is pressed back into the well.
7. Verfahren nach Anspruch 5, dadurch gekennzeichnet, daß als Gas C02 in das Bohrloch eingepreßt wird.
7. The method according to claim 5, characterized in that the gas C0 2 is pressed into the borehole.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19839866A DE19839866A1 (en) | 1998-09-02 | 1998-09-02 | Process for in-situ production of gas from coal beds |
| DE19839866 | 1998-09-02 | ||
| PCT/DE1999/002693 WO2000014379A1 (en) | 1998-09-02 | 1999-08-27 | Method for the in-situ extraction of gas from coal seams |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP1112437A1 true EP1112437A1 (en) | 2001-07-04 |
| EP1112437B1 EP1112437B1 (en) | 2003-07-23 |
Family
ID=7879472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP99953624A Expired - Lifetime EP1112437B1 (en) | 1998-09-02 | 1999-08-27 | Method for the in-situ extraction of gas from coal seams |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US6571874B1 (en) |
| EP (1) | EP1112437B1 (en) |
| CN (1) | CN1097136C (en) |
| DE (2) | DE19839866A1 (en) |
| ES (1) | ES2204166T3 (en) |
| PL (1) | PL346410A1 (en) |
| RU (1) | RU2206718C2 (en) |
| WO (1) | WO2000014379A1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10159311B4 (en) * | 2001-08-03 | 2007-02-01 | Wolfgang Herr | In-situ evaporation |
| US6877566B2 (en) * | 2002-07-24 | 2005-04-12 | Richard Selinger | Method and apparatus for causing pressure variations in a wellbore |
| US20050082058A1 (en) * | 2003-09-23 | 2005-04-21 | Bustin Robert M. | Method for enhancing methane production from coal seams |
| AU2006279679B2 (en) * | 2005-08-12 | 2011-08-04 | University Of Wyoming Research Corporation D/B/A Western Research Institute | Biogenic methane production enhancement systems |
| US8256282B2 (en) * | 2007-07-19 | 2012-09-04 | Schlumberger Technology Corporation | In situ determination of critical desorption pressures |
| CN104342459A (en) | 2008-07-02 | 2015-02-11 | 西里斯能源公司 | Method For Optimizing In-Situ Bioconversion of Carbon-Bearing Formations |
| CN101539008B (en) * | 2009-04-14 | 2012-04-04 | 赵万福 | Ground stereoscopic discharge and mining method of coal bed methane |
| AU2010332294C1 (en) | 2009-12-18 | 2015-06-18 | Ciris Energy, Inc. | Biogasification of coal to methane and other useful products |
| WO2013005082A1 (en) * | 2011-07-07 | 2013-01-10 | Seeden Foundation | Device and method for enhancing oil production by generating shock waves |
| CN103670338B (en) * | 2012-09-21 | 2016-06-15 | 新奥气化采煤有限公司 | A kind of coal bed gas and coal mining method altogether |
| RU2524583C1 (en) * | 2013-03-25 | 2014-07-27 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Национальный минерально-сырьевой университет "Горный" | Intensification of natural gas extraction from coal seams via wells |
| RU2625829C2 (en) * | 2015-12-30 | 2017-07-19 | Федеральное государственное бюджетное учреждение науки Институт проблем нефти и газа Российской академии наук (ИПНГ РАН) | Method of hydrocarbons deposit develompent in low-permeability sediments |
| CN109026128A (en) * | 2018-06-22 | 2018-12-18 | 中国矿业大学 | Multistage combustion shock wave fracturing coal body and heat injection alternation strengthen gas pumping method |
| CN115163021B (en) * | 2022-07-13 | 2023-11-03 | 中国矿业大学 | Water injection and nitrogen injection gas extraction hole sealing device and drilling arrangement method |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3794116A (en) * | 1972-05-30 | 1974-02-26 | Atomic Energy Commission | Situ coal bed gasification |
| US5014788A (en) * | 1990-04-20 | 1991-05-14 | Amoco Corporation | Method of increasing the permeability of a coal seam |
| US5566755A (en) * | 1993-11-03 | 1996-10-22 | Amoco Corporation | Method for recovering methane from a solid carbonaceous subterranean formation |
| US5388640A (en) * | 1993-11-03 | 1995-02-14 | Amoco Corporation | Method for producing methane-containing gaseous mixtures |
| US5388643A (en) * | 1993-11-03 | 1995-02-14 | Amoco Corporation | Coalbed methane recovery using pressure swing adsorption separation |
| US5411098A (en) * | 1993-11-09 | 1995-05-02 | Atlantic Richfield Company | Method of stimulating gas-producing wells |
| US5419396A (en) * | 1993-12-29 | 1995-05-30 | Amoco Corporation | Method for stimulating a coal seam to enhance the recovery of methane from the coal seam |
| US6412559B1 (en) * | 2000-11-24 | 2002-07-02 | Alberta Research Council Inc. | Process for recovering methane and/or sequestering fluids |
-
1998
- 1998-09-02 DE DE19839866A patent/DE19839866A1/en not_active Withdrawn
-
1999
- 1999-08-27 US US09/786,488 patent/US6571874B1/en not_active Expired - Fee Related
- 1999-08-27 EP EP99953624A patent/EP1112437B1/en not_active Expired - Lifetime
- 1999-08-27 RU RU2001108537/03A patent/RU2206718C2/en not_active IP Right Cessation
- 1999-08-27 WO PCT/DE1999/002693 patent/WO2000014379A1/en active IP Right Grant
- 1999-08-27 PL PL99346410A patent/PL346410A1/en unknown
- 1999-08-27 ES ES99953624T patent/ES2204166T3/en not_active Expired - Lifetime
- 1999-08-27 DE DE59906375T patent/DE59906375D1/en not_active Expired - Lifetime
- 1999-08-27 CN CN99810233A patent/CN1097136C/en not_active Expired - Fee Related
Non-Patent Citations (1)
| Title |
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| See references of WO0014379A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| RU2206718C2 (en) | 2003-06-20 |
| US6571874B1 (en) | 2003-06-03 |
| PL346410A1 (en) | 2002-02-11 |
| WO2000014379A1 (en) | 2000-03-16 |
| CN1097136C (en) | 2002-12-25 |
| DE59906375D1 (en) | 2003-08-28 |
| EP1112437B1 (en) | 2003-07-23 |
| ES2204166T3 (en) | 2004-04-16 |
| DE19839866A1 (en) | 2000-03-09 |
| CN1320189A (en) | 2001-10-31 |
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