Abstract
In order to determine a reasonable sealing depth for seam gas drainage boreholes, an innovative method is proposed to study the geological conditions in the coal seam by monitoring the response of the drift while drilling the boreholes. Based on the investigation of the in-situ tests on the drift, we found that the idle pressure of the hydraulic motor, which features a rapid increase at the depth of approximately 14 to 16 m from the roadway wall, appeared to be suitable for characterizing the coal mass condition. Then, a numerical simulation was performed to investigate the reason for the response of the idle pressure. It reveals that high stress and gas pressure are the main factors accounting for the rapid increase of the idle pressure. Accordingly, the rapid increase of idle pressure becomes an indication for high stress and gas pressure. Next, for determining the sealing depth, the gas drainage process with different sealing depths was studied via numerical simulation, and a simplified theoretical analysis was conducted to comprehend the flow of air from the roadway to the borehole. The analysis reveals that the reasonable sealing depth should be several meters larger than the stress concentration area, which is indicated in practice by the idle pressure. Then, a sealing depth of 16 to 18 m is determined for the III1011 mining face in the Haizi coal mine. This research provide a real-time method to determine the sealing depth for in-seam boreholes.
| Original language | English |
|---|---|
| Pages (from-to) | 115-123 |
| Number of pages | 9 |
| Journal | Engineering Geology |
| Volume | 210 |
| DOIs | |
| Publication status | Published - 5 Aug 2016 |
Keywords
- Cross-measure borehole
- Gas drainage simulation
- In-seam borehole
- Sealing depth
- Seam gas drainage
Cite this
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Determination of sealing depth of in-seam boreholes for seam gas drainage based on drilling process of a drifter. / Zhang, Kai; Sun, Kai; Yu, Bangyong; Gamage, Ranjith Pathegama.
In: Engineering Geology, Vol. 210, 05.08.2016, p. 115-123.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Determination of sealing depth of in-seam boreholes for seam gas drainage based on drilling process of a drifter
AU - Zhang, Kai
AU - Sun, Kai
AU - Yu, Bangyong
AU - Gamage, Ranjith Pathegama
PY - 2016/8/5
Y1 - 2016/8/5
N2 - In order to determine a reasonable sealing depth for seam gas drainage boreholes, an innovative method is proposed to study the geological conditions in the coal seam by monitoring the response of the drift while drilling the boreholes. Based on the investigation of the in-situ tests on the drift, we found that the idle pressure of the hydraulic motor, which features a rapid increase at the depth of approximately 14 to 16 m from the roadway wall, appeared to be suitable for characterizing the coal mass condition. Then, a numerical simulation was performed to investigate the reason for the response of the idle pressure. It reveals that high stress and gas pressure are the main factors accounting for the rapid increase of the idle pressure. Accordingly, the rapid increase of idle pressure becomes an indication for high stress and gas pressure. Next, for determining the sealing depth, the gas drainage process with different sealing depths was studied via numerical simulation, and a simplified theoretical analysis was conducted to comprehend the flow of air from the roadway to the borehole. The analysis reveals that the reasonable sealing depth should be several meters larger than the stress concentration area, which is indicated in practice by the idle pressure. Then, a sealing depth of 16 to 18 m is determined for the III1011 mining face in the Haizi coal mine. This research provide a real-time method to determine the sealing depth for in-seam boreholes.
AB - In order to determine a reasonable sealing depth for seam gas drainage boreholes, an innovative method is proposed to study the geological conditions in the coal seam by monitoring the response of the drift while drilling the boreholes. Based on the investigation of the in-situ tests on the drift, we found that the idle pressure of the hydraulic motor, which features a rapid increase at the depth of approximately 14 to 16 m from the roadway wall, appeared to be suitable for characterizing the coal mass condition. Then, a numerical simulation was performed to investigate the reason for the response of the idle pressure. It reveals that high stress and gas pressure are the main factors accounting for the rapid increase of the idle pressure. Accordingly, the rapid increase of idle pressure becomes an indication for high stress and gas pressure. Next, for determining the sealing depth, the gas drainage process with different sealing depths was studied via numerical simulation, and a simplified theoretical analysis was conducted to comprehend the flow of air from the roadway to the borehole. The analysis reveals that the reasonable sealing depth should be several meters larger than the stress concentration area, which is indicated in practice by the idle pressure. Then, a sealing depth of 16 to 18 m is determined for the III1011 mining face in the Haizi coal mine. This research provide a real-time method to determine the sealing depth for in-seam boreholes.
KW - Cross-measure borehole
KW - Gas drainage simulation
KW - In-seam borehole
KW - Sealing depth
KW - Seam gas drainage
UR - http://www.scopus.com/inward/record.url?scp=84975480561&partnerID=8YFLogxK
U2 - 10.1016/j.enggeo.2016.06.006
DO - 10.1016/j.enggeo.2016.06.006
M3 - Article
AN - SCOPUS:84975480561
VL - 210
SP - 115
EP - 123
JO - Engineering Geology
JF - Engineering Geology
SN - 0013-7952
ER -