TY - JOUR
T1 - Interference Analysis of Methane Co-Production from Two Coal Seams in Southern Qinshui Basin
AU - Quan, Fangkai
AU - Wei, Chongtao
AU - Hao, Shuqing
AU - Ma, Jingsheng
AU - Song, Yu
AU - Lian, Da
N1 - Funding Information:
This research was sponsored by the Natural Science Foundation of Jiangsu Province (Grant No. BK20200663), Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education (China University of Mining and Technology) (No. 2020-009), the Fundamental Research Funds for the Central Universities (No. 2020ZDPYZD03), and Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). We also appreciate the support given by China Scholarship Council for study abroad.
Publisher Copyright:
© 2022, International Association for Mathematical Geosciences.
PY - 2022/6
Y1 - 2022/6
N2 - Gas co-production has been touted to be a cost-effective way to increase the recoverable coal-bed methane (CBM) resource in multiple coal seams. However, co-production in the southern Qinshui Basin has met with disappointing results due to interlayer interference. In this study, a reservoir model was established around one co-production well with high water production and low gas production; with respect to seven reservoir parameters, the interferences were analyzed quantitatively. The results show that, for a given aquifer communicated with the lower reservoir, it can not only restrain the output of water from itself but it can also reduce the effective water production from the upper reservoir, and thus, reservoir pressure cannot be reduced in both layers effectively. Moreover, the interference intensity, which is triggered by discrepancies in reservoir parameters between the two CBM systems, varies from strong to weak and is due to reservoir pressure, aquifer thickness and permeability, coal seam thickness, fracturing permeability, in situ permeability, and gas content. Finally, when progressive drainage from either layer is considered, drainage from the lower seam first is more advantageous than the other; besides, the placement of co-production well in the well-pattern was verified to be an effective approach to improve gas recovery. This study can provide a reference for the development of CBM resources in the study area and as basis for the theoretical study of gas co-production from coal measures.
AB - Gas co-production has been touted to be a cost-effective way to increase the recoverable coal-bed methane (CBM) resource in multiple coal seams. However, co-production in the southern Qinshui Basin has met with disappointing results due to interlayer interference. In this study, a reservoir model was established around one co-production well with high water production and low gas production; with respect to seven reservoir parameters, the interferences were analyzed quantitatively. The results show that, for a given aquifer communicated with the lower reservoir, it can not only restrain the output of water from itself but it can also reduce the effective water production from the upper reservoir, and thus, reservoir pressure cannot be reduced in both layers effectively. Moreover, the interference intensity, which is triggered by discrepancies in reservoir parameters between the two CBM systems, varies from strong to weak and is due to reservoir pressure, aquifer thickness and permeability, coal seam thickness, fracturing permeability, in situ permeability, and gas content. Finally, when progressive drainage from either layer is considered, drainage from the lower seam first is more advantageous than the other; besides, the placement of co-production well in the well-pattern was verified to be an effective approach to improve gas recovery. This study can provide a reference for the development of CBM resources in the study area and as basis for the theoretical study of gas co-production from coal measures.
KW - Co-production
KW - Coalbed methane
KW - Interlayer interference
KW - Multiple coal seams
KW - Reservoir parameter discrepancy rate
UR - http://www.scopus.com/inward/record.url?scp=85127298534&partnerID=8YFLogxK
U2 - 10.1007/s11053-022-10043-w
DO - 10.1007/s11053-022-10043-w
M3 - Article
AN - SCOPUS:85127298534
SN - 1520-7439
VL - 31
SP - 1475
EP - 1502
JO - Natural Resources Research
JF - Natural Resources Research
IS - 3
ER -