Determination of Suitable Pillar Size for Protecting Gas Well Drilled Through a Longwall Mining Abutment Pillar Using Nu
- PDF / 2,300,268 Bytes
- 19 Pages / 547.087 x 737.008 pts Page_size
- 13 Downloads / 149 Views
(0123456789().,-volV) ( 01234567 89().,-volV)
ORIGINAL PAPER
Determination of Suitable Pillar Size for Protecting Gas Well Drilled Through a Longwall Mining Abutment Pillar Using Numerical Modelling Approach: A Case Study Bonaventura Alves Mangu Bali . Brijes Mishra
Received: 2 March 2020 / Accepted: 5 September 2020 Ó Springer Nature Switzerland AG 2020
Abstract Gas well drilled through longwall mining abutment pillar could potentially face instability issue due to the strata deformation following longwall panel extraction. Therefore, it is imperative to adequately design the pillar size of a longwall mining in order to ensure the stability of the gas well penetrated longwall mining abutment pillar. In this paper, the determination of suitable pillar size for protecting gas well subjected to longwall mining operation was investigated. Two scenarios of longwall gateroad system including the three and four entry system with varying pillar sizes were assessed using numerical modelling approach. The results of this study indicate that the pillar geometry plays an important role on the vertical gas well stability. In addressing the suitable pillar size for the given case study considering three entry system, the suitable chain pillar and abutment pillar size were found to be 80 ft (24.4 m) wide by 120 ft (36.6 m) length and 104 ft (31.7 m) wide by 120 ft (36.6 m) length rib to rib, respectively. Whereas, if four entry system is used, the suitable chain pillar size is 48 ft (14.6) wide by 120 ft (36.6 m) length and the abutment pillar size is 104 ft (31.7 m) wide by 120 ft (36.6 m) length rib to rib. The proposed numerical modelling procedure presented in this paper can be a viable alternative and applied to other similar projects B. A. M. Bali B. Mishra (&) Department of Mining Engineering, West Virginia University, Morgantown, USA e-mail: [email protected]
in order to determine an optimal pillar size for protecting gas well in longwall mining area. Keywords Gas well stability Pillar size Numerical modelling Longwall mining
1 Introduction Two primary methods for mining the coal deposit are surface and underground mining method. The mentioned methods will be selected based on an extensive techno-economic feasibility study. Underground mining will typically be selected when surface mining is not technically feasible. Among various underground mining methods, longwall mining has been one of the unique underground mining methods in the United States. In longwall mining method, the extraction face of a mine panel is equipped with a row of hydraulic roof supports or shields, a machine to break the coal from the coal panel face or shearer, and an armoured face conveyor to transport the mined coal to the surface (Peng 2008). Longwall mining method is designed to support only the area at the coal panel face and allow caving of the mine roof behind the support system. The roof support system and conveyor automatically advances with the mining. Longwall mining method has been one of the prominent methods us
Data Loading...
