An assessment of groundwater inflow into a proposed shaft and drift in the warwickshire coalfield using packer test data in an electrical analogue model

Abstract

The assessment was carried out in multilayered permeability ground using packer testing techniques to ascertain permeability. Borehole instability occurred through using water as a drilling fluid in the variable lithologies. This resulted in some difficulty in obtaining good packer seating with foundation engineering equipment. Oil industry drill stem test strings proved more effective. Reliable permeabilities were, however, eventually obtained and a permeability assessment was carried out using various weighting techniques to provide a complete vertical distribution on which analogue models of potential inflows were based. The analogue models allowed a detailed investigation of the flow patterns around both the proposed shaft and drift. Very high inflows were predicted at certain depths and therefore neither the shaft nor the drift were constructed.