Discussion. The Present Position of the Pressure-Charged Heavy Oil Machine.

Abstract

During 1982, the cumulative wellfield abstraction from the Jwaneng groundwater supply increased from a little over 1000 M1 to beyond 5000 M1. Regional drawdowns continued significantly less than predicted in the worst case, and the state of resources looked most satisfactory. Some isolated operational problems have been encountered in individual boreholes, relating to pump performance, corrosion and excess drawdown. These are being handled on an ad hoc basis. Dr M. H. de Freitas, Imperial CollegeAlthough the geophysical data appear to have been treated in an analytical way The Authors seem to have been able to do quite a large suite of different types of investigation work in getting towards their answers. Usually a pre-development groundwater investigation is cut back to the bone, and beyond, and it is interesting to see the proportion of the investigation costs compared with the total capital cost. In the figure of $1.85 million quoted for the total cost of the investigation, are the costs of the tritium work and the other research-type investigations included?If not, what effect do they have on the overall cost? 49. Do the Authors think that the proportion of investigation cost to capital c@t is a fair one for the average developing-country groundwater development of this type and size? Also, with the benefit of hindsight, which techniques would they regard as being superfluous? Looking back, at what point would they say that the expenditure would have been at an optimum? Mr G. P. Jones, University College, LondonAs someone who was involved in this work in both the field work and the office work, including the mathematical modelling (in the feasibility stage), I find my