Water borehole ageing monitoring procedure - monitoring set parameters in static and pumping modes to detect deterioration of borehole apparatus

摘要

The procedure, for use on a borehole with a sleeve (5), a strainer (1) in the water-bearing rocks, and a motor/pump unit (6), consists of producing a diagraph in a static mode of the boreholes flow and physical-chemical parameters such as temperature, electrical conductivity, dissolved oxygen content and turbidity, putting the borehole into operation in controlled conditions and monitoring the same parameters, and constructing a new diagraph. The two diagraphs are used to produce a relationship between the depth of the borehole and the measured parameters. The control parameters are measured during pumping, at a fixed flowrate which is close to the operating rate of the borehole, with variations in the parameters indicating borehole ageing, e.g. as a result of corrosion, abnormal circulation, sleeve micro-perforations or a breakdown of cement. ADVANTAGE - More reliable detection of borehole ageing and deterioration.