Your assignment is to prepare and submit a paper on ground water well drilling. Whether drilling below or above water table the method is very much suitable. Small volumes of easily contained cuttings are produced. Little or no outside drilling fluids are needed normally and fluids which are used are primarily to facilitate cuttings removal by a bailer or sand pump. Sufficient annular space has to be maintained between the drilling casing and monitoring-well casing to allow effective placement of filter and sealing material. The size of test holes or steel casing around the good casings should be 3 to 5 inches greater in diameter than the monitoring-well casings. 2-inch diameter monitoring well should be installed within 5.5-inch diameter or larger test hole or drilling casing.
Cable tool drilling surpasses all other techniques in detection and isolation of water fluid bearing intervals and ease of development of grilling surface. It helps to easily obtain excellent sediment samples while drilling for water, this helps in testing the site when drilling for obtaining water to check whether the use of water from the site is hygienic or not. The successively smaller casing may be easily telescoped within the previously installed casing to avoid carrying shallow contaminated materials into lower strata units. Cable tool drilling is very useful as the sampling of soil and water during drilling and the installation of monitoring equipment is easily accomplished during cable-tool drilling.
The rigs used in cable tool are very much simple with very few lubricated parts at positions likely to contaminate test hole or monitoring well. There are other cable tool rigs which are dual purpose rigs which can also be used in rotary drilling techniques.
The primary disadvantage of cable-tool drilling is its relatively slow rate of penetration. It varies from 10 ft per day to 45 ft per day depending on the type of strata. .