Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 AGH Drilling, Oil, Gas

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: intake well

Sortuj według:

Ogranicz wyniki do:

Many years’ extraction of groundwater in the context of established usable groundwater reserves

Macuda J., Styrkowiec E.

AGH Drilling, Oil, Gas

2017

Vol. 34, no. 2

419--427

The operation of water supply networks basically relies on the ability of supply water, which in the case of groundwater intakes, is defined by usable reserves offered by the wells involved. Their establishing is the last stage of an investment, i.e. building of groundwater intakes, and their value determines the type of infrastructure and technological hardware in the wells. Owing to the fact that the usable groundwater reserves are conditioned by a number of factors (economic, technological, environmental) their correct determining depends on the correct definition of the number and quality of measurements and hydrogeological observations. In practice, these measurements tend to be shortened to minimum (test pumping) or discarded (diagnostics of well construction) for financial reasons. As a result the user obtains either over- or underestimated information about the intake parameters. Exploitation of a well with overestimated capacity brings about serious technological and economic consequences, starting from the lowered productivity (drop of water table, lower yield), change of chemical composition of water, sanding up of the well as well as well failures and damage. The use of a well with underrated output does not shorten the life of the well, though is disadvantageous for the economic reasons. The productivity of wells can be verified after a few years of controlled extraction, on the basis of which the cost of water extraction, stability of chemical composition or impact on other intakes in given work conditions. Accordingly, this is a basis for updating usable groundwater reserves of the wells. Moreover, after many years of observation of groundwater intakes, one can formulate recommendations warrantying long life of wells, rational management of pump aggregates and well renovation plans.

Drilling large diameter intake wells with cutter bits in loose and weakly consolidated rocks

Macuda J., Macuda M.

AGH Drilling, Oil, Gas

2016

Vol. 33, no. 1

23--30

Most of the useful aquifers in Poland occur in the Quaternary and Tertiary horizons, which are deposited at a depth of tens to hundreds of meters. Owing to the need of providing large quantities of water for municipal and industrial purposes, the aquifers are more and more frequently opened with large diameter wells of various designs. Such wells are mostly drilled with the rotary method with reverse mud circulation with the use of various bits. The Quaternary and Tertiary strata abound in loose and weakly consolidated rocks therefore cutter bits are predominantly used. They allow for high rates of drilling and shorter time of drilling of the well. This significantly influences the negative influence of drilling mud on the near screen zone of the aquifer and better hydraulic properties of the well. Drillability tests were performed with cutter bits of 0.86 and 0.67 m diameter for providing high rates of drilling of large diameter intake wells in loose and weakly consolidated rocks. The research was made for measurement sections 0.5 to 1.0 m long, and each of them was drilled at con- stant rotational velocity and axial weight on bit. Prior to the drillability tests the limitation of weight on bit and rotational velocity of bit imposed by the technical characteristic of Prakla B50 rig, strength of the string and butter bit were established. Various regression models were analyzed for the sake of finding a dependence between drilling rate and axial weight on bit and rotational velocity of bit for particular macroscopically homogeneous layers. The best results were obtained for the exponent model illustrating the influence of axial weight on bit and rotational velocity of bit on the drilling rate, which has been proved by the calculated regression coefficients and statistical parameters.