The analysis of technology of drilling with roller bits on the Carpathian foreland area in the years 1995-2011.
Mirosław Rzyczniak, Grzegorz Rajchel
Vol. 31, no. 1 (2014), s. 135-146, 
In the article, there has been described results of the statistical analysis lead towards two groups of roller bits, with bit teeth, with diameters 0,216 m and 0,4445 m produced by Drilling Equipment and Device Company "GLINIK". Using these bits, there had been conducted a process of drilling holes on the Carpathian foreland area in the years 1995-2011. According to the analysis of a dispersion of measure points it was assigned linear regression equations and lead significance tests for values of the correlation factors and linear regression factors, drilling technology parameters dependency (weight on bit, rotational speed, product of normalized weight on bit and rotational speed, drilling mud capacity flow rate) and bit performances (rebore, drilling time, average rate of penetration), since the year in which analyzed bits were used. The results of the researches has been showed in the form of charts of dispersion of measure points with lines and regression equations and lines of confidence intervals. The results of significance tests for correlation factors and linear regression factors has been inserted in tables. The purpose of lead analyses were acquiring information about changes of drilling technology parameters in a long period of time and about their influence on bit performances' values.