Abstract
The use of jarring accelerators in drilling assemblies has been technically substantiated for many years.1-6 However, the practical applications and actual effectiveness of drilling jar accelerators are not well documented or transparent. This paper provides a case history comparison of stuck bottom hole assembly situations in eight offset wells of similar geology and the effectiveness of drilling jar accelerators when included in the drilling assembly.
The location of the wells in this comparison is the Mak-Ban geothermal field in the Philippines. While the primary focus of this paper will illustrate the actual effectiveness of the drilling jar accelerator, operational theory and field applications of the tool will also be explained. This paper will document that the use of jarring accelerators in conjunction with drilling jars not only eliminated the number of occurrences per that the drilling assembly could not be jarred free, but also reduced the amount of jarring time required to free a stuck workstring. The analysis data for this paper was obtained directly from documented daily drilling reports and comparisons will be made between those wells drilled without using drilling jar accelerators and those wells drilled using drilling jar accelerators. The two primary comparison measures will be jarring time required on stuck pipe incidents per well and lost-in-hole occurrences per well. Theoretical data comparisons for stuck point displacement, impact and impulse will also be drawn for each stuck situation utilizing the proprietary jarring analysis software package discussed in Wang et al.1
