Selected aspects of drilling waste management in Poland

The continuous increase of global demand for energy resources prompts humanity to intensify the onshore and off shore prospecting for petroleum and natural gas. The increased interest in prospecting for and exploration of hydrocarbon deposits from conventional and unconventional sources requires drilling sometimes hundreds of boreholes. Each such activity, no matter the advancement of methods used, leads to environmental degradation. One of such harmful eff ects is the generation of considerable quantities of drilling wastes. The waste materials from borehole drilling consist of crushed rock cuttings from the borehole and remnants of the drilling mud. The function of the mud is to lubricate and cool drill bits, stabilize the borehole, control pressure, and bring cuttings up to the platform. Drilling waste also comprises the spent drilling mud that has lost its technical properties [1]. Drilling waste diff ers in the material it is made of, physicochemical composition and also properties resulting from, e.g. its constituents. Drilling waste generated in the drilling process assumes solid, semi-liquid and liquid forms. Solid waste is basically the cuttings from the whole profi le transported with the mud from the bottom of the well to the surface, where they are separated using vibration sieves and other mud-cleaning equipment. Solid waste is also produced while, e.g. cementing casing pipes in the well. Liquid and semi-liquid wastes are mostly waste drilling muds and, to a lesser degree, working fl uids which are useless upon the completion of a given stage of drilling. Liquid waste also include technological waters mixed with drilling mud [11].