The search for offshore fossil fuels generates large volumes of drilled cuttings which under certain conditions are defined hazardous, negating disposal at sea. Much of the cuttings end up in onshore landfills. The types of fluids used in well drilling operations determine to which extent the cuttings are considered hazardous. The three main types of fluids are oil based mud (OBM), water based mud (WBM) and synthetic based mud (SBM). The purpose of adding fluids or mud in the drilling operations is to cool and lubricate the drill bit, to stabilize the well bore, to control subsurface pressure, formation pressure, well stability and corrosion, and to carry cuttings to the surface. OBM is based on either diesel or mineral oil. One advantage of OBM is enhanced drilling performance, especially in technical challenging environments. A drawback, however, is the toxicity of OBM, prohibiting discharge of cuttings to the marine environment. Drilled cuttings are rocks produced during drilling operations, becoming coated with drilling fluids. Historically, cuttings have been disposed to sea. However, recent environmental laws and regulations prohibit such practice. Re-injection of cuttings as a slurry into subsurface formations has also been discontinued due to leaks and re-entering of slurry into the bottom waters. Transport of cuttings to shore is therefore the choice. For logistics and cost reasons emphasis is put on offshore waste minimization and reuse/recycle. Total fluid management (TFM) leads to environmental impact reduction (EIR). Minimization of drilling fluids and reuse of fluids lead to cost reduction. Volume of cuttings is reduced through directional drilling and by drilling smaller diameter holes. Synthetic based drilling fluids (SBM) are replacing OBM. Drilling wastes are further separated into a fluid and a solid phase. The solids may be used for road and other construction purposes, whereas the OBM is burned for energy recovery. The purpose of the thermo-mechanical cuttings cleaner (TCC) is to convert hazardous oily cuttings into useful products. TCC facilities are only available onshore in Norway. However, offshore TCC units will in due time be introduced, negating the need for transport of cuttings to shore. Cuttings are allowed disposed to sea when no toxic fluids are attached. TCC separation is accomplished by generating temperatures of 240-300 degrees of Celsius sufficient for evaporation of oil and water from the mineral solids.
Analizując problemy przeróbki surowego urobku węglowego, można stwierdzić, że: - w powszechnie znanych i stosowanych technologiach przygotowania nadawy do wzbogacania brakuje węzła produkcji kruszyw budowlanych ze skały płonnej; - odmulanie nadawy przed wzbogacaniem odbywa się przy ziarnie podziałowym powyżej 0,5 mm; - wzbogacanie w osadzarkach prowadzi się przeważnie dla ziaren powyżej 0,75 mm; - brakuje skutecznych propozycji klasyfikacji i odwadniania mułów w klasie powyżej 0,05 mm. Przedstawione w artykule propozycje optymalizacji pracy układów węgla polegają na: - budowie nowych węzłów odkamieniania urobku węglowego, którego nie można realizować w już istniejących rozwiązaniach; - zastąpieniu zwyczajowego odmulania urobku surowego efektywnym procesem przy ziarnie podziałowym (zdecydowanie większym od dotychczasowego); - wzbogacaniu w osadzarce miałowej prowadzonym dla klas powyżej 0,2 mm; - klasyfikacji i odwadnianiu mułów wzbogaconych w nowatorski sposób przy ziarnach podziałowych powyżej 0,05 mm. W artykule zaprezentowano nowy model technologiczno-maszynowy oraz niekonwencjonalne podejście do procesu przeróbki węgla surowego.
EN
Considering and describing problems of raw coal processing the following conclusions can be reached: - in common known and used technologies of coal feed preparation a technology modules for coal processing of grained building aggregates out of waste rock is not noted, - so far disludging of raw coal feed in a washer jig before processing takes place for grain size exceeding 0,5 mm, - so far processing in a washer jig is carried out for a majority of grain sizes over 0,75 mm, - no effective proposal of classification and sludge dewatering for size over 0,05m are noted. The proposals presented in this article, being a trial of its authors to optimize processing, are based on the following findings: - raw coal quality when considering ash contain is decreasing, processing installations are not modernizing in a proper manner, therefore technology installation improvement requires constriction of new modules for stone removing which can not be carried out as per analogy to the existing solutions, - common used desludging of raw coal has been replaced by effective process applied for grain size much bigger to the existing so far, - processing in a fine jig is carried out for size over 0,2 mm, - classification and dewatering of sludges being processed is carried out in an innovative manner for grain sizes over 0,05 mm. This article presents new model of technology and equipment as well as modern approach to raw coal processing.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.