Offshore drilled cuttings management

• Autorzy: Bilstad T. , Stenberg E. S. , Jensen B. , Larsen T. , Toft M.
• Języki publikacji: EN

Abstrakty

EN

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.

Słowa kluczowe

EN

drilling; fluids; muds; cuttings; cleaning; TCC; reuse; disposal; regulations

PL

wiercenie; płyny; muły; ponowne użycie; regulacje

• Wydawca: AGH University of Science and Technology Press
• Czasopismo: AGH Drilling, Oil, Gas
• Rocznik: 2013
• Tom: Vol. 30, no. 1
• Strony: 47--50
• Opis fizyczny: Bibliogr. 6 poz., tab.

Twórcy

autor

Bilstad T.

• Environmental Engineering, University of Stavanger, 4036 Stavanger, Norway

autor

Stenberg E. S.

• Environmental Engineering, University of Stavanger, 4036 Stavanger, Norway

autor

Jensen B.

• Halliburton, Baroid Surface Solutions, Eldfiskv. 1, 4056 Tananger, Norway

autor

Larsen T.

• Halliburton, Baroid Surface Solutions, Eldfiskv. 1, 4056 Tananger, Norway

autor

Toft M.

• Halliburton, Baroid Surface Solutions, Eldfiskv. 1, 4056 Tananger, Norway

Bibliografia

• [1] Halliburton: Presentation by B. Jensen at MinNovation Seminar at the University of Stavanger, April 26, 2012.
• [2] NIVA, Norwegian Institute for Water Research (2010). PAH-forurensning av sj0bunn - En oversikt over kunnskapsstatus Oslo.
• [3] Paulsen J.E., Omland T.H., Igeltjrrn H., Aas N., Aabye S.S.: Drill cuttings disposal, balancing zero discharge and use of best available technique. SPE/IADC Middle East Drilling Technology Conference & Exhibition. Abu Dhabi: Society of Petroleum Engineers 2003.
• [4] Singsaas I., Garpestad I.E., Skare I., Bakke K., Falcao L., Veiga, Buffagni M., Follum O.A., Johnsen S., Moltu U.E.: Environmental Risk Management System (ERMS) - development of a risk-based environmental management tool for drilling discharges. A Summary paper, 2007.
• [5] Svensen T., Taugbol K.: Drilling Waste Handling in Challenging Offshore Operations. SPE Arctic and Extreme Environments Conference and Exhibition. Moscow, Russia 2011.
• [6] Thermtech (2006). How does a TCC work [Online]. Bergen: Thermtech. Available: http://www.thermtech.no/home/the_tcc/how-does-a-tcc-reg_-work/