Approaches for Derivation of Environmental Quality Criteria for Substances Applied in Risk Assessment of Discharges from Offshore Drilling Operations

2008 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Dag Altin ◽  
Tone Karin Frost ◽  
Ingunn Nilssen
Keyword(s):  
Risk Assessment ◽  
Environmental Quality ◽  
Quality Criteria ◽  
Offshore Drilling ◽  
Drilling Operations

A Study on the Main Parameters That Affects the Reliability of Fatigue Failure in a Marine Drilling Riser

2021 ◽  
Author(s):  
Bruno Luiz Barbosa das Chagas ◽  
Celso Kazuyuki Morooka
Keyword(s):  
Fatigue Damage ◽  
Fatigue Failure ◽  
Petroleum Reservoirs ◽  
Offshore Drilling ◽  
Deepwater Drilling ◽  
Sea Bottom ◽  
Reliability Method ◽  
Drilling Operations ◽  
Maritime Operations ◽  
Sea Currents

Abstract Advances in subsea exploration in the oceans to discover new petroleum reservoirs and sometimes different kind of minerals at the seabed in ultra deepwater, continuously introduce new challenges in offshore drilling operations. This motivates the development of increasingly safe maritime operations. In offshore petroleum, a marine drilling riser is the pipe that connects a wellhead at the sea bottom to a drillship at the sea surface, as an access to the wellbore. It serves as a guide for the drilling column with the drill bit and conductor to carry cuttings of rock coming from the wellbore drilling and its construction. Drilling riser is constantly exposed to adversity from the environment, such as waves, sea currents and platform motions induced by waves. These elements of the environment are prevailing factors that can cause a riser failure during deepwater drilling operations with undesirable consequences for the environment. In the present work, key parameters that influence the probability of fatigue failure in a marine drilling riser are identified, and a parametric evaluation with those parameters are carried out. Dynamic behavior of a riser is previously calculated and fatigue damage is estimated. Afterwards, the First Order Reliability Method (FORM) is applied to determine the probability of fatigue failure on the riser. Fundamentals of the procedure are described, and results are illustrated through the analysis for a typical riser in deepwater drilling operation. Parametric evaluations are done observing points considered as critical along the riser length, and looking to the sensitivity of key parameters in the process. For this study, the SN curve from API guidelines is applied and accumulated fatigue damage is estimated from simulations of the stress time series and applying the Palmgren-Miner’s rule. Finally, the influence of each parameter in the reliability of fatigue failure is verified and discussions given.

Periphyton collectors as a tool to measure environmental performance of ocean outlets

2003 ◽  
Vol 47 (7-8) ◽  
pp. 125-131 ◽  
Author(s):  
S. Lemmens
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Environmental Quality ◽  
Coastal Waters ◽  
Quality Criteria ◽  
Carbonate Content ◽  
Total Biomass ◽  
Effective Measure ◽  
North East ◽  
The North

Brown and Root has participated in extensive investigations of the effects of the discharges from Perth's Ocean Outlets, as part of the Perth Long-Term Ocean Outlet Monitoring (PLOOM) Programme (1995 to 2001). The major environmental concern with these discharges is the potential for nutrients in the wastewater to stimulate excess primary production in the sea. PLOOM, and its predecessor, the Perth Coastal Waters Study, have been instrumental in developing parameters for the measurement of the performance of Perth's ocean outlets. These parameters are currently being integrated in the development of Environmental Quality Criteria (EQC) for the Perth region. EQC play an important role in the management framework by providing the quantitative benchmarks for measuring success in achieving the environmental quality objectives. PLOOM has monitored a range of environmental parameters in the Perth Metropolitan area, including water quality, nutrient levels, water circulation and plume dilution, levels of metals and pesticides present in the marine environment, and the environmental health of benthic communities, in particular of temperate reef systems. During the PLOOM studies, a valuable tool was being developed to monitor outlet performance. Artificial reef structures (“periphyton collectors”) were placed in the plume trajectory. Here, periphyton is defined as: the microalgae (diatoms and microscopic filamentous forms), algal propagules, bacteria, microfauna and particulate material that are found in a mucous-like layer commonly coating seagrass leaves, and that initially colonise artificial surfaces. The advantage of periphyton collectors is that these largely remove the effects of natural variability, can be placed at any depth and distance from a potential nutrient source, provide an easy, cost effective measure of environmental impact, integrated over an extended period (one month), and produce tangible results which can be interpreted by the wider community, as well as legislative authorities and by outlet managers. In addition, outlet performance can be measured by means of these tools, and tested against accepted environmental criteria. Between 1995-2001, periphyton collectors, consisting of 15 × 15 cm PVC plates attached to moorings at fixed depths (2, 4 and 8 m), were deployed for one month during spring, summer and autumn, at increasing distance from the source (250 and 500 m distance to the north, east, west, and south, and at 1,000, 2,000, 4,000 m to the north and south only). After retrieval, the collectors were analysed for total biomass (g AFDW m−2), calcium carbonate content (% AFDW) and chlorophyll levels (chlorophyll a m−2). The results confirmed the predictions made by hydrodynamic modelling (e.g. Zic and Gondinoudis, 2002) and are in accordance with measured nutrient and chlorophyll a levels around the outlets, and demonstrated that the zone of influence was strongly determined by the prevailing currents (to the north), and largely restricted to surface layers (2-4 m depth). Both biomass and chlorophyll content proved reliable parameters, which have the potential to be used as Environmental Quality Criteria (EQC's) for the management of Perth's coastal waters. These EQC's were developed in collaboration with legislative authorities, as part of draft criteria, in accordance with national guidelines: ANZECC/ARMCANZ (2000) Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

scholarly journals Speciation and ultra trace determination of mercury in produced waters from offshore drilling operations using portable instrumentation and matrix-matching calibration

2019 ◽  
Vol 146 ◽  
pp. 1072-1082 ◽  
Author(s):  
Jarol R. Miranda-Andrades ◽  
Sarzamin Khan ◽  
Carlos A.T. Toloza ◽  
Roberta M. Maciel ◽  
Rainério Escalfoni ◽  
...  
Keyword(s):  
Trace Determination ◽  
Offshore Drilling ◽  
Portable Instrumentation ◽  
Drilling Operations ◽  
Produced Waters ◽  
Ultra Trace
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