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Drilling at remote sites, such as artificial islands, comes with challenges, not least of which is drilling-waste management. Drill cuttings, generated from the wellbore during drilling, traditionally are the focus of attention, and a solution is available to treat this waste stream at source. In many projects, however, slop waste and, in some cases, conductor drilling waste is also generated. Until now, no one process has been able to treat these two additional waste streams at source. Adopting traditional waste treatment methods for these waste streams at a remote site could increase project overheads by more than 200%, vs. a conventional wellsite.
Drilling at remote sites, such as artificial islands, comes with challenges, not least of which is drilling waste management. Drill cuttings, generated from the wellbore during drilling, are traditionally the focus of attention and a solution is available to treat this waste stream at source. However, in many projects slop waste and, in some cases, conductor drilling waste is also generated. Until now, no one process has been able to treat these two additional waste streams at source. Adopting traditional waste treatment methods for these waste streams at a remote site could increase project overheads by more than 200%, versus a conventional well site location. Therefore, it is important to maximise efficiencies when it comes to recycling all drilling waste streams, recovering value and reducing disposal requirements at remote sites.
This paper outlines how a single process using modular equipment, originally deployed to process drill cuttings, has now been developed to deal with all three key waste streams. The process was developed when a major operator in the United Arab Emirates (UAE) required a solution for the treatment of conductor drilling waste produced at one of the region's largest fields at an artificial island complex. The ground-breaking solution developed allows for conductor drilling waste, created by a piling rig, and legacy slop stored at the location for nearly seven years, to be treated on site using a single process. This was done in addition to day-to-day drilling waste management, resulting in economic, operational, safety and environmental benefits.
This achievement was primarily through the identification by TWMA of capacity within its thermal drilling waste treatment technology to eliminate the waste streams generated at source. Opening the operating window of the technology eliminated significant haul-off costs, reduced emissions and health, safety and environmental (HSE) risk and improved operational efficiency.
The new strategy was implemented in 2019. Since then, the solution has successfully dealt with a legacy waste stream amounting to seven years' worth or 13,500 MT of conductor drilling waste and 40,000 bbl of stored slop waste, in addition to ongoing drill cuttings treatment. Removing both of these waste streams has achieved significant operational, safety and environmental savings including: the elimination of onshore transportation, processing and landfill costs, elimination of island services and storage, a significant reduction in skip lifting operations and waste handling, a reduction in manpower requirements due to use of existing equipment and personnel, and a reduction of risk to the environment posed by the storage of the waste streams. The operator now also has significantly more land area available for other purposes.
By processing at source, clear tangible savings have been achieved in all areas of the operation. This strategy allowed the operator to set new standards with regards to drilling waste management in the UAE. It has also driven a discussion globally about how to deal with multiple waste streams by opening the operating window of existing single-process systems instead of requiring additional processing equipment.
Additive Manufacturing (AM) or 3D printing is a relatively new manufacturing technology and Powder Bed Fusion (PBF) is one of the major modalities of this technology. There is a misconception that it is "plug-and-play" with no greater risks involved. The focus of this study is to raise awareness about the hazards associated with, AM operations and waste management, mitigation and change the mindset. In the AM processes a lot of chemicals are used in the whole AM cycle; feedstock, pre-processing and post-processing. Feedstock for metallic 3D printers is very fine metal powder (less than 100µm in size) with various health and fire hazards associated with it. This metal powder is spread on the build plate to create layers for selectively melting it until the whole structure is built. Un-melted powder is recycled for the next manufacturing job. However, some of the powder will remain on the manufactured part structure and some will go to multiple filters during the process. This powder is to be safely removed from the built part and managed as hazardous waste. Similarly, clogged filters are also to be safely removed and treated as hazardous waste. A well-defined chemicals waste management process for 3D printing is presented and discussed in this paper. Examples of waste sources are metal powder characterization, unloading printed jobs and contaminated tools and equipment.
In this paper, the authors have presented topics related to AM waste management, including but not limited to the sources of chemical wastes, waste types that generated by AM processes, waste control and management, waste disposal, international standards associated with hazardous waste management and some recommendations and remedies.
An oil field located about 80km west of the African coast at the water depth of 818m had reached its end of economic life. The facilities and wells would need to be decommissioned and abandoned (D&A). The Floating Production Storage & Offloading (FPSO), which was the key component of the facilities, would need to undergo the disconnection and demobilization (D&D) phase. The objective of this campaign was to restore the field back to its safe condition whilst minimising the environmental impact, complying with local and international legislative. The abandonment & decommissioning works was performed in line with good industry decommissioning practices at the most optimize cost. Upon completion of the D&D, the FPSO would need to be demobilised to her original base in the South East Asia (SEA).
This paper discusses a case study for a D&D campaign and activities of the FPSO which includes the Subsea, Umbilical, Riser and Flowline (SURF) and mooring system. One of the crucial areas during the execution phase was pertinent to the management and disposal of the hazardous waste that is subjected to transboundary movement as per the relevant convention. Amongst the hazardous waste were Natural Radioactive Occurrence Material (NORM), low specific activity (LSA) material, hydrocarbon sludge and contaminated water. The FPSO need to be cleared from the above said hazardous waste for her to be accepted by the receiving base country.
This paper also describes the actual experiences and lessons learnt which can be applied for future projects.
Mozzhegorova, Yu. V. (Perm National Research Polytechnic University) | Ilinykh, G. V. (Perm National Research Polytechnic University) | Sliusar, N. N. (Perm National Research Polytechnic University) | Korotaev, V. N. (Perm National Research Polytechnic University) | Bagautdinova, I. A. (Gaspromneft-GEO LLC)
The article deals with the issue of selecting treatment technologies at different stages of the drilling waste life cycle: from waste generation to environmental assimilation or use in economic activity as waste-produced materials. The existence of alternative technological solutions for drilling waste recycling or landfilling and a wide variety of waste generation conditions highlights the relevance of adequate comparative assessment of technologies and selection of the best option for a particular oil field. Choice of waste management technologies should be based on reliable data; therefore, it has to include information and analysis of drilling waste treatment technologies, legal restrictions, climatic and geological conditions of the territory, as well as information on field development program, existing and planned technologies and infrastructure. The proposed approach to the choice of technologies includes a feasibility analysis of specific techniques for certain fields, and a comparative technological and economic assessment for implementing appropriate technologies. The analysis puts forward a list of technologies that comply with legislation, meet the limitations of application, and other mandatory criteria. At the same time, technologies are excluded from further consideration that, despite possible advantages over other options (for example, low costs, high productivity, etc.), cannot be implemented in this field in principle (for example, they have a temperature limitation, at the field no peat available, etc.). The economical assessment stage compares technical and economic indicators of different waste management options and selects the best technology. Thus, the proposed systematic approach to the integrated assessment of technologies by technological, environmental, economic, and other criteria generates a list of technologies, recommended for use at a specific facility, and ranks them.
The economic downturn of 2020 led many oil and gas (O&G) companies and exploration and production (E&P) operators looking for ways to reduce cost while also trying to reduce their carbon footprint. For oilfield-waste-disposal providers, waste-slurry injection is one way to accomplish both economic and environmental objectives. Slurry injection is used to treat, dispose of, and contain toxic and nontoxic waste without damaging the environment while efficiently producing a dependable resource. It involves the grinding and processing of solids into small particles, which are mixed with water or liquids to create a slurry. Waste management companies such as Advantek and Milestone Environmental Services use slurry injection to deposit oilfield waste deep underground where it poses a reduced risk to the environment.
Fracture abundance refers to the quantity of fracturing in a rock mass, and as such is important in all areas of rock engineering and fractured rock hydrology. The abundance measures we discuss are density, intensity and porosity. These measures comprise a unified, self-consistent system that allows for conversion between measures and from one dimension to another (e.g., 1-d to 3-d). This paper extends the Fracture Abundance Matrix of Dershowitz (1985). The new system is consistent with the original system of abundance measures, but extends the treatment of porosity, and adds a more general family of conversion coefficients for conversion between different dimensions and types of abundance measures.
Saceanu, M. C. (Imperial College) | Paluszny, A. (Imperial College) | Zimmerman, R. W. (Imperial College) | Mas Ivars, D. (Swedish Nuclear Fuel and Waste Management Company (SKB) / Division of Soil and Rock Mechanics, Royal Institute of Technology (KTH))
ABSTRACT Fracture growth leading to mechanical spalling around a deposition borehole for disused nuclear fuel waste is modelled numerically. Simulations are conducted using a finite-element-based discrete fracture growth simulator, which computes deformation in the system based on the mechanical properties of the rock. Fractures are grown by computing stress intensity factors at each fracture tip, and the mesh is re-generated to accommodate the changing fracture geometries at every growth step. Several numerical models are created to explore the effect of boundary conditions on the initiation and development of spalling fractures at Forsmark, where the Swedish repository for nuclear waste is planned to be constructed. It is shown that the reported uncertainty in the principal stress magnitudes and orientations will affect the predicted fracture nucleation and growth patterns, and implicitly the final repository design. The potential effect of spalling on the structural integrity of the deposition borehole is illustrated for each stress scenario. 1. INTRODUCTION Spalling is a common type of rock failure that occurs at the boundaries of deep excavations, and it is usually defined as tensile failure that occurs when the tangential stress at the borehole boundary exceeds the tensile strength of the rock (Martin 2005). Spalling failure is entirely stress-induced, as opposed to fractured rock in the damaged or influenced zones around the borehole that is created by the excavation process (Fig. 1). The terms "spalling" and "borehole breakout" are often used interchangeably to denote the V-shaped notch that forms in the direction of the minimum compressive stress after the rock failure process has stabilized and fracture growth has been arrested. However, the failure mechanism by which a borehole breakout occurs can be tensile, shear, or a combination thereof, whereas "spalling" is usually associated with tensile cracking only. In both cases, the breakout is oriented in the direction of the least compressive stress, as shown in Fig. 1. While this type of failure has been observed since the 1950s, and the mechanism underlying spalling is generally well understood, there has been a recent resurgence of studies concerning spalling due to the increasing need of finding long-term solutions to the problem of nuclear waste disposal.