The characteristics of leachate and its probable risks on surface and groundwater pollution were investigated following the analysis of some chemical parameters of the leachate generated in Groundwater parameters, however, satisfy drinking water quality standard except, the concentration of NH 4 + -N (maximum 74.2 ppm) and K (maximum 25 ppm).

Oil and gas operators are now being driven to now operate beyond their originally conceived design life and field life. Asset life extension (ALE) beyond these thresholds presents unique safety and business risk challenges for the oil and gas industry. With aging equipment and facilities, operators face increasing challenges in maintaining equipment reliability and integrity as well as operational safety. Aging factors do not only involve hardware but also human and organizational factors. Factors include corrosion, erosion, fatigue, equipment obsolescence, normalization of deviance (accepting degraded conditions as being normal), changes in codes and standards and lack of data to forecast future risks. The challenge is magnified if there is a large fleet or large amount of aging assets that needs to be managed. In this chapter, a responsible approach to ALE, where assets can continue to be operated safely and resources are adequately managed, is provided herein.

The study examines the long-term and seasonal climatic variations in north-western part of Bangladesh (NWPB). Long-term variation of different climatic parameters reveals that significant increases in temperature are associated with decreasing evaporation which could be attributed to wind speed variation and seasonal variation of temperature. Increase of monsoon rainfall during monsoon period and scarcity or absence of rainfall during dry periods increase the region’s vulnerability to monsoon flood and seasonal drought, respectively. The area witnesses a single peak of rainfall in July during the first half of the study period (1964-1985), whereas the same experiences bimodal peak of rainfall during July and September in the second half of the study period (1986-2007). This may signify the changes of climatic condition in the studied area. Annual variability of rainfall as well as the unpredictable shifting of rainfall periods might be a possible reason for the seasonal drought. The aridity index indicates that the overall dryness of the area has increased during winter season. The study shows that humidity increases at all stations throughout the year. The study also shows that long-term seasonal variation of both surface and groundwater level is also prominent. Gradual decrease of surface water level was observed in Teesta River which might be due to unilateral withdrawal of surface water in the upper riparian. Detailed investigation on hydrometeorology of the study area is required to see whether there is any trend of climate change in the area. Asiat. Soc. Bangladesh, Sci. 44(2): 195-210 December 2018

The objectives of this research were to examine the long term fate of CO[subscript 2] injected into the Morrow B Sandstone, a hydrocarbon reservoir in the Farnsworth Unit in northern Texas. A suite of numerical multiphase reactive transport models was constructed simulating continuous and water-alternating-gas (WAG) CO[subscript 2] injection through nine wells into an initially water-saturated reservoir. The simulations predicted little change in the pressure or temperature of the reservoir as a result of fluid injection. However, the injectedCO[subscript 2] temporarily reduced the pH of the formation water from near neutral to as low as 4.7, which induced further changes in the formation water composition and reservoir mineral matrix. Much of the injected CO[subscript 2] also initially existed as a separate immiscible gas phase, but this CO[subscript 2] appears to have leaked vertically through the overlying Morrow Shale cap rock and disappeared from the Morrow B Sandstone within 30-50years. However, some of the injected CO[subscript 2] dissolved into the Morrow B formation water and migrated westward. This acidified CO[subscript 2]-enriched formation water initially dissolved native calcite and ankerite in the reservoir but later in the simulations calcite, dolomite, and siderite began to precipitate, serving as minor sinks for CO[subscript 2]. Among non-carbonate minerals, albite and illite, both initial constituents of the Morrow B Sandstone matrix, were predicted to dissolve, whereas quartz, kaolinite, and smectite were predicted consistently to precipitate. However, these changes in mineral precipitation and dissolution caused negligible changes in porosity on the order of only 0.001%, causing correspondingly negligible changes in the patterns of fluid flow and CO[subscript 2] storage capacity of the Morrow B Sandstone. Based on the results of the simulations, because of significant leakage of CO[subscript 2] through the overlying Morrow Shale, the Morrow B Sandstone is judged to be a minor reservoir for CO[subscript 2] sequestration for at least decadal to century time scales, where the CO[subscript 2] is sequestered primarily in aqueous solution in the Morrow B formation water. However, petroleum, a likely major sink for injected CO[subscript 2], was not considered in the models and likely would significantly improve the CO[subscript 2] sequestration capacity of the Morrow B Sandstone.

The Strengthening, Modification & Repair (SMR) toolkit is currently integrated into PETRONAS Carigali Sdn Bhd (PCSB) Structural Integrity Compliance System (SICS) which is a web-based application for the Structural Integrity Management (SIM) of fixed offshore structures. The objective of the SMR toolkit is to allow a user (engineer/manager) to quickly and efficiently determine all available SMR options for both jacket and topsides. The toolkit aids in the selection of suitable SMR technologies for a range of applications based on several key information as entered by the user. The Toolkit provides a variety of SMR options from key case studies from global and local databases and provides the most appropriate solutions for the SMR on both jacket and topsides structures of fixed offshore structures. The toolkit also has the ability to make use of other resources such as availability of particular vessels in specific operating regions, financials, logistics, technical expertise and other decision-making criteria prior to the engagement of implementation of any costly SMR scheme. The SMR decision-making toolkit is ideal for practising structural integrity engineers in operations to perform high level feasibility studies in determining preferred SMR options. The database is continuously updated to provide new options on case studies, availability of other resources and expertise, including availability of vessel and technical resources including the pricing, to ensure operators have the best information at hand prior to making decisions on SMR.