Integrating Various Sources of Indicators and Water Measurements Data of Different Degree of Uncertainty: Understanding Aquifer Encroachment and Resulted Water Breakthrough to Gas Producers

Opishnyanske Field is a mature Ukrainian gas field that began producing in 1972 from three formations: Visean, Serpukhovian, and Bashkirian. A reservoir simulation study was implemented to understand the movement of the water in the reservoir and to maximize the field recovery. Some wells showed high water production at their late life and this was the key question that we wanted to understand. If this was a water breakthrough, which means that the aquifer water swept the gas in the reservoir and reached these wells, then there is little potential left in this field. If this was not a water breakthrough, there could still exist some unswept areas to be produced. The second key question was to understand the aquifer strength and direction to be integrated into the simulation model. The field has different sources of data that could be used to understand the water movement in the reservoir, which are: Observed production data Water analysis reports (surface water salinity and density measurements) Production logging data Pressure data and geological maps to understand the communication between the wells Although different sources of data are available, each one has a level of inaccuracy, which was the key challenge. The field also has some other challenges, such as: Commingled production Contradiction between the observed water/gas ratio (WGR) and water analysis data Limited water analysis data points in some wells Issues with backallocation of the observed data. Integrating all the available data had a significant effect on understating the water behavior. Data analysis and integration resulted in excluding all the data anomalies and reaching a good understating regarding: The wells that are showing a water breakthrough Aquifer strength and direction

Ternary Nanocomposite System Composing of Graphene Nanoplatelet, Cellulose Nanofiber and Jatropha Oil Based Waterborne Polyurethane: Characterizations, Mechanical, Thermal Properties and Conductivity

This work aims to evaluate the performance of graphene nanoplatelet (GNP) as conductive filler with the presence of 0.5 wt.% cellulose nanofiber (CNF) on the physical, mechanical, conductivity and thermal properties of jatropha oil based waterborne polyurethane. Polyurethane was made from crude jatropha oil using an epoxidation and ring-opening process. 0.5, 1.0, 1.5, 2.0 wt.% GNP and 0.5 wt.% CNF were incorporated using casting method to enhance film performance. Mechanical properties were studied following standard method as stated in ASTM D638-03 Type V. Thermal stability of the nanocomposite system was studied using thermal gravimetric analysis (TGA). Filler interaction and chemical crosslinking was monitored using Fourier-transform infrared spectroscopy (FTIR) and film morphology were observed with field emission scanning electron microscopy (FESEM). Water uptake analysis, water contact angle and conductivity tests are also carried out. The results showed that when the GNP was incorporated at fixed CNF content, it was found to enhance the nanocomposite film, its mechanical, thermal and water behavior properties as supported by morphology and water uptake. Nanocomposite film with 0.5 wt.% GNP shows the highest improvement in term of tensile strength, Young’s modulus, thermal degradation and water behavior. As the GNP loading increases, water uptake of the nanocomposite film was found relatively small (<1%). Contact angle test also indicates that the film is hydrophobic with addition of GNP. The conductivity properties of the nanocomposite film were not enhanced due to electrostatic repulsion force between GNP sheet and hard segment of WBPU. Overall, with addition of GNP, mechanical and thermal properties was greatly enhanced. However, conductivity value was not enhanced as expected due to electrostatic repulsion force. Therefore, ternary nanocomposite system is a suitable candidate for coating application.

Understanding the Mechanical Biases of Tipping-Bucket Rain Gauges: A Semi-Analytical Calibration Approach

Tipping bucket rain gauges (TBR) are widely used worldwide because they are simple, cheap, and have low-energy consumption. However, their main disadvantage lies in measurement errors, such as those caused by rainfall intensity (RI) variation, which results in data underestimation, especially during extreme rainfall events. This work aims to understand these types of errors, identifying some of their causes through an analysis of water behavior and its effect on the TBR mechanism when RI increases. The mechanical biases of TBR effects on data were studied using 13 years of data measured at 10 TBRs in a mountain basin, and two semi-analytical approaches based on the TBR mechanism response to RI have been proposed, validated in the laboratory, and contrasted with a simple linear regression dynamic calibration and a static calibration through a root-mean-square error analysis in two different TBR models. Two main sources of underestimation were identified: one due to the cumulative surplus during the tipping movement and the other due to the surplus water contributed by the critical drop. Moreover, a random variation, not related to RI, was also observed, and three regions in the calibration curve were identified. Proposed calibration methods have proved to be an efficient alternative for TBR calibration, reducing data error by more than 50% in contrast with traditional static calibration.

Understanding Diver Behavior on Underwater Cultural Heritage: Enriching the Observation Record Using Video Methods

Successful underwater heritage management requires a sound understanding of visitor behavior. Primary visitors to underwater heritage sites are divers whose behavior can pose risks to the integrity of site cultural heritage and tourism values. This study seeks to understand wreck diver in-water behavior. Conventional observation of diver behavior is limiting. Wearable cameras are becoming popular across many recreational activities and potentially expand the scope and quality of diver observation. Video observation is rarely used in such research. This article demonstrates the potential of video observation, describing the analysis of first-person video records to explore details of diver behavior on shipwrecks. The evidence demonstrates that while most divers behaved responsibly, a few contributed to most contact behaviors. The analysis details this behavior, identifying, for example, that deliberate holding and touching comprised most contacts. Such findings on diver behavior inform heritage and tourism management decisions and provide a baseline for future studies. Methodologically, the study demonstrates the power of this method of observing divers and other recreationists. This is particularly valuable for researching recreationalists in confined spaces, such as caves or shipwrecks. The quality of results allows for further evidence-based examination of motivations, values, intentions and meanings underlying observed diver behavior.