Water Entry Points Research Articles

Cavity evolution of the high-speed cylinder entering the water under different ice-hole diameter constraints

In this study, experimental research on the oblique water-entry process of the high-speed cylinder under the ice-free condition and three different ice-hole diameter conditions based on the high-speed photography technology is carried out. The experimental repeatability is verified. The influence of the ice-hole constraint on the evolution process of the cavity of the cylinder is investigated by dividing in three stages: the cavity expansion stage, the surface closure stage, and the deep closure stage. Besides, the evolution characteristics of the cavity under four different experimental conditions are studied. Results show that during the cavity expansion stage, the cavity expansion is constrained by the ice-hole. The left side of the cavity near the free surface is curved. With the increase of the ice-hole diameter, the curvature of the left side profile of the cavity gradually decreases. The liquid around the water-entry point impacts the inner wall of the ice-hole to generate a reflective flow. During the surface closure stage, the impact of the reflective flow inhibits the contraction of the right side of the cavity wall, which further induces that the surface closure of the cavity is delayed. Besides, under the influence of smaller ice-hole, the right tail of the cavity wall is impacted by the reflective flow and a local impact collapse occurs. As the diameter of the ice-hole increases, the right tail of the cavity wall is folded but does not collapse significantly, and independent surface closure jet and reflective flow can be observed. During the deep closure stage, under the ice-hole constraint, in addition to the puff-off collapse, it can be found that the shedding collapse is accompanied by the local impact collapse. The occurrence of cavity deep closure of the cylinder is accelerated.

Numerical Study on the Water Entry Impact Forces of an Air-Launched Underwater Glider under Wave Conditions

In this study, the water entry of an air-launched underwater glider under wave conditions is numerically simulated by the computational fluid dynamics method. The numerical model is validated by the comparison of nondimensional water entry impact force with published experimental and numerical results. And the influence of water entry points, water entry angles, and water entry attack angles on impact force is studied, which provides guidance for the design of air-launched underwater gliders. The results show that the water entry point has a great influence on the peak value of vertical impact force. In the present study, the peak value of the maximum vertical impact force at different water entry points is almost twice the minimum peak value with the same water entry velocity. The water entry angle at the same water entry point has great influence on the peak value of horizontal impact force, which is mainly related to the horizontal component of the impact velocity. The greater the horizontal component of impact velocity, the greater the peak value of impact force. In addition, the attack angle hardly affects the water entry impact force of the glider with hemispherical head.

Water leak control for the oil-producing wells using Downhole Water Sink Technology

Casing or tubing leaks cause unwanted water production from oil-producing wells. Many chemical and mechanic water control technologies can be used to solve this problem, including squeezing chemical shutoff fluids into the targeted zone or using plugs, cement, packers, patches to block the leakage. Although those methods are field-proven to be effective, the mechanical solutions may require well logs to detect the water entry point in the well. Chemical methods may present environment risks. In this study, an alternative method, Downhole Water Sink, is proposed to solve the problem of unwanted water production from a casing or tubing leak. The effectiveness of this method to control water production in a well with casing or tubing leaks is tested using the Hele-Shaw experimental model. The results show that this method can control unwanted water production via dynamic control of the pressure drawdown in the reservoir. From a technical standpoint, the advantage of this technology is that it eliminates the need to run logs to locate the water entry point and does not require chemical injection into the formation. From an environmental standpoint, this technology has the circular economy elements. Because the produced water in this technology contains little or no oil, it can be reused for reinjection into the reservoir for water flooding or pressure maintenance purposes. Therefore, a production-reinjection process to recycle the produced water is established to reduce the pollution caused by discharging the wastewater into the environment.

Residence Time Analysis in the Albufera of Valencia, a Mediterranean Coastal Lagoon, Spain

The Albufera of Valencia is a coastal lagoon located in the western area of the Mediterranean Sea, in the Iberian Peninsula. It has an area of 23.1 km2 and an average depth of only 1 m, with a maximum depth of 1.6 m. This lagoon is the remnants of an original and more extensive wetland of about 220 km2 which is now mostly dedicated to rice cultivation. Surface water is supplied through several main and many secondary canals for a total of 64 water entry points and three exit points to the sea. It is difficult to evaluate the residence time due to the lack of reliable measurements of the inflow or outflow, as well as continuous measurements. Between 1988 and 2018, several procedures were used, the results of which are outlined in this document. Overall, a decrease in the inflow during these thirty years was observed and, therefore, it can be concluded that the residence time is increasing. There is a temporal variation during the year due to rainfall and cultivation periods. Likewise, the results found that the natural hydrological zoning of the lagoon causes a spatial heterogeneity with small Northern areas with low residence time of 4.7 days, almost on a weekly basis and large Western extensions with high residence time of 222.9 days. It is impossible to know this information if individual flow measurements are not taken from each of the main watercourses.

Study on the Steepness of Landslide-Induced Wave and Nonlinear Motion of Container Ships

Large-scale instability of a landslide body, sliding down a bank slope and entering water at a high speed, arouses landslide surges. Taking the water entry point as a source point, they spread rapidly to surrounding areas, increasing the danger risk of vessel passages in the water area. In this paper, adopting an orthogonal experimental design method, based on the test data, the Three Gorges Reservoir area was derived in order to calculate the height of the first wave of the bank landslide surge: to analyze the slope angle, the geological environment, the volume of the landslide surge, and the landslide surge wave steepness; to study the landslide volume effect on ship rolling and the swaying motion rule; and to explore the landslide surge in different ship rolling positions and transverse oscillation characteristics. This study can provide theoretical support for the navigation safety of ships in landslide surge waters.

Parasites in fishery products - Laboratorial and educational strategies to control

The presence of parasites, including Anisakis spp. larvae in fishery products jeopardizes their safety and quality, which is a matter of concern and a challenge for official authorities, as well as for food businesses operators, and a potential health risk to consumers. In the last ten years, a total of 2367 samples from different seafood products, whole fish (n = 1022), fish steaks (n = 417), fish fillets (n = 46), roes (n = 11), canned fish fillets (n = 35), fish fingers (n = 705), and ready-made Japanese dishes (n = 131) were analysed at the Laboratory of Pathology of Aquatic Animals of IPMA. From the fishery products analysed, a total of 4643 visible Anisakis larvae were collected from eighteen different species of whole fish and there were two cases with numerous larvae, although live larvae were only found in fresh fish. Anisakis larvae (n = 523) were collected from fish steaks, (n = 20) from frozen fish fillets, (n = 7) from five different brands of fish fingers, (n = 2) from two cans of cod fillets and numerous viable larvae were collected from the serosae of European hake fresh roes. The great majority of the larvae were identified as L3 Anisakis larvae. Plerocercoids of Gymnorhynchus gigas and Hepatoxylon trichiuri and the myxosporean, Kudoa spp. were also observed and led to the withdrawal of the fish from the supply chain. No Anisakis larvae were collected from the farmed fish as well as from the ready-made Japanese dishes. However, Kudoa hexapunctata spores were observed in the tuna muscle from one sashimi meal. The data shows that fresh fish with live Anisakis larvae have been marketed. Educational strategies concerning parasites were implemented with workshops, “Parasites in Fishery Products” to train and instruct professionals within the fish supply chain and training activities for target groups, including children, were promoted, to raise awareness of this issue. One of the most relevant outcomes obtained was the improvement of implementation of parasite identification techniques in the industry, including private labs, and consequently: (1) decrease in the parasitological analysis number of common parasites and (2) reduction in the analysis of anatomical structures confused with parasites requested to IPMA's Laboratory of Pathology. In addition, the practice of freezing trash fish used to feed farmed fish, and the placement of nets at the water entry points of the earth ponds, in order to avoid wild fish introduction, were simple and important measures that were implemented to prevent Anisakis and other parasites entering fish farms. The two complementary parts of this work, laboratorial activities used to support the fish supply chain, and the educational strategies concerning parasites, have made an essential contribution towards the availability of data for assessing and minimizing the level of risk associated with fish consumption, and have particularly increased and improved awareness, regarding foodborne parasites.

Oil Well Testing Using Production Logging Tool in Khurmala field in Kurdistan Region-Iraq

Production logging tools (PLTs) in oil and gas industries are used for obtaining fluid types and measuring fluid rates in the borehole for both production and injection wells and to better understand the well productivity or the well injectivity of the interest zones. Additionally, it can be used to detect well problems, such as early water or gas breakthrough, channeling behind casing or tubing, and water or gas coning. The Khurmala field is a big oil field in the Kurdistan region of Iraq. PLTs have been acquired in many of the Khurmala oil wells, and the log records took into consideration the production technique decisions. In this study, results of the PLT log will be discussed in one of the Khurmala oil wells. Owing to the long history of production of oil or gas wells, many problems have been seen, such as coning either water or gas, formation damage, casing corrosion, and well obstruct. This research will evaluate the production profile across the slotted liner interval of (W1) well in the Khurmala oil field in the Iraq-Kurdistan region and detect possible water entry points, verify the distribution and nature of fluids, and estimate fluid segregation after the shut-in period. This was done by applying PLTs and interpreting the data by using Emeraude software. The performance of each choke size was studied and assessed. It was found that a choke size of 48/64̎gives the best favorable production gas, oil ratio, and profile. Results from the PL survey showed that no water entry was detected across the logged interval. All the water was coming from below a depth of 990 m; most of the hydrocarbons were coming from the slotted interval across 981.8-982.9 m, and the flowing pressure across the logged interval using maximum choke was less than the saturation pressure.

Microbial load of white cheese process lines after CIP and COP: A case study in Turkey

Microbial adhesion, contamination and biofilm formation are major problems in the dairy industry, in cheese production, and for consumer health. In our study, the microbial loads of white cheese process lines were examined after cleaning treatments. Bacillus spp. was determined as the most common species on process lines. Drainage, air, and water entry points were found as important contamination points. Biofilm forming capacity of Enterobacteriaceae as revealed using Congo Red agar, was very high. In addition, the standard counting and ATP-Bioluminescence methods were applied and compared for evaluating biofilms. The ATP-Bioluminescence method was found useful for rapidly identifying the biofilm-formable surfaces.

Comprehensive review of water shutoff methods for horizontal wells

Abstract This paper provides a comprehensive review of the water control techniques that have been applied in horizontal wells and presents the water control methods for wells of different completion types. Water shutoff techniques are classified as mechanical methods and chemical methods. These methods can be used individually or in combination. Mechanical methods are usually used to deal with wellbore water shutoff or near wellbore water control. Chemical methods are used in plugging matrix or fractures. Completion type should be considered when designing a water shutoff project. Both mechanical methods and chemical methods can be used in open hole and cased hole horizontal wells. In the wells that completed with perforated liners and wells completed with sand screen pipe, only chemical methods can be used to control excess water production, while the mechanical methods can only provide temporary zonal isolation. Mechanical methods are slightly higher in cost than chemical methods, and the depth correction is a challenge. Mechanical and chemical methods can be individually used if the water entry point is at the toe. A combination of packers should be designed for the wells with water entry point near the heel or along the lateral.

Role of the lens in controlling physical dormancy break and germination of Delonix regia (Fabaceae: Caesalpinioideae).

Physical dormancy occurs in all three subfamilies of Fabaceae, namely Mimosoideae, Papilionoideae and Caesalpinioideae, making it one of the largest plant families in terms of number of species with physical dormancy. However, little is known about the water gap structure and germination ecology of species in Caesalpinioideae. Freshly collected seeds of Delonix regia (Caesalpinioideae) did not imbibe water, thus they had physical dormancy. Both dry heat and wet heat were effective in breaking dormancy, however, longer duration was required at 80°C and shorter duration at 90°C. Seeds buried in the field for 2years germinated to 21% and 42% after the first and second summer, respectively, compared with 3% germination in seeds at the time of maturity. Seeds incubated at 15/60°C in the laboratory (mimicking summer conditions) for 3months supported this conclusion, as dormancy was relieved in 18% and 24% of seeds stored dry and watered intermediately, respectively. All the dormancy breaking treatments resulted in lifting of palisade layers in the lens region to form a circular lid-like opening, i.e. water gap (Type II simple). Blocking experiments confirmed that water entered only through the lens and no secondary water entry point was observed. No apparent changes in morphology/anatomy of the hilum region were noted in dormant and non-dormant (water permeable) seeds. These results suggest that summer temperatures could open the lens in a proportion of seeds every year and that germination occurs during the subsequent wet season in the tropics.

Direction Estimation of Water-Entry Point with Single Vector Sensor

The water-entry point was the first information collecting point on detecting an object which was dropped into water from air. Single vector sensor could estimate the direction of the water-entry point with its sound field pressure and particle velocity signals. The complex sound intensity method was applied in vector signal processing. The simulating experiment and the practical experiment on the lake were all based on the estimation deviation of the theory on different SNR. By processing the devided signal in time domain with this theory, the water-entry object could be tracing timely.

Modeling DBPs formation in drinking water in residential plumbing pipes and hot water tanks

Disinfection byproducts (DBPs) in municipal supply water are a concern because of their possible risks to human health. Risk assessment studies often use DBP data in water distribution systems (WDS). However, DBPs in tap water may be different because of stagnation of the water in plumbing pipes (PP) and heating in hot water tanks (HWT). This study investigated occurrences and developed predictive models for DBPs in the PP and the HWT of six houses from three municipal water systems in Quebec (Canada) in a year-round study. Trihalomethanes (THMs) in PP and HWT were observed to be 1.4–1.8 and 1.9–2.7 times the THMs in the WDS, respectively. Haloacetic acid (HAAs) in PP and HWT were observed to be variable (PP/WDS = 0.23–2.24; HWT/WDS = 0.53–2.61). Using DBPs occurrence data from these systems, three types of linear models (main factors; main factors, interactions and higher orders; logarithmic) and two types of nonlinear models (three parameters Logistic and four parameters Weibull) were investigated to predict DBPs in the PP and HWT. Significant factors affecting DBPs formation in the PP and HWT were identified through numerical and graphical techniques. The R 2 values of the models varied between 0.77 and 0.96, indicating excellent predictive ability for THMs and HAAs in the PP and the HWT. The models were found to be statistically significant. The models were validated using additional data. These models can be used to predict DBPs increase from WDS (water entry point of house) to the PP and HWT, and could thereby help gain a better understanding of human exposure to DBPs and their associated risks.

Importance of drainage channels for waders foraging on tidal flats: relevasnce for the management of estuarine wetlands

Summary Despite covering a relatively small area on a global scale, estuarine tidal flats are vital to many aquatic bird species during much of the yearly cycle. Small‐scale features of tidal flats, such as water drainage channels, can influence the carrying capacity of estuarine wetlands, yet their ecological impact is poorly understood. In this study we evaluated the influence of drainage channels on the quality of feeding habitat for waders in the Tagus estuary, Portugal. We measured the abundance of seven wader species at five distance classes from drainage channels, and analysed the variation in peck rates, step rates, turning rates and success rates. In addition we measured the density of macroinvertebrate prey and the sediment physical–chemical characteristics at different distances from the channels. All wader species occurred at higher densities near the channels. In the study area 44% of the birds fed on just 12% of the available surface, less than 5 m away from drainage channels. Wader foraging behaviour also suggests a greater feeding effort near the channels. While the characteristics of the sediments did not change significantly with distance from channels, prey abundance corresponded closely with wader abundance, suggesting that the small scale distribution of birds on the tidal flats may be related to the presence of their prey. Synthesis and applications. Our study shows that the areas around drainage channels are particularly important feeding sites for waders foraging on tidal flats. Consequently, managers of estuarine wetlands should strive to preserve or improve channel networks. This can be achieved by (i) preserving saltmarshes and saltpans adjacent to tidal flats, (ii) minimizing the reclamation of upshore flats and (iii) avoiding embankments and canalizations of inland water flows that reduce the number of water entry points onto tidal flats.

Integrated Mainframe/PC Approach for Well-Data-Acquisition Selection

Summary This paper discusses Saudi Aramco's integration of the corporate mainframe database management system (DBMS), a commercial statistical analysis package (SAP), and a PC database program to facilitate the selection of dataacquisition candidates and to track the completion of their requirements. Data-acquisition candidate selection includes wells that require flowmeters, pulse-neutron logs (PNL's), PI tests, and bottomhole static PI tests, and bottomhole static pressure (BHSP) surveys for prudent pressure (BHSP) surveys for prudent reservoir management. Data are easily extracted from the DBMS with user-language programming techniques. Then a SAP uses predefined reservoir-management criteria to process the more than 100 logical process the more than 100 logical records extracted per well. Output from the mainframe program is then imported to a PC data base using batch files. Multiple tabular forms allow the engineer to preview the rulesbased selections, to edit the data-acquisition requirements, and to add comments. In urge fields with hundreds of wells, selection of the optimum data-acquisition candidates is extremely important. The PC database application helps novice computer users select and track dataacquisition candidates more systematically and allows users to have direct control of screen presentations. Other routine work, such as presentations. Other routine work, such as well producing priority, business development plans, and workover selection and tracking, has also been included in the PC data base. Introduction The Northern Area Reservoir Management (NARM) Div. of Saudi Aramco is responsible for reservoir-management activities in the company's offshore oil fields. Reservoir engineers specify the data-acquisition requirements necessary in their area of responsibility. Collecting reservoir-management data is expensive; typical costs are $25,000 for flowmeters, $10,000 for production/injection testing, $40,000 for PNL's, and $2,500 for BHSP surveys. For the purposes of this paper, PNL's, flowmeters, production/injection tests, and BHSP surveys are production/injection tests, and BHSP surveys are used to acquire the following types of data. 1. PNL's are used to monitor bottom- and edge-water encroachment throughout a field. Data are used to specify rate restrictions and well producing priority and to evaluate recovery efficiency. 2. Flowmeters are run to ascertain the contribution of each reservoir layer to the total flow rate and to identify the water entry point, plugged perforations, etc. point, plugged perforations, etc. 3. Production/injection tests are run at various intervals over the life of a well to determine the reservoir parameters that best define the reservoir and to identify workover opportunities. 4. BHSP surveys are run quarterly, semiannually, annually, or biennially at field locations that provide good area coverage for monitoring reservoir pressure, evaluating pressure support, and verifying pressure support, and verifying communication between layers. Previously, the selection of data-acquisition candidates required a time consuming well-by-well evaluation of hundreds of wells. The task was often delegated to entrylevel engineers, and well-defined guidelines on how to do the job best were not provided. The task required many trips to the files, many telephone calls to production engineers, and a great deal of wasted time. In 1988, this task was faciliated for one major field by using the DBMS and a commercial SAP. Standardized, simple criteria were applied to each well to determine whether it required a PNL, a flowmeter, etc. For example, if a producing well had not had a PNL for 3 years it would be identified as PNL for 3 years it would be identified as a PNL candidate. Improvements since 1988 include a menu-driven system that allows the DBMS information-extract program and the SAP to be submitted simultaneously. The SAP can also generate graphic files, if requested on the submission panel. Currently, each major field has a more sophisticated rules-based system stored in a macro library that the SAP accesses. Guidelines for lessexperienced engineers are now readily available and the selection is more systematic. Thus, this routine task is now completed much faster and documented better, and the time saved is used to analyze the data collected.

Features of fault processes due to leaks of water into sodium in a counterflow steam generator

A so-called counterflow generator (sodium in the tubes, water between them) enables simplification of the protection system and increases the reliability in preventing a small leak from becoming a large one. A figure shows the typical limits to the conditions. The equation used shows that the transition to the displacement mode occurs at low gas flow rates when the lifting force produced by a gas bubble exceeds the pressure loss between the chambers. At the end of each experiment it was found that there was a solid deposit below the water entry point, which occupied much of the cross section, which contained sodium oxide, hydride, and hydroxide as well as the metal. The authors note that the conterflow generator has already passed testbed examination, and that industrial tests on the generator will provide information on the desirability of using that type of generator in nuclear power stations containing high-power BN reactors.