Reservoirs

Knowledge of the in‐situ sound velocity of drilling mud can be used in mud‐pulse acoustic telemetry for evaluating the presence and amount of gas invasion in the drilling mud. We propose a model for calculating the in‐situ density and sound velocity of water‐based and oil‐based drilling muds containing formation gas. Drilling muds are modeled as a suspension of clay particles and high‐gravity solids in water or oil, with the acoustic properties of these fluids depending on pressure and temperature. Since mud at different depths experiences different pressures and temperatures, downhole mud weights can be significantly different from those measured at the surface. Taking this fact into consideration, we assume constant clay composition and obtained the fraction of high‐gravity solids to balance the formation pressure corresponding to a given drilling plan. This gives the in‐situ density of the drilling mud, which together with the bulk moduli of the single constituents allow us to co...

To illustrate and test the applicability and performance of the innovative honey-bee mating optimization (HBMO) algorithm in highly non-convex hydropower system design and operation, two problems are considered: single reservoir and multi-reservoir. Both hydropower problems are formulated to minimize the total present net cost of the system, while achieving the maximum possible ratio for generated power to installed capacity. The single hydropower reservoir problem is approached by the developed algorithm in 10 different runs. The first feasible solution was generated initially and later improved significantly and solutions converged to a near optimal solution very rapidly. In the application of the proposed algorithm to a five-reservoir hydropower system with 48 periods and a total of 230 decision variables, in early mating flights, the first feasible solution was identified and the results converged to a near optimal solution in later mating flights. In the case of the multi-reservoir problem, an efficient gradient-based nonlinear-programming solver (LINGO 8.0) failed to find a feasible solution and for the single hydropower reservoir design problem it performed much worse than the proposed algorithm.

The conservation of endemic fauna in freshwater ecosystems is a topical issue on small oceanic islands. Because these endemics have limited distributions, they are more vulnerable to extinction. This study is the first to clarify the distribution of freshwater macroinvertebrates including endemic and alien species in streams with dams and associated reservoirs on the Ogasawara Islands in the northwestern Pacific Ocean. In 2007, we conducted a field survey in streams and reservoirs of the Yatsuse River system and collected 22 taxonomic groups from 13 stations. Hierarchal cluster analysis and non-metric multi-dimensional scaling (NMDS) were performed for the presence/absence data of the macroinvertebrates, and the results indicated that (1) most of endemic species were present in inlet streams of dam reservoirs, (2) these endemic species were absent in the bottom sediments of the reservoirs because of oxygen depletion and (3) dams may be barriers to the migration of some species of amphidromous crustaceans. Because human modifications, such as dams and associated reservoirs, on a small oceanic island can rapidly result in fragmentation or loss of freshwater habitats of endemic species, the remaining habitat of these species, such as headwater streams, must be protected and preserved to avoid species extinction.

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of ...

Correlations are presented to compute the mutual solubilities of CO2 and chloride brines at temperatures 12–300°C, pressures 1–600 bar (0.1–60 MPa), and salinities 0–6 m NaCl. The formulation is computationally efficient and primarily intended for numerical simulations of CO2-water flow in carbon sequestration and geothermal studies. The phase-partitioning model relies on experimental data from literature for phase partitioning between CO2 and NaCl brines, and extends the previously published correlations to higher temperatures. The model relies on activity coefficients for the H2O-rich (aqueous) phase and fugacity coefficients for the CO2-rich phase. Activity coefficients are treated using a Margules expression for CO2 in pure water, and a Pitzer expression for salting-out effects. Fugacity coefficients are computed using a modified Redlich–Kwong equation of state and mixing rules that incorporate asymmetric binary interaction parameters. Parameters for the calculation of activity and fugacity coefficients were fitted to published solubility data over the P–T range of interest. In doing so, mutual solubilities and gas-phase volumetric data are typically reproduced within the scatter of the available data. An example of multiphase flow simulation implementing the mutual solubility model is presented for the case of a hypothetical, enhanced geothermal system where CO2 is used as the heat extraction fluid. In this simulation, dry supercritical CO2 at 20°C is injected into a 200°C hot-water reservoir. Results show that the injected CO2 displaces the formation water relatively quickly, but that the produced CO2 contains significant water for long periods of time. The amount of water in the CO2 could have implications for reactivity with reservoir rocks and engineered materials.

The Pelana Field is a mature waterflood field in the Central Sumatera Basin that consists of multi-layer sands with contrasted properties. Waterflood has been applied since 1997, targeting all producing reservoirs. These layering reservoirs are challenging in achieving a good alignment in term of waterflood optimization. In multi-layer injectors, such a condition will lead to bad vertical distribution of injection, where the poorest quality sand receives the least water injected.

This is a problem occurring in some injectors in the Pelana Field, where the injection is not evenly distributed vertically so that the topmost reservoir, which also has the poorest quality with permeability of around 100 mD, does not receive enough injection to balance its production. Most of the injected water goes to MN_XX sand which has permeability of about 1000 md. Injector PL-55, for instance, injects into both sands to support the production from both reservoirs. However, the previous completion uses only open ended tubing and therefore, based on the spinner result, the water will be distributed naturally based on the well-to-reservoir pressure difference, being directly affected by reservoir permeability. This practice resulted in an unbalanced performance for both sands. While MN_XX has a good sweep efficiency with recovery factor (RF) increment > 8%, the BK_AA sand would has an opportunity to be optimized due to its current low incremental of RF.

Side Pocket Mandrel has been chosen to resolve the vertical distribution problem in PL-55 and improve the injection rate into BK_AA sand. It is observed that the well can finally split its injection into more desirable allocation, allowing more water to flow into BK_AA sand. This paper presents the application of this technology in PL-55 well, including the technology principles, the tool design, the strategy to improve the injection distribution and the enhanced performance to the surrounding producers.

"Ostroumov S. A. Biodiversity protection and quality of water: the role of feedbacks in ecosystems. - Doklady Biological Sciences. 2002 (January). Volume 382, Numbers 1- 6, p. 18-21.
Full text free: http://www.scribd.com/doc/42558469/

A new aspect of ecosystem service is identified and shown in this paper.

The article presents a new vision of how biodiversity helps towards better stability and water quality. The author made an innovative analysis of his experimental data and formulated the following fundamental principle: to maintain water quality, it is vital to protect the functionally active biodiversity of water ecosystems. In other words, according to his vision, the protection of functionally active biodiversity, including filter-feeders, is a key to maintenance of water quality.

Among the new facts that were established in the author's experiments that were reported in this paper: the detergent IXI 20 mg/L inhibited water filtration by marine mussels Mytilus galloprovincialis; the detergent Deni-Automat 30 mg/L also inhibited the water filtration by oysters Crassostrea gigas Thunberg .
DOI 10.1023/A:1014465220673. http://www.springerlink.com/content/p89cugy9ddk053g7/; MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC. ISSN0012-4966 (Print) 1608-3105 (Online). http://scipeople.ru/users/2943391/; http://sites.google.com/site/2dbs382p18biodivers/; http://www.citeulike.org/user/ATP/article/9734342;"

Water reservoirs and dams are major water resources, being diverse in terms of both size and fisheries potential. Reservoir productivity is variable, with significant variations being observed for reservoirs of comparable size and geology, even within the same geographical area. The ability to estimate fish yields through the application of predictive models is an important step for the effective management of fisheries resources in freshwater basins and flowing waters. Various physical, chemical and biological processes establish limits on the yield of commercial fish species. Various physicochemical parameters were measured in this present study during 2001–2002 on a monthly basis for Shahpur Dam in Pakistan. Morphoedaphic indices were derived as MEIt, MEIc and MEIa. A number of different predictive models proposed for different regions are used to predict fish production in Shahpur Dam, for comparison with the actual fish production. From a management perspective, fish yield predictive models based on MEI appeared to be most useful as fish yield predictors.

The objective of this study is to provide information on source organic matter input, depositional conditions and the correlation between crude oils recovered from Sunah oilfield and Upper Jurassic Madbi Formation. A suite of twenty-six crude oils from the Lower Cretaceous reservoirs (Qishn clastic) of the Masila Region (Eastern Yemen) were analysed and geochemically compared with extracts from source rock of the Upper Jurassic (Madbi Formation). The investigated biomarkers indicated that the Sunah oils were derived from mixed marine and terrigenous organic matter and deposited under suboxic conditions. This has been achieved from normal alkane and acyclic isoprenoids distributions, terpane and sterane biomarkers. These oils were also generated from source rock with a wide range of thermal maturity and ranging from early-mature to peak oil window. Based on molecular indicators of organic source input and depositional environment diagnostic biomarkers, one petroleum system operates in the Masila Region; this derived from Upper Jurassic Madbi organic-rich shales as source rock. Therefore, the hydrocarbon exploration processes should be focused on the known location of the Upper Jurassic Madbi strata for predicting the source kitchen.

Many dams are being built in Lao PDR for hydropower and irrigation. Dams generally cause negative effects on river fisheries, but they also provide opportunities for increased fisheries and aquaculture production in reservoirs, as well as for aquaculture downstream, in or near rivers or irrigation canals, where reservoirs may provide a year-round supply of relatively clean water. This study aimed to describe the main commercial aquaculture systems associated with six selected reservoirs in Lao PDR, and to obtain data on production and value from aquaculture. While the study shows that there are various issues to be addressed by agencies responsible for aquaculture, the main intention is that the agencies and developers who are responsible for dams and reservoirs will take aquaculture into account in their planning and management.
Aquaculture is a developing industry in Lao PDR, with total production in the country now officially estimated at over 100,000 tonnes per year. About 20 species of fish are commonly cultured, with Nile tilapia, silver barb, and Indian and Chinese carps dominating production. The main systems that have developed near or downstream of the studied reservoirs are (1) pond culture of fish, typically polyculture (i.e. several fish species), (2) pond fish polyculture of fish integrated with chicken or pig farming, mainly near irrigation canals (3) cage farming of fish – mainly Nile tilapia - in rivers or reservoirs, 4) cove culture, in which part of a reservoir is fenced-off and stocked with fish as a polyculture. Fish are also grown in rice-fields or floodplain lakes.
The main study results are summarised in Table 12, which shows that the studied reservoirs conservatively support about 173 commercial aquaculture farms which produce about 10,700 tonnes of fish per year worth around US$19.6 million at first sale. All farms are family businesses, which directly employ about 500 people, as well as supporting suppliers and those who sell their fish through markets, stores and restaurants. Private households also grow fish, which would add a small amount to the total estimate.
Production of Nile tilapia in cages, mainly in the Nam Ngum River (which is regulated by dams) is carried out by about 25% of the farms, but supplies more than 90% of the quantity and value of all of the estimated aquaculture fish production, and is now an extremely important industry for supplying food fish in Vientiane and nearby centres. Near Vientiane, there are now about nine times as many tilapia cages in the Nam Ngum River as in the Mekong River, reflecting the more favourable conditions for fish farming provided by regulation of this large Mekong tributary.
Pond fish polyculture of fish integrated with chicken or pig farming is also an important and growing industry. Fish production is secondary to the main outputs from these farms, but is nevertheless significant at about 800 tonnes of fish per year worth about US$1 million; production of eggs, chickens and fish is much greater, showing the importance of water supply for meat production. Growing fish in ponds enriched with animal wastes adds little to farm costs and is a way of capturing nutrients that would otherwise be lost. The additional value from fish can mean that a farm makes a profit, and fish also provide some insurance against fluctuating prices for livestock, poultry and eggs. The farms also provide some benefit to downstream users, as their ponds drain to irrigation canals, which transport waste nutrients to farmland.
While aquaculture is a growing industry, particularly associated with reservoirs, it is facing various challenges: 1) lack of technical and business capacity of farmers, 2) poor disease management, 3) competition among farmers, including with immigrants, 4) limited availability and the need to import large quantities of fish fry and feed, 5) possible impacts of wastes on other uses of downstream rivers (in the case of cage farming), 6) water quality problems caused by hydropower dams upstream during commissioning and operations and 7) unreliable supply of water from irrigation dams. Page 3 of 66
The study also indicates that commercial aquaculture has limited viability where reservoirs are remote from urban centres, because costs are higher and wild fish can supply local demand. The relative merits of capture versus culture fisheries should be considered case-by-case and management efforts applied where most appropriate.
By highlighting the scale and value of aquaculture, it is hoped that this study will improve the support for aquaculture in Lao PDR, and also influence the planning and management of dam and reservoir projects.
Specifically, maintenance and operation of irrigation systems should be improved so they provide irrigation water when needed, and also provide water for fish farmers, particularly at the hottest and driest time of year, the end of the dry season. At present, many irrigation reservoirs and associated systems are not functioning well. Integrated chicken-fish and pig-fish farms downstream of irrigation reservoirs could provide significant revenue and might be re-considered as the primary users of water from some reservoirs, based on their value and potential to support maintenance of infrastructure. Currently, irrigation reservoirs are the responsibility of the Dept of Irrigation, but management of some selected reservoirs could readily be transferred to the Dept of Livestock and Fisheries, as both departments are within the Ministry of Agriculture and Forestry.
Hydropower dam commissioning procedures need to be improved to reduce the impacts of ‘bad water’ which may affect fish farmers downstream, which has been a problem for cage fish farmers in the Nam Ngum River. Hydropower operation also needs to take into account downstream users, particularly regarding water quality, as well as flow variation caused by hydro-peaking, which should be mitigated according to license conditions and advised to farmers downstream.

Celem opracowania jest analiza możliwości wykorzystania zbiornika wodnego na terenie gminy Kluczbork, na rzece Stobrawie, w kierunku rekreacyjno-turystycznym. Przeanalizowano wyniki dwóch ankiet
przeprowadzonych wśród mieszkańców przyległej do zbiornika wsi Ligota Zamecka. Termin pierwszej ankietyzacji został wybrany w momencie, kiedy mieszkańcy znali jedynie projekt budowy zbiornika retencyjno-rekreacyjnego w Kluczborku. Drugą ankietę przeprowadzono, kiedy zbiornik był już ukończony i napełniony wodą. Wyniki ankietyzacji pokazują, że opinia mieszkańców, zmieniła się wraz z wybudowaniem zbiornika (więcej jest opinii pozytywnych). Ponadto wykonano dwukrotnie orientacyjne badanie fizykochemiczne wody w zbiorniku.
Próby pobrano jesienią i wiosną poniżej miejsca wlotu rzeki Stobrawa do zbiornika wstępnego oraz na wlocie do właściwego zbiornika retencyjnego.

The accuracy of determination of the crude oil PVT properties is essential for solving many reservoir engineering, production engineering, reserve accurate estimates and surface production and operational problems. A large number of PVT correlations for oil exist in the petroleum literature and numerous studies are also present for with data favoring one correlation over the other. In the absence of PVT representative data from laboratory experiments, it is often difficult to choose which correlation to use to calculate different PVT properties. We approached this problem in two ways. First, we developed an expert system that checks the input parameters (e.g. reservoir parameters) against the valid ranges of input data for different correlations as cited by the author of each correlation, and then recommends which correlations to use for specific input parameters. Second, we tested all available PVT correlations for black oil on a database of selected 3500 data points of crudes to develop criteria on which correlations to use for each PVT property for any specific range of input data. These specific crudes were selected to allow testing of those guidelines on a wide range of reservoir input data for black oils. Our database included oils with oAPI ranging from 17 to 51, gas-oil-ratios of 8 to 7,800 scf/STB, formation volume factor at bubble point of 1.04 to 4.47 bbl/STB, bubble point pressures of 60 to 4,739 psia, and reservoir temperatures of 40 to 270 ◦F.
The present work included 14 bubble points, 6 solution-gas-oil ratio, 14 formation volume factors, 13 oil compressibilities, 14 dead oil viscosities, 9 saturated oil viscosities, 10 under saturated oil viscosities ,12 under-saturated densities, 2 total formation volume factors and 2 saturated oil density correlations.
An amazing match was concluded due to combining both the developed PVT-Calculator and PVT-Expert System, which made the conclusion more applicable to be tested to different PVT data points in all future applications.
Based on this study, guidelines for selecting an appropriate correlation for PVT oil properties and specific guiding ranges are introduced for black oil PVT properties correlations .These guidelines are recommended in programming of PVT correlations regardless of their geographic origin.

The identification of fluid contacts (gas–water contact—GWC, oil–water contact—OWC and gas–oil contact—GOC) is essential for field reserve estimates and field development and, also, for detailed formation evaluation. For the accurate calculation of some petrophysical parameters, such as porosity, the reservoir interval has to be zoned by fluid type, to account for differences in fluid saturations and fluid properties (e.g., hydrogen index, density, sonic transit time) in the various intervals: gas cap, oil column and aquifer zone. The fluid contacts may vary over a reservoir either because of faults, semipermeable barriers, rock quality variations / reservoir heterogeneity, hydrocarbon-filling history or a hydrodynamic activity. Horizontal contacts are typically taken into consideration, although irregular or tilted contacts occur in some reservoirs. The methods used for determining the fluid contacts include fluid sampling, water and hydrocarbons saturation estimation from geophysical well logs, analyses of conventional or sidewall cores, and formation pressure measurements. The pressure profiles obtained with various formation testing tools over reservoir intervals are, frequently, the primary source of data for defining the fluid contacts. When good quality pressure data can be collected, the fluid contacts can be determined by identifying the depths at which the pressure gradients (pressure versus depth trends) change. This study addresses some issues related to the identification of GWC for two gas fields of Early Pliocene age (Dacian stage), belonging to the biogenic hydrocarbon system of western Black Sea basin-Romanian continental shelf. We show that the identification of these contacts based exclusively on pressure gradients analysis is uncertain or may be inaccurate. The pressure gradients approach should be checked against the results of the conventional interpretation of geophysical well logs (e.g. changes in the computed fluid saturations as a function of depth) and, if available, the results of nuclear magnetic resonance (NMR) log investigations, which are able to indicate the intervals with clay-bound water, capillary-bound water and movable fluids.

Ostroumov S. A. On some issues of maintaining water quality and self-purification.- Water Resources, 2005. Volume 32, Number 3, p. 305-313. http://www.scribd.com/doc/57511892/0305 [Generalizations presented in this paper represent, in systematized form, the basic elements of the qualitative theory of water self-purification in freshwater and marine ecosystems. Recommendations are given for maintaining water quality and sustainable development of water resources.

New experimental data were generated: Results of experimental studies of the effect exerted by the surfactant Triton X-100 and the OMO synthetic detergent on freshwater bivaqlve mollusks, freshwater mussels Unio tumidus]. ISSN 0097-8078 (Print) 1608-344X (Online). DOI 10.1007/s11268-005-0039-7.

Main discoveries made by the same author:
Публикации того же автора. Основные результаты. Main Results: http://www.scribd.com/doc/59437439/;
On the author / Об авторе (С.А.О.):
http://www.famous-scientists.ru/3732/;

Fearnside, Philip M. (ed.) 2015. Hidrelétricas na Amazônia: Impactos Ambientais e Sociais na Tomada de Decisões sobre Grandes Obras. Vol. 2. Editora do INPA, Manaus. 297 pp. ISBN print: 978-85-211-0144-4 online: 978-85-211-0150-5 [Samuel, Hidrelétricas de Roraima, Rio Tapajós, Efeito estufa, Política energética].