A tarefa de regular um mercado estruturado sob a forma de monopólio natural, como no caso da distribuição de gás canalizado no Brasil, implica assegurar o equilíbrio econômicofinanceiro das firmas reguladas, garantindo, ao mesmo tempo, modicidade tarifária e nível de excelência na qualidade dos serviços prestados. Para isso, a questão da formação de preços é crítica, pois envolve aspectos do excedente e sua distribuição. Por esta razão, dentre as atribuições do órgão regulador, destaca-se o estabelecimento de regras tarifárias que conciliem os interesses dos consumidores e da empresa regulada. Entretanto, a tarefa de desenhar tarifas justas é afetada pela assimetria de informações entre o órgão regulador e a firma regulada, em favor da última. Este trabalho sugere a incorporação da metodologia do Economic Value Added EVA® no processo de revisão tarifária. Tal incorporação, conforme demonstrado, permite ao regulador avaliar a geração de valor do setor e reduzir a assimetria informacional entre concessionárias e agência reguladora. Além disso, facilita o repasse de eventuais excessos de geração de valor aos consumidores, em benefício da sociedade. Palavras-chaves: Assimetria de informação, Economic value added (EVA®), gás canalizado, gás natural, geração de valor, revisão tarifária. / Regulating a structured market under natural monopoly such as the Brazilian pipeline gas distribution implies in assuring an economic and financial equilibrium of the regulated firms as well as guaranteeing the tariff moderateness and service quality excellence. In order to achieve this pricing is crucial, for it encompasses surplus and surplus distribution. Therefore, the role of setting tariff rules of the regulator agency, stands out so that these rules conciliate the interests of both consumers and the regulated companies. However, outlining fair tariffs is impacted by asymmetrical information between regulator agency and regulated firms in favor of the latter. This study suggests incorporating the Economic Value Added methodology in tariff revision process. This incorporation allows the regulator to evaluate the value generation in the sector and to reduce asymmetrical information between companies regulated and the regulator. In addition to this, it makes it easier to allocate the possible value generation surplus to the consumers in favor of the society. Key words: Asymmetrical information, economics regulation, tariff revision, value generation, economic value added (EVA®), natural gas, and pipeline gas.

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / Bibliography: leaves 63-65. / M.S.

Thesis. 1978. Sc.D.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibliography: leaves 421-426. / by Jaime A. Valencia-Chávez. / Sc.D.

As drilling for natural gas in the Marcellus Shale becomes increasingly prevalent, both human safety and environmental concerns have arisen. The aim of this study was to assemble an environmental baseline to make an accurate assessment of its possible impacts. Water samples and chemical parameters were collected from Bates Fork, a stream with Marcellus Shale drilling activity and Fonner Run, a sister stream with no drilling activity, on a monthly basis beginning in the summer of 2010. Bacterial DNA was also extracted from water collected at each site and then amplified using primers for the variable ribosomal internal transcribed spacer (ITS) region of 16S and 23S rRNA. The bacterial ribosomal ITS has both sequence and length variability, which can be used to approximate species abundance and diversity along both streams. The conserved 16S rRNA gene was also amplified, and sequenced to taxonomically categorize organisms. To date, it has been observed that Bates Fork has consistently higher conductivity and chloride levels than Fonner Run. The bacterial diversity was found to be similar between the two streams. As a baseline study, these results show that there have not been any detectable impacts to Bates Fork thus far, but the stream should continue to be monitored. / Bayer School of Natural and Environmental Sciences / Biological Sciences / MS / Thesis

Petrophysical evaluation of the Albian age gas bearing sandstone reservoirs of the O-M field, Offshore South Africa has been performed. The main goal of the thesis is to evaluate the reservoir potentials of the field through the integration and comparison of results from core analysis, production data and petrography studies for the evaluation and correction of key petrophysical parameters from wireline logs which could be used to generate an effective reservoir model. A total of ten wells were evaluated and twenty eight sandstone reservoirs were encountered of which twenty four are gas bearing and four are wet within the Albian age depth interval of 2800m to 3500m. Six lithofacies (A1, A2, A3, A4, A5 and A6) were grouped according to textural and structural features and grain size from the key wells (OP1, OP2 and OP3). Facies A6 was identified as non reservoir rock in terms of reservoir rock quality and facies A1 and A2 were regarded as the best reservoir rock quality. This study identifies the different rock types that comprise reservoir and non reservoirs. Porosity and permeability are the key parameters for identifying the rock types and reservoir characterization.

Historically, Ukraine has been a net energy importer, needing oil and natural gas for the effective functioning of its industries and satisfaction of domestic needs. Ukraine's independence immediately followed the disintegration of the Soviet Union in 1991, resulting in its ultimate dependency on oil and natural gas imports from Russia. During the last few years, the parties had undergone a number of disagreements that led to the disruption of natural gas supply to Ukraine, and political instability within the country. The necessity to redevelop Ukraine's domestic energy industry and adjust it to an available domestic natural gas source became vitally important for the national government. The present project provides a summary of the Ukrainian energy policy dynamics from 2006-present time. It specifies current energy trends, renewable energy sources, alternatives, and provides recommendations for the Ukrainian government on how to integrate successful international experiences into the development of coalbed methane in the local environment. / McAnulty College and Graduate School of Liberal Arts; / Graduate Center for Social and Public Policy / MA; / Thesis;

Transiente motstrøms tyngdekrafts-drevne olje-vann strømningsforsøk ble gjort i en to meter lang lukket plexiglass sylinder. Et enkelt eksperimentelt oppsett baser på visuelle observasjoner ble laget med formål for disse forsøkene. Eksperimenter ble gjort for et stort utvalg av inklinasjoner mellom 0 og 90 grader fra horisontalen. Effektene av ulike eksperimentelle parametere ble undersøkt ved å bruke to typer olje, Exxsol D80 og Marcol 52, to sylindere med ulik indre diameter, 50mm og 90mm, i tillegg til tre ulike vannkutt; 0,25, 0,5 og 0,75. For å simulere et bredt utvalg av strømnings situasjoner ble det brukt tre ulike start kondisjoner med varierende grad av miksing av innholdet. Totalt ble det gjort 755 eksperimenter i løpet av denne oppgaven. Resultatene fra observasjonene har blitt brukt til å danne slip relasjoner som skal bli implementert i en slug-tracking simulator som blir utviklet ved NTNU. Fire ulike strømningsmønster har blitt identifisert for denne type strømning. Kun små forskjeller i strømningsmønster ble observert for ulike olje faser og sylinder diametere. Helninger mellom 15 og 30 grader ble funnet til å gi høyest slip hastighet mellom olje og vann fasene.

Most of nowadays base load LNG plants are localized in the area around equator, with stable warm air and cooling water temperature. For new LNG developments in arctic areas there are several features that differ them from plants operating further south. In this work a ConocoPhillips Optimized Cascade LNG process model has been established in HYSYS® and evaluated. The evaluation focus on the driver configuration and cooling method used in order to optimize process efficiency and capacity of the plant for operation in cold climate. Simulations with air cooling and water cooling have been done. Each cooling method has been evaluated for an aero derivative gas turbine compressor driver, an industrial heavy duty gas turbine compressor driver, and an electric compressor driver configuration. Yearly temperature statistics from Kola has been used. The air cooled simulations have a design temperature of 20°C and the water cooled simulations have a design temperature of 4°C seawater temperature and an air temperature of 5°C. The air cooled cases are not close to design operation the entire year. The aero derivative driver configuration will have problems operating at high air temperatures and a higher design temperature is needed. The heavy duty gas turbine driver configurations have limitation in speed variation and this leads to low process efficiency at low temperatures. The electrical driver configuration will not have problems operating. The results show that air cooling is not the desired cooling method because of lower production variation and lower process efficiency. The water cooled cases are close to design conditions the entire year; hence it has the highest flexibility when it comes to production variation and highest process efficiency. The aero derivative driver configuration varies most throughout the year with lowest production in the summer. The heavy duty gas turbine driver configuration has a lower variation in production. The power delivered to the electrical motors will not be affected by air temperature which lead to high process efficiency and stable production plateau throughout the year.

As the main goal achieved with this master thesis, a plant design was constructed for an acid gas removal process with methanol operating at low temperatures. First, a bibliographical research was made in terms of sour gas treatment; with special focus of physical absorption processes involving methanol as the solvent to achieve separation; such as Rectisol and Ifpexsol. The literature research was extended to thermodynamic data; compiling equilibrium values for binary systems between methanol and carbon dioxide (CO2), hydrogen sulphide (H2¬S) and methane (CH4); respectively. The simulator Pro II with Provision was selected as the computational tool to achieve thermodynamic calculations for the gas stream to be treated. The thermodynamic Equation of State (EOS) utilized to model the properties of the system was a simulator built in modified version of the Soave-Redlich-Kwong-Panagiotopuolos-Reid EOS. Comparisons between the researched equilibrium values and the simulated data were done; corroborating that the model was strong enough to perform calculations for components related with acid gas removal. A natural gas stream rich in Carbon Dioxide (CO2), Nitrogen (N2) and heavy-hydrocarbons was selected from Statoil’s Snøhvit gas treatment processing in order to be subject of acid gas removal. The plant design for the sour gas treatment was developed in three individual stages that were later integrated: heavy-hydrocarbons removal, absorption with methanol and solvent regeneration. The design proposed was effective into removing the CO2 present in the natural gas stream down to a value of 40 ppmv.Finally, a brief pinch analysis was sketched; thus identifying the actual possibility of heat integrating the system with an LNG processing unit. In conclusion, simple simulation and thermodynamic tools can conduct to efficient designs for integral acid gas removal plants.

Severe slugging is an undesirable unsteady multiphase flow phenomenon which occurs in riser-pipeline systems. During the course of this masters thesis work, a dynamic coupling has been shown to exist between this flow phenomenon and the flexible riser in which it occurs. To analyse the influence of this coupling, the cyclic displacement of the riser and the loads exerted by this cyclic displacement on the risers attachment point to a topside vessel have been evaluated.A small scale experiment has been set up of a flexible riser (L and S configurations) undergoing the severe slugging cycle. The flexible risers were produced from a flexible transparent hose of internal diameter 0.016 metres and a load cell was used to measure the loads on the riser attachment point to a topside vessel. Three accelerometers were attached along the riser to measure the acceleration of the riser at defined points. The experiment was video recorded and from this, video analysis was used to calculate the displacement of the flexible riser during the severe slugging cycle. Data from the experiments was logged by Catman analysis tool and was compared with numerical simulations from OLGA.Substantial displacement of the flexible riser has been recorded on both configurations of the flexible riser. Displacements in the order of approximately 1 metre have been recorded on some riser points on both riser configurations. When this occurs, there is a cyclic loading on the attachment point of the flexible riser to the topside vessel and this loading in the long term could lead to fatigue of the riser and probable failure. This loading has been illustrated, and maximum and minimum values for both riser configurations have been recorded.For the constructed L-riser, the displacement of the riser at the top, middle and bottom sections were found to be 0.8588, 0.9760 and 0.5856 metres respectively. The maximum and minimum loads on the attachment points of the L-riser to the topside vessel during the severe slugging cycle have been found to be 0.1 and 6.4 Newtons respectively.For the constructed S-riser, the displacement of the riser at the top, middle and bottom section were found to be 0.112, 0.7760 and 0.957 metres respectively. The maximum and minimum loads on the attachment point of the S-riser to the topside vessel during the severe slugging cycle have been found to be 8.0 and 13.6 Newton respectively.