Geostatistics and more specifically stochastic modeling of reservoir heterogeneities are being increasingly considered by reservoir analysts and engineers for their potential in generating more accurate reservoir models together with usable measures of spatial uncertainty. Geostatistics provides a probabilistic framework and a toolbox for data analysis with early integration of information. The uncertainty about the spatial distribution of critical reservoir parameters is modeled and transferred all the way to a risk conscious reservoir management. The stochastic imaging (modeling) algorithms allow the generation of multiple, equiprobable, unsmoothed reservoir models yet all honoring the data available. This thesis presents stochastic reserve estimation methods as related to the various stages of development of an oil field. Advances in technology are leading to better deterministic estimates as well as stochastic estimates with narrower ranges. Practices in the industry vary from complete dedication to deterministic or stochastic to a choice of the method depending on the stage of the development. In this study, reserves are calculated from the data available in Southeastern Turkey by using stochastic methods. Probability density functions, number of iterations are important statistical concepts. Increasing number of iterations leads to a normal distribution of histogram.

Reasons like increases in the price and demand of energy in the last years, growing interest and support in the renewable energy resources, development of social environmental consciousness, interest in using domestic resources, having legal regulations has promoted the interest in the electricity production from geothermal energy. For the effective and productive use of existing resources, important data of geothermal regions are obtained with well tests. Well tests are the studies which starts while the well is drilling, continues after the well completion during the process of operation planning with optimum performance suitable to geothermal source and presents continuation also in the operation stage as required for the dynamic structure of geothermal systems. In Aydin Kuyucak Pamuk&ouml / ren region three wells are drilled, achieved results are positive. At AP1 well only CO2 emission is present, no test is done for this well. With the tests for AP2 and AP3 wells temperature, pressure and production values are determined. By the results of these tests, it is determined that this region will be one of the important fields in the West Anatolian Region with current temperature and production rate. In this study, the geothermal energy recoverable from this region is calculated with volume method of geothermal resource assessment. Monte Carlo simulation technique is used with an add-in software program @RISK to Microsoft EXCEL. Electrical power capacity of Aydin-Pamuk&ouml / ren geothermal field is determined as 45.2 MW with 90 % probability. The most likely electrical power value was found to be 78.75 MW with a probability of 69 %. The number of wells required are 10 for a production capacity of 200 t/hr and 7 for a production capacity of 300 t/hr at each well head.

In this thesis, quantitative risk assessment study of several oil field transportation lines that belong to a private oil production company located in S. East Turkey has been conducted. In order to achieve this goal, first primary risk drivers were identified. Then relative ranking of all pipeline segments were conducted. Quantitative risk assessment was based on Monte Carlo simulations and a relative scoring index approach. In these simulations frequency of occurrence of pipeline failures for different oil field pipeline systems was used. Consequences of failures were also based on historical data gathered from the same oil fields. Results of corrosion rate calculations in oil and water pipeline systems were also reported. iv Most significant failures are identified as corrosion, third party damage, mechanical failure, operational failure, weather effect and sabotage. It was suggested that in order to reduce corrosion rate, thin metal sheets must be inserted in pipelines. Aluminum sheets (anodes) must be used to reduce corrosion rate in water pipeline system. The required number of anodes was calculated as 266 for BE field water pipeline (the life of anode is 1.28 years), 959 for KA water pipelines system (the life of anode is 3.2 years.) and 992 for KW water pipelines (the life of anode is approximately 2 years). Furthermore high risk pipeline segments for further assessment were identified. As a result of Monte Carlo simulations, the highest risk was observed in return lines followed by flow lines, water lines and trunk lines. The most risky field was field BE for which the risk value in trunk lines were the highest followed by flow lines. Field SA was the second risky region for flow lines and it was followed by KU region. Field KA was forth-risky. Prioritization of maintenance activities was suggested and areas of missing or incomplete data were identified.