The objective of this study is to determine hydrate formation conditions of a multicomponent polymer based drilling fluid. During the study, experimental work is carried out by using a system that contains a high-pressure hydrate formation cell and pressure-temperature data is recorded in each experiment. Different concentrations of four components of drilling fluid, namely potassium chloride (KCl), partially hydrolyzed polyacrylicamide (PHPA), xanthan gum (XCD) and polyalkylene glycol (poly.glycol) were used in the experiments, to study their effect on hydrate formation conditions.

In this study, the structure sensitivity of hydrogen, oxygen and carbon monoxide adsorption was investigated by changing the metal particle size of Pt/Al2O3 catalysts. 2 % Pt/Al2O3 catalysts were prepared by incipient wetness method / the particle size of the catalysts was manipulated by calcining at different temperatures. The dispersion values for the catalysts calcined in air at 683K, 773K and 823K were measured as 0.62, 0.20 and 0.03 respectively. The differential heats of adsorption of hydrogen, carbon monoxide and oxygen were measured using a SETARAM C80 Tian-Calvet calorimeter. No structure dependency was observed for hydrogen, carbon monoxide or oxygen initial heats of adsorption. The adsorbate:metal stoichiometries at saturation systematically decreased with increasing particle size. Hydrogen chemisorption sites with low and intermediate heats were lost when the particle size increased. On the other hand, oxygen and carbon monoxide initial heats and adsorption site energy distributions did not change appreciably with the metal particle size.

The aim of this experimental study is to investigate the inhibitive properties of polyglycol and polyglycol+KCl aqueous solutions on hydrate formation, which causes serious fluid flow problems, especially during deepwater drilling operations. As the petroleum industry continues to search oil in deeper and deeper seas, the possibility of facing hydrate problems during drilling operations increases because of the suitable conditions for hydrate formation. The main goal of this study is to investigate the hydrate inhibition capacity (thermodynamic and/or kinetic inhibition) of polyglycol and KCl which are mainly used in drilling fluids for shale inhibition and wellbore stability. A high pressure hydrate forming reactor is used to form and dissociate methane hydrate from aqueous solutions of polyglycol and polyglycol+KCl. In total 10 experiments were carried out, 5 of them with 0%, 1%, 3%, 5% and 7 % by volume of polyglycol solutions (Group-A experiments). The remaining 5 experiments (Group-B) had 8% by weight of KCl in solution in addition to the same polyglycol concentrations of Group-A experiments. Among the two chemicals tested for their hydrate inhibiting potentials, polyglycol did not exhibit any thermodynamic inhibition capacity while KCl was observed to have the ability of hydrate inhibition thermodynamically. On the other hand, increase in polyglycol concentration at constant KCl concentration (Group-B) increases the hydrate formation depression capacity of KCl. Polyglycol inhibits methane hydrate formation kinetically. The higher the polyglycol concentration in aqueous solution, the lower is the initial rate of methane hydrate formation (corresponding to first 15 minutes of hydrate formation). On the other hand, there exists a slower change of methane hydrate formation rate as polyglycol concentration increases.

The continuous rising of anthropogenic emission into the atmosphere as a consequence of industrial growth is becoming uncontrollable, which causes heating up the atmosphere and changes in global climate. Therefore, CO2 emission becomes a big problem and key issue in environmental concerns. There are several options discussed for reducing the amount of CO2 emitted into the atmosphere. CO2 sequestration is one of these options, which involves the capture of CO2 from hydrocarbon emission sources, e.g. power plants, the injection and storage of CO2 into deep geological formations, e.g. depleted oil reservoirs. The complexity in the structure of geological formations and the processes involved in this method necessitates the use of numerical simulations in revealing the potential problems, determining feasibility, storage capacity, and life span credibility. Field K having 32o API gravity oil in a carbonate formation from southeast Turkey was studied. Field K was put on production in 1982 and produced until 2006, which was very close to its economic lifetime. Thus, it was considered as a candidate for enhanced oil recovery and CO2 sequestration. Reservoir rock and fluid data was first interpreted with available well logging, core and drill stem test data. Monte Carlo simulation was used to evaluate the probable reserve that was 7 million STB, original oil in place (OOIP). The data were then merged into CMG/STARS simulator. History matching study was done with production data to verify the results of the simulator with field data. After obtaining a good match, the different scenarios were realized by using the simulator. From the results of simulation runs, it was realized that CO2 injection can be applied to increase oil recovery, but sequestering of high amount of CO2 was found out to be inappropriate for field K. Therefore, it was decided to focus on oil recovery while CO2 was sequestered within the reservoir. Oil recovery was about 23% of OOIP in 2006 for field K, it reached to 43 % of OOIP by injecting CO2 after defining production and injection scenarios, properly.