Ημερολόγιο Εκδηλώσεων

Περιγραφή:
ΠΟΛΥΤΕΧΝΕΙΟ ΚΡΗΤΗΣ Σχολή Μηχανικών Ορυκτών Πόρων Εξεταζόμενος μεταπτυχιακός φοιτητής: Τυράκης Νικόλαος Θέμα Μεταπτυχιακής Εργασίας: «Development of a simple correlation utilizing field data and the Standing Katz gas Z-factor method for predicting the Oil Formation Volume Factor at undersaturated conditions» Τριμελής Εξεταστική Επιτροπή: Καθ. Βαρότσης Νικόλαος (επιβλέπων) Καθ. Χριστόπουλος Διονύσιος Καθ. Καλογεράκης Νικόλαος Περίληψη The Oil Formation Volume Factor, Bo, is used in almost all the Reservoir and Production Engineering calculations for converting subsurface fluid volumes to surface ones. The knowledge of its value is a prerequisite for evaluating reliably initial hydrocarbon volumes in place, predicting hydrocarbon recovery and future reservoir performance and identifying the drive mechanism. The values of the Oil Formation Volume Factor are measured during the PVT study and they become usually available several months after the well has been tested. In the meanwhile, crucial reservoir engineering decisions have to be made by the Operator, including the estimation of the reserves and the future production plans for which values of Bo are provided by widely used correlations which only require data that are measured in the field during the Well Test (solution GOR, API, Sg, Tres). Given that these correlations are equations fitted against experimental data of oils from certain origin and composition, their accuracy is doubtful. The present dissertation deals with the development of a simple correlation, called liquid Z-factor based method, using fundamental relationships, for the determination of the Bo at undersaturated conditions. The correlation expresses the Bo as a function of data that are measured in the field during the Well Test and the reservoir density at reservoir pressure. The DAK representation of the Standing-Katz Z-factor chart was used for the computation of the crude oil density, and an Excel spreadsheet was developed to incorporate all the above calculations. A literature review was conducted to qualify 5 correlations among the most frequently used ones by the oil industry and to assess their performances. These correlations were also included in the Excel spreadsheet. A database of reservoir oils from all over the world was used for testing the performance of the developed correlation as well as the performance of the other well-known correlations. The results are very encouraging, since, the proposed method proved not only comparable but even more accurate and applicable in a wider range of Bo than the other currently used correlations.