Ağır petrol sahalarında sagd uygulamalarında kuyu testleri

Thermal Recovery is one of the common EOR recovery methods. Thermal recovery methods are used worldwide to recover heavy oil and bitumen. Thin layer of water between the quartz and the bitumen makes the oil sands water-wet, this plays an important role in the separation of bitumen from the quartz by use of a hot-water extraction technique. High oil prices are pushing the application of horizontal wells in thermal recovery methods. The possibility of horizontal drilling has created a pathway for SAGD (Steam Assisted Gravity Drainage), which is the most preferred heavy oil and bitumen recovery method. Oil recovery by steam injection requires knowledge of the steam-swept pore volume. The determination of the swept volume in a thermal oil recovery process makes it possibile to do early economic evaluation; it means rapid measurement of the fuel concentration for an in-situ combustion operation, and the heat loss from a steam zone. In field operations, the swept volume has been determined by coring and/or temperature observations made at wells during passage of the displacement front. Well testing evaluates the steam-swept volume by inexpensive and a relatively quick way. The aim of the thesis will be to estimate swept volume and steam chamber mobility by using pressure falloff tests of vertical well. Satman, Eggenschwiler and Ramey (1980) presented a method to estimate the steam zone mobility and swept volume using pressure falloff test; assuming two regions of highly contrasting fluid mobility and an impermeable boundary interface in a composite reservoir. Consequently, for a short duration, the swept zone acts as a closed reservoir, during which the pressure response shows the pseudo steady state behavior. Falloff tests are simulated by shutting-in the injector and recording the wellbore pressure with time. The MDH (Miller-Dyes-Hutchinson) method for the analysis of falloff data is used because the shut-in time is much less than the injection time in practical steam injection falloff tests. The pseudosteady state (PSS) method is used to estimate the swept volume, from pressure fall off testing of vertical wells. A homogeneous square box reservoir, in CMG (STARS) simulator, is used to model steam chamber profile. Injection rate, injection time, steam injection quality and gas (steam) mobility relations with time are investigated by using simulator and comparison with PSS method. The simulation and application of case model is described and finally, comprehensive discussion of the analyses, results and conclusions are given. The results obtained in this study yields reliable results when the swept volume is sufficiently large, so that a proper Cartesian straight line behavior exist.