TY - THES

T1 - Methods of monitoring flow paths in the Gaiselberg-field with a special focus on tracers

AU - Zechner, Markus

N1 - embargoed until null

PY - 2008

Y1 - 2008

N2 - The aim of this thesis was to find an appropriate method to identify flow channels within the waterflood of the Gaiselberg Field. At present the waterflood in the Gaiselberg Field consists of 12 injectors which inject the produced water back into the reservoir. As the Gaiselberg Field can be regarded as very complex, large uncertainties are existent concerning how the channel flow influences the overall sweep efficiency. On the basis of these cognitions, the remaining reserve potential should be identified and with a new waterflooding strategy be able to be produced. The chapters 2 to 6 describe the different surveillance methods to monitor the fluid flow. The chapter Simulation gives an overview about reservoir simulation and about data necessary to run one. The Production Data and the Material Balance chapter introduce some easy-to-use tools which can assess the performance of an entire waterflood as well as an individual well. The Salinity chapter presents an approach to identify wells which are influenced by the waterflood. With the help of a salinity history of individual wells and the waterflood those wells can be identified. For that reason a salinity data-base of the Gaiselberg Field has been created. In the chapter Tracer the different groups of tracers and the analytical methods to determine those are explained. A review of the possible surveillance methods showed that only a tracer test could give reasonable results. The other techniques are limited in their use mainly because of data-frequency and data-quality reasons. A successful tracer test always requires proper design and implementation. Those chapters focus on the selection of a tracer, the computation of the tracer amounts and concentrations, the selection of a test pattern, the different analysis methods and the realization in the Gaiselberg Field. Due to the relatively small production and the above-average recovery factor, a costly multiple FBA tracer test is fraught with risk. For that reason it is recommended to perform a pilot-tracer-test before to gain knowledge which significantly can reduce the costs of a FBA tracer test. The last chapter deals with injector measurements to allocate the injected water to different perforations. Spinner runs and different temperature measurements were tested. The results and best practice are presented.

AB - The aim of this thesis was to find an appropriate method to identify flow channels within the waterflood of the Gaiselberg Field. At present the waterflood in the Gaiselberg Field consists of 12 injectors which inject the produced water back into the reservoir. As the Gaiselberg Field can be regarded as very complex, large uncertainties are existent concerning how the channel flow influences the overall sweep efficiency. On the basis of these cognitions, the remaining reserve potential should be identified and with a new waterflooding strategy be able to be produced. The chapters 2 to 6 describe the different surveillance methods to monitor the fluid flow. The chapter Simulation gives an overview about reservoir simulation and about data necessary to run one. The Production Data and the Material Balance chapter introduce some easy-to-use tools which can assess the performance of an entire waterflood as well as an individual well. The Salinity chapter presents an approach to identify wells which are influenced by the waterflood. With the help of a salinity history of individual wells and the waterflood those wells can be identified. For that reason a salinity data-base of the Gaiselberg Field has been created. In the chapter Tracer the different groups of tracers and the analytical methods to determine those are explained. A review of the possible surveillance methods showed that only a tracer test could give reasonable results. The other techniques are limited in their use mainly because of data-frequency and data-quality reasons. A successful tracer test always requires proper design and implementation. Those chapters focus on the selection of a tracer, the computation of the tracer amounts and concentrations, the selection of a test pattern, the different analysis methods and the realization in the Gaiselberg Field. Due to the relatively small production and the above-average recovery factor, a costly multiple FBA tracer test is fraught with risk. For that reason it is recommended to perform a pilot-tracer-test before to gain knowledge which significantly can reduce the costs of a FBA tracer test. The last chapter deals with injector measurements to allocate the injected water to different perforations. Spinner runs and different temperature measurements were tested. The results and best practice are presented.

KW - Wasserflut Flutwege waterflood waterflooding tracer oil

KW - bypassed injector measurements

KW - waterflood waterflooding tracer oil

KW - bypassed injector measurements

M3 - Master's Thesis

ER -