OMV Austria E&P GmbH operates 26 oil fields in Lower Austria. The majority was developed in the 1950s and 1960s and shows an extended decline period. The challenge of operating brown fields is seen to maintain a reasonable oil production over time in a cost effective manner - this can be tackled by a major chemical enhanced oil recovery field redevelopment project. The scope of the polymer field rollout is to create and efficiently operate horizontal polymer injection patterns in two horizons in Lower Austria. OMV follows the strategy to pilot new reservoir and production technologies before their application in field rollouts. Due to the large project investment volume it is crucial to derive information and lessons learned from existing pilot patterns to optimize conceptual decisions on artificial lift, completion, sand control and injection strategy and to reduce technical risk. In the past 10 years several vertical pilot patterns were created to analyze the efficacy of polymer injection in the Tortonian Horizon. Significant operational experience in water treatment, polymer injection and polymer back production, but also in tracer testing was established. Since already the vertical polymer patterns showed not only operational success, but also significant incremental oil production, the idea of horizontal flooding patterns was born. To confirm and understand the impact of polymer injection also in horizontal wells, a first horizontal pilot pattern was drilled; additional pilot wells are currently following. For a future field redevelopment the technology selection should be de facto based on either standard or pilot-proven technologies. This paper describes measures undertaken in the discipline of production technology to prepare for one of the largest field redevelopment projects in the history of OMV Austria. These measures include the application of several pilot projects in the field of artificial lift, completion design and sand control, production and injection allocation. Therewith production technology serves the needs for active reservoir management and thus, follows a holistic field development approach.

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This paper presents the first application of a Dual Electrical Submersible Pump (ESP) system in an onshore well in OMV. It describes the whole process starting with the selection of the technology and candidate wells to the installation of the equipment and the start-up phase. Challenges in the operations as well as the methods for production allocation are addressed. Commingled production was seen as a key approach for production acceleration in the development of a field with multiple-stacked reservoirs. To proof this idea, a number of candidate wells and technologies were screened and the concept of "Dual ESP" was finally selected for a pilot in the well Erdpress 6. The design process required simulations and preparative selective production tests. Production allocation was crucial to evaluate the performance of the pilot; therefore several techniques were used, like fingerprinting based on chromatography and chloride content. The Dual ESP system was a completely new approach in producing multiple targets in one well. The selective production tests proved to be essential for an optimum design of the ESPs. Two different methods were used to allocate the production rates to the respective intervals. The most significant finding was that results of the nodal analysis could be verified by chemical fingerprints. This also proved that the investment in downhole sensors was valuable. Interferences between the two pumps could be determined with the information of the sensors resulting in adjustments in the ESP settings. The conclusions from that pilot are that the application of the Dual ESP system is fulfilling the expectations from a technical point of view and that the information gathered prior to the design was crucial. However it is obvious that the application of this expensive technology has to be evaluated and justified in every technical and economical aspect. In the case of this pilot, an unexpected steep water cut rise impaired the forecasted profitability. The use of the Dual ESP system was an exceptional approach to tackle the concept of commingled production. This paper covers the whole process from design to operation and shares the experiences and lessons learned to support future applications.

Summary Horizontal wells are frequently used to increase injectivity and for cost-efficient production of mobilized oil in polymer-augmented waterfloods. Usually, only fluid and polymer production data at the wellhead of the production well are available. We used inflow tracer technology to determine changes in hydrocarbon influx owing to polymer injection and to determine the connection from various zones of the horizontal injector to the horizontal producer. Inflow tracer technology was introduced in horizontal polymer injection and production wells. In the production wells, tracers are released when they are contacted by water and oil. Oil and water tracer systems were used in the horizontal production wells. The changes in the observed tracer concentration were used to quantify changes in influx from various sections of the horizontal producers owing to polymer injection. The inflow tracer technology applied in the horizontal injection wells demonstrates connectivity between different sections of the injection wells and two surrounding vertical and horizontal production wells and opens the usage of this technology for interwell water tracer applications. Inflow tracer technology enables one to elucidate the inflow from various sections of the horizontal wells and the changes thereof, even quantifying changes in influx of various fluids (oil and water). The information shows which sections are contributing and the substantial changes in the influx of oil from the various zones due to polymer solution injection. The overall incremental oil could be allocated to the various horizontal well sections based on the tracer results. Even zones that almost exclusively produced water before polymer injection showed a significant increase in oil influx. The inflow tracer technology installed in the injection well allowed us to analyze the connectivity of the injector to producer not only globally but spatially along the horizontal well. These data are used for reservoir characterization, to condition numerical models, and for reservoir management. Conventional interwell tracer technology allows one to determine the connectivity and connected volumes of horizontal well polymer field developments. However, it reveals neither information about influx of the sections nor the connectivity of various sections of the horizontal wells. Inflow tracer technology closes this gap; it allows one to quantify changes in influx of the fluids. Furthermore, the newly developed installed injection well tracer technology gives spatial information about the connectivity of the horizontal well sections.