| Popis: |
The Casabe Field has been supported by Waterflooding as Secondary Oil Recovery method for 23 years now. In Addition, the reservoir has some particulars characteristic like; high heterogeneous sandstones, low lateral continuity, swelling shale and high structural complexity. Since the beginning of the waterflooding project there were some problems in the field like; preferential injection, low injectivity, repressure reservoirs, which have caused casing collapse, lost of producer wells and low recovery factor. Along the time, the field was managed with a traditional geological model built with wells, which limited the production and injection surveillance. Between 2007 and 2008, a 3D seismic cube was acquired, processed and interpreted for the whole field, covering an area of about 100 km2. With this new information, a detailed structural geological model was built, what allowed visualizing new development areas and optimizing the production and injection process which boosted the oil production and increased the oil reserves. This paper covers the implemented methodologies and solutions about waterflooding pattern remodeling starting from seismic cube as a seismic inversion product that generate a stratigraphic model and more reliable facies distribution. At the same time this interpretation was used to implement and design the flooding strategy in the new zones, producer wells completion optimization and well selective injection design, abandoned pattern reactivation, explanations about unusual production and injection phenomenon and expand waterflooding implementation in new areas This process resulted in the incorporation of 5 MMbls of oil as proven reserves, 20 MMbls of oil as probably reserves and 5 MMbls of oil as possible reserves. |
