Novel Applications of Formation Testing to Optimize Field Redevelopment Program and Gas Injection EOR Project in Mature Fields

Formation testing has been utilized widely worldwide as well as in China for field exploration and appraisal, helping reservoir characterization and evaluating hydrocarbon reserve. However, using formation testing technology at development stage in order to improve the reservoir ultimate recovery is not mentioned much in published literatures. In this paper, two case studies were summarized on how formation testing was used at the secondary and tertiary stage of development field in west China including the first domestic gas injection monitoring application. HD Field is one of the oilfields of PetroChina which contributes significant oil production in Tarim basin. With strong aquifer support, one challenge in the adjustment of oilfield development plan is to identify how a potential zone has been water flooded. This case study demonstrates how data acquired from the formation testing helps reservoir engineering study, revises the field development plan and eventually identify the new wells locations with encouraging production result. The second case study demonstrates the first ever application in China of gas injection monitoring in field YH. This field is rich of gas condensate and utilizes gas injection as the main approach to drive the field production and to maintain the reservoir pressure. Because of commingle gas production from multiple zones; it is challenging to understand the sweeping efficiency of injected gas from different formation. With the help of real time downhole fluid composition measurement and innovative new designed probes, formation testing is able to pin point zones that have been swept by injected gas. So the gas injection strategy was adjusted accordingly to improve the overall field recovery.