The paper reviews the performance evaluation of measures against condensate banks in bottomhole zone. The study is based on compositional simulation. According to the results, optimal parameters for LNG injection and dry gas displacement in the formation are selected; duration of the measures taken and incremental recovery are evaluated.

No abstract

Development of Achimov formations is one of the most promising prospects to increase gas and gas condensate production for ROSPAN INTERNATIONAL Inc. Despite large amount of fluid data for Achimov formations, marked by abnormally high pressures (55-60 MPa) and temperatures (104-115 °С), considerable uncertainties still remain, owing to areal and vertical heterogeneity of formation gas within single formation: gas condensate content varies more than twice in a range 150-330 g/m3. Given that the current reservoir pressure has fallen below the dew point pressure for the most part of the license area, it is impossible to acquire new data on the initial gas composition, and existing data is not sufficient to eliminate the uncertainty. Under these circumstances simulation modeling becomes a powerful tool, enabling an engineer to reduce uncertainties by the consistent use of all existing data from various sources, such as geological, lab and production data.

Specific of gas field development suggests a constant level of gas production in order to provide stable loading of gas field processing and transport facilities. At this point, when production of major development objects commences to fall, start of minor objects production is supposed to occur. Having united surface facility and separate reservoir simulation of segregated layers with joint well stock a question of accuracy in measurement of hydrocarbon production is arisen. In addition, at the entry of production of minor objects with distinctive reservoir pressure a problem of appropriate distribution of wellhead and downstream pressures can be revealed.In this paper mechanism of building of a multiple layer oil and gas condensate field integrated simulation model (ISM) is described. Construction of integrated model will allow resolving the problems outlined above. Besides, running of field development simulation cases with different order and tempo of production will be significantly simplified.Separate compositional models made for each development object have been selected for integration in the ISM. However, consolidation of these models is complicated by the issue of demanding a lot of resources for storage and computation time. Therefore, a transition from compositional to black oil models has been performed in order to obtain production data. Detailed gas composition required for integration with a gas processing system can be gained by a delamping procedure.As a result of building integrated simulation model a flexible tool of effective management of field development has been obtained that makes it possible to run simulations for both major and minor objects simultaneously and taking into account the field infrastructure (gathering and compressor facility); to assess the possibility of joint production of separate layers and consider the impact of gathering system on hydrocarbon production as well. When comparing the simulation time in different types of models, without significant loss of simulation quality, the average acceleration is about twenty times. This allows obtaining results much faster and further improving it.

No abstract