Well productivities of gas-condensate AXX and TS reservoirs are severely impaired by condensate banking. Production decline has been observed. The most obvious evidence of condensate banking is increase in GCR (decline of CGR). Besides production data, laboratory data undoubtedly indicated condensate banking in the wells: decline in dew point with time, decrease in heavier, C6+, components, density and molecular mass of condensate.
Moreover, the liquid drop out curves, i.e. volume of liquid phase vs. pressure, show that volume of liquid decreases with time. The later samples behaved as leaner gas condensate compared to those sampled at the beginning of production providing less volume of liquid phase, indicating condensate drop out.
AXX reservoir is built up of clastic and carbonate sediments. Predominant part of the horizon represents a typical coarsening upward clastic formation, which is characterized by increasing sand content and decreasing clay and carbonate content toward the top of the formation. Clastic formation is topped with limestones. Upper clastic zone represent the main productive zone in AXX reservoir.
The T1 TS reservoir is built up of peloidal-bioclastic limestones (packstones). The horizon features an alternation of thin reservoir and non-reservoir layers. Reservoir layers are from several decimetres to 3 metres thick, while non-reservoir layers have thicknesses from several decimetres to 8 metres.
I would appreciate receiving suggestions for solvents (alcohols, ethers, etc) application, i. e. types, how to estimate volumes for a treatment, and any other advice regarding condensate banking problems.
Snezana Sevic
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Snezana Sevic
PM Lucas Enterprises Ltd
Kac
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