Research and application of dynamic reserves appraising methods in Sulige gas field under downhole throttling production mode

Dynamic reserves, as the material basis of a gas reservoir, are crucial to the determination and adjustment of development strategy including the production scale and its stable period, as well as the control of well spacing etc. The limited reservoir pressure data due to down-hole throttling production mode, together with the low permeability and lengthen transient flow period in the Sulige gas field, make it difficult to evaluate the dynamic reserve based on material balance and rate transient analysis. To solve this problem, two new methodologies, the improved rate transient analysis and dynamic index regression technique, are proposed. Those two methods, not just rely on the regular casing pressure and production data, but an integrated application of the casing pressure and production data with the dynamic reserve considering the low permeability, heterogeneity and dynamic feature of the formation. The investigation indicates that a more comprehensive and accurate dynamic reserve was provided by the new methodology.