A balance equation of gas materials with recharge capacity and their performance prediction

作者：Sun Hedong^*

来源：Acta Petrolei Sinica, 2011, 32(4): 683-686.

• Low-permeability gas reservoir
• Material balance
• Performance prediction
• Unbalance recovery
• Wall model

The traditional method of material balance takes a gas reservoir as a container, while the heterogeneity and seepage flow resistance of strata are commonly neglected. Therefore, the results generally tend to be optimistic when the binomial deliverability and material balance equations are employed to predict the early performance of heterogeneous low-permeability gas reservoirs. Aiming at solving this issue, we assumed that a gas reservoir could be divided into two interconnected and relatively homogeneous blocks by a low-permeability zone. According to the mass conservation law, a balance equation of gas materials with recharge capacity and a dynamic prediction model for their performance were established using the semi-permeable wall model. The proposed model has considered the regional heterogeneity and flow resistance of gas reservoirs, making the material balance model much closer to practical cases and capable of easily and quickly predicting a trend of dynamic variations in gas wells. In addition, varying rules of pressure-time and rate-time relationships in these two blocks could be revealed in this model. Data calculated from real cases indicated that the proposed model could improve the prediction result of the early performance and various indicators derived from the model were close to the production practice. Therefore, this study is of instructive significance in rational and effective development of similar gas reservoirs.

• 出版日期2011