Abstract
The stress sensitivity is an important factor which affects the deliverability of gas wells in carbonate reservoirs with natural fractures. At present, the influence of the stress sensitivity on deliverability is mostly based on the results of core experiment analysis. Considering the limitation of difficult coring for carbonate sample with natural fractures and the experimental results varying with different fracture development degree, the method of using the well testing dynamic models to forecast the deliverability of gas wells was presented. Firstly, using the well testing data of the typical gas wells, the permeability stress sensitivity was analyzed. Secondly, based on the reliability verification of pressure buildup testing model by the actual deliverability testing data, the deliverability testing design whether considering stress sensitivity or not was carried out. Finally, according to the forecasting results, the influence factors on deliverability change were quantitatively analyzed. The case study has indicated that the dropping of formation pressure is the primary factor which causes deliverability decreasing of gas wells, but the deliverability decline caused by stress sensitivity cannot be ignored. Furthermore, with the increase of producing time, the effect of stress sensitivity on deliverability is gradually reduced. This method can effectively predict the productivity of gas wells in carbonate reservoirs with natural fractures.
论文详情