关键词: 压裂, 出砂, 诱导应力, 稳定性系数

Abstract:

Based on the stress distribution in the zone near the well, and by the consideration of the artificial fracture induced stress, we found out the stress field around the wellbore of the fractured wells. According to the Drucker-Prage criteria, we obtained the formation stability coefficients under the different conditions. The calculation results showed that the main factors of the formation sanding are induced stress caused by the high production pressure difference instead of the gas drag. More fractures, larger induced stress and more unstable formation made the sanding easier. Meanwhile, the formation stability coefficient decreased with the increase of the permeability, and the speed of the growth overall dropped down. However, the porosity had little impact on the formation stability coefficient. As the length of the fracture increased, the stability coefficient increased as well, on the contrary, the risk of the sanding decreased. By considering the impacts of the induced stress on the stability coefficient in the process of the production, we studied the influencing factors of the sanding comprehensively, to provide the theoretical references for the sanding control design.

Key words: fracturing, sanding, induced stress, stability coefficient