Study on gas-liquid two-phase flow law considering gas dissolution during gas invasion in gas field drilling

During the drilling and development of sour natural gas (including CO 2 H S) fields, due to high solubility in fluid, concealment after invasion increases, resulting well control accidents. Therefore, it is great significance for field deeply study understand acid flow law annular air liquid invasion. In this paper, a multiphase equation considering dissolution established. Based on existing experimental data, state predicting optimized. It found that fugacity activity method using Peng Robinson has highest accuracy. The analysis gas-liquid two-phase through specific example shows influence dissolution, increment mud pit changes slowly strong. When content fluid higher, time gain change monitored ground increases further which more harmful safety wellbore pressure.