Tóm tắt:

In a gas well, liquid loading is one of the most important technical problems impacting on production rate. If it is not supervised and given any treatments measure, the liquid will be accumulated in the bottom hole of the well. Therefore, it will prevent the gas moving into the bore hole. Moreover, a lower gas production rate implies a lower gas velocity which will ultimately stop the production. Liquid loading is characterized by the critical gas velocity which is the minimum gas velocity to lift the liquid to the surface. In this paper, we simulate and predict the liquid loading in well X, Nam Con Son basin, Vietnam by using an experiment and modeling approach to recommend some suitable treatment methods for this issue. The results showed that the risk of liquid loading may happen in well X, Nam Con Son basin when gas rate continues to fall because the current gas production rate (2.885 MMscf/d) is quite close to critical gas rate (2.217 MMscf/d). On the other hand, the results showed obviously affecting factors on liquid loading including tubing diameter, wellhead pressure, reservoir pressure and productivity index. When there is an increasing of wellhead pressure and tubing diameter the risk of liquid loading happens quickly. On the contrary, if reservoir pressure and PI increase, the liquid loading will be unlikely to occur.