Optimizing gas production with innovative approach to evaporative halite precipitation and liquid loading management

Abstract

Abstract The article discusses two issues that affect the productivity of gas wells: halite precipitation and liquid loading. Halite precipitation occurs when salt crystals form in the well, while liquid loading happens when liquids build up in the well, reducing gas production. Accurate prediction of these issues is essential to mitigate them effectively. While liquid loading can be managing by reducing the size of tubing, halite precipitation is more challenging to predict and manage. The existing approaches have not sufficiently validated, and the current halite management measures are not cost-effective. The article reports on a study that aims to develop a model using halite envelope to predict the onset of halite precipitation in a gas field in Oman. The study simulated halite envelopes for thirty different gas wells known to have experienced halite precipitation problems. The results showed that there is significant variation in the size and shape of halite envelopes in different wells, making it infeasible to construct a single envelope for the entire field. However, grouping halite envelopes based on inflow resistance and constructing a model for each group proved to be a powerful tool for halite prediction. The study also investigated the use of velocity string (VS) technology as a new approach to managing halite precipitation. The study simulated halite envelopes for a few wells with different sizes of VS installed, estimating the timing of halite precipitation reoccurrence. The results showed that the effectiveness of VS as a halite remedial technique depends mainly on the rock quality and the time of installation. Additionally, the study assessed the impact of installing VS on liquid loading and the synergy between halite management and de-liquefaction by using VS. The results showed that the synergy between halite management and de-liquefaction using VS depends mainly on rock quality and the size of the installed VS.