Salt Deposition
The precipitation of salt (e.g. NaCl, KCl) is a serious problem and can block the flow path of hydrocarbons. Salt scaling is particularly severe in wells with high saline (>200 g/l) formation brines which may be near saturation with respect to sodium chloride. The phenomena occurs more frequently in gas wells than in oil wells, and can be caused by low pressures, decreasing temperatures and/or the addition of organic hydrate inhibitors.
Pipeline fouling due to salt deposition
Mature reservoirs usually have low pressure in perforations, tubing nipples or chokes. When gas and formation brines are retrieved from these reservoirs, water vapour can be stripped from the fluid, increasing the residual salt concentration. Saturation may be accelerated if fluids are cooled during transit from the well bore into transfer lines.
The addition of organic liquids to prevent gas hydrate formation can also increase the risk of salt deposition as commonly used inhibitors such as glycols and alcohols generally reduce the aqueous solubility of salts.
Salts readily adhere to surfaces, particularly rough surfaces, and are capable of forming very dense plugs, severely restricting flow and thus production efficiency.
At Hydrafact, for salt deposition technical studies we offer:
- Measurement of salt solubility at surface and reservoir conditions, including the effects of organic inhibitors
- Assessment of salt inhibitors (e.g. crystal grow modifiers) on deposition conditions and surface adherence
