Salt Precipitation during Gas Production

The decline in productivity in mature gas fields is often attributed to liquid loading but in reality it may be a result of salt deposition which can have similar consequences. The phenomenon of salt precipitation is gradually increasing and is becoming a serious issue in the North Sea.During gas production the reservoir brine will evaporate leading to an increase of dissolved salt concentration. Once the solubility limit is exceeded salt precipitation occurs which can have a detrimental impact. Salt precipitation results in a decrease in porosity and ultimately in a decrease of gas production eventually killing the well. Salt precipitation increases towards the end of the life time of gas fields. Currently water washes are used to remove and dissolve the salts but a good understanding is still lacking as the problem is complex.In this study we develop a radial flow model which is then further enhanced to help predict the location and rate of salt deposition in order to help in increasing the productivity.The Contents of this book are specifically targeted towards operators of oil companies who face salt precipitation problems during gas production.