Brine
Brine is water with high salt concentration. It contains salts such as sodium, calcium, or bromides in solution. Brine is commonly produced along with oil from the reservoir. Various brine formulations are also used as completion fluid where salt is used to increase fluid density. It is also used for drilling in sensitive formations where either clay swelling is expected or where solid particles as weighting agent could cause formation damage.
Brines formulations can be prepared to achieve densities ranging from 8.4 to over 20 ppg. Common salts used in the preparation of simple brine systems include sodium chloride, calcium chloride, and potassium chloride. Complex brine systems may contain zinc, bromide, or iodine salts, but these brines are more corrosive and costly.