Definition - What does Calcium Chloride mean?
Calcium Chloride is a chemical salt which is used to make drilling and workover fluids or brines which have a density of between 8.33 and 11.6 lbm/gal at saturation. It is considered to be a highly valuable salt in oilfield operations and has the chemical formula CaCl2. The blending of calcium chloride can also be done with other brines such as calcium bromide (CaBr2), zinc bromide (ZnBr2) and sodium chloride (NaCl). Emulsification of CaCl2 brine as the internal phase of oil-base or synthetic-base mud is an important use because the brine provides osmotic wellbore stability while drilling water-sensitive shale zones.
Petropedia explains Calcium Chloride
One important functionality of calcium chloride is that it is used in maintaining and establishing oil and gas wells. The following are other advantages and functionalities of calcium chloride:
- It is used in Drilling mud – Calcium chloride is along with drilling mud in order to reduce the wellbore temperature (cooling effect) and provide lubrication for drilling bits. It also helps in removing solids (drilled mud and granules) from the wellbore and increasing the density of mud to overcome the formation pressure and keep hydrocarbons in place.
- It is used as a completion fluid - Calcium chloride is ideal as a completion fluid with a density range of 10 to 12 pounds per gallon as it flushes the hole to remove solids so that the casing can be cemented.
- It acts as a concrete accelerator – Calcium Chloride helps in reducing the concrete setting time in the well by a large amount.
- It acts as a packer fluid – Once the casing of a wellbore is cemented, calcium chloride is used in packing the annular space between the casing and the tubing, thereby helping in maintaining the required pressure levels.
- It acts as a workover fluid – It helps in flushing out the solids from the wellbore.