Drilling and completion fluid

Diagram 1: Drill rig





Diagram 2: Drilling Fluid Classification

Another talk on drilling and completion fluid, conducted by IEM this Saturday morning. Diagram 1 represents the drill rig. Drilling engineer can be said as mud engineer because one of their duties is to maintain a density of mud in the hole in order to counter the natural pressures of fluid and gasses that might otherwise release into the well hole.

Completion fluid is a complex mixture of chemical and additives which used to serve various function driiling the hole. This fluid is like mud that helping to remove the drilled cuttings from the hole. In general, there are 2 types of drilling fluid - Oil based mud and water based mud. Diagram 2 indicates the drilling fluid classification.

Presence of drilling mud is important to maintain borehole stability, minimise loss of fluid to the formation, control formation pressure, lubricate the drill string, suspend solids under static condition , remove drilled cutting from the hole, and keep the bit cool .

The mud is pumpped to the well and then combination of cuttings and mud are sent to cleaning process for removing the sands and cuttings from mud. Several testings are required to determined the physical and chemical properties of fluid. These testing are viscocity, gel strength, sand, pH, methylene Blue Capacity, lubricity, particle size distribution, solid analysis, shale inhibition, electrical stablity, anilline point test , and aromatic content. There are two types of drilling hole - openhole and cased hole. Filter cake is like casing for openhole.