Imerys has a long history of supplying materials to the oil sector. Our products are used mainly in upstream petroleum operations and specifically in the drilling, cementing and completion phases. In particular Imerys provides Drilling Bentonites for the drilling phase, Raw Perlite intended for expansion and Micrasil appropriate for the cementing.
Drilling phase: In geotechnical engineering, drilling fluids or muds are used together with drilling equipment to drill boreholes into the earth. Drilling muds are designed in such a way so as control pressures and support the wellbore, to remove cuttings from the bit, to suspend them and carry them to the surface and to cool and lubricate the bit and drillstring. Drilling mud is the single component of the well-construction process that remains in contact with the wellbore throughout the entire drilling operation.
Bentonite, together with Baryte, are main components of water- and oil-based drilling fluids. Since the early days of the drilling industry, bentonite has really no substitutes that are as versatile and economical for everyday applications.
The role of bentonite is mainly to seal the borehole walls by forming a filter cake, to remove debris and cut material and to lubricate the cutting head of the drilling equipment. The requirements and testing methods for drilling muds are described in the globally acknowledged API Recommended Practice 13 B.
Cementing phase: During the cementing phase, a cement based grout is injected between the casing and the soil. The cement mix should have the right density so as to stabilize the wellbore while also being impermeable. In this process, expanded perlite is used as a lightweight aggregate for controlling the density of the cementitious grout. Superfine pozzolanic additives, such as Micrasil, are also used in this process. Because of their fineness and reactivity with cement, they control permeability by reducing the porosity of the hardened cement grout.