Micro silica or silica fume includes silicon dioxide is very reactive mineral additive. It uses in wide areas such as drilling mud, construction, electrical and furnaces during reduction of very pure quartz. Micro silica cools so rapidly and forms extremely fine in a minute. It used as a filler or extender in rubber or plastic industry. It is weighting agent in down hole and also decreases permeability. In construction it improves the strong and permeability of roofing panel
A lot of transportation agencies are using this material in their concrete for construction of new bridges or rehabilitation of existing structures. It is for use in concrete is available in wet or dry forms. It is usually added during production at a plant. These compositions concrete has been successfully produced in both central-mix and dry-batch plants.
Micro silica is used in oil industry for many purposes such as drag reduction in porous media, foam and emulsion stability in water invasion reduction in shale, filtration control in fluids and rheology control in fluid. Micro silica is a highly effective pozzolanic material consisting of extremely fine that is added to drilling mud for oil field, civil engineering and construction applications. Micro silica consists of vitreous particles whose size is approximately 1000 times less than the average cement particle size. It improves strength and durability of the mud and decreases permeability within the cement. Micro silica can increase the compressive strength of the cement, can reduce fluid loss, can reduce porosity and permeability within the cement, and can reduce the setting time of the cement by accelerating the heat of hydration reaction. Oil industry can be benefit from this excellent material. Majority of its applications are found in oil well cementing and further research is going on its economic feasibility and their imposed environmental concerns. With its entailing benefits it can be an emerging technology in the cementation arena.
As a part of drilling operation, a cement slurry is prepared by mixing raw with water and other additives and it is run down the casing up to the annulus. Generally, oil well cements are exposed to different conditions as compared to cements used in construction industry. The primary objectives of micro silica are to support and hold the casing, to prevent corrosion of the casing by formation fluids. The purpose of usages of this excellent filling material is to provide zonal isolation of the formations which have been penetrated by the wellbore. This mud or drilling fluid is also used to close an abandoned portion of the well. It confines abnormal pore pressure and increases the possibility to hit the target. It prevents undesirable migration of the formation fluids in the annulus between casing and hole. Most oil and gas fields around the world have faced traces of gas migration in the annulus. The aim of every cementation job is to ensure proper setting of cement behind the casing ensuring a negligible probability of channeling.
Main purposes of using micro silica in construction industry is acting kind of destiny material especially on concreate because of have excellent filling properties in cement. It fill the cement particle and make these more strength.It also increase the density construction material and have a frost resistance properties. It also punch the resistance of micro 2,5 times than ordinary cement. It is usually added during concrete production at a concrete plant.It concrete has been successfully produced in both central-mix and dry-batch plants. Assistance is readily available on all aspects of handling using it to produce consistent, high-quality concrete. This constriction material hould be transported, placed, finished, and cured following the good concreting practices by well-known Institutes.