Gas and Oil Field Applications
The FRILITE® cenospheres offer many advantages for gas and oil field applications, especially for reducing and controlling bottom hole pressure.
Advantages
- Low density: will reduce the weight or density of slurries and fluids
- High strength: withstands high pressures of the application
- Spherical shape: improves flow characteristics
- Closed surface: avoids water / oil absorption
- Low thermal conductivity
- High melting point: good temperature stability over a wide range
Lightweight oilwell cements
The technology of using artificial hollow glass microspheres for lightweight oilwell cement formulations has been publicly known since Halliburton and Schlumberger filed respective patents in the late 1970’s and early 1980’s. But it was only after the “arrival” of the less costly fly-ash cenospheres that this principle became an industry standard. If added to the slurry, cenospheres effectively displace water and cement components to a certain amount. This method yields a homogeneous mix, and finished cement slurries containing cenospheres have lower water content, an increased strength-to-density ratio and lower permeability compared to water extended slurry. Still, they have better flow characteristics, so they are easy to apply. This is particularly important in lost circulation and zonal isolation when drilling and cementing casings. The cementing procedure has a decisive effect on completions, perforating and fracturing.
Drilling, completion and workover fluids
Cenospheres can as well be used in drilling, completion and workover fluids. The primary cause of wellbore damage and reduced production in any perforated completion is the invasion of pulverized rock formation grains that create a restrictive “low-permeability crushed zone.” It is desirable to achieve an under-balanced pressure differential between the well bore and the reservoir prior to perforation so that the hydrostatic pressure inside the well casing is lower than the pressure in the formation. Only then perforation allows for efficient flow of hydrocarbons into the well hole by minimizing the invasion of this pulverized debris. The pressure balance can be achieved by adjusting the density of the fluids with adding the proper amount of cenospheres to the fluid formulation.