General abstract Gilsonite Cement Additive
Since Gilsonite, a solid hydrocarbon, was Introduced to the Oil Industry in August 1957 as a cement additive, over 200 jobs have been performed using the material. Designed primarily as a combination low-density, lost-circulation slurry, Gilsonite cement additive has yielded excellent results In areas of incompetent formations as well as in other types of lost-circulation zones Field results generally show that fill-up of 80 to 90 percent.
An amount of a petroleum solvent which depends upon the amount of Gilsonite present may be added to the wet or dry mix for wetting the surface of the gilsonite particles and causing them to form an intimate bond with casing and earth formations of the borehole, thus preventing corrosion and minimizing pulling away of the cement from the casing and/or borehole wall by reason of the shrinkage normal to setting of the cement.
Instead of adding the solvent directly to the mix, it may be pumped through the casing and into the cementing zone in advance of the gilsonite-cement slurry.
Introduction of Gilsonite Cement additive
The expansion of the oil industry has emphasized the need for low-density cementing slurries with effective lost-circulation control, particularly during primary cementing in complex formations. Lost circulation leads to challenges like reduced drilling rates, mechanical issues, loss of drilling fluids, and in severe cases, well abandonment. Traditional methods, such as reducing slurry density or adding bridging materials like nutshells or plastics, can mitigate minor issues but often fail in severe conditions, sometimes compromising cement strength.
Innovative solutions, including pozzolanic additives and expanded perlites, improve slurry performance by reducing weight while maintaining adequate strength and allowing the use of bridging materials. Gilsonite, a unique solid hydrocarbon from Utah, stands out as a highly effective additive for controlling lost circulation. Unlike traditional asphalts, its distinct mineral properties make it particularly suited for severe conditions, providing enhanced performance without significantly sacrificing other desirable slurry characteristics.
Application of cementing additive in oil & gas
- Increasing cement function
- The weight of Slurry would be very lower
- prevent from spread of free waters
- will reduce water quantity of slurry
- reducing the mud quantity
- improving scours of wellbore
- preventing from wellbore rheology
Advantages of Gilsonite cementing additive
Gilsonite should be realized that there are various classes with respect to melting points. The lower the melting point, the faster the Gilsonite will dissolve in a solvent therefore or soften under conditions of heat. Therefore, the use of gilsonite in an oil & gas well-cementing composition affords an opportunity to select a class of that material that best serves the particular purpose. The heat softening characteristic of Gilsonite becomes of particular importance in instances of relatively high bottom-hole temperatures, where there is a tendency for the Gilsonite to soften and diffuse into the surrounding cement.
The blending of Gilsonite with other drilling mud additives increase performance in cementing and drilling fluids in a way no other single additive can. gilsonite, the recognized industry standard for filtration control, is equally effective at controlling lost circulation and improving wellbore stability.
