Gilsonite in cementing

General description about Gilsonite in cementing

Gilsonite in Cementing is suitable for blocking or plugging an abandoned pipeline or backfilling a mine shaft, tunnel or excavations contains Portland cement or a mixture of at least two components selected from Portland cement, A cementitious slurry, formulated from the cement mix, may have a density less than or equal to 1500 kg/m3, and exhibits good compressive strength. Cement integrity and wellbore architecture are considered vital to the performance and total recovery of wells.

Since Gilsonite, a solid hydrocarbon, was introduced to the oil industry in August 1957 as a cement additive, several thousands of jobs have been performed using the material. These operations have included primary cementing through lost-circulation zones of surface, intermediate, and production pipe in both single and multiple stages as well as various remedial jobs such as squeezing, re-cementing above inadequate fill-up, and plugging back to reestablish drilling-fluid circulation.

The Natural Bitumen which needs to be applied in oil well cementing is standard quality lump grade Gilsonite. Basically, when an oil well is finished off, a mixture of cement and rock aggregate is pumped down the well to encase the oil pipe into the formation. Pumping such a heavy mix down into a well and pulling it back up again is a very expensive process. Replacing a great extent of the heavy rock with light–weight Gilsonite particles reduces the pumping costs dramatically. Therefore applying Gilsonite in Oil Well Cementing is simply a “rock replacement.”

Gilsonite in Cementing is the process of introducing cement to the annular space between the wellbore. A wellbore means it is a hole that is drilled to aid in the exploration and recovery of natural resources, including oil, gas, or water. A wellbore is the actual hole that forms the well. A wellbore can be encased by materials such as steel and cement, or it may be uncased. The motivation for drilling a wellbore is usually to extract oil or gas for a protracted period of time.

Gilsonite Cementing is used in bonding slurries (Slurry means, it is a mixture of solids denser than water suspended in liquid, usually water. The most common use of slurry is as a means of transporting solids, the liquid being a carrier that is pumped on a device such as a centrifugal pump. The size of solid particles may vary from 1 micron up to hundreds of millimeters) to provide density control.

It is also scouring action for mud removal, and to support compressive strength development. It has a unique reaction with shale that improves cement bond development and strength. The wellbore is the primary hole on which the final well will be made. also, wellbores can be encased by steel or cement or in some cases, depending on the situation, may not be encased. In oil wells, it is necessary to encase the wellbore by cement. Adding the Gilsonite material during oil well cementing enhances the isolation characteristics while decreasing the vertiginous gas flows. These characteristics can result in more effective mud removal which also enhances the environmental factors.

Designed primarily as a combination low-density lost-circulation slurry, Gilsonite 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 can be obtained in areas where only 50 to 60 percent fill-up was possible with other types of slurries.

In the formulation of cementing composition, it`s preferable to employ Gilsonite in an amount ranging from approximately 1/5 to approximately 10times. By volume the amount of cement utilized, depending upon the particular result desired.

Thanks to its distinctive chemical properties and physical appearances, Gilsonite is the supreme cement additive for a wide range of wellbore configurations.

Usage of Gilsonite in Cementing for Oil & Gas Well

For many years, the drilling industry has used Gilsonite Cementing Grade as a basic and recyclable medium in the worst parts of the world to cement the walls of oil wells.Using Gilsonite as additive during the operation of wall cementing of oil wells its the biggest advantage will be that the Gilsonite will prevent the spread of gas and hydrocarbon to the environment.

An oil well is made primary to the final well which will be filled later on and also needs to be encased during the primary works. For cementing an oil well, different ways can be used while several include applying of Gilsonite. The material should be pumped into the well for to encase the piping, therefore applying Gilsonite as a soft rock decreases the material density.

Gilsonite Cementing Grade is an effective ingredient in insulation and it would be recyclable in the environmental cycling, reducing the risk of environmental damage to a very high level.Today, following the very fundamental challenges of insulating deep wells during drilling, due to the use of a variety of chemicals to insulate the walls of the well, these chemicals are very harmful to the environment, which is why the environment’s supporters Has lived.

Advantages of Gilsonite in Cementing

Gilsonite significantly improves cement properties, cuts cost, and difficulty of consuming several additives. Gilsonite guarantees zonal isolation, diminishes environmental hazard, enhances ultimate recovery, and lowers total cost of ownership for the life of a well. Cementing with Gilsonite significantly decreases the cost of water agents caused by loss of free water.

Benefits of Gilsonite cementing

• Increases flexibility
• Reduces cracking
• Heals micro fissures
• Reduces permeability
• Strengthens bond to the formation and the casing
• Reduces environmental risk
• Assures zonal isolation
• Zonal isolation for the life of the well
• Eradication of fluid cross flow
• Avoidance of gas migration to the surface
• Safeguarding fresh water aquifers

Benefits of Slurry Cement

• Controls free water
• Reduces slurry weight
• Increases yield
• Scours wellbore/enhances mud removal
• Promotes favorable rheologies resulting in lower ECDs
• Prevents lost circulation
• Lowers slurry water ratio

Packing of Gilsonite Cementing 

Specification of Gilsonite in Cementing