Gilsonite (FLC) Drilling Mud Additive

 

What is Gilsonite?

Gilsonite is a naturally occurring solid hydrocarbon, often referred to as natural asphalt or uintaite. It is widely used in the oil and gas industry as an additive in drilling fluids to improve fluid loss control, wellbore stability, and shale inhibition.

By uniquely functioning as both a malleable and solid plugging agent, Gilsonite controls fluid loss and seepage, prevents lost circulation, and protects reactive and low-reactive shale surfaces, even at elevated bottom hole temperatures.

he addition of specially-treated Gilsonite to water-based drilling fluids helps minimize hole washout by stabilizing troublesome shale and sealing off highly permeable sands while reducing torque and drag. The drilling fluid loss control or mud is supplied at the surface of the well in large earthen pits or metal tanks and is pumped from these into the borehole through the drill pipe and the drill bit to the bottom of the hole. The mud returns to the surface between the drill pipe and the borehole wall, bringing with it the drill cuttings. The circulation of the mud serves not only to carry the cuttings to the surface but also to cool and lubricate the drill bit, thus making possible the further effective penetration of the bit into deeper geological strata. In conventional drilling operation a drilling mud based on bentonite or other materials such cane fiber, ground walnut hulls, sawdust, etc.

Gilsonite or Natural Bitumen has long been used in oilfields as a fluid loss additive in drilling fluids. In numerous grades and formulations, Gilsonite has been utilized to fight borehole instability complications, offer lubricity particularly in greatly diverged holes, and lately, as a bridging instrument to contest differential pressure sticking and deliver a less invasive coring fluid. It has scientifically proven that suitably framed Gilsonite products can minimalize hole collapse in foundations comprising water-sensitive sloughing shales, and diminish stuck pipe problems by creating a thin wall cake and an inter-matrix filter cake. Gilsonite products are broadly employed worldwide in water based, oil based, and synthetic based mud systems. Furthermore, Blended Gilsonite (Natural Asphalt) is effectively utilized in all water-based systems.
Gilsonite in Drilling fluids loss control component appears to be particularly important to fluid loss control as FLC and to act as a shale inhibitor. This loss control by itself would tend to cause an increase in fluid viscosity but this is effectively dealt with by the other components which make up the additive of the invention.

The invention relates to a composition comprising an HPHT fluid loss control aid, stable at elevated temperatures, and acting as an excellent shale stabilizer, borehole lubricant, sealant for depleted sand, and wall cake conditioner. The additive comprises a Gilsonite (natural asphalt) which contains a surfactant such as a nonionic surfactant. The fluid loss control aid reduces HPHT filtrate loss, has good stability at elevated temperatures, stabilizes troublesome shales, decreases borehole erosion, helps seal depleted sands, reduces torque and drag, causes no adverse effects on the flow properties of the properly conditioned drilling fluid, and lowers total well costs.
Gilsonite in the oil and gas industry, drilling muds or fluids perform various functions that impact drilling speed, cost, efficiency, and safety of the driller. By uniquely functioning as both a malleable and solid plugging agent, Gilsonite controls fluid loss and seepage, prevents lost circulation, and protects reactive and low-reactive shale surfaces, even at elevated bottom hole temperatures.

The reaction conditions used to make the product of the invention can be fairly widely varied, but usually involves heating the indicated components in a sealed reaction vessel at a temperature between 100 to 150C for 120 to 30 minutes. The resulting composition is essentially water-soluble, preferably dried and stored for subsequent blending with conventional clay-based aqueous drilling dispersions or drilling fluids. This blending advantageously is carried out on site, although it may be pre-packed with the drilling fluids.

Role of Gilsonite in Drilling Fluids

In drilling operations, fluid loss control is critical to maintaining wellbore integrity and preventing excessive filtration of drilling fluids into the formation. Gilsonite acts as an effective fluid loss control (FLC) additive by:

1. Reducing Filtration Losses:
   Forms a thin, tough, and impermeable filter cake on the wellbore walls.
   Prevents drilling fluid from seeping into porous formations.
2. Strengthening Wellbore Stability:
   Helps prevent sloughing and collapse of weak formations.
   Enhances the bonding strength of the filter cake, supporting fragile zones.
3. Shale Inhibition:
   Minimizes water interaction with reactive shales, reducing swelling and instability.
   Forms a protective seal, preventing shale hydration.
4. Thermal Stability:
   Withstands high bottom-hole temperatures without degrading, making it ideal for deep wells.
   Maintains its properties in high-pressure, high-temperature (HPHT) environments.
5. Compatibility with Various Fluid Systems:
   Can be used in both water-based and oil-based mud systems.
   Works well with other drilling fluid additives.

The best additive in avoiding differential sticking

With its unique chemical properties and physical characteristics, Gilsonite is scientifically proven to improve wellbore stability, plug micro-fractures, and bond and seal all types of formations. Gilsonite is the only drilling fluid additive that provides all of these benefits:

• Controls fluid loss
• Stabilizes shales
• Prevents lost circulation
• Strengthens the wellbore
• Minimizes differential sticking
• Performs in oil- and water-based drilling muds
• Performs in HP/HT environments
• Minimizes HSE risks

Benefits of Using Gilsonite in Drilling Fluids

1. Effective Fluid Loss Control
   – Reduces differential pressure sticking by creating an effective barrier on the wellbore wall.
   – Lowers the risk of formation damage caused by excessive filtrate invasion.
2. Improved Lubrication
   – Provides better lubricity, reducing torque and drag in the drill string.
   – Enhances drilling efficiency, especially in deviated and horizontal wells.
3. Environmentally Friendly
   – – Gilsonite is a natural, non-toxic material, making it a more sustainable choice compared to synthetic alternatives.
4. Cost-Effectiveness
   – Reduces the need for expensive synthetic polymers and minimizes fluid losses, lowering overall operational costs.
5. Resistance to Acid and Alkali Conditions
   – Chemically stable in a wide range of pH conditions, ensuring effectiveness in various drilling environments.

How Gilsonite is Used in Drilling Fluids

Gilsonite is typically added to drilling mud formulations in powder or granular form, with recommended concentrations ranging from 2% to 6% by weight, depending on well conditions and mud system requirements.

Application Methods:

• Pre-mixing: Gilsonite is mixed directly with drilling fluids before the operation starts.
• On-the-fly addition: It can be added during drilling operations to adjust fluid properties as needed.

Applications of Gilsonite in Drilling Operations

Gilsonite is widely used in:

• Exploratory and production wells
• High-temperature, high-pressure (HTHP) wells
• Unconsolidated formations
• Shale-prone zones prone to swelling
• Offshore and onshore drilling operations

Packing of Gilsonite Drilling Fluid

Gilsonite in Drilling Fluid Loss Control is packed in 25Kg or 50 LBS multi paper bag on pallet shrink wrapped or 500Kg/1000Kg super bag.

Datasheet of Drilling Fluid loss control

 

Data Sheet of Drilling Fluid loss control (FCL)