CarbDRIL All-Oil-Based Drilling Fluid Technology is a sophisticated system that uses oil as the continuous phase (dispersing medium) and is characterized by its unique water-free formulation. This formulation provides superior properties such as high-temperature resistance, salt and calcium contamination resistance, low viscosity and filtration loss, and corrosion prevention. The absence of water helps to precisely control the rheological properties of the drilling fluid, while the all-oil filtrate significantly enhances the inhibition and protection of oil and gas reservoirs. The oleophilic colloid adsorption and micro-sealing effect on the borehole wall further improve borehole stability, ensuring safe and efficient drilling operations.

Features

1. High Temperature and Pressure Resistance: Capable of maintaining stable performance in environments exceeding 220°C, meeting the demands of deep, ultra-deep, and      geothermal wells with complex geological conditions.

2. Strong Inhibition: The filtrate, composed almost entirely of base oil, effectively inhibits the  hydration, dispersion, and swelling of clay minerals (e.g.montmorillonite), reducing formation damage and protecting oil and gas reservoirs.

3. Low Viscosity and Low Filtration Loss: The unique formulation allows the drilling fluid  to maintain low viscosity while achieving low filtration loss, minimizing mud loss and formation pollution during drilling.

4. Strong Sealing Performance:Oleophilic colloids form a dense filter cake on the borehole wall, effectively sealing micro-fractures and pores, enhancing borehole stability, and reducing collapse and loss risks.

5. High Stability: The fluid system boasts excellent chemical and physical stability, with a high electrical stability (≥1500V), maintaining stable performance over extended periods.

Advantages

1. Improved Drilling Efficiency: Low viscosity and filtration loss features help reduce frictional resistance and pump pressure losses, increasing drilling speed.

2. Reservoir Protection: Strong inhibition and low filtration significantly minimize damage to oil and gas reservoirs, enhancing recovery rates.

3. Reduced Risk of Accidents: Sealing capability and enhanced borehole stability lower the risk of accidents like sticking and collapse during drilling.

4. Environmentally Friendly: The all-oil formulation presents a lower environmental pollution risk compared to traditional water-based drilling fluids.

Applications

1. Shale Gas Wells: Successfully applied in shale gas wells in Sichuan, reducing sticking frequency, enhancing borehole stability, and shortening drilling cycles.

2. Deepwater Wells: Suitable for offshore deepwater drilling operations, thanks to its excellent high-temperature, salt, and calcium contamination resistance, and low filtration loss.

3. Horizontal Wells: Plays a crucial role in horizontal well drilling that demands precise trajectory control and borehole stability maintenance.

4. Special Process Wells: Effective in various operations such as unblocking fluids, completion fluids, workover fluids, and coring fluids.

Overall, CarbDRIL All-Oil-Based Drilling Fluid Technology demonstrates remarkable effectiveness and technical advantages across diverse well types and formations. Its resistance to high temperatures, salt, and calcium contamination, combined with low viscosity and filtration loss, corrosion prevention, and strong inhibition and sealing capabilities, make it an essential choice for drilling operations in complex formations.

System Additives

• CarbEMUL Primary Emulsifier

• CarbCOAT Secondary Emulsifier

• RHEVIS Rheology Modifier

• HIFLO Filtration Reducer

Key Additive: CarbEMUL Primary Emulsifier

CarbEMUL serves as the key primary emulsifier in the CarbDRIL All-Oil-Based Drilling Fluid Technology. It presents superior emulsification and stability, forming stable emulsions from oil and water, enhancing the fluid's performance and stability during drilling.

Functions:

1. Emulsification: Forms a robust adsorptive film at the oil-water interface, preventing separation and creating stable emulsions that aid application under complex geological conditions.

2. Lowering Interfacial Tension: Reduces oil-water interfacial tension, improving lubricity and fluidity to  diminish frictional resistance during drilling.

3. Enhanced Stability: Boosts fluid stability, preventing emulsion breakdown or layering under high-temperature and high-pressure conditions.

4. Contamination Resistance:Displays some contamination resistance, minimizing external impurity impacts on fluid performance during drilling.

Applicable Range:

1. Temperature: Withstands temperatures exceeding 220°C, suitable for high-temperature well drilling.

2. System: Fits into the CarbDRIL All-Oil-Based Drilling Fluid system and serves as a critical agent in unblocking, completion, workover, and coring fluids.

Key Additive: CarbCOAT Secondary Emulsifier

CarbCOAT acts as the secondary emulsifier, playing a crucial role in reinforcing emulsification and stability within the CarbDRIL All-Oil-Based Drilling Fluid Technology. It works in synergy with the primary emulsifier to enhance stability and rheology, among other properties.

Functions:

1. Enhanced Emulsion Stability: Strengthens oil-water interfacial stability, preventing coalescence of oil droplets and maintaining emulsification.

2. Improved Rheology: Regulates viscosity and shear strength to facilitate easier pumping and circulation.

3. Increased Inhibition: Potentially limits clay hydration dispersion and swelling, aiding borehole stability.

4. Reduced Filtration: Facilitates stable emulsions, minimizing filtration loss and protecting reservoirs.

Applicable Range:

1. Temperature:Generally exceeds 220°C resistance, suitable for high-temperature, deep-well drilling.

2. System: Employs the CarbDRIL All-Oil-Based Drilling Fluid system.

Case Study

Successfully implemented in shale gas wells in Sichuan and over ten wells in CNOOC's Huizhou block, this system substantially decreased sticking frequency, improved borehole stability, and achieved excellent results, reducing drilling cycles by 12% compared to traditional methods.

Huizhou 25-7, located on a fault conversion zone, comprises complex structural styles with deep strata compaction and high rock hardness, presenting challenges due to low mechanical drilling speeds and high drill bit wear from abrasive formations. The high formation dip angle increases borehole trajectory control challenges and drilling uncertainty. The bottom hole high temperature demanded robust temperature resistance from the drilling fluid.

With a final depth of 4455m and 265m drilling in 2 days, the CarbDRIL All-Oil-Based Drilling Fluid displayed strong adaptability, excellent high-temperature tolerance, and stable rheological performance. Its high plasticity, electrical stability, and contamination resistance were evident, with low additive amounts required, resulting in reduced operational costs during the drilling of Huizhou 25-7.