Product Details

Poly Anionic Cellulose (PAC)

1. Product Overview

Poly Anionic Cellulose (PAC) is a high-performance water-soluble polymer synthesized from cellulose and carboxymethyl anionic groups. Widely used as a drilling fluid and fracturing fluid additive, it provides excellent thickening, fluid-loss control, salt tolerance, and high-temperature resistance. It is also applied in food, pharmaceutical, textile, and paper-making industries.

2. Appearance & Technical Specifications

Core Technical Parameters

PAC-HV (High Viscosity Grade）

PAC-LV (Low Viscosity Grade)

3. Core Functions

3.1 Suspension Stabilizer & Fluid-Loss Control for Drilling Mud

PAC maintains excellent stability in drilling fluids even above 150°C, forming a thin, tough, low-permeability filter cake to reduce filtration loss. It provides good rheological properties, strong salt tolerance, and anti-microbial performance, ensuring stable drilling operations.

3.2 Thickener for Oilfield Fracturing

It rapidly increases the viscosity of fracturing fluids, efficiently carrying proppants into fractures to establish permeability channels. It reduces filtration loss, increases bottomhole pressure, and transmits pressure efficiently, with no residue and no formation damage.

3.3 General Industrial Applications

Its aqueous solution provides thickening, film-forming, adhesion, moisture retention, colloid protection, emulsification, and suspension properties, making it widely used in food, pharmaceutical, textile, and paper-making industries.

4. Product Advantages

✅ Environmentally Friendly & Non-ToxicOdorless, harmless, and compliant with environmental protection requirements.

✅ Excellent Performance Over CMCSuperior to CMC in thickening, suspension, dispersion, emulsification, salt tolerance, and colloid protection.

✅ High Thermal, Acid/Alkali/Salt StabilityMaintains performance integrity under high temperatures, acids, alkalis, and high-salinity environments.

✅ Versatile CompatibilitySuitable for freshwater, brine, saturated brine, and seawater drilling fluid systems.

5. Packaging Specification

· Standard: 25 kg/bag in triple-layer composite moisture-proof kraft paper bags.

· Customizable packaging specifications are available according to client requirements.

6. Storage & Transportation

· Store in a clean, ventilated area at 15°C–30°C.

· Avoid direct sunlight and UV exposure.

· Keep dry, cool, and away from fire and flammable materials during storage and transportation.

7. Disclaimer & Technical Support

All specifications and descriptions in this document are for reference only. The product shall be used in accordance with the customer’s actual working conditions and technical requirements. Customized formulations and solutions are available upon request.

Application Cases of Polyanionic Cellulose for Drilling Fluids

1.High-temperature Filtration Reduction and System Stabilization Case for Medium-deep Wells

Case Background: Medium-deep formations in oilfields have formation temperatures ranging from 120–160℃. Conventional cellulose and natural polymer additives are prone to thermal degradation and molecular chain breaking under medium and high temperature conditions, resulting in increased HTHP filtration loss, loose and rough filter cake, and fluctuating drilling fluid rheology. It easily causes wellbore hydration instability and filtrate invasion, restricting safe and stable drilling of medium-deep high-temperature wells.

Application Formula & Dosage: On the basis of medium-temperature water-based drilling fluid system, 1.0%–1.8% polyanionic cellulose (PAC) was added as the core high-temperature filtration reducer and rheology stabilizer. It is compounded with high-temperature protective agents to optimize system comprehensive performance.

Application Effect: PAC features stable molecular structure and excellent medium and high temperature resistance, no thermal aging failure after long-term high-temperature rolling. It can significantly reduce HTHP and API filtration loss, form thin, dense and smooth filter cake, and effectively isolate water molecule invasion. It stably regulates drilling fluid viscosity and shear force, avoids performance fluctuation caused by high-temperature aging, controls wellbore hydration and enlargement, and ensures long-cycle stable drilling of medium-deep high-temperature formations.

2. Anti-pollution and Colloid Protection Case for High-salt and High-mineralization Formations

Case Background: Salt-gypsum and brine-bearing formations have high salinity and strong ion interference. Conventional polymer treating agents are sensitive to salt pollution, prone to flocculation, gel breaking and performance attenuation, resulting in deteriorated filtration performance, unstable system rheology and frequent wellbore micro-collapse and micro-leakage, which cannot adapt to long-term drilling in high-salt complex formations.

Application Method & Dosage: 1.2%–2.0% high salt resistant polyanionic cellulose was applied in saturated brine drilling fluid systems. It relies on strong electrolyte resistance to stabilize colloid structure and filtration performance of high-salt systems.

Application Effect: The product has outstanding salt and calcium resistance, stable molecular activity under full salinity pollution without flocculation and degradation. It can effectively protect drilling fluid colloids, optimize filter cake compactness, and stably control system rheological parameters. It solves the problems of system thickening, filtration surge and wellbore instability caused by salt pollution, significantly improves the anti-interference ability of high-salt drilling fluid, and ensures safe and efficient drilling of salt-bearing complex formations.

3. High-efficiency Cuttings Carrying and Wellbore Cleaning Case for Shallow Large-hole Drilling

Case Background: Shallow large-open-hole drilling has fast footage speed, large cuttings discharge and loose formation lithology. Conventional drilling fluid has insufficient low-speed viscosity and poor suspension and carrying capacity, which easily causes bottom hole cuttings accumulation, sand settling and poor wellbore cleaning. It leads to increased tripping resistance and pump pressure fluctuation, restricting rapid drilling efficiency improvement of shallow large-hole wells.

Application Dosage: 0.8%–1.5% polyanionic cellulose was added to conventional shallow drilling fluid systems. It is used to optimize rheological structure, improve low-speed shear viscosity, and balance thickening and filtration reduction performance.

Application Effect: PAC has excellent rheological regulation performance, which can effectively improve the low-speed gel strength and suspension capacity of drilling fluid. It ensures thorough transportation and cleaning of cuttings during fast drilling, avoids bottom hole sand settling and cuttings accumulation, and maintains low circulating viscosity to reduce pump pressure load. The wellbore is kept clean and stable all the time, the rate of downhole complex accidents is reduced, and the mechanical drilling speed of shallow large-hole wells is significantly improved.

4. Offshore Non-fluorescent Environment-friendly Low-damage Drilling Case

Case Background: Offshore drilling and logging evaluation wells have strict requirements on drilling fluid fluorescence, environmental protection and reservoir protection performance. Conventional synthetic polymer additives have high fluorescence and certain residual toxicity, which interfere with logging interpretation accuracy and cause irreversible damage to reservoir pore throats, failing to meet offshore green and low-damage drilling standards.

Application Method & Effect: Polyanionic cellulose was applied at 1.0%–1.6% in offshore seawater-based environmental-friendly drilling fluid systems. The product is modified natural cellulose, non-toxic, non-fluorescent and highly degradable. It can stably control filtration loss and optimize mud cake quality, effectively reduce reservoir filtrate invasion and solid phase blockage, and does not interfere with logging and reservoir evaluation. It fully meets offshore environmental protection and low-damage drilling requirements.

5. Wellbore Stabilization Case for Long Horizontal Sections of Tight Reservoirs

Case Background: Tight reservoir horizontal wells have long open-hole soaking time, developed formation micro-fractures and severe hydration spalling risks. Conventional filtration reducers have poor long-term film-forming stability, resulting in continuous filtrate invasion, gradual wellbore enlargement and increased downhole torque, which easily induce differential pressure stuck pipe and affect the smooth completion of long horizontal section construction.

Application Method & Effect: The conventional dosage is 1.0%–1.7%. Polyanionic cellulose has excellent long-term adsorption film-forming performance. It can form a flexible and dense polymer protective film on shale and fracture surfaces for a long time, block micro-fracture channels, stably control filtration loss, and inhibit clay hydration and dispersion. It effectively controls wellbore enlargement rate, reduces downhole friction torque, ensures long-term stable wellbore performance, and guarantees safe and efficient construction of tight horizontal wells.