AMC CR-650 is a high-performance anionic polymer designed for use in drilling, horizontal directional drilling (HDD), geotechnical construction, mineral exploration and water-well drilling. As a partially hydrolyzed polyacrylamide (PHPA-type) polymer, AMC CR-650 provides viscosity, cuttings encapsulation, shale inhibition, fluid-loss control and borehole stabilization—all of which are essential for maintaining an efficient and stable drilling environment. The unique molecular architecture of AMC CR-650 allows it to perform several functions simultaneously, making it a versatile polymer across multiple drilling applications.
1. Application in Water-Based Drilling Fluids
The most significant application of AMC CR-650 is its use as a primary polymer additive in water-based drilling fluids. When added to fresh or slightly brackish water, it dissolves to create a viscous solution that enhances the carrying capacity of the drilling fluid. This improved viscosity helps suspend and transport drill cuttings from the bit to the surface, reducing the risk of bottom-hole accumulation, stuck pipe or mechanical blockages.
Its low solids content makes AMC CR-650 ideal for drilling environments where solids control is crucial. By helping maintain a low-solids mud system, it improves rate of penetration (ROP), minimizes formation damage and enhances overall drilling efficiency. This makes it especially valuable in water-well drilling, geothermal well development, mineral exploration holes and HDD projects.
2. Clay and Shale Stabilization
One of the defining applications of AMC CR-650 is its ability to stabilize reactive clays and swelling shale formations. Many geological formations contain clays—such as smectite, bentonite or illite—that hydrate and expand when exposed to fresh water. This hydration leads to sloughing, caving, hole enlargement and formation instability.
AMC CR-650 functions as a clay encapsulator. Its long-chain anionic polymer molecules attach to clay particles, forming a protective coating that restricts water penetration into the clay platelets. By reducing clay hydration, the polymer minimizes:
This inhibition effect makes AMC CR-650 essential when drilling through troublesome formations that are highly sensitive to water invasion.
3. Cuttings Encapsulation and Hole Cleaning
In addition to shale stability, AMC CR-650 enhances cuttings encapsulation. As drilled cuttings are generated, the polymer wraps around the particles, creating firm, non-dispersed cuttings that are easily transported to the surface. Well-encapsulated cuttings maintain their structural integrity, which leads to:
-
Improved hole cleaning
-
Lower solids loading in the drilling fluid
-
Better performance of shale shakers and solids-control equipment
-
Reduced wear on pumps and drill string
This property is particularly beneficial in HDD, where long horizontal drilling intervals demand efficient cuttings transport to avoid blockages and hydro-locking.
4. Borehole Stabilization in Civil and Geotechnical Drilling
AMC CR-650 is widely used in civil engineering and geotechnical drilling applications, such as:
In these applications, the polymer helps maintain the integrity of uncased boreholes, especially in loose, unconsolidated or collapsing formations. Its ability to create a thin, stable polymeric film on the borehole wall prevents sand, gravel and clay from falling into the hole, thus ensuring accurate dimensions and minimizing the risk of collapse.
For geotechnical sampling, the polymer improves core quality by reducing disturbance of fragile formations. This makes AMC CR-650 valuable in exploration drilling where high-quality core recovery is essential for geological assessment.
5. Fluid-Loss Control and Formation Protection
AMC CR-650 also acts as a fluid-loss reducer. When circulating through the borehole, its polymer chains create a semi-permeable filter layer on the formation wall, which limits the amount of filtrate entering the surrounding rock. Reduced filtrate invasion results in:
-
Less formation swelling
-
Lower risk of differential sticking
-
Better formation integrity
-
Improved wellbore stability
This is crucial in fractured or porous formations where excessive fluid loss can lead to instability or costly circulation problems.
6. Solids-Control Support and Mud Cleaning
Although AMC CR-650 is not a classical flocculant, its molecular behavior provides mild flocculation benefits when small, dispersed solids accumulate in the system. It gently agglomerates fine particles, making it easier for solids-control equipment—such as shakers, hydrocyclones and centrifuges—to remove unwanted solids.
In drilling operations where clean mud is essential, such as long-distance HDD or deep mineral exploration, AMC CR-650 helps maintain desirable rheology and reduces the need for frequent dilution or fluid replacement.
7. Reverse Circulation (RC) and Diamond Core Drilling
In mineral exploration, AMC CR-650 is used in reverse circulation drilling and diamond coring. Its stabilizing and encapsulating properties enhance sample quality and reduce line blockages. For diamond drilling, the polymer helps maintain a thin, lubricating fluid that reduces torque and provides smoother drilling, especially in formations containing reactive or plastic clays.
8. Environmental Drilling and Groundwater Wells
Because AMC CR-650 is non-toxic and environmentally acceptable, it is extensively used in:
-
Environmental monitoring wells
-
Groundwater extraction wells
-
Remediation boreholes
-
Soil vapor extraction drilling
Its polymer system ensures borehole stability without introducing harmful contaminants, making it ideal for projects requiring regulatory compliance.
9. Trenchless Construction and Infrastructure Projects
In HDD, pipe-jacking, micro-tunneling and tunneling support systems, AMC CR-650 improves slurry stability and reduces friction. The polymer’s lubricating effect assists in steering control and prevents blockages in long bores or curved sections.
