CGE WUXI PW Geological Drilling Casing Pipe

CGE WUXI PW casing is a DCDMA standard W-series wireline coring casing. It features large diameter, heavy wall and flush joint design. It is mainly applied for PQ wireline coring drilling and borehole wall protection in deep and complex formations, and can be run in place once or permanently left in the hole. 

1、Flush Joint (Coupling-free)

Male and female threads on both ends enable direct connection with inner and outer shoulders closely fitted. The contact area is twice that of conventional coupled casings, delivering high torque and collapse resistance and preventing thread loosening under heavy torque.

2、Parallel Heavy-wall Body

Uniform wall thickness, excellent concentricity and straightness. Fully compatible with PQ wireline coring systems and allows smooth passage of PQ inner tube assemblies.

3、High-strength Threads

With surface heat treatment, the threads feature superior pull and shear resistance under impact and vibration, effectively reducing thread galling, wear and seizing.

4、Full-body Heat Treatment

The entire pipe undergoes quenching and tempering to enhance strength and toughness, extending service life in deep-hole and hard rock drilling conditions.

1、Deep Geological Core Drilling

Matched with PQ wireline coring tools. Featuring large bore diameter and great drilling depth, it is applicable to metal mineral exploration, hydrological projects, geothermal development and general geological survey.

2、Borehole Stabilization for Complex Formations

Performs well in loose strata, fractured zones, karst caves and aquifers. It delivers excellent anti-collapse, anti-leakage and water isolation performance to keep boreholes stable.

3、Permanent / Semi-permanent Borehole Casing

Can be run in place for permanent use without retrieval, or serve as surface casing and intermediate casing, providing a stable passage for subsequent drilling operations.

4、Engineering Geology & Water Well Applications

Ideal for borehole stabilization of large-diameter exploration holes, water wells and pile foundation holes.

1、Large bore diameter: 139.7mm outer diameter, excellent passability. Compatible with PQ coring and high-flow flushing fluid.

2、High strength & reliability: Thick wall and direct connection design deliver superior collapse, torsion and tensile resistance, ensuring safe operation in deep holes and complex formations.

3、Wireline coring compatible: Fully matched with PQ system. Coring without tripping out improves working efficiency and reduces labor intensity.

4、Wear resistance & anti-galling thread: Threads are quenched for enhanced performance, preventing thread seizing during repeated make-and-break and lowering failure rates.

Q1: When drilling deep holes and complex formations, the borehole wall is prone to collapse and slurry leakage. Can PW casing solve these problems?
A: Yes. PW casing is a heavy-wall high-strength pipe with excellent rigidity. It effectively supports unconsolidated layers, fractured zones and aquifers to prevent borehole collapse. Its good sealing performance also isolates water-leaking formations and resolves slurry loss, ensuring stable borehole conditions.

Q2: For large-diameter wireline coring, conventional casings have insufficient inner diameter and block drill tools. How does PW casing improve this?
A: PW casing is fully compatible with the complete PQ wireline coring system. It features standard and ample inner diameter, allowing smooth movement of inner tube assemblies and overshots. It eliminates tool jamming and guarantees normal wireline coring operations.

Q3: Casing with couplings has larger outer diameter, leading to high running resistance and sticking risks. What are the advantages of PW casing?
A: PW casing adopts flush joint design without couplings. The uniform outer diameter greatly reduces running and pulling resistance. It avoids coupling sticking and scraping against the borehole wall, especially ideal for deep and deviated holes.

Q4: Under high torque in deep-hole drilling, threads of ordinary casings are easy to slip, seize or break. Does PW casing perform better?
A: Absolutely. Equipped with dedicated 4 TPI high-strength threads and internal/external shoulder positioning, it delivers outstanding torque, tension and shear resistance. Thread hardening treatment prevents galling and seizing during repeated make-and-break, avoiding thread failure under heavy loads.

Q5: Poor concentricity of regular casings causes borehole deviation and severe wear. Can PW casing fix this issue?
A: Yes. Manufactured with high precision, the pipe has superior straightness and concentricity. It provides reliable guidance during drilling, reduces tool wear and borehole deviation, and extends service life of both drill tools and casing.

Q6: Frequent casing damage and replacement in deep drilling cause project delays. How to solve it?
A: Made of high-strength alloy steel (R780 / 4130) and available with overall quenching and tempering treatment, PW casing boasts great mechanical properties. It resists deformation and damage under high pressure and complex forces in deep holes, cutting replacement frequency and downtime loss.

Q7: Lack of suitable permanent protective casing for large-diameter holes affects subsequent operations. What is the solution?
A: PW casing can be used as surface casing or intermediate casing and left permanently in the hole. It maintains a stable borehole for subsequent multi-stage drilling, hydrological testing and downhole operations, with no need for secondary wall protection.

Q8: Standard-length pipes cannot fit shallow sections and stepped holes due to limited specifications.
A: Besides the standard 3m length, custom short sections (1.5m, 1.0m, 0.5m) are available for flexible assembly. It adapts to stepped holes, shallow holes and surface reinforcement, solving poor applicability of single-size casing.
Q9: Is there a compatible large-diameter casing for ultra-deep holes within the W-series range?
A: As the largest size of W-series casing, PW casing is fully interchangeable with BW, NW and HW models. They can be matched stage by stage to form a complete wall protection system, realizing seamless connection for drilling from conventional holes to ultra-deep large-diameter holes.