Selecting the Right Core Bit for Rock Hardness Choosing the correct core bit is paramount for efficient and successful drilling operations. The hardness of the formation is the primary factor influencing this choice, as it directly impacts the rate of penetration (ROP), bit life, and overall cost-effectiveness. The general principle is to match the bit's cutting mechanism and material to the compressive strength and abrasiveness of the rock. 1. Soft to Medium Formations Examples: Shale, Limestone, Sandstone, Chalk For softer, less abrasive rocks, Surface Set Diamond Bits are highly effective. These bits feature industrial diamonds (either natural or synthetic) set directly onto the surface of the metal matrix. They cut the rock through a grinding action. Their sharp diamonds provide fast penetration rates in soft formations, but they can wear down quickly if used in harder, more abrasive ground. According to Matrix code, 1#–3# bits are recommended for broken, abrasive, and harder rock. 2. Medium to Hard and Abrasive Formations Examples: Hard Sandstone, Granite, Gneiss As rock hardness and abrasiveness increase, Impregnated Diamond Bits are the best choice. Instead of having diamonds on the surface, these bits have diamonds uniformly mixed throughout a wear-resistant metal matrix (usually tungsten carbide). As the matrix wears down during drilling, it continuously exposes fresh, sharp diamonds. This self-sharpening characteristic makes them exceptionally durable and ideal for drilling through hard, abrasive rock where surface-set bits would blunt rapidly. According to Matrix code, 4#–6# bits are suitable for broken, abrasive, and harder rock. 3. Very Hard and Fractured Formations Examples: Magnetite, Metamorphic Schist, Gneiss, Granite, Basalt, Gabbro, Rhyolite, Diorite, Conglomerate, TaconiTe For extremely hard, brittle, or heavily fractured rock, free-cutting Impregnated Diamond Bits are recommended. They provide fast penetration in very hard, competent formations. According to Matrix code, 7#–11# bits are free-cutting bits suitable for fast penetration in very hard rock. JCDRILL Diamond Core Bits JCDRILL provides a wide range of impregnated diamond bit matrices for diverse drilling requirements. Whether drilling through soft, abrasive sediments or hard, fractured rock, JCDRILL offers customized bit specifications to match specific ground conditions. This versatility ensures peak performance, extended bit life, and maximum efficiency across various drilling projects.

Subsurface exploration is a fundamental process in geotechnical engineering, mining, and geology, aimed at understanding the physical properties and composition of the earth beneath the surface. It provides critical data for designing foundations, assessing slope stability, exploring mineral resources, and mitigating geological hazards. Among the various techniques employed, the Standard Penetration Test (SPT), Core Drilling, and Reverse Circulation (RC) Drilling are widely used methods, each with distinct applications and advantages. 1. Standard Penetration Test (SPT)         The Standard Penetration Test is an in-situ dynamic penetration test primarily used in geotechnical site investigations to evaluate the geotechnical properties of soils and weak rocks. Method: A thick-walled split-barrel sampler is driven into the ground at the bottom of a borehole by a drop hammer with a standard weight (63.5 kg) and height (760 mm). The number of blows required to drive the sampler through three consecutive 150 mm intervals is recorded. The sum of blows for the last two intervals (300 mm of penetration) is reported as the SPT N-value. Applications: Estimating soil strength parameters (e.g., friction angle, relative density). Evaluating liquefaction potential of sandy soils during earthquakes. Determining bearing capacity for shallow foundations. Advantages: Simple, cost-effective, and provides immediate data for preliminary soil classification. Limitations: Less reliable in cohesive soils or gravelly layers; results can be influenced by drilling practices and equipment. 2. Core Drilling   Core drilling is a technique used to retrieve intact cylindrical samples (core samples) of rock and sometimes soil for detailed visual inspection, laboratory testing, and geological analysis. Method: A rotary drill with a diamond- or alloy-impregnated core bit cuts an annular ring into the subsurface, leaving a central core that enters a core barrel. The core barrel is retrieved periodically to extract the sample. Applications: Geotechnical characterization of rock mass (e.g., RQD - Rock Quality Designation). Mineral exploration and ore grade estimation. Structural geology studies (e.g., fault zones, bedding planes). Advantages: Provides high-quality, undisturbed samples for comprehensive analysis (strength, permeability, mineralogy). Limitations: Expensive, time-consuming, and less effective in unconsolidated or fractured formations. 3. Reverse Circulation (RC) Drilling   Reverse Circulation Drilling is a fast and efficient method primarily used in mineral exploration and large-scale geotechnical projects to obtain representative chip samples from depth. Method: A dual-wall drill pipe is used: the drilling fluid (air or water) is pumped down the annular space between the inner and outer tubes, flushing cuttings up through the inner tube to the surface. This prevents sample contamination and allows continuous sample collection. Applications: Rapid exploration for minerals (e.g., gold, copper, iron ore). Geochemical analysis and resource estimation. Investigating deep soil profiles or alluvial deposits. Advantages: High penetration rates, minimal cross-contamination, cost-effective for deep holes. Limitations: Samples are disturbed (chips rather than cores), limiting detailed geotechnical testing; not suitable for cohesive soils or requiring intact samples. Conclusion Each of these methods—SPT, Core Drilling, and RC Drilling—serves a unique purpose in subsurface investigation. The choice depends on project objectives, material types, depth requirements, and budget constraints. While SPT is ideal for shallow soil assessments, core drilling excels in detailed rock characterization, and RC drilling offers speed and efficiency for mineral exploration. Integrating these techniques often provides the most comprehensive understanding of subsurface conditions. If you have any needs in this regard, please contact JCDRILL to learn more and get a quote for the equipment.

We are proud to showcase the JRC200 Reverse Circulation Drilling Rig in action, conquering challenging mountainous terrain in the Middle East! Our client shared impressive on-site photos, demonstrating its power, precision, and adaptability in demanding conditions. Key Features & Performance Highlights 1. 200m Depth Capacity & 115–143 mm Hole DiameterThe JRC200 meets drilling requirements for depths up to 200 m and hole diameters of 115–143 mm. Our Middle Eastern customer successfully completed drilling to a depth of 180 m with a 127 mm diameter, obtaining high-quality samples efficiently. 2. Powerful & Convenient Power SystemEquipped with an 85 kW Yunnei engine, the JRC200 can achieve drilling angles from 45° to 90°. To improve operational efficiency and reduce time and cost, our customer selected a power head with 0–90° reversal, enabling easier loading and unloading of drill pipes. Optional features for other customers include hydraulic clamps, hydraulic blowback valves, and winch hydraulic reversal. 3. Complete Sampling SystemThe sample splitter, cyclone, and wind box work together to ensure accurate sample collection, splitting, and storage. The sample splitter evenly divides collected rock cuttings, proportionally splitting them (e.g., 1/2, 1/4) to eliminate human error and maintain consistent mineral composition, ensuring accuracy and representativeness for subsequent testing and analysis. 4. Equipped with JAC29/23 Air Compressor (29 m³/min, 23 bar)The reverse circulation system, combined with DTH technology, uses the air compressor to provide compressed air for impact and dust collection. In operation, the reverse circulation hammer and double tube design allow compressed air to enter between the two tubes, while dust and cuttings are discharged through the inner tube. This process delivers clean, dry rock chips for sampling, meeting customer requirements. The JRC200 continues to prove itself as a compact yet powerful RC drilling solution, ideal for mining exploration, geotechnical surveys, and operations in remote or challenging terrain.

In July, we are glad to announce that our JCDRILL overseas team successfully completed a training program for our CWD200 model water well drilling rig in South America. The overseas training process for drilling rig operation involves three key phases: pre-deployment preparation, technical training, and field practice. Each stage is designed to ensure safe and effective guidance. 1. Pre-deployment PreparationParticipants are required to complete a safety induction program. This includes familiarization with local environmental standards. Meanwhile, a detailed training plan is developed, and relevant materials are prepared. 2. Technical Training MeetingIntroduction to the rig’s technical specifications and drilling functions:The CWD200 is a fully hydraulic, multi-functional, track-mounted water well drilling rig.It is powered by a 76 kW diesel engine, which provides high torque. The rig is equipped with a main winch, ensuring high efficiency when drilling in mud rock or weathered formations.It also comes with a BW250 diesel mud pump and a JAC 1817 diesel air compressor, offering an 18 m³/min flow rate and 17 bar air pressure. The CWD200 supports both air DTH hammer drilling and mud rotary drilling. 3. Field PracticeWith extensive drilling experience, our overseas team worked alongside the client’s operators, providing detailed and patient on-site operational guidance and answering questions during the drilling process. Introduction to Equipment:Present the components of the CWD200 drilling rig, BW250 mud pump, and JAC 1817 air compressor. Components include the mast, drill pipe, rotary head, hydraulic system, controls, tricone bit, DTH hammer bit, etc., along with their functions and operational considerations. Pre-Operation Checks:Inspect fluid levels, hydraulic systems, and cables to ensure they are in proper condition. Hands-On Demonstration:Demonstrate rig setup, pipe handling, and drilling techniques. Guide trainees through control panel operations (RPM, feed pressure, torque), as well as BW250 mud pump and air compressor connection and operation. Supervised Practice:Trainees perform drilling under supervision, starting with shallow test holes.   Review & Maintenance:Review daily maintenance procedures, including lubrication, filter checks, and post-shutdown steps. After completing the training, our South American customer gave our overseas team high praise and expressed deep gratitude. They look forward to the next cooperation with JCDRILL in the near future.

The Standard Penetration Test (SPT) is a widely used in-situ geotechnical investigation method to evaluate soil/rock strength and stratification. When integrated with a rock core drilling rig, it combines rotary drilling for core sampling with dynamic penetration testing, providing comprehensive subsurface data. Key Features: 1. Procedure:A split-barrel sampler is driven into the borehole bottom by a 63.5 kg hammer dropped from 760 mm height.The number of blows required for each 150 mm penetration (total 450 mm) is recorded as the N-value (blow count).2. Drilling Rig Compatibility:Adaptable to hydraulic/pneumatic rock core drills (e.g., wireline systems).Maintains borehole stability during SPT in fractured rock or overburden layers.3. Applications:Assess bearing capacity for foundations.Correlate N-values with shear strength (e.g., for liquefaction analysis).Complement rock quality designation (RQD) data in core samples.4. Advantages:Dual function: Continuous coring + SPT profiling.Depth capability: Typically, up to 100m, depending on rig capacity. JCDRILL Core drilling rig provides full hydraulic automatically SPT function, working perfectly in the mining site!

Choosing the right diamond core drilling rig depends on several factors, including the type of drilling project, geological conditions, depth requirements, and budget. Here’s a step-by-step guide to help you select the best rig for your needs >> Determine the Drilling Purpose1. Exploration drilling (mineral, geotechnical, oil/gas)2. Construction drilling (concrete, reinforced structures)3. Water well drilling4. Scientific/research drilling (deep core sampling) 5. Grade control(GC) drilling rig(RC drilling rig)>> Consider Drilling Depth & Diameter1. Depth:(1) Shallow holes (0–100m): Light-duty rigs (2) Medium-depth (100–500m): Mid-sized rigs(3) Deep drilling (500m+): Heavy-duty rigs with high torque 2. Core Diameter:(1) Small (BQ/NQ sizes: 47–63mm)(2) Large (HQ/PQ sizes: 85–122mm)>> Power Source & Mobility1. Electric: Best for indoor construction (low noise, no fumes)2. Hydraulic: High torque, suitable for tough rock formations3. Diesel: Portable, ideal for remote locations4. Track-mounted vs. Truck-mounted: Choose based on terrain>> Rock Hardness & Formation Type1. Soft to medium rock (limestone, sandstone): Standard diamond bits2. Hard rock (granite, basalt): High-quality impregnated diamond bits3. Fractured/abrasive formations: Use surface-set diamond bits >> Rig Features to Look For1. Rotation speed (RPM): Adjustable for different formations2. Torque capacity: Higher torque for deeper/harder drilling3. Auto-feed system: Ensures consistent drilling pressure4. Core recovery system: Important for geological sampling 5. Stability & rig weight: Heavy rigs reduce vibration in deep drilling>> Final Recommendation1. For mining/exploration: Choose a hydraulic or diesel-powered rig with high torque.2. Construction/core sampling: A compact electric rig.3. Deep scientific drilling: A heavy-duty drilling rig with auto-feed.   Would you like recommendations based on a specific project type?