Posts

Diamond Coring, Exploration Drilling Q & A (From Boart Longyear expert)

Image
Q. For readers who may not be familiar with diamond coring (e.g., strict water well guys or HDD utility installers), can you give me a quick definition? A. Diamond coring is a drilling technique that uses a  diamond impregnated bit  to cut a “core” sample, which is then typically assayed for a valuable mineral or chemical content. As such, it is used primarily in the mineral exploration business, gold and copper being the two most prevalent commodities for which Boart Longyear is contracted to drill for in the United States. Q. What challenges are specific to diamond coring that drillers might not encounter in other types of drilling? A. In diamond coring, we have a very small annular space between the drill rod and the drill hole. At best a couple tenths of an inch on each side. Special care must be taken to maintain the stability of the borehole is in such tight quarters. Drilling fluid properties and dynamics are a key here. Q. Talk a bit about fluids for d...

Wireline core drilling, diamond exploration core drilling

Image
How will you recover the core samples in mining exploration operations? As we know, there are basically two ways to do core drilling jobs, conventional and wireline, the answer for this question tell us the main difference between conventional and wireline core drilling. In conventional core drilling jobs, the whole drill string needs to be pulled out of the bore holes to recover the core samples; while in wireline core drilling, no needs to remove the  drill rods  to recover each core sample. An overshot is sent down the hole to retrieve the inner tube, the overshot and inner tube are then brought up to the surface using a wireline hoist, allowing the rods and core bit to remain in the hole. A complete set of wireline core drilling tools include drill rods, drill bits,  core barrel  assembly, overshot assembly, holding dog, hoisting plug, circle wrench etc. Wireline core drilling method is more common nowadays due to its’ high penetration rate...

Selecting a right bit for your diamond core drilling jobs

Image
An exploration core driller’s success depends on the productivity and performance of their drilling equipment. With today’s contractors facing heightened pressure to increase productivity and reduce costs, choosing the right diamond coring bit for the job has never been so important. Improper bit selection can lead to productivity loss, poor core recovery, hole problems and unnecessary wear and tear on rigs, rods and downhole tools. A driller, whether drilling a shallow hole or a deep hole, is very important. The driller is responsible for finding the best cutting performance and production of a diamond core bit. The balances penetration rates and bit life by altering weight on bit to maximize results. Experienced drillers can typically get more out of bits because they have a better understanding of drilling practices and experience cutting multiple types of ground formations. Another critical consideration when selecting a bit is the ground formation. It is import...

Core barrel, Wireline coring barrel, Geotechnical drilling core barrel

Image
Product description: A core barrel is used to collect core samples, which guarantee the core samples not drop out of the inside of the core barrel when lifted. Core barrel part de tails Item Name Qty 1 Head assembly 1 2 Inner tube 1 3 Stop ring 1 4 Core lifter 1 5 Core lifter case 1 6 Locking coupling 1 7 Adapter sub 1 8 Landing ring 1 9 Outer tube 1 10 stabilizer 1 11 Thread protector case 1 Weight Item 1 (kg) Item 2-11 (kg) BQ 1.5m length 6.5 24.8 BQ 3m length 6.5 35.8 NQ 1.5m length 12.5 37.2 NQ 3m length 12.5 59.7 HQ 1.5m length 19.2 49.5 HQ 3m length 19.2 87.3 PQ 1.5m length 30 72.5 PQ 3m length 30 117 Diamond core drilling   differs from other geological drilling, which utilizes an annular diamond drill bit attached to the end of hollow  drill rods  to cut a cylindrical core of solid rock ...

Wireline drill rods, diamond drill rods

Image
Product description: Wireline drill rods or named diamond drill rods are manufactured by CNC machines; in exploration diamond drilling, a diamond drill bit is attached to the end of wireline drill rods to cut a core. Our wireline drill rods are manufactured by CNC machines, and made of high quality alloy steel. All our wireline drill rods are heat treated. General Characteristic: * Both ends thickened; * Good concentricity; * High precision; * Long life. The specifications for wireline drill rods we are supplying. Size O.D I.D Weight (kg/3m) Desc BQ 55.6mm 46.1mm 18.0 Heat treated at two ends NQ 69.9mm 60.3mm 23.5 HQ 88.9mm 77.8mm 34.5 PQ 114.3mm 101.6mm 52.2 Exploration diamond drilling   differs from other geological drilling, which utilizes an annular  diamond drill bit  attached to the end of hollow drill rods to cut a cylindrical core of solid rock for examination on the surface. The core does n...

Diamond reaming shell, reamer shell

Image
Product description: Diamond reaming shell, reamer shell, AQ, BQ, NQ, HQ, PQ. Diamond Reaming Shell  or called reamer shell  is set with natural or synthetic diamonds, which is designed to sit above the  diamond bit or high on the outer tube. It's main function is to ream the hole to the correct constant specific diameter, which ensures adequate clearance for the core barrel and sufficient clearance for the new bit which replace an old one. It also acts as a stabilizer for drill bits. Helical type reaming shells provides good passages for water flowing, the matrix is wear proof and its service life is long. Size Outer Diameter (in.) (mm) AQ 1.895 48.1 BQ 2.365 60.1 NQ 2.985 75.8 HQ 3.782 96.1 PQ 4.835 122.8 NQ3 2.985 75.8 HQ3 3.782 96.1 PQ3 4.835 122.8 Diamond core drilling   differs from other geological drilling, which utilizes an annular diamond drill bit attached to the end of...

Diamond surface set bits, Surface set core bits, surface-set bits

Image
Product description: Diamond surface set core bits or written as surface-set bits or surface set bits differ from impregnated bits in that they only have a single layer of natural diamonds set onto bits' working surface. Diamond surface set core bits  or written as surface set bits or  surface-set bits  differ from impregnated bits in that they only have a single layer of natural diamonds set onto the working surface of bits according to a pre-determined pattern, Its waterways are usually shallower than an  impregnated bit  because of the single layer of diamonds. Some bits are designed with face discharge holes to minimize core wash when drilling soft and fractured formations. We supply a wide range of surface set core bits, which includes a variety of profiles, diamond grades and sizes designed to provide the most efficient cutting ability in all different rock formations. Number of Stones  is a very important factor in determining how...