How to select your site investigation system

STEP 1:  Determine if the application requires conventional or wireline system

Conventional core barrels produce a larger core diameter compared to equivalent wire line size. The rugged construction and design features ensure optimization of productivity in applications where the use of wire line system is not practical or cost effective.

Guizhou Vilong provide Wireline Q series BQ NQ HQ PQ core barrels and conventional T2 T6 core barrels. The T2 double tube conventional core barrel is a thin–wall all round core barrel for most type of homogenous or somewhat broken formations where water flush can be used, faster penetration, lower diamond cost and larger core; the T6 double tube conventional system is a standard wall all round core barrel for core sampling in all formations, despite the relatively thin wall, T6 can very well be used with high viscous mud or in special cases with air flushing, conventional core barrels are typically used in shorter bore holes, the core barrels can drill in all directions.

STEP 2:  Determine drill rod and casing

For conventional core barrels the rod OD size is recommended to be as large as possible, however it must not restrict the annulus circulation flow, you also have to consider machine capacity. You have to consider the rod length to fit the overall length that can be handled efficiently, It is recommended to select a few smaller rods to compensate the drill string length even though the main part of selected rods are longer. Wire line drill rods are manufactured from highest available carbon seamless steel tubes for superior yield capacity and ultimate strength, which are always flush jointed to allow inner tube and other tools to pass through, pin threads are surface treated, for easy jointing and extended life.

STEP 3:  Determine accessories

Details often make the difference in quality of the drilling operation, In this section, we offer products selected for their quality and technical superiority, It is important to use recommended wrenches to avoid risk of equipment damage, and please be noted wrenches always used in pairs. Don’t forget trouble shooting tools (recovery taps etc), which might save you some problems. This section also include a selection of subs, core boxes, additives and water swivels, water swivels should be selected in accordance with type of drill rig used and fluid demands for the application.

STEP 4:  Determine diamond products

Bit selection for impregnated bits is guided by the impregnated bits selection chart, The rock formation characteristics with corresponding samples of rock types are organized in application rock groups 1–12. Choose suitable bit based on application number that matches your formation characteristics. Basically the scale indicates a harder formation for a higher number, In application range 1–4, diamond surface set, and PDC bits should be considered as well.