APC/XCB System Core Bits
- The APC/XCB coring system can use three types of bits for coring soft to firm sediments:
- 11 in. four roller cone bit with tungsten carbide chisel teeth (Fig. 1),
- 10 in. PDC "anti-whirl" (Fig. 4) bits, which are rarely used, or
- 10 in. tungsten carbide blade "drag" bits, which are also rarely used.
1) Formation Compatibility
APC/XCB bits are compatible with sediments ranging from soft silts, sands, and sticky clays to moderately firm limestones, claystones, and dolomites.
2) Large Bit Throat The APC/XCB bit throat has a 3.80-in. opening.
Benefits:samplers; temperature probes; and logging tools, which can pass through the bit throat without requiring a trip to remove the bit or drop it; therefore, coring and logging operations can be resumed without a trip.
- Maximum inner core barrel length: 9.5 m
- APC/XCB bit throat diameter: 9.652 cm (3.80 in.)
- APC shoe throat diameter: 6.197 cm (2.440 in.)
- XCB shoe throat diameter: 5.872 cm (2.312 in.)