250P Series Core Barrel
250P Series Core Barrel
250P Series Core Barrel
The 250P consists of an inner and outer tube – the outer tube
protects the barrel’s inner tube components. Reinforced with
either wear rib subs or core barrel stabilizers, it reduces core
bending, core blockage and bit wobble, permitting more weight-
on-bit for improved penetration rates.
The 250P also features a drop ball that permits cleaning of the
bottom of the hole before coring, a positive safety joint that allows
the inner tube to be removed with the core if the barrel becomes
stuck, and adjustable shims that prevent lower shoe drag.
FEATURES
BENEFITS
1. Provides a durable threaded connection that can be easily broken on the rig
floor to expedite the core retrieval process. If core barrel sticks downhole,
enables backing off of core barrel which permits inner tube and core to be
removed; eliminates rig delays and maintenance expense; ensures core
retrieval.
2. Permits maximum free rotation for maintaining penetration rates and smooth
core recovery. Allows optimized mud flow through the core barrel to enhance
bit hydraulics and maintain circulation.
A. Same drilling fluid or air used to clean the hole is used for bearing
lubrication, eliminating the need for surface lubricating devices. Ball
bearings, unaffected by bottom-hole temperature or pressure, enable hot
hole or high-pressure applications.
B. Permits operator to circulate pre-scribed volume through the core barrel,
ensuring a clean inner tube and hole before coring begins. When seated in
the relief plug, the steel ball diverts drilling fluids through ports above the
inner tube causing mud flow between the inner and outer tube which
minimizes core contaimination and maintains circulation to the bit for proper
cleaning and cooling.
C. Enables correct positioning of the inner tube above the bit.
3. Provides a ribbed sub to reduce core barrel outer tube contact against the
wellbore wall; reduces risk of differential sticking; prevents premature core
barrel wear; extends too life.
4. Provides high tensile strenght for increased tool durability in a wide range of
coring situations.
5. Provides holding compartment for the core; protects core from fluid
contamination and erosion.
6. Provides a threaded sub that reduces thread damage between inner tube and
inner tube shoe; enables longer thread life and subsequent component use.
7. Stabilizes the lower end of the inner tube against the core bit; serves as a pilot
to guide core into catcher and inner tube; enables quick and efficient core
entry; reduces core erosion.
8. Provides gripping of cores to prevent core loss; ensures core retrieval when
pulling the string.