BK-HT Semi Premium Connection
Precision Connections BK-HT Semi Premium Connection Designed Primarily for: - High Torque Frac Strings - High Collapse P110 and L80 - 125 ksi min yield P110 grades - Extreme torque & tension - Pipe with thicker walls like 5.5” 26#. Not covered by API.
BK-HT Features Higher Torque and Improved Sealing • – The BK-HT uses a thicker coupling with a larger OD to increase strength and torque resistance. – The thicker coupling can take higher frac pressures and supports thicker wall pipe with 100% matched pipe strength. – Provides more strength when utilizing high collapse or enhanced burst strength pipe. Third Generation BK-HT was designed for Frac • Strings unlike first generation designs which were primarily for drilling with casing in shallow vertical wells.
BK-HT Features Higher Torque & Lower Drag A thicker coupling is stiffer and will stretch less axially and radially as the pin noses react to torque. The OD is beveled to reduce drag in horizontal wells. Offered on 4.5”, 5”, 5.5” and 7” pipe. 7” Pipe always comes with BK-HT.
BK-HT Features • Buttress Compatible for cost savings on hangers, float shoes, float collars, crossovers and custom tools. BK-HT , BK and BK- FX are interchangeable. BK-HT & BK Profile The triangle stamp position is identical to API for easy make up verification.
• Better Buttress Sealing Uses a modified buttress thread for tighter thread sealing and pin nose seal stabilization. The thicker coupling is ideal for high collapse or enhanced burst strength pipe. The BK-HT allows the use of corrosion resistant control yield couplings with the higher yield pipe. API Thread Tolerance – Verified BK Thread Tolerance – Minimizes • • fit of several major insert thread gap for better thread manufacturers. sealing. Uses a Custom Premium Insert.
Better Buttress Pipe Threads for Sealing and Easy Makeup • Tighter tolerances on lead, taper, ovality and pitch diameter. • More pin nose area from OD and ID bevel design. • More perfect threads are engaged in the coupling. Up to four more than some competitors. • Aggressive de-burr for trouble free make-ups. Good Bad Black Crested Threads provide a leak path. Shiny threads seal.
Advanced Relief Groove ensures more threads are engaged for maximum sealing. The thicker midpoint cross sectional area provides additional coupling strength. BK-HT Relief Groove Dark areas indicate unengaged thread regions First Generation Relief Groove
Torque The BK-HT has better high torque running characteristics which will keep the coupling intact past pin nose yield. The strength comes from more engaged threads with a thicker center. 5.5” 17# P110 BK-HT Yield Torque Testing
Fast and Consistent Shoulder Torque Installation Better threading • techniques and coupling coatings allow for a quick low cost installation. The BK-HT will run quickly, reducing the run time per well.
Strength Pin Nose to Pin Nose contact for high torque resistance, • higher pressure ratings, higher bending loads and higher structural compressive loading . Smooth Premium Bore with no J-Area to get hung up on. BK Buttress Pressure
Strength A low hoop stress design reduces the chance of coupling splits and leaks from high frac pressures. Stress is kept below material yield strength. The coupling will return to its Installed original shape after the frac Stress without high residual stresses and deformations that accelerate corrosion and crack growth. Frac Stress
High RPM Fatigue Resistance from Low Stress Runout Threads The BK uses the field proven buttress thread with low stress runout threads to extend the time it can be rotated through a dogleg at high RPM.
Self Centering Anti Rotation Prevents the coupling from turning past center during make up with a thread interlock. US Patent # 9,261,207 & 9,261,208. Thread Interlock Anti-rotation The pin tooth will lock up past center as it is forced into a groove that is a mirror image. The connection acts like a shouldered coupling. Phase locked grooves The grooves (Coupling Thread Roots) are cut in phase / lead so they meet in the middle of the coupling. Eliminates the possibility that the pin thread can cross thread into the other side of the coupling under high torque.
The BK Anti-Rotation Mechanism Prevents Cross threading. When over-torqued the BK-HT provides an extra level of protection that • is not provided by any other semi premium. The threads are cut in lead with each other on both sides of the • coupling so they can’t cross thread. The benefit is huge on thin wall pipe where it reduces no drift • situations. Thin pin noses are easily bent inward when cross threaded.
Major Competitors and API Couplings can cross thread. • The pin tooth crest can ride on top of the box tooth crest past the coupling center; the cross threading leads to a crack initiated washout. • Single largest cause of failure of pin nose to pin nose semi premium connections.
Reliable Materials Unlike first generation drilling with casing connections, the BK-HT addresses the problems that have caused couplings to fail. Low hoop stress and controlled yield and hardness couplings are utilized to reduce the chance of stress induced corrosion and embrittlement. Above 80% Yield Strength • Elements of Bad Make-up & cross threading • material failures Frac pressure • Manufacturing tolerance stacking • Hydrogen • Salt Water • Clean Steel Practices Acid • Brittleness • H2S • Chemistry • Exposure Time • • Temperature • Brittle High Stress Couplings =
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