About SJ Double-Way Shock Absorber

The SJ Type double-way shock absorber is used to dampen or eliminate both vertical and horizontal shock / vibration caused by the drill string. The primary benefit of shock absorption is that it helps to reduce damages to the drill bit and drilling tools, reduce drilling cost and enhance drilling efficiency.

Working principle

The torsion on the drill string at the bottom of the well bore changes with respect to the type of bit structure, ground formation and bit weight. During drilling operation, the lower portion of the drill tool needs to withstand both the axial pressure and torque. This causes the drill string to undergo both torque and resonance vibration when the drilling speed reaches a certain range of values. When weight on bit exceeds its critical value (buckling load limit), the drilling operation will normally be interrupted due to stick-slip or BHA whirl (backward    or forward).This is because the drilling tool will become unstable due to high transverse vibration (bending motion) and high torsional vibration (torsional motion, twist on the rod).

The vertical damping unit is made of mandrel, piston assembly, annular space damping unit and a fluid working chamber. In this mechanism, the compressible fluid in the working chamber acts as a spring to absorb or release the vibrational energy of the drill bit and drill string. For example, under pressure the fluid can  be compressed like a deformed spring. The mandrel moves axially relative to   the outer barrel when the fluid is in compression or expansion. Meanwhile the absorbed vibrational energy will be dissipated as the non-compressible fluid in the damping chamber flows through the damping space creating a great amount of heat  and friction.  Thus the vertical damping unit can absorb and reduce the lateral and vertical vibrational energy in the drilling tools.

The piston change-over assembly helps to maintain constant torque on the drill stem by instantly converting the torsional vibration and impact load into a vertical force component in the working chamber. The unit is composed of the spline outer barrel which is connected with the piston via a pair of rectangular spline and the piston inner surface is connected with mandrel by a pair of ladder-shaped spiral spline.

Specifications - SJ Double-Way Shock Absorber

Tianhe Oil Group is an integrated corporation engaged in petroleum equipment design, manufacture, sale, rental, and maintenance, oil engineering services and oilfield exploration and development.Tianhe Oil Group has 5 business scopes throughout 50 countries and regions as follows:

1. Drilling Tools Scope :

Taking advantage of the geographical logistics of Shanghai Free Trade Zone and Yangshan Port, Shanghai Tianhe undertakes processing on giving materials or samples, seeking the common development of diversified forms such as cooperation or joint venture, both domestically and internationally.
Over the years, Tianhe Oil Group, regarding "people-oriented, technology first, continuous improvement, casting brand" as our management guidance, continuously strives to innovate and improve our products and expand business related to oilfield. Meanwhile, The company also increases investment in technology research and development, always takes providing the global customers with the best technical products and services as our company's mission.
Tianhe Oil Group strongly believes and promotes Total Quality Management, implement the ISO quality management system and HSE management system and API Standard, which has been deeply implanted into every person's thought and carried out into every aspect of work.
Our manufacturing facilities are well equipped with four automated induction heat treatment lines and dozens of other types of heat treatment ovens and well furnaces to ensure full coverage of heat treatment requirements by different products to achieve the required mechanical properties.
In order to ensure the quality consistency and interchangeability of high precision components, Tianhe has introduced WFL 5-axis Linkage Turning & Milling Machining Center from Austria, Mazak's turn milling machining center from Japan and the Haas vertical machining center from USA. These processes are facilitated with precise quality inspection equipment such as the Brunker OES Metal Analyzers from Germany, Ultrasonic and Magnetic Powder Flaw Detector and high precision Hexagon Three Coordinate Measuring Machine and Farco Portable Three Coordinate Measuring Machine.
So far, Tianhe Oil Group has established strong business relationships with over 200 international oil & gas companies in supporting the top 50 oil producing countries.

1.Q:Are you a factory or trading company?
We are a factory and the Top 3 of oildrilling equipment manufacturer.
2.Q:Where is your factory located? 
We locate in Heilongjiang Province, China.
3. Q:What do your factory do regarding quality control?
From material to products, we inspect each process to keep good quality.
And SGS inspection can be accepted.
4.Q:How about MOQ ?
We have stock of common sizes at hand, so even few ton is accepted.
5.Q:How about payment ?
Both T/T and L/C can be accepted.
6.Q: How long does your warranty?
We can assured the quality within 90 days after receiving the cargoes.