1. Drilling jar Types
Drilling jars are generally categorized by application into drilling and fishing jars, and by operating principle into mechanical and hydraulic jars.
◆Drill jars are designed into the drill string for downhole use during drilling. If sticking occurs while drilling or tripping, it can immediately be employed to free the stuck point. Using it helps prevent drilling incidents, reduces or avoids unnecessary fishing costs, and lowers overall drilling expenses. Therefore, jars should be considered in drill string design for complex wells.
To meet the demands of extended downhole service, drilling jars typically incorporate high-capacity torque transmission and reliable sealing systems.
◆Fishing jars are only run when needed to free stuck pipes. Since they do not require extended downhole service, the design is relatively simple. In general, drill jars can substitute for fishing jars, but fishing jars cannot be used for extended drilling services.
The key drill jar component is the release mechanism. Based on operating principles, there are mechanical jars, hydraulic jars, and hybrid mechanical-hydraulic jars. Mechanical jars, especially tandem upward and downward jarring tools, offer advantages like simple construction, reliable operation, and suitability for various conditions including high temperatures. They are commonly used overseas. In past years, mechanical jars were rarely used domestically due to demanding requirements for materials, heat treatment, and machining capabilities.
◆Hydraulic jar performance can be adjusted by the driller's operations, offering flexibility. However, components like seals are susceptible to wear and temperature effects, leading to instability in service life, adaptability, and reliability. Advanced sealing materials and designs implemented by our company significantly improve hydraulic jar reliability. Hybrid mechanical-hydraulic jars combine the benefits of both principles for greatly enhanced performance and represent the development trend.
2. Drilling jar Models
Per the latest industry-standard SY/T5496-2000 "Drilling jars and Accelerators", Products are modeled as follows:
- QJ - Mechanical tandem drilling product
- SS - Hydraulic upward jarring drilling product
- SX - Mechanical downward jarring drilling product
- CS - Hydraulic upward jarring fishing jar
- DX - Mechanical downward jarring fishing jar
178 - Drill Jar Size (diameter in mm)
Design Code
- A - Surface adjustable release force
- K - Non-adjustable release force
Choose VIGOR as your supplier, Vigor has different types of jars available, including mechanical, full-hydraulic, integral mechanical, hydro-mechanical, and mechanical & hydraulic jars, please contact us at info@vigorpetroleum.com.
