Product Overview

The Junchi (SANMON) Hydraulic Drilling Jar is a critical downhole tool designed to deliver powerful upward or downward impact forces to free stuck Drill Strings, Tubing strings, and downhole assemblies during drilling and workover operations. Unlike mechanical jars that rely on preset spring tension, the hydraulic jar features an innovative time-delay metering system that provides precise control over tripping force regardless of overpull. The operator simply applies tension (or compression) to the string, and the hydraulic timer delays jar activation by a consistent interval (typically 90-120 seconds), after which the jar fires with full stored energy.

Manufactured from premium AISI 4340/4145H alloy steel with full-length heat treatment and precision machining, our hydraulic jars are engineered for high-cycle durability and consistent performance in demanding conditions. The internal hydraulic metering system uses specially formulated high-temperature silicone fluid and precision-ground metering pistons for repeatable time-delay performance. All jars are assembled, function tested, and serialized in our Tianjin facility before shipment.

Technical Specifications

Applications

• Drilling Stuck Pipe Recovery: Primary application in drilling operations where differential sticking, mechanical sticking, or key seating requires jarring to free the drill string.

• Workover Fishing: Essential component of fishing BHAs, providing impact force to dislodge stuck fish when combined with an overshot, taper tap, or spear.

• Coiled Tubing Operations: Compact jar configurations available for coiled tubing drilling and workover applications in live wells.

• Well Testing: Used in DST (Drill Stem Testing) strings to provide a contingency release mechanism for stuck test tools.

• Completion Operations: Deployed in completion strings in wells with known sticking tendencies to provide a first-response recovery tool.

Advantages

• Precision Timing: Hydraulic time-delay mechanism provides consistent, repeatable tripping time regardless of overpull magnitude, giving the operator precise control over jar activation.

• Maximum Impact Energy: Hydraulic design allows full string stretch energy to be stored and released instantly through the jar stroke, delivering more impact force than mechanical jars of the same size.

• Adjustable Force: Operator controls jar impact force by varying the applied overpull, allowing gentle jarring for stuck completions or maximum force for stuck drill strings.

• Bi-Directional Operation: Provides both upward and downward jarring capability, enabling the operator to work the fish in both directions without tripping to change tools.

• High-Temperature Reliability: Specially formulated silicone hydraulic fluid and high-tolerance internal components maintain consistent performance at temperatures up to 204 deg C.

• Long Service Life: Robust internal components with wear-resistant surfaces and high-strength splines provide extended service life with minimal maintenance between runs.

Why Choose SANMON

SANMON brings precision engineering and rigorous manufacturing standards to every hydraulic jar we produce. Our Tianjin facility features advanced CNC machining centers with multi-axis capability for complex internal profile machining, deep-hole drilling equipment for long body components, and computer-controlled heat treatment furnaces for achieving precise hardness and toughness profiles. The hydraulic metering system undergoes individual calibration and function testing to verify time-delay consistency within +/- 10% of specification. We utilize tensile testing machines for component strength verification and ultrasonic C-scan inspection for detecting internal material defects. Every completed jar assembly undergoes a full-cycle function test at our facility before packaging and shipment. Our engineering team understands the critical nature of jarring operations and provides comprehensive technical support for BHA design, operational procedures, and post-job analysis. Junchi/SANMON hydraulic jars deliver the reliability and performance that stuck-pipe recovery operations demand, at competitive prices with responsive global support.

FAQ

Q: How is the jar tripping time adjusted?
A: The time delay is adjusted by changing the metering orifice size or hydraulic fluid viscosity during assembly. The desired tripping time should be specified when ordering. Field adjustment is not recommended.

Q: Can the jar be used in horizontal wells?
A: Yes, hydraulic jars work effectively in horizontal wells since the time-delay mechanism functions independent of tool orientation. Up-jarring is activated by tension; down-jarring by compression.

Q: How often should the jar be serviced?
A: We recommend inspection and fluid replacement after 100 jarring cycles or 500 rotating hours, whichever comes first. Complete rebuild is recommended after 500 cycles.

Q: Is the jar compatible with MWD/LWD tools?
A: Yes, the jar is non-magnetic friendly and can be run above or below MWD/LWD tools. We recommend running the jar above directional tools for maximum impact at the stuck point.

Q: Do you provide jar placement consulting?
A: Yes, our engineering team offers BHA design consultation including optimal jar placement, recommended overpull limits, and contingency planning for your specific well conditions.