Slickline Stem

Description

Slickline Stem / Sinker Bar

Technical Description and Specifications

The Slickline Stem is a passive, solid-body tool string component critical for wellbore intervention. Its primary function is to provide the necessary inertial mass (weight) to overcome hydrostatic wellbore pressure, counter static and dynamic friction (stuffing box packing, downhole fluid drag), and allow the tool string to descend to the target depth. The Stem also stores and transfers potential energy for jarring operations.

Key Technical Specifications and Operation

• Function: Provides controlled weight and inertia to the tool string for gravity-assisted descent and to increase the impact force during upward or downward mechanical jarring operations (Force = Mass \times Acceleration).

• Design: Typically a solid, cylindrical bar machined to precise ODs and supplied in modular lengths (e.g., 2 ft, 3 ft, 5 ft sections) to allow operators to fine-tune the total weight.

• Calculation: The required stem weight is calculated based on well conditions (pressure, fluid density) and the desired jarring load. Weight per foot for standard alloy steel is approximately D^2 \times 2.66 lb/ft, where D is the Diameter in inches.

• Types:

  • Standard Stem: Solid alloy steel.

  • Heavy Weight Stem: Lead or Tungsten-filled variants are available for high-pressure, high-angle, or deep wells, providing significantly greater mass per unit length (higher density) without increasing the OD.

• Connection (Customizable):

  • Standard connections include common proprietary slickline threads (e.g., 15/16″-10 UN, 1-1/16″-10 UN) or API Sucker Rod threads.

  • Custom order connections are available to ensure interchangeability with all major competitor quick-connect systems (e.g., Halliburton HQC, Petroline QLS) and non-standard thread profiles.

• Material (Customizable):

  • Standard Stem: High-grade alloy steel (e.g., AISI 4140).

  • Custom material options are available, including NACE MR0175 compliant alloys for sour service, and materials certified for low-temperature or critical fatigue applications. Material certification reports are provided.

• Critical Parameters (Customizable Size & Weight):

  • Stem OD and Length: Standard ODs range from 0.75″ to 3.00″. Standard modular lengths are available in 2′, 3′, and 5′ sections.

  • Custom dimensions (ODs and lengths) are fabricated to meet exact weight and dimensional requirements for specific tubing ID and minimum restriction constraints, optimizing for maximum weight and clearance.