Choke and Kill Hoses: The Lifeline of Well Control in Oil and Gas Drilling

Choke and kill hoses are critical components in drilling operations, designed to handle high-pressure fluids during well control situations. Their technical parameters are crucial for ensuring safety and reliability. These parameters can vary between manufacturers and specific applications, but they generally fall within certain ranges and conform to industry standards like API Spec 16C.

Technical parameters for choke and kill hoses:

Working Pressure (WP): The maximum pressure at which the hose is designed to operate continuously. Common ratings include: 5,000 psi (34.5 MPa), 10,000 psi (69.0 MPa), 15,000 psi (103.5 MPa), 20,000 psi (138.0 MPa)

Test Pressure (TP): The pressure to which the hose is hydrostatically tested to ensure its integrity. This is typically 1.5 times the working pressure. For example:

7500 psi for a 5000 psi WP hose.

15000 psi for a 10000 psi WP hose.

22500 psi for a 15000 psi WP hose.

Minimum Burst Pressure (MBP): The minimum pressure at which the hose is expected to burst. This is a safety factor, typically 2.25 times the working pressure. For example:

11250 psi for a 5000 psi WP hose.

22500 psi for a 10000 psi WP hose.

33750 psi for a 15000 psi WP hose.

Dimensions and Construction

Internal Diameter (ID): The inner diameter of the hose, which dictates the flow rate. Common sizes range from 2″ to 4″.

Outer Diameter (OD): The external diameter of the hose, which is important for installation and clearance.

Reinforcement: The hose’s strength is provided by multiple layers of high-strength steel cables or spiral wire.

Inner Tube: The material of the inner lining must be resistant to the fluids being pumped, such as oil-based and water-based drilling muds. Materials like Nitrile rubber or specialized polymers are often used, and they are frequently specified to be resistant to hydrogen sulfide (H2 S) service.

Cover: The outer cover is designed to be resistant to abrasion, ozone, petroleum, and weathering. Fire-resistant covers are also available with stainless steel armor.

Length: Choke and kill hoses are available in various lengths up to 100 feet.

Minimum Bending Radius (MBR): The smallest radius the hose can be bent without causing damage or kinking. This is a crucial consideration for installation and operation.

Temperature Ratings

Operating Temperature: The range of temperatures the hose can withstand during normal use. A typical range is −20∘F to 212∘F (−29∘ C to 100∘  C).

End Connections

Types: End connections are available in various styles to fit different manifold setups, include API flanges, Butt-weld hammer unions, API male nipples

Materials: Connection materials are often treated for corrosion resistance and heat, and they must meet standards like NACE MR0175/ISO 15156 for sour gas service.