What Are Gun Barrel Tanks and How Do They Work in Oil & Gas Separation?

The oil and gas industry relies on efficient separation processes to extract crude oil while removing water and sediments. Gun barrel tanks play a vital role in this operation by using gravity and mechanical separation to improve oil processing efficiency. These tanks have been widely used in oilfields for decades, providing a cost-effective way to handle produced fluids before sending oil to storage or transportation.

Smith Industries specializes in manufacturing API 12F and 12D gun barrel tanks, designed to meet the unique needs of oilfield operators. With multiple sizes available and the ability to customize configurations, these tanks offer a reliable solution for efficient separation. In this guide, we’ll explore how gun barrel tanks function, their components, and why they are a preferred choice for oil-water separation.

How Do Gun Barrel Tanks Work?

Gun barrel tanks function as oil-water separators by utilizing gravity, retention time, and mechanical features to divide different phases of produced fluids. The process works in the following steps:

1. Fluid Entry – A mixture of crude oil, water, and solids enters the gun barrel tank through an inlet.

2. Separation Begins – Inside the tank, a removable flume and gas boot assembly slow down the flow, prevent turbulence, and distributing the fluids in the appropriate section of the tank.

3. Settling Process – The heavier water and sediment settle at the bottom, while oil remains at the top.

4. Spreader Table Efficiency – A flat spreader table further enhances the separation process by distributing fluids evenly, while reducing disturbance in the emulsion as it begins the settling process.

5. Discharge System – Oil exits through an upper skim outlet, while water is removed utilizing head pressure and the waterleg outlet connections.

   
   

The design of these tanks allows for natural separation without the need for high-maintenance mechanical equipment. By using gravity and strategic tank components, gun barrel tanks help reduce oil cut in produced water before it moves to storage.

Key Components of Gun Barrel Tanks

Several structural features allow gun barrel tanks to function effectively:

1. Flume and Gas Boot Assembly

A removable flume and gas boot assembly plays a crucial role in reducing fluid velocity as it enters the tank. This minimizes turbulence, allowing gravity to work more efficiently in separating oil and water. The gas boot also helps remove unwanted gas from the fluid mixture.

2. Spreader Table

A spreader table is positioned inside the tank to distribute the liquid mixture evenly. This component improves separation by maximizing the contact surface area between oil and water, helping heavier elements settle more quickly.

3. Waterleg Outlet Connections

To remove water efficiently, Smith Industries’ standard gun barrel tanks come with 4” API 5L threaded couplings and 8” ANSI raised face slip-on flanges. These outlet connections allow for the proper discharge of water from the system while retaining oil for further processing.

4. Internal Coating and Paint Protection

Smith Industries blasts each tank with steel shot inside an indoor facility before applying exterior paint and internal coatings. Temperature-controlled coating shops help speed up the curing process, resulting in high-quality protection against corrosion and environmental wear.

Standard and Custom Gun Barrel Tanks from Smith Industries

Gun barrel tanks come in various standard sizes, but some projects require customized designs to fit specific operational needs. Smith Industries manufactures the following standard sizes:

• 500 BBL

• 750 BBL

• 1000 BBL

• 1150 BBL

• 1500 BBL

While these configurations meet most industry needs, Smith Industries also provides monogrammed or non-monogrammed tanks and can assist in modifying designs based on unique customer requirements.

Why Gun barrel Tanks Are Essential in Oil & Gas Operations

Oilfield operators need cost-effective and low-maintenance solutions to process crude oil efficiently. Gun barrel tanks offer multiple advantages:

1. Improved Oil Quality

By removing excess water and sediments, these tanks enhance oil quality before it enters storage or transportation. This reduces costs related to downstream processing.

2. Reduced Equipment Wear

Separating water and sediments before oil reaches pumps and storage tanks helps prevent corrosion and damage to expensive equipment.

3. Lower Operating Costs

Unlike mechanical separators, gun barrel tanks do not require energy-intensive operations. Their passive separation process saves money on power and maintenance.

4. Adaptability to Different Oilfield Conditions

Smith Industries offers customized tank designs to accommodate unique site requirements. Whether dealing with high water content or variable crude oil characteristics, a properly designed gun barrel tank can optimize separation efficiency.

Industry Standards and Compliance

Gun barrel tanks must meet strict industry standards to ensure safety and operational efficiency. Smith Industries builds API 12F and 12D compliant storage tanks, which are widely recognized standards in the oil and gas industry.

According to the American Petroleum Institute (API), API 12F tanks are designed specifically for production tank facilities and oilfield storage. Compliance with these standards helps improve safety and reliability in oil production sites.

Delivery and Installation Services

One of the biggest challenges in setting up gun barrel tanks is transportation and installation. Smith Industries simplifies this process by offering knuckleboom truck delivery to safely transport and place tanks on-site. This reduces setup time and helps operators start production sooner.

Final Thoughts: Choosing the Right Gun Barrel Tank

Gun barrel tanks remain one of the most cost-effective and efficient methods for oil-water separation in production fields. By using gravity-based separation and well-engineered internal components, these tanks reduce operational costs, improve oil quality, and help protect downstream equipment.

Smith Industries' API-compliant tanks offer proven performance, and their ability to customize designs based on project needs makes them a reliable choice for oilfield operators. With multiple size options, high-quality coatings, and industry-standard compliance, Smith Industries provides an end-to-end solution for separation and storage needs.

If you’re looking for a dependable and field-tested gun barrel tank, consider Smith Industries’ products for your next oil and gas project.