Choosing the Right Heater Treater for Your Oil Production Needs

When produced fluids reach the surface, they rarely arrive in neat, separate streams. Crude oil, water, gas, and fine solids often travel together as tight emulsions that are difficult to break in a reasonable footprint or timeframe. A heater treater is the workhorse that warms, settles, and separates those phases so downstream equipment, storage, and sales points run smoothly. Choosing the right heater treater is not a one size fits all decision. It depends on your production chemistry, expected flow rates, site conditions, environmental objectives, and how you plan to maintain and scale the facility over time.

At Smith Industries, we build ASME code and non-code vertical and horizontal heater treaters in typical sizes from 4' x 20' to 10' x 30'. That range covers a wide spectrum of treating needs, from lower rate wells to multi-well batteries. This guide explains how heater treaters work, what variables matter most, and how to match a configuration to your field conditions with confidence.

Heater Treater Basics

A heater treater combines controlled heat with gravity separation and internals that promote droplet coalescence. Heat reduces the viscosity of oil and water, helps release dissolved gases, and weakens the interfacial films that keep emulsions stable. Gravity and residence time then allow gas to disengage and oil and water to separate into distinct layers.

Mechanical features like inlets, spreaders, weirs, coalescers, and mist extractors guide that process efficiently. In many operations, modest chemical demulsified dosage complements the thermal and mechanical steps to reach sales oil specifications. Public guidance from the Global Methane Initiative describes heater treaters as thermal and mechanical devices designed to condition oil emulsions, reduce carryover, and achieve better separation performance. 

From an environmental perspective, the burner or firetube produces the heat. That combustion creates emissions similar to other small industrial heaters. The U.S. Environmental Protection Agency includes heater treaters among typical oil and gas production equipment categories when preparing emissions inventories, which is one reason sizing, tuning, and temperature control all matter. 

Key Choice 1: ASME Code vs Non-Code

Your first decision is whether to select an ASME Section VIII code vessel or a non-code unit. Code vessels are designed, fabricated, and inspected to a well defined set of engineering rules for unfired pressure vessels. They come with nameplates and documentation that many midstream and downstream partners require, especially where higher pressures, sour service, or stricter corporate standards apply. Non-code vessels are often suitable for lower pressure treating on private leases where regulations and purchasers allow. The best path depends on your operating pressure, safety philosophy, and the expectations of your purchasers and insurers. If you plan to move the unit to different fields, or anticipate higher pressures later, an ASME code vessel provides flexibility and peace of mind.

Smith Industries offers both ASME code and non-code heater treaters so you can align cost with compliance and risk tolerance without sacrificing build quality.

Key Choice 2: Vertical vs Horizontal

Heater treaters come in vertical and horizontal configurations, and each has strengths.

Vertical heater treaters have a smaller footprint. They are helpful where pad space is limited, or where you want a tall liquid column to promote separation in a compact plan area. A vertical geometry can provide good gas disengagement, and maintenance access around a single small slab is straightforward. Vertical units are common on sites with tight spacing, rough terrain, or access roads that favor shorter trailer lengths during transport.

Horizontal heater treaters provide more cross sectional area and longer settling distances, which can improve oil and water separation when emulsions are particularly tight. In many designs, a horizontal vessel allows more flexibility in arranging internals, coalescers, and weirs so you can fine tune residence times. Field and research literature on three phase separation consistently highlights how residence time, flow distribution, and droplet size distributions drive performance. A horizontal geometry makes it easier to tune those parameters without excessive height.

If your wells produce high water cut, paraffin prone crude, or slugs that upset smaller vertical vessels, a horizontal unit often smooths operation. If you need to minimize civil work and crane time, or want a smaller pad, the vertical unit can be the practical choice.

Heater Treater Sizing Considerations

Smith Industries builds typical heater treater sizes from 4' x 20' to 10' x 30'. Selecting within that range starts with your expected peak production and the quality targets at the sales point. The most common mistake in early facility design is to size on average rates instead of peaks. Undersized treaters run hot, cycle frequently, and can send off spec oil forward, which increases trucking, reprocessing, and chemical spend.

Use these practical sizing inputs as a starting checklist:

1. Liquid rate and gas fraction. More total throughput and more entrained gas require larger cross sectional area and disengagement zones.

2. Water cut and emulsion tightness. Higher water cut and tighter emulsions demand longer residence times or larger vessels. Thermal input may need to increase as well to reduce viscosity and break films. The EPA notes that heater treaters are fired devices whose combustion creates typical heater emissions, so heat input increases should be balanced with environmental and efficiency objectives.

3. Crude properties. API gravity, pour point, paraffin tendency, and solids content affect emulsion stability and fouling.

4. Operating pressure and temperature. Higher pressure service may steer you toward ASME code vessels. Temperature setpoint should be the minimum that achieves spec to reduce fuel use and emissions. The Global Methane Initiative describes practices that reduce methane and fuel consumption, including lowering heater treater temperature when separation goals allow.

5. Future tie ins. If a pad may grow from one to several wells, oversizing now can cost less than replacing the unit later.

Our team can translate those inputs into a recommended diameter and length within the 4' x 20' to 10' x 30' envelope, along with burner sizing and control setpoints.

Internals and Controls That Matter

Performance is not only about the shell size. Internals and controls define stability, chemical usage, and how often operators touch the unit.

Inlet devices should dissipate momentum to avoid re-emulsifying fluids. Spreaders and weirs distribute flow so the full cross section participates in separation instead of short circuiting. Coalescing packs or plates create controlled impingement and film drainage that accelerate droplet growth without large chemical doses. Mist extractors reduce entrainment to the gas outlet. Field experience and published methods for sizing separators point to distribution quality and coalescence as major levers for dehydrating oil efficiently.

On the controls side, a temperature controller should maintain the lowest effective setpoint. A fuel gas train with proper regulators and safety interlocks protects the burner and operators. Level control on oil and water phases must be robust against foam and solids. Add pressure relief that complies with applicable standards, and make sure relief sizing accounts for both operating and fire contingencies. Industry standards for relief devices provide guidance for unfired pressure equipment in related facilities.

Environmental and Regulatory Lens for Heater Treaters

Many operators now select heater treaters with environmental performance in mind, not just separation efficiency. You can reduce total fuel use by:

1. Improving inlet distribution and coalescence so you can run at a lower temperature.

2. Insulating the vessel shell and treating sections to minimize heat loss.

3. Using modern burners with proven turndown and combustion efficiency.

4. Maintaining firetubes and cleaning scale that insulates heat transfer surfaces.

EPA guidance treats heater treaters like other small fired devices and points to fuel combustion as the primary emission source category. Good design and disciplined operation both lower the fuel you burn and the emissions per barrel of oil conditioned. If your facility prepares emissions inventories for state reporting, classifying heater treater operation accurately will simplify the annual process and help you demonstrate improvements over time.

Global Methane Initiative case materials also describe simple operational steps, such as lowering temperature and avoiding unnecessary circulation where separation targets still hold, which can reduce methane and fuel consumption. These are practical no regret actions to consider during commissioning.

Making the Choice for Heater Treaters

Use the following decision flow to narrow your options before you call us:

1. Compliance needs. Do purchasers or company standards require ASME nameplates, or is your design pressure high enough that code compliance is prudent. If yes, select ASME code. If not, and pressures are modest, non-code may be acceptable.

2. Site constraints. Do you have limited pad space or crane limits that favor small footprints. If yes, lean vertical. If you have room and want to maximize settling area, lean horizontal.

3. Emulsion severity. If emulsions are tight, water cuts are high, or slugs are expected, horizontal often gives you more residence time and calmer hydraulics. Literature on separator performance shows the importance of residence time and droplet dynamics in achieving specified BS&W quickly, which favors horizontal geometries at similar shell sizes.

4. Temperature strategy. Start with the lowest temperature that meets spec. Match burner size and control turndown so you can hold that point steadily. Use insulation to protect that investment in heat. Guidance from EPA and Global Methane Initiative both support minimizing fuel where separation still meets spec.

5. Growth plan. If tie ins are likely, select the next larger shell diameter or length in our standard range from 4' x 20' through 10' x 30' to avoid replacement later.

Why Work With Smith Industries

Smith Industries manufactures both ASME code and non-code heater treaters in vertical and horizontal configurations across the industry standard size range of 4' x 20' to 10' x 30'. We pair heavy duty shells and firetubes with field proven internals that balance separation performance with low chemical usage. Our team configures inlets, coalescers, and weirs for your crude properties and expected flow regimes, then sizes burners and control loops to hold the lowest effective temperature. The result is straightforward operation, on spec oil, and less rework.

We also support:

• Applications engineering. Send us your rates, water cuts, and any lab bottle tests. We will translate those into residence time, suggested geometry, and heat input.

• Environmental alignment. We set targets to minimize fuel usage and provide options for insulation and efficient burners. EPA inventory categories and Global Methane Initiative practices inform our recommendations so you can meet operational and reporting goals.

• Lifecycle support. From startup to maintenance, we help you train operators on temperature control, level tuning, and periodic firetube inspection.

The Bottom Line

The right heater treater is the one that delivers on spec oil every day with the least fuel, chemical, and operator attention. Start by deciding on ASME code versus non-code, then select vertical or horizontal based on space and emulsion behavior. Size for peaks, not averages, and invest in internals and controls that maintain low, stable temperature. With Smith Industries, you can choose from vertical or horizontal designs, ASME code or non-code construction, and a practical size range from 4' x 20' to 10' x 30' that covers the majority of treating applications. Our team will help you align performance, compliance, and cost from day one.