All You Need to Know About Wet Measurement vs Wellsite Separation

Wet Measurement vs Wellsite Separation

The Alberta Energy Regulator (AER) stipulates standards of accuracy for gas and liquid measurement considering the essential aspects such as reservoir engineering, royalty, equity, declining production rates, and aging equipment. The Saskatchewan Energy & Resources Ministry (SERM) and the British Columbia Oil & Gas Commission (BC OGC) also have similar regulations in place.

As a prominent name when it comes to oil and gas equipment such as meter packages, orifice meters, wellsite separators, and more, we are well-versed in the equipment requirements and best practices. Read on to learn more about wellsite separation and wet gas management from our experts.

  • Wet Measurement vs Wellsite Separation
  • Wet Measurement vs Wellsite Separation

Wellsite Separation

A natural gas wellsite separator typically uses a pressure vessel to separate the liquids from the gas. The most accurate method of measurement is to have the gas phase separate from the liquid phase. It is of the following types:

Two-Phase Separator

When the hydrocarbons and water are measured together, the separation is called two-phase separation: liquid phase and gas phase.

Three-Phase Wellsite Separator

When the fluids are further separated into a condensate or hydrocarbon phase and a water phase, it is commonly known as three-phase separation.

Wet Gas Measurement

Wet gas measurement is an industry term that refers to the process of measuring the gas and liquids produced from natural gas using the same meter. According to the AER, this is known as continuous effluent measurement. In wet gas measurement applications, the volume of the gas phase is more than the liquid phase. Typically, an orifice meter is used for this process.

Measurement Uncertainty

Before we decide to use a wellsite separator package or a wet gas meter, it helps to understand measurement uncertainty. The AER Directive 017: Measurement Requirements for Oil and Gas Operations stipulates the single point measurement uncertainty and maximum uncertainty of monthly volume for each method of measurement.

The volumes determined at the sales or delivery points have a direct impact on royalty determination, which is why the measurement at these points should meet the highest accuracy standards. Other measurement points in the overall accounting process are subject to less stringent standards to accommodate physical limitations and economics.

Well Site Separation Measurement

In this case, the maximum uncertainty of the monthly volume is as follows:

  • > 16.9 103 m3 /d = 5.0%
  • ≤ 16.9 103 m3 /d = 10.0%
  • Single point measurement uncertainty = 3.0%

Figure 1.15 (Well Gas - Wellsite Separator)

Wet Gas Measurement

Here, the maximum uncertainty of monthly volume is 15%, and the single point measurement uncertainty is equal to 3.0%.

The wells are continuously measured and are subject to a proration accounting system. Based on the measurement of group gas and liquid components, the wet gas measurement is prorated from actual production, following separation at a central location.

Figure 1.16 (Well Gas - Effluent Proration Battery)

Advantages of the Wet Gas Metering

The main benefit of using a wet gas meter package instead of a wellsite separation package is the simple operation process and low cost of equipment. The addition of a separator at the site also requires the consideration of the following:

  • The addition of level controllers and valves may increase the maintenance costs
  • More instruments for venting may be required, increasing fugitive emissions
  • If the fluids are separated on-site, it may add to the cost of production tank and secondary containment, increasing operating expenses due to trucking
  • More area may be needed for the separator and equipment, often increasing property taxes

Wet gas metering is worth considering if you can prove to the regulator that the well meets the measurement uncertainty requirements.

Get the Right Wellsite Separator & Wet Gas Meter for Your Project

Aspire Energy Resources Inc. has a wide selection of wet gas meter and wellsite separation packages in stock for quick delivery. We also have the expertise and resources to modify them to meet your exact requirements. Call us toll-free at 1-800-993-9958 or 403-314-5422 to get started. We can help you select the right measurement equipment for your next project.

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