Mass spectrometry: challenging industry norms

Strong oil prices and the potential to tap vast reserves in frontier basins are driving increased investment in mature, conventional campaigns and growing enthusiasm for unconventional projects.

But whether a company’s exploration centers on a frontier area or a well-explored play, data remain a critical component of success. Operators need increased insight into the chemistry of rocks, oil, and gas to narrow down the different compounds found in a play and, more importantly, to zero in on and effectively tap into a pay zone.

To meet these new demands, operators are increasingly turning to mass spectrometry for valuable insight into the heavier hydrocarbons and inorganic components within mud gas. This innovative technology produces a full mass spectrum, including water-soluble compounds and inert gases.

FIGURE 1. Gas condensate zones are indicated from mass spectrometry data. The log shows reservoir compartmentalization within the lateral, probably controlled by permeability changes (see second track from left). (Images courtesy of Empirica)

As a result of this technology, operators can more quickly identify gas, condensate, oil, and water zones, allowing geologists to determine permeability, saturation, seal quality, biodegradation, and souring with incredible sensitivity. This in-depth analysis isn’t available through other tools that are common in the industry such as the chromatograph.

More actionable information than hotwire

Historically, the industry has relied on hotwire technology for this kind of geological data. A total gas detector that has been around since the 1940s, hotwire provides operators with data that help determine if substantial amounts of gas exist. The gas chromatograph, which typically accompanies the gas detector, resolves the lightest hydrocarbons, from methane (C) through pentane (C). What hotwire fails to offer, though, are the deeper details that help determine where the sweet spots – and ultimate pay zones – are within a formation. Mass spectrometry provides more useful results because it can read up through C, read other classes of hydrocarbons such as aromatics, and detect many important inorganic compounds.

More data, better decisions

Due to advances in ruggedization and miniaturization, mass spectrometry is now field-portable. Operators can take a mass spectrometer out in the field and attain tangible data without having to extend rig time. In the right hands – that is to say, when its information is analyzed by a team with the right mix of expertise and experience – a mass spectrometer provides far more actionable information much more quickly. That information is rich in the specific data that help operators make decisions that can result in the ability to find and stay in the sweet spots.

When the raw data from a mass spectrometer are analyzed correctly, they in essence say, “Here are your sweet spots,” including lateral and stratigraphic views. Operators then can make decisions about an entire field and granular decisions about a single well, including how to get the field or the well to produce more. A mass spectrometer helps steer the well in relation to the zone.

Improving efficiency and results

Empirica has used mass spectrometers with proven success on dozens of wells. The key is to combine mass spectrometry with sophisticated data analysis and interpretation by experienced engineers.

FIGURE 2. Separate oil zones within a lateral are interpreted to be due to fault-repetition of stratigraphy.

One common benefit of mass spectrometry is helping determine the heterogeneity within the lateral and finding superior pay zones. A West Texas example is shown in Figure 1.

On a separate well, also in Texas, Empirica’s mass spectrometer also demonstrated the repetition of oil and condensate zones in the lateral (Figure 2). A seismic study for this field had identified possible faults or, alternatively, processing artifacts along the well path. However, the precision and real-time analysis of mud gases available with the mass spectrometer, coupled with petrographic work, supported the fault-block model. This helped the operator pick the best fracturing points and better understand the field.

In a similar project (Figure 3), hotwire technology had indicated fairly low gas within the lateral – an incomplete look that could have cost the driller considerable revenue. Mass spectrometry resolved the heavier hydrocarbons and inorganic components within the mud gas with great sensitivity, giving geologists the information they needed to pick out superior pay zones.

In the Permian basin of West Texas, mass spectrometry can enable a company to avoid and seal off common sour zones so it can focus on more productive areas. The result is reduced treatment costs and increased well productivity. The mass spectrometer, coupled with the ability to analyze the results, can provide the information drillers need to quickly make the right decisions.

What to look for

The equipment must be simple enough for field personnel to install and troubleshoot and robust enough to do its job in real-world conditions.

It’s also vital to find a vendor whose engineers are trained in analyzing the data. While cutting-edge technology can make a huge difference in production, the true differentiator comes with the combination of the technology and the ability to accurately and effectively interpret the data. With real-time analysis, operators are finding guidance and identifying their target zone in less time, allowing them to operate with more facts and rely less on assumptions, which can be costly.

A bright future

FIGURE 3. In this limestone play all three tracks shown indicate oil.

The successful exploration of shale and other unconventional plays will require detailed geological knowledge. By greatly reducing uncertainty about reservoir geofluids, the mass spectrometer is poised to help sustain current hydrocarbon demand.

Demands on the oil and gas industry will continue to increase both in developing and mature locations. By employing mass spectrometry and the informed analysis of an experienced partner, the industry will enjoy enhanced success – both onshore and offshore.