petro-find geochem ltd specializing in soil gas surveys for oil and gas
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NEW CONCEPTS AND GEOCHEMICAL METHODS
HYDROCARBON EXPLORATION AND ENVIRONMENTAL ASSESSMENTS


Petro-Find Geochem Ltd is inviting proposals from industry and governments to participate in the development of new concepts and methodologies for hydrocarbon exploration. The objective is to bring oil and gas exploration to a higher level of expertise and discovery, especially in risky and frontier areas. New concepts and methods are applicable to environmental assessments as well. Some of these exploration and environmental approaches are based on the application of already available Petro-Find soil gas technology, while others require development of different sampling and analytical procedures.

The “ mature” nature of oil and gas fields has lead companies to seek new production sources such as complex and deeper reservoir targets, fractured reservoirs, tight sands, so-called shale gas, coal bed methane, heavy oil amd bitumen extraction, enhanced oil recovery, and exploration in inhospitable frontier areas. The successful exploration and development of these resources depend on “pushing the envelope” with traditional technologies as well as developing new concepts, including the incorporation of new sampling and analytical methods. Geochemical soil gas surveys can be considered a new technology in this context because, unfortunately, it has been used only minimally by industry. The new methods being proposed simply provide another layer of information to reduce the increased risks associated with exploration of these new sources of hydrocarbons.

New concepts can be based on either already available soil gas geochemical methods, or new sampling and analytical methods including portable and in situ equipment. Instruments ranging from high performance gas chromatographs with sophisticated detectors to spectrometers are already available from numerous manufacturers to measure hydrocarbons in soils and water. The following new technologies are of particular interest: H2S and aromatics/PAH analysis of soils/gases/water; XRF detection of heavy metals in soils to locate diagenetic natural gas traps; stable carbon and hydrogen isotopes in methane as an exploration tool for frontier basins; benzene analysis of brines from dry wells as a proximity indicator of petroleum reservoirs; and IR thermographic and UV scanning applications for assessment of oil and gas pipeline integrity.

Governments, especially those in Developing Countries, can play a major role in kick starting oil and gas exploration using geochemical soil gas surveys. These types of surveys would require the close coordination with government geoscience groups beginning with Proof of Concept followed by systematic surveys using a state-of-the-art mobile laboratory equipped with appropriate analytical instruments. Other sampling and analytical methods could be tested as well. The costs would be far outweighed by increased revenue accruing from resultant higher exploration activity and discovery. These costs could be shared by industry who may have a land position in those specific areas. In Canada, both Provinces and the Federal Government have in the past conducted large-scale cartographic, airphoto, geologic, magnetic and other surveys to stimulate exploration activity, both mineral and hydrocarbon. This baseline data should be supplemented by soil gas surveys as well as application of new sampling/analytical technologies to enhance exploration efforts and expand the potential for discovery.

Petro-Find welcomes contracts with pipeline and service companies as well as governments to develop better technology and methods for finding leaks in natural gas and oil pipelines along right-of-ways to prevent ruptures and maximize throughput. The high pressure of pipelines and the corrosion from hydrogen sulfide, carbon dioxide. oxygen and even microbes can cause spills or failures with tremendous consequences. Assessment is particulary important for older pipelines with steels that are more vulnerable to corrosion than the high-alloy steels used today. Inspection methods are not the same for oil and gas pipelines, mainly because of different pressures and the commodities carried. Numerous commercial methods exist and are being developed for both internal and external inspection of pipelines.

Canada's vast network of natural gas pipelines need to be inspected on a continuous basis from year to year to prevent incidents. Current methods for locating leaks include: walking with various handheld gas “sniffers”; low flying planes and helicopters with spectrometers; and open path laser technology. Currently, the hand-held sniffers based on flame ionization technology are the most common tools for detecting leaks. But to sense Methane, a sniffer must physically probe into the gas-filled area or plume. Leak surveyors need to walk above each gas pipeline, sometimes in areas impossible to access. This process is very labor intensive, often hazardous and very impractical in view of the fact that over a half million kilometers of gas pipelines would need to be assessed each year.

Aerial and open path techniques (including truck mounted Optical Methane Detectors) for natural gas pipelines have their unique problems as well. Aerial spectrometer surveys can be inaccurate because plumes from pipeline leaks are affected spatially by cross winds and are unable to detect incipient problems where cracks are just beginning to develop. Widely used open path laser infrared technology, which can assess as much as 1000 meters at a time, has limited application because of cross winds, topography, dust and the sinuous nature of pipelines. Any positive readings from airplane and open path surveys need to be followed up with a hand-held sniffer to locate the leaks. Electrically run equipment including trucks and instruments can cause explosions in cases of major ruptures when the lower explosive limit is exceeded.

TDLAS and infra-red thermography, a passive sytem, may be the best options to assess the integrity of gas pipelines. The Remote Methane Leak Detector(RMLD), a commercial instrument based on TDLAS technology, can locate external leaks in gas pipelines. A hand-held device, it can detect leaks up to 100 feet away allowing remote detection of gases in hard-to-reach areas and difficult terrain. However, it is not as effective in open fields because the laser beam needs to be reflected by back scattering to deduce the presence of anomalous methane in its path. Therefore, modifications are required for its full application.

Current oil pipeline leak detection includes direct or indirect visual methods such as aerial patrol, third party reports and inspections by employees. However, oil pipelines are usually buried and leaks are not easily detectable until major spills occur. Leak detection devices, such as combustible gas detectors, hydrocarbon sensing cables and computerized monitoring, are employed. Dogs have been also trained for this purpose. A leak detection system now in use for oil field pipelines on the North Slope of Alaska as well as the trans-Alaska pipeline, involves the detection of minor changes in pipeline pressure and volumes. However, current systems are ineffective with very small leaks that could presage large spills. The oil pipeline industry is highly dependent on sophisticated internal methods to locate incipient cracks and corrosion.

For oil pipelines, Petro-Find would be using thermographic methods supplemented by its own techhnologies to locate incipient or pinhole leaks before major ruptures occur. Crude oil pipeline leaks, even in cold climates, release hydrocarbon gases, including ethane, into the environment. Various hand-held detectors and instruments for aerial detection of ethane are commercially available, but the systems face some of the same problems as those used for gas pipeline assessments. Fast, accurate, highly sensitive and low-cost technologies for sensing of oil pipeline leaks are available but need to to be adapted for monitoring of pipelines. Infra-red thermography has the most potential. Any development of prototype detection systems will require suitable test or leak simulation sites, which Petro-Find can design.


PETRO-FIND GEOCHEM LTD

215 Mallin Crescent
Saskatoon, Saskatchewan, Canada S7K 7X3
Contact: Paul Lafleur, President
View Paul Lafleur's profile on LinkedIn
Phone: (306)931-3156 Fax: (306)931-9773
E-Mail: plafleur@sasktel.net