The benefits of ground penetrating radar

O&G spoke with Brian Wright from MALÅ Geoscience, the global leader in the design and manufacture of GPR.

O&G. You’re a world leader in Ground Penetrating Radar. Can you start by telling us about GPR can be used in the oil and gas industry?

BW. The obvious use for Ground Penetrating Radar in the oil and gas industry is in the detection of buried pipes. The pipe infrastructure is a valuable asset that needs to be managed and protected, so, asset management is a primary application. First, and this is an important point to note, GPR is the only technology available that does not require a physical connection to the pipe, nor does it rely on radiating electromagnetic (EM) fields that may or may not be present or detectable. Therefore, GPR surveys can be performed without interfering with the pipe itself, or any systems connected to it, such as cathodic protection systems for example. Second, GPR can detect both metallic and non-metallic materials and therefore non-metallic pipes. This is a major advantage over more traditional locate technologies and can be a big plus in asset management, particularly when trying to find illegal connections, or even legitimate service connections that are generally non-metallic and hard to find. Another use for GPR within this industry is in environmental protection; contamination of ground, ground water, rivers or lakes from damaged and leaking pipes or tanks occurs frequently, particularly from poorly sealed illegal connections. GPR can be used to identify the area of contamination.

O&G. One area where GPR can be useful is in detecting pipes and cables around production plants. What kind of value does this use of the technology give?

BW. The value GPR technology offers with its ability to detect pipes and cables around production plants can be counted in a number of ways. GPR as a tool in asset management offers value in being able to reduce costs by allowing operators to quickly and efficiently locate these buried services. Pipes and cables are often difficult to find once they have been buried, particularly non-metallic services such as plastic pipes or fiber optic cables. For older production plants, the original as-built drawings may have been lost or perhaps non-existent in the first place. During the expansion of production plants, pipes and cables may be moved and the new positions not recorded, so using GPR allows these services to be located. GPR also adds value in this regard for health & safety, by protecting operators involved in construction or excavation activities. Hitting a buried service, even a low voltage power cable during these activities can lead to serious injury or even loss of live. The value of investing in GPR technology can easily be realized by avoiding just one cable or pipe strike. Forget the cost of repair, downtime and loss of service, what value can be put against a human life!?

O&G. And what about geological investigations? Can GPR technology be used in the search for new sources of oil?

BW. The use of GPR technology really stems from the geophysical field and this is still an important market today. Geological investigations are a prime application for GPR and the search for oil falls into this category. In theory, GPR signals directly ‘probe’ beneath the Earth’s surface and detect sub-surface features through reflections caused by changes in the dielectric permittivity of the ground. So in theory, GPR may be able to detect oil reservoirs as anomalies or reflections in GPR data. However, even with low frequency antennas at say 25MHz, GPR is only able to see approx. 80m into the ground (pending the local ground properties), unless working over ice, where the penetration could be several hundred meters. GPR could probably detect an oil reserve within its operating range; however, it would not be able to identify a sub-surface feature as oil rather than say water, ice or some other density variation, so other complementary technologies, such as seismic would need to be used alongside it.

O&G. Are there challenges in physically using the technology in the field? How can these be overcome?

BW. Yes and no. The systems used for pipe and cable detection are generally very easy to use in the field. These systems utilize shielded antenna designs that combine the transmit and receive antenna elements into one housing that can easily be mounted into carts or trolleys and pushed over the survey area. However, when conducting geological investigations, low frequency GPR systems are needed in order for the signal to penetrate and to reach greater depths. These low frequency antennas are physically quite large and have long antenna elements (up to 4 m). These antennas are also of the unshielded design, which means they consist of separate transmit and receive antenna elements that need to be spaced some distance apart. This obviously creates physical challenges for field use and often requires pre-clearing of the survey area and additional manpower to handle the equipment. However, MALÅ has revolutionized this field through the introduction of its unique Rough Terrain Antenna (RTA) concept. The flexible ‘snake’ like design allows the antenna to be manoeuvred easily and efficiently through the densest or most uneven of terrain without affecting ground contact, providing optimum results in the most difficult of environments and significantly reducing survey time and manpower costs.

O&G. And how easy is it to process the raw data into a usable output? How do you help your customers with this aspect?

BW. Our systems are designed so that the operator can view the raw data in real time as it is being collected and this is often sufficient to make immediate decisions. This is particularly true for pipe and cable location where the user sees the raw radar data on-screen and is able to mark reflections caused by these features without the need for post processing. Filters can be added to clean up the screen image, but it is already in a usable format. Of course, we do allow the data to be exported if further processing is required for more detailed analysis or report generation. For geological investigations, post processing of the radar data is generally required. MALÅ offers a number of processing software packages to assist our customers in this regard. These software packages allow radar data to be exported into other usable formats for importing into CAD or GIS packages. One important point to note is that MALÅ GPR systems always save raw data; there is no pre-processing of the data prior to it being saved. This means that it is always possible to go back to raw data if needed.

O&G. How much opportunity do you see for your company in the Russian/CIS market? What are your plans for growth?

BW. We see a great deal of opportunity for MALÅ in the Russian market. The developing economic status and improved financial position through the management of its oil wealth suggest that this will grow to be an important market for us in the future. We have already experienced some preliminary success in promoting and selling our products in this emerging market and of course wish to see this continue. We have appointed a number of in-country sales partners who are experienced in specific market areas and we anticipate that as these relationships grow, so will our brand awareness and revenues. The increasing awareness in GPR technology and its use in an increasing range of sub-surface applications are driving growth in our business internationally. We believe by sharing this knowledge and experience with our in-country sales partners we can develop the same demand in Russia. MALÅ is an innovative company that is committed to work with its sales partners and customers to bring to market products that provide solutions at affordable prices, and to support those products with quality service. We are currently strengthening our European sales team to enable us to focus more directly on important emerging markets such as Russia.

With over 70-years of experience, we understand the needs of our customers and have developed a versatile range of products that offer solutions across a broad range of applications. From the non-destructive imaging of concrete, utility detection and mapping to geophysical and geotechnical investigations, MALÅ has a solution for you.