Archive for category Technology

Supervised Neural Network Targeting and Classification Analysis for Mineral Exploration

Posted by on Tuesday, 29 April, 2014

Karl Kwan (Geotech LTD) presented at Canadian Exploration Geophysical Society meeting (8 April 2014) methodology and examples of using Neural Network Targeting and Classification at mineral exploration.

“Geophysical survey contractors routinely offer multi-parameter data to clients. For example, a helicopter-borne survey may acquire Time-domain electromagnetic (TDEM), magnetic gradiometer and even gamma-ray spectrometer data (i.e., VTEMplus, Geotech LTD). Exploration geophysicists can certainly take advantage some of the readily available multi-disciplinary (geology, geophysics and remote sensing) and multi-parameter (potential field, EM, gamma-ray spectrometry, and others) datasets for mineral exploration. However, the integration and interpretation of these datasets can be time-consuming and even challenging, especially for large-scale datasets covering large areas with diverse geological conditions. The Supervised Neural Network (NN) Targeting and Classification technique for mineral exploration described and demonstrated by Reford, Lipton and Ugalde, 2004, “Predictive Ore Deposit Targeting Using Neural Network Analysis” (http://www.pgw.on.ca/downloads.html), can be a useful and promising tool for the analysis of multi-disciplinary and multi-parameter data.

In this presentation, the properties or responses of the two feed-forward multilayer Neural Networks, Levenberg-Marquardt (NN with LM training) and Fast Classification (FCNN), as implemented in the current version by PGW, are studied in detail. The supervised NN simulations are performed on specially constructed synthetic data. Intended as a tutorial and the NNs treated as black boxes, the objectives of the exercise are twofold, to demonstrate the targeting as well as classification capabilities of the Neural Networks, and at the same time to show one of the known limitations and to suggest a way to get around it. The utility of the NN tool is demonstrated again with real cases from the Republic of Niger.”

Geosoft is delighted to host the online portion of the Canadian Exploration Geophysical Society meeting with keynote speaker Karl Kwan, Geotech LTD.

YouTube:  


From Latest Geoscience Australia News

Posted by on Friday, 7 March, 2014

New geophysical data helps identify suitable CO2 storage sites

 

“New geophysical data collected in the Browse Basin off the northwest coast of Western Australia has been released today by Geoscience Australia. The new data will be used to map the location of faults and volcanic rocks that can influence the suitably of particular areas for the geological storage of carbon dioxide (CO2).” More…

 

 

 

Potential-field data as an aid to identifying the elements of a petroleum system

“Potential-field (gravity and magnetic) data are a valuable addition to geological studies of the systems within the Earth’s crust that host mineral, petroleum and groundwater resources. They provide constraints on density and magnetic susceptibility, both key rock properties that are intricately linked with geology.” More..


The technology for fracture estimation

Posted by on Wednesday, 5 June, 2013

MicroSeismic, Inc. (MicroSeismic) has announced that is has introduced the Productive-SRV™ (Productive-Stimulated Reservoir Volume). The multiple patents pending technology introduces a novel method to estimate how much of the stimulated fracture remains open through proppant placement. Productive-SRV incorporates three microseismically derived calculations to estimate target zone productivity; a magnitude calibrated Discrete Fracture Network (DFN), the Propped Fracture Estimation and the Fat Fracture™ Drainage Estimation. The combination of these techniques can be used to estimate 90-day cumulative production.

“Hydraulic fracturing has been effective at stimulating fractures in the subsurface for more than 60 years,” said Michael Thornton, Ph.D., Chief Technology Officer, MicroSeismic. “However, increasing hydrocarbon recovery requires those fractures to stay open. The overburden pressure of 10,000 feet of rock will quickly close a fracture if it is not wedged open with proppant. Productive-SRV helps our clients quickly determine which completion techniques are most effective by estimating the effects of proppant placement at optimum well spacing.”

Productive-SRV is determined from integrating microseismic data with known treatment parameters and near wellbore geology and geomechanics. By estimating the volume of fractures that are likely proppant filled, on a per stage basis, a more constrained area of stimulation is determined, providing a more accurate correlation to early production.

Productive-SRV is to be included as part of the standard surface, near surface and downhole microseismic services provided by MicroSeismic.


Wireless Seismic Technology in Alaska’s Cook Inlet

Posted by on Thursday, 4 October, 2012

Houston-based Apache Corp. has become the first producer to use true-cable free wireless seismic technology offshore Alaska to limit the impact of seismic activity on Cook Inlet’s wildlife, communities and environment – including Cook Inlet beluga whales.

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The use of wireless 3-D seismic is part of Apache’s commitment to conducting 3-D seismic operations in Alaska’s Cook Inlet “in ways that limit the impact on communities and the environment,” the company said in a July 24 article on its website, addressing criticisms of its seismic program.

Apache is using true cable-free nodal recording systems, designed and manufactured by Sugar Land, Texas-based FairfieldNodal, in order to minimize the impact of its seismic survey on Cook Inlet’s wildlife population and environment.

“Because we’re shooting onshore and offshore, we have to go back and meld and blend the data for the different sections together,” said Lisa Parker.

The company is using the technology for its ongoing 3D seismic survey of Cook Inlet, which will encompass onshore, offshore and the transition zone of Apache’s acreage. The seismic survey will continue for the next two and a half years.

After acquiring leases on 850,000 acres in Cook Inlet in August 2010, Apache began the permitting process for its seismic and exploration programs. In an effort to address concerns over the impact of seismic activity on local wildlife and the environment, Apache conducted a technology test to compare how traditional cable seismic would perform versus a wireless system.

Impressed with what it saw, the company initiated the permitting process to utilize wireless seismic and received approval to use this technology in the spring of 2011.
Apache began its Cook Inlet seismic program in November 2011, and has been working continuously since then, save for a six-week break from Christmas through the first part of February.

Approximately 1.4 billion barrels of oil was discovered in Cook Inlet in its early development in the 1950s and 1960s. Exploration and production in Cook Inlet declined after the discovery of Prudhoe Bay. Only a handful of fields have been discovered in Cook Inlet, but the field size distribution strongly suggests another 1.3 to 1.4 billion barrels of oil remain to be discovered in the Cook Inlet basin, Apache said.

Apache will begin drilling in Cook Inlet in October.

Fairfield’s product is truly cable free, unlike nodes from manufacturers who have elected to keep the power supply, electronics and sensor connected with short cables and connectors, said Roger Keyte head of marketing and business development at FairfieldNodal.

The nodes are placed on the ocean floor or buried onshore. Except for a rope tied to nodes placed offshore to retrieve them – the rope is not involved in the spacing of the node – the nodes have no cables, said Keyte.

Marine nodes weigh 65 pounds and look like a 50-pound free weight, but are a bit thicker, said Lisa Parker, head of government relations for Apache in Alaska. Land nodes weigh 4.8 pounds and look like a two-pound coffee can with a spike on the bottom. Both types of nodes are made of plastic and stainless steel.

The nodes are retrieved after a period time and taken back to the office, where the data is downloaded and the nodes are recharged. The data is then forwarded to Apache’s geoscientists for interpretation.

“Because we’re shooting onshore and offshore, we have to go back and meld and blend the data for the different sections together,” said Lisa Parker, head of government relations for Apache in Alaska. “It’s like putting the pieces of a puzzle back together.”

Since 1924, traditional seismic systems have involved sensors connected to cables. These sensors transmitted signals back to a localized recording system to be converted into digits, said Keyte.

Using a system with heavy, cumbersome cables presents difficulties onshore and offshore, Keyte noted. Offshore, the cables mean seismic vessels can’t get close to structures in the water such as rigs and platforms. Traditional systems also tend to be noisier.

Using cabled system onshore was especially problematic, with electrical leakages occurring due to animals biting or chewing the cables or sweat from the hands of workers, said Keyte.

Utilizing a true cable-free system cuts down on the amount of time crews spend troubleshooting to fix leakages. The cable free system increases the reliability of data and allows the recording time to be controlled.

More details


“Detecting vanadium and graphite deposits with EM methods”

Posted by on Monday, 23 July, 2012

CARMELA BURNS on JULY 19, 2012

“The recent rush to find graphite and vanadium deposits to satisfy potential demand in green energy applications is reigniting airborne electromagnetic (EM) methods as highly effective exploration tools.”

read more..


Airborne EM for permafrost mapping

Posted by on Wednesday, 25 January, 2012

ANCHORAGE, Alaska — A tool used by mining companies to find mineral ores has been adapted to map frozen soils below the ground in Alaska and could be used to track the effects of global warming, according to the U.S. Geological Survey.

The agency announced Monday that an airborne survey conducted in Alaska’s Yukon River drainage collected unprecedented images of the presence and absence of permafrost down to 328 feet. The study used an electromagnetic survey tool flown beneath a helicopter.

“We really think we’ve got the story nailed down from these data,” research geophysicist Burke Minsley said by phone from the Crustal Geophysics and Geochemistry Science Center in Denver.

Minsley is lead author of the study published Friday in the journal Geophysical Research Letters (http://www.agu.org/pubs/crossref/2012/2011GL050079.shtml).

Mapping permafrost extents has been done by satellite, Minsley said.

“It’s hard to get any information at depth, and that’s what’s unique here,” he said.

Permafrost is below about 24 percent of the land area in North America. The research will be important for climate scientists looking at the thawing of permafrost as a greenhouse gas contributor, studying ecology in lake systems, or looking at the effects of thawing ground on river chemistry, Minsley said. Thawing also will bring important impacts for northern infrastructure such as buildings and roads.

The Yukon River begins in Yukon Territory, Canada, and spans Alaska from east to west.

The research team surveyed more than 116 square miles of the Yukon Flats in an area centered 140 miles northeast of Fairbanks. The area was picked in part because it’s between continuous permafrost to the north and discontinuous permafrost to the south, according to the agency.

Electromagnetic surveys have been used in mining for years, Minsley said. Scientists recently have used it to define the geometry of aquifers in Nebraska.

“What’s new about it is that it’s being used for more discrimination of more subtle features related to things like groundwater and permafrost,” Minsley said.

The tool is torpedo-shaped and about 33 feet long. In front are coils oscillating at different frequencies, Minsley said. Towed by a helicopter and flown just under 100 feet off the ground, the tool sends electromagnetic pulses into the ground and determines what’s below by measuring how well the pulse is conducted. The ground itself has conductors and resistors. Permafrost is not as conductive as solid ground.

“It induces currents in the ground. Those currents induct a signal, a magnetic field, that’s picked up by another set of coils that’s in the back of that thing that we’re towing under the helicopter,” Minsley said.

The tool collected data that showed a lack of permafrost below the Yukon River and other water bodies that don’t completely freeze in the harsh interior Alaska winter.

“That’s consistent with a lot of conceptual models that people have developed, but they haven’t really had the solid measurements that we have to see that,” Minsley said.

The mapping also showed “thermal relics” where the Yukon River had been centuries ago. As the river migrated to a new location, ground slowly refroze. The farther away from the new location, the more it had frozen in a downward slope. Minsley said it was the biggest surprise of the study.

“It was not something we expected to capture in this data set, to actually see that thermal legacy over a thousand-year history. That’s pretty rare for this kind of data,” he said.

The tool collected data over only one week in June 2010. Minsley said he spent four to five months analyzing and processing data to make images, and the research team spent many more hours interpreting the results.

Drilling boreholes to acquire the same information would have taken a much greater effort, he said.

Source: http://www.therepublic.com/view/story/ad6b2e26841f4a43b94544da1fc50b34/AK–Permafrost-Mapping/


Technology tie ups boost seismic sensing capabilities

Posted by on Sunday, 7 August, 2011

Shell and HP have announced a breakthrough in the capability of their jointly developed inertial sensing technology to shoot and record seismic data at much higher sensitivity and at ultra-low frequencies.

The new onshore wireless seismic acquisition system is designed to provide a clearer understanding of the earth’s subsurface, thus increasing prospects for discovering greater quantities of oil and gas to meet the world’s increasing energy needs.

The sensing technology has now been demonstrated to have a noise floor – a measure of the smallest detectable acceleration over a range of frequencies – of 10 nano-g per square root Hertz (ng/rtHz), which is equal to the noise created by the earth’s ocean waves at the quietest locations on earth as defined by the Peterson low noise model. The tests were conducted in the seismic testing vault at the US Geological Survey’s (USGS) Albuquerque Seismological Laboratory facility in New Mexico.

The seismic system uses the breadth of HP’s technology development capabilities as well as Shell’s advanced geophysical expertise in seismic data acquisition systems and operations. As such, this collaboration builds on the core strengths of each company to advance technology in this field.

The system will be delivered by HP Enterprise Services and the company’s IPG. It is based in part on the high-performance sensing technology originally co-developed by HP Labs – the company’s central research arm – along with IPG and Shell research in seismic network design.

Fig. 1. The survey will be flown using BlueQube technology.

http://www.engineerlive.com


Mapping the footprint of ore deposits in 3D using geophysical data

Posted by on Thursday, 31 March, 2011

Potential field data provides alteration signatures

Linking geology and geophysical data

Chemical alteration in 3D

3D inversion of geophysical data

Changes in alteration types

This technique has allowed us to attribute anomalies in physical properties, with respect to the ‘normal’ host properties, with an expected alteration type. The technique is particularly applicable in the Cobar region because there is limited physical property contrast between host units and alteration is the predominant cause of geophysical anomalies. The technique is also applicable in regions that are under significant cover. As with any geophysical technique, the exact results will depend on the property contrast from host to altered product. A strong host-to-host property contrast will require a more detailed geological model to obtain the best results, but mapping of gross alteration trends should still be possible with only a very simple inversion reference model.



The history of seismic resolution from John and Les Denham

Posted by on Friday, 18 February, 2011
Actual time resolution achieved in typical seismic exploration has not improved since 1930. There appears to be an abrupt drop in resolution at the time when multifold techniques were introduced about forty years ago, and since then there may have been a slow improvement in resolution; but the achieved resolution is still not as good as that achieved in the very earliest reflection surveys. Many of the techniques used to improve other aspects of the data – signal-to-noise ratio, horizontal resolution and lithology discrimination, in particular – probably limit time resolution. In most projects there is a trade-off between cost, resolution and noise. The chosen techniques always seem to result in similar resolution, and this suggests that the cost – in money or other desirable signal characteristics – of improving resolution beyond this level is very high.

Kim Frankcombe – How real is Real Section IP?

Posted by on Friday, 18 February, 2011
Real Section is a pseudosection plotting method developed by Perparim Alikay and is described in a paper by Langore et al. (1989). It was originally based on a Schlumberger array but has been generalised more recently to gradient arrays. It assumes the plot depth for the pseudosection is between 0.125 and 0.2 of the current electrode separation A–B. According to the Langore paper, the factor to use in a given area was derived empirically from drill hole control. These values compare well with those given earlier by Edwards (1977) of 0.103 near the edges of the array to 0.192 at the centre. These are the depths at which, for a half space, half the signal comes from above the plot point and half from below. Despite the prevalence of relatively cheap 3D inversion software, the Zeus data is plotted in Real Section form for presentation to geologists rather than as inversions with sensitivity cut offs.
Prof. Perparim Alikaj (right) and Alexander Prikhodko (left) on Real Section site (Far East of Russia)

Two kilometres with time-domain AEM

Posted by on Friday, 18 February, 2011

Newly acquired data from an Airborne Electromagnetic (AEM) survey has revealed geological features to depths below the Earth’s surface well beyond any previously recorded by airborne systems.
The Versatile Time Domain Electromagnetics (VTEM) system operated by Geotech penetrated to depths approaching two kilometres which allows detailed identification of particular features and major structures at depths greater than has been mapped previously using AEM methods.
The data was acquired by Geoscience Australia in the Pine Creek region of the Northern Territory as part of its Onshore Energy Security Program to obtain pre-competitive data in areas which are considered to have potential for uranium or thorium mineralisation.
Prior to the enhancement of the VTEMTM dataset, AEM systems used throughout the world had been able to achieve imaging to a maximum depth of about 800 metres.
An enhanced set of conductivity estimates for the Kombolgie region within the Pine Creek survey area are available as a free download.
Geoscience of Australia selected the VTEM system to fly the Kombolgie survey from the various candidates submitted by members of the Panel of AEM contractors after an assessment of the probability of detecting hypothetical geological targets in the presence of a given background. GA selected the VTEM system to fly the Kombolgie surveyfrom the various candidates submitted by members of the Panelof AEM contractors after an assessment of the probability of detecting hypothetical geological targets in the presence of agiven background.

NEOS’s G&G methodology

Posted by on Sunday, 30 January, 2011

NEOS believes that an integrated analysis of multiple geological and geophysical (G&G) data sources – including seismicgravitymagneticelectromagnetic (EM), radiometric, and hyperspectral – can individually and collectively deliver improved insights into the rocks and fluids contained within the Earth.

“NEOS was formed to be a different kind of geosciences company where “Silicon Valley meets the oil patch.” We aspire to help our clients unlock the riches of the Earth by bringing to bear the latest technologies and the best people, wherever they might be located.”

One of our largest investors is the venture capital firm Kleiner Perkins Caufield & Byers (KPCB), the entity that backed pioneering companies such as Google, Symantec, Amazon, and Electronic Arts. By tapping into the networks of KPCB and our two other lead investors – Goldman Sachs and Passport Capital – we ensure our methods incorporate the latest thinking in sensors, computing, neural networks, visualization and intelligent search.

NEOS has been working over the last several years with leading technologists to develop the NeoSphere™, their proprietary data management system that allows a statistically-driven, multivariate inversion to be performed using all available data and modeling products. NEOS’s multi-measurement inversion incorporates all G&G data that has been obtained, acquired, or computed, along with additional geochemical and hydrocarbon production (and mineral resource) data provided by our clients and third parties.

Fixed Wing

NEOS generally uses company-owned Twin Otter aircraft for airborne sensor deployment. The Twin Otter offers a reliable platform that is capable of operating in remote, low-service locations. NEOS’s Twin Otter platforms are outfitted with advanced gravitymagnetic, and hyperspectral sensors.  NEOS’s hyperspectral sensor package records more than 600 contiguous channels – from ultraviolet to thermal infrared – with a spatial resolution of 3m. The Twin Otter is also capable of safely operating across a range of altitudes, providing the flexibility needed to tailor acquisition to the resolution and penetration depths required by the subsurface imaging objectives.

Satellite

NEOS does not own or operate satellite systems, but instead licenses existing geophysical datasets – primarily low-resolution hyperspectral data from known satellite operators.  The ready availability, wide areal coverage, and cost effectiveness of most satellite datasets adds to their appeal. While the quality of satellite-based hyperspectral data(100 channels, ~10m resolution) is insufficient for detailed basin-level or prospect-level mapping, it is usually sufficient to feed into our neoSCAN ‘quick look’ solution.

Rotary Wing

When the next level of resolution and subsurface penetration is required, NEOS secures widely available helicopter platforms capable of deploying our advanced sensor payload system. Towed beneath the helicopter at an elevation of 30 meters above the ground, our typical rotary-wing payload package includes electromagneticradiometric, high resolution magnetic, hyperspectral, and gas detection sensors that NEOS has refined and optimized for natural resource mapping.

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3D modeling of ERA’s gradient survey results

Posted by on Friday, 14 January, 2011

UBC-GIF has finished 3D modeling of resistivity gradient survey data with EH3Dinv code (http://era-max.ca/examples.html, last two examples ). EH3Dinv is a computing code developed at UBC − GIF for inverting controlled source frequency-domain EM data to recover a 3D electrical conductivity (Inversion of 3D electromagnetic data in frequency and time domain using an inexact all-at-once approach. Eldad Haber, Uri M. Ascher, and Douglas W. Oldenburg. GEOPHYSICS, VOL. 69, NO. 5, 2004; P. 1216–1228).

The ERA’s technology, in brief, is “cross-disciplinary” – between frequency-domain and direct current (DC) concepts. The technology provides high resistivity resolution by grounded, non-contact and/or combined modes of electrical field measurements at 1.22-2500Hz. In comparison with DC method ERA equipment is several times more sensitive and in comparison with frequency-domain is defined as high-resolution.


Great Minds: Significant Advances in Geophysics

Posted by on Thursday, 18 November, 2010

Geophysics is a constantly evolving science, but once in a while a truly revolutionary idea or concept comes to the fore. Reflecting the true anisotropic nature of the earth in seismic models, adding resistivity to the marine geophysics toolbox, or imaging complex targets from multiple angles are at least somewhat commonplace today, but when these ideas were introduced they were radical departures from conventional wisdom. In this webcast you’ll hear from the “great thinkers” who had the inspiration and courage to follow their instincts and change geophysics in the process.


Mineral DIAGNOSe with CARDS

Posted by on Friday, 12 November, 2010
November 12th, 2010 – DIAGNOS inc.,  a leader in the use of artificial intelligence and advanced knowledge-extraction techniques, announced today it has signed a contract with Creso Exploration Inc. (“CRESO”) for the analysis of a large geophysical survey in the Shining Tree region based in Ontario. The Corporation will use its CARDS system (Computer Aided Resources Detection System) which is used to identify areas with high similarities to known mineral deposits, in order to identify lateral extensions of the Minto property as well as to define the signatures of other gold mineralization within the survey area. CRESO has 35 distinct gold occurrences, as reported by the Ministry of Northern Development, within its 280 square kilometers claim position and is using the Helicopter survey, the surface IP survey, the down-hole geophysical data, as well as the DIAGNOS CARDS system to prioritize prospective deep drill targets In a press release dated November 11, 2010, CRESO announced that it has received the final High Resolution Magnetic, Radiometric & XDS VLF-EM Helicopter Survey (the “Survey”) representing a total of 4,938 linekilometers. The Survey covers an area of 84 square kilometers surrounding the Minto property, 11.4 kilometers in a North-South direction and 7.4 kilometers in an East-West direction. The Survey was flown at 15 meter line spacing intervals.
In addition, the Survey covers an area of 11.65 square kilometers in Morel Township where two historical shafts are located 2 kilometers apart with historical values ranging up to 5.5 grams per tonne of gold, 14% Copper, 600 grams per tonne of Silver and 0.89% per tonne of Cobalt. As part of its mandate, DIAGNOS will help establish exploration priorities within the Morel property as well.

CARDS

CARDS is a vertical application developed by DIAGNOS to assist scientists and professionals of natural resources exploration companies in their search for profitable sites. CARDS uses MCubiX-KE’s, the latest artificial intelligence and pattern recognition algorithms to learn the “signatures” or “finger prints” of resources areas with a high economic potential and to automatically detect similar sites across unexploited regions. The result? A powerful tool that allows prospectors to spend more time exploring high potential areas.

CARDS’ use is simple. CARDS requires two types of data sets: a training set, used to discover the signature or fingerprints of highly profitable regions (compared to unprofitable ones), and one or many surveys describing the territory that is prospected. The final output is a map or layer that indicates the regions where economical resources are likely to be found.

CARDS can be applied to prospecting for diamonds, gold, copper, zinc, copper, oil and gas, etc. Each resource requires a special methodology supported by CARDS.


Educational Animation – Introduction to Well Logging

Posted by on Tuesday, 2 November, 2010


New compilation of Magnetic Anomaly Map of Australia released

Posted by on Tuesday, 7 September, 2010

Geoscience Australia has just released a new fifth edition full-colour Magnetic Anomaly Map of Australia at a scale of 1:5 million. It is estimated that 27 million line-kilometres of survey data were acquired to produce this new edition which is eight million line-kilometres more than were acquired for the previous edition released in 2004.

Information in the new magnetic anomaly map and associated grid database provides insights into the distribution of magnetically susceptible minerals within the Earth’s crust. Such insights are of great value to energy and mineral exploration companies and for research into the solid earth and the environment. Magnetic minerals in small amounts are widespread in the crust, and become concentrated in zones which highlight the structure of the crust. This is particularly important for areas which have a significant thickness of surface cover (regolith and sedimentary basins) which can mask the underlying crystalline basement rocks. The magnetic signatures of the basement are measured through the cover and provide important information to help determine the nature and depth of the basement.

For more information phone Peter Milligan on +61 2 6249 9224 (email peter.milligan@ga.gov.au) or visit www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&catno=70282
Geophysical datasets phone Murray Richardson on +61 2 6249 9229 (e-mail murray.richardson@ga.gov.au)