What does it take to communicate?

---

Finding Petroleum, London. 6th February 2014.

Advances in Seismic Technology.

[Cableless systems.] What does it really take to communicate? Robert G Heath, * iSeis Company. International Marketing Manager. Sayed-Amr El-Hamamsy, SRD Innovations (Canada).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it really take to communicate?

• Many bold claims made for benefits of cableless (wireless – cablefree) recording. • Feedback from the field sometimes tells different story. • The very places where real time cableless systems would be most beneficial seem to be those were communications fails most often.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it really take to communicate?

• Industry reports growing no’s of “disappointed” customers both for shoot blind and (so-called) “real time” systems. • Increasingly, users now demand some level of “guaranteed communications”.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it really take to communicate?

• So what works/how can you predict functionality in environment where you need to work before purchase? • What happens when we cannot communicate? • Does recorder have fallback modes?

• A review of how we got here is useful. • A review of the basic physics and engineering principles which affect comms in the seismic environment. • Nullius in verba!

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place? Because cables are good at this---

Iraq Gravel plain, Oman.

Kansas Saudi Arabia.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place? Not so good at this---

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place? Unsuited to this ---

Industry usually wants to use fewer helicopters and cut fewer lines.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place? Even worse at this ---

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place? Almost everywhere except simple fairly flat terrain cableless has advantages over telemetry cable.

Courtesy: Ascend Geo.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place? Even in deserts, some parts of survey better done without digital telemetry cables.

Courtesy: BP Exploration.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place?

Simple desert terrain can use high channel count cabled systems and HPV techniques.

Sercel 508XT

WGC UniQ

30,000 channels.

Inova G3i Recent announcements of 100,000 – 1,000,000 channel cable systems.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place?

Optical interferometry-based land acquisition systems may replace (copper) cables bit by bit.

iDAS

Geophone

Land seismic data comparison.

Courtesy Silixa Ltd, iDAS technology.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Why did we want to explore without cables in the first place?

Most of the world is best done with cableless or hybrid (multi-recorder) approach.

• High population density centres (cities, towns, villages, roads). • Paddy fields and swamps. • Jungles and forests. • Rapid elevation changes. • Static and rapidly moving water bodies. • Plantation, farms, cereals, crops.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start? “Industry” asks for:

• Hardware which is lower in cost to use, better HSE exposure etc. • Equipment better suited to tough locations. • “Land 3D for same price as marine 3D”.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start?

Ian Jack’s (BP) “article” Nov 1996 “System 2000” --- a system based on a cableless approach.

Input also from ENI (AGIP). • In following years, workshops etc.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start?

System 2000: • Essentially shoot blind system with remote control. • •

• • • • •

Wake up and configuration commands. Options for just QC or full real time.

1 - 4 ch/box. Imagined use of VHF comms band, not WiFi 2.4 GHz. Options for cable communication of some channels. Local collecting hubs for any remotely stored data. Believed that “standardisation” would result.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start? AGIP/ENI System 2000:

• Send back QC - this is what they again concluded necessary 16 years later when testing a cableless system.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start? AGIP/ENI System 2000:

• ENI conclusions from test of SN408/428 cable telemetry system and Unite cableless system: •

•

Cableless operation required half the people for the same production, but: At least QC info must be available on in real time cableless systems.

Spread layout times. Cableless is about 50% in this real example. Courtesy ENI Italy. SEG paper 2012. “Wireless vs. Wireline Land 3D in N. Italy”.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start?

System 2000 - generally: Initially, some requirements seemed “made-up-on-thespot”. Now, they seem to have exceptional foresight as to what industry would need------and what technology would make possible.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start? System 2000 (less foresight): • Gain curve sent to each box. •

Not practical with delta-sigma convertors, but good reason to have 32 bit.

• Paid no attention to commercial reality in terms of: • •

what makes manufacturers develop systems, the basis on which customers make their equipment choices.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did this start? System 2000 (less foresight):

• Did not foresee role of GPS-based timing for source-receiver synchronisation – or the potential problems this would bring. • Over-stated the relationship between weight per channel and productivity and crew cost. • •

Flexibility and “convenience” (weight of cableless systems can be greater than cabled but flexibility may be much greater). ENI demonstrate this 2012.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond to call for “System 2000”?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond to call for “System 2000”?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Thinking that increased productivity just matter of reducing system weight: • Thinner, lighter cables. • Fewer data pairs.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

Thinking that increased productivity just a matter of reducing system weight: • Cables definitely became lighter - - and less reliable?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

Thinking that increased productivity just a matter of reducing system weight:

• But complexity, serial dependence and lack of fallback modes are also MAJOR downtime issues for cabled systems.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

Thinking that increased productivity just a matter of reducing system weight:

• But complexity, serial dependence and lack of fallback modes are also MAJOR downtime issues for cabled systems.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

As usual, smaller manufacturers more inventive. ”Innovation drives our industry forward ......and it originates in small companies”. David Bamford.

Network Telemetry. GeoX Systems ARAM24 system.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

As usual, smaller manufacturers more inventive. • “Network Telemetry”, flexibility more important to productivity than weight saving ---- as it helps overcome serial dependency. Probability of system failure made from n identical elements serially connected (applies to cabled point-to-single-point and radio comms). Psf = 1 – (1-Pef)n Since 0 < Pef< 1, as n gets larger (e.g no. of channels, connectors etc) so Psf tends to 1, = system failure.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

As usual, smaller manufacturers more inventive. • “Network Telemetry”, flexibility more important to productivity than weight saving ---- as it helps overcome serial dependency.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond?

As usual, smaller manufacturers more inventive. • “Fallback mode” is major advance - insurance that operations can continue as conditions get worse and cause communication failures.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Multiple fallback modes offered as solution to improving productivity. “Remote Hybrid Telemetry” (GeoX Systems ~1998). World’s first automatic or intelligent network approach. VHF/UHF or Microwave link

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Multiple fallback modes offered as solution to improving productivity. “Remote Hybrid Telemetry” (GeoX Systems ~1998). World’s first automatic or intelligent network approach. VHF/UHF or Microwave link

“Orphaned” channels.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Multiple fallback modes offered as solution to improving productivity. “Remote Hybrid Telemetry” (GeoX Systems ~1998).

World’s first automatic or intelligent network approach. • Local power and memory. Timing and • Channels can communicate by radio remote or autonomous. control

Seismic ground unit

Battery

Seismic ground unit

Battery

Seismic ground unit

Battery

Remote Hybrid Telemetry Unit

Battery

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Multiple fallback modes offered as solution to improving productivity. “Remote Hybrid Telemetry” (GeoX Systems ~1998). • Radio link with Central System. • Onboard memory. • Activates automatically if cable breaks or operates on deliberated “orphaned” parts of spread. • Central system keeps track of “delayed” files. • Local power.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Multiple fallback modes offered as solution to improving productivity.

“Remote Combined Telemetry” independently developed by Seismic Source Co (2001) using WiFi (emerging technology) to enable use of seismographs in tough locations.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Multiple fallback modes offered as solution to improving productivity.

“Remote Combined Telemetry” independently developed by Seismic Source Co (2001) using WiFi (emerging technology) to enable use of seismographs in tough locations. WiFi links start to replace some cables.

WiFi

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? “Remote Combined Telemetry” evolves into cableless system.

Multiple recorders connected by appropriately configured WiFi and antenna. WiFi antenna

WiFi directional antenna

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? “Remote Combined Telemetry” evolves into cableless system. A “recorder” can be a single channel box, 3C or an number. WiFi antenna

WiFi directional antenna

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? “Remote Combined Telemetry” evolves into cableless system. Discovering limitation of WiFi @ 2.4 GHz! WiFi directional antenna

WiFi directional antenna

Seismic Source Co. 2001.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Eventually, industry starts to produce many different types of cableless systems. Most seem to ignore most of “System 2000” ideal.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Recent industry news. Most acquisition contracts unchanged to allow for problems with shooting without reliable comms: • No. of dead adjacent channels. • Noise levels etc.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Recent industry news. 100’000 ch’s sold.

• Disappointment from users with systems having no built-in communication or communication which does not work well. • Both types of systems referred to as shoot blind by customers.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Recent industry news:

• At least one contractor gone out of business as could not afford to reshoot poor data at own expense. • Two co’s in US announced will no longer acquire data using cableless equipment without some ability to monitor data/noise in real time.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Recent industry news:

• Increasing calls from contractors with communication-less equipment to add “guaranteed comms” to existing cableless system operation. • In this way, a third party device provides a fallback mode. • Hybrid operations, e.g: Sigma cableless system plus any other cableless system. “Adding sight to shoot blind”.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Hybrid operations.

• The hybrid telemetry philosophy starts to come of age! • While allowing systems from different manufacturers to work together.

Sigma cableless system + other cableless system + cabled system.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Hybrid operations.

• Multi-system-manufacturer hybrid operations are the future, not just cableless or single manufacturer.

GeoExpro article, Nov 2013.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? Eventually, industry starts to produce many different types of cableless systems. A useful exercise would have been to compare each system against System 2000 ideal?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

How did manufacturers respond? A more useful exercise is to compare each system against System 2000 ideal and against hybrid requirement. • In this case need to compare:

• No of channels per ground unit. • Ability to work side by side other cabled or cableless recorders. • Ability to add sight to other cableless recorder, or can only be used on its own. • Configurable system, for optimisation in different environments. • Level of source control integration, FULL support for SPS/SEGP1? • Batteries: internal or external (or both). • Battery chemistry choices available? • Ability to work on water. • Suited to wide range of passive/permanent. • Suitability for analog sensor 3C. • Ease of deployment and equipment tracking. • Ability to use multiple different passive and active sensors. • Multiple types of harvesting methods, or only 2.4 GHz-based. • Serially dependent comms architecture or other. • Recording to stop during harvesting or recording continues. • Levels of built in hardware and data security.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

Hybrid systems need some form of guaranteed comms. What does it take to communicate in the environments we’d most like to use cableless recorders in?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? No technology exists which can provide everything needed for the environments where cableless functionality would be most beneficial. Why?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

• All systems must used “2.4 GHz ISM band” (2.40 – 2.48 GHz). • Internationally must limit power to 10-100 mW EIRP (20 dBm). Excludes USA. • This is ONLY internationally accepted licence-free band.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Why is this the only worldwide licence-free band? • Because it is frequency of microwave ovens. • It is very easily absorbed, thus inherently short range.

• Also is frequency of most cordless phones, WiFi and other “gadgets”. • Significant use of this band already exists. • Significant interference risk already exists.

Microwave oven frequency.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

• Problem of water molecules (in atmosphere, vegetation etc). • Water is polarised molecule. 2.4 GHz EM waves lose energy on encountering water molecules by dielectric heating.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? • Absorption worse for 5.6 – 5.8 GHz.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? • Absorption worse for 5.6 – 5.8 GHz. Even where legal.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Given these physical characteristics of 2.4 GHz radio wave propagation:

• It is simple to guarantee good levels of high bandwidth and/or long range communication in locations where water vapour/vegetation are not issues. • Small elevation changes can sometimes even be used to advantage but---

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

• --- it’s very difficult to assure such “high quality” communications in environments typically encountered everywhere else. • Except in one environment---

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

• Dielectric loss (2.4 GHz) almost non-existent in ice, snow. • Ice is one of most transparent media at microwave frequencies with very low dielectric loss (defrost mode on microwave ovens).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

• So important communication characteristics @ 2.4 GHz can be difficult to predict (e.g: near surface water vapour). • And are dependent on:

• vegetation type, weather, time of day, season, antenna height, etc. • Cabled systems did not have to worry about these issues.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Further:

• Easy to go from “good” to “poor” quality of radio reception, may happen several times during 24 hour period. • And BTW: Communication link quality is usually quite anisotropic.

Cutting line for 2.4 GHz is not possible in most places.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

We have to match the geophysical requirement to the physics of 2.4 GHz to make best use of the technology. • The seismic model effectively dictates trace interval and count. • These in turn dictate necessary radio range, radio system topology and data transfer rate.

Seismic data acquisition ground unit with some forms of 2.4 GHz comms system.

Distance between these units, and how much data can be sent in real time, ideally dictated only by geophysical requirements.

The next bit of seismic kit on the way to the central system.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

A radio receiver must collect enough energy from the transmission so that some piece of information can be recognised above noise level of the receiving apparatus.

Noise level in receiver (combined with antenna sensitivity).

Sufficient energy (power x time) taken in by receiver.

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

Level of signal picked up by receiver reduces with: • Increasing range (e.g. greater trace interval, more channels in one box). • Increasing absorption and interference (in case of 2.4 GHz more bushes, worse weather, populated areas, dew on leaves etc).

Noise level in receiver (combined with antenna sensitivity).

Increased range and/or increased absorption radio path.

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Increasing transmit power:

• Not legal in most countries. • Extremely heavy on additional battery power. • Even using 10x power may make very little difference at 2.4 GHz.

Noise level in receiver (combined with antenna sensitivity).

Illegal or impractical to increase transmit power so that higher signal picked up by receiver.

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

Cannot change power, so to pick up sufficient energy at receiver for same piece of information to be recognised. • Increase duration of time used to transmit that bit. i.e. reduce bandwidth.

Noise level in receiver (combined with antenna sensitivity).

Must instead take longer transmitting same piece of information (power x time)

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Without changing physical set up:

• Ratio between maximum likely achievable data rate under ideal conditions (e.g: desert) and that possible on many seismic environments varies from 10:1 to 1,000:1 (or more). • 3dB loss can mean halving bit rate.

Noise level in receiver (combined with antenna sensitivity).

Must instead take longer transmitting same piece of information (power x time)

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Changing physical set up:

• E.g: More directional antenna, elevated antenna, improve SNR and thus available data transfer rate. • May require extra equipment, deployment effort, etc. • Where to make the compromise between effort and data rate/range?

Noise level in receiver (combined with antenna sensitivity). Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Fortunately, seismic information comes in two groups:

• Everything including the digitised sensor data - very high bandwidth (call this “data type A”) • Everything excluding the digitised sensor data, i.e. only system I-tests, QC, status, GPS reception quality, remote control, system security and health, noise etc (call this “data type B”). Data type A – everything. Noise level in receiver (combined with antenna sensitivity).

Data type B – everything but real time sensor data.

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate? Ratio of B:A can also be ~ 1:1,000.

• This is a hint about how a seismic recording system may be designed. • Basic system could include comms system for type B data, and offer type A comms system as option – the user decides on compromise to make. Data type A – everything. Noise level in receiver (combined with antenna sensitivity).

Data type B – everything but real time sensor data.

Receiving apparatus noise level.

Duration of transmitted pulse (bandwidth).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate?

Many studies already performed show problems using 2.4 GHz band for outdoor communications. E.g:

• Effects of rainfall on link quality in an outdoor forest deployment. ww.cs.ox.ac.uk/files/3204/WinSys.pdf • Outdoor links for 2.4 GHz frequencies. www.adv-radio-sci.net/1/301/2003/ars1-301-2003.pdf • Cuinas A. et al. A comparison of radioelectric propagation in mature forests at wireless network frequency bands. Dept. Teoria do Sinal e Communicacions, Vigo University, Spain. • Perras, S et al. Fading characteristics of RF signal due to foliage in frequency bands from 2 to 60 GHz. Communication Research Centre, Ottawa, Canada. • Gupta, P. The capacity of wireless networks. IEEE Transactions on Information Theory. Vol 46, 388-404 leads to understanding mesh communications.

These studies were mostly for fixed installations.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate None consider seismic exploration situation of: • Deployment by “non-radio professionals”. • Deployment at/near ground level. And so on----

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

What does it take to communicate

It is essential to understand all issues in order to know what can work in seismic. • All radio comms is compromise between 5 competing issues:

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? 1: Coverage. Does the chosen technology allow practical application to cover wide areas (and wide variety of areas) typical in the seismic environment?

Courtesy iSeis, Sigma operation, old city, Quito Ecuador.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? 2: Range. Depending on communication topology how easy it for each ground unit to make connection to next point(s) along?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? 3: Ease of deployment. Can the technology be quickly and reliably deployed by relatively untrained labour, even when using many thousands of units?

Courtesy GSL Sigma operation, Indonesian jungle

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? 4: Capacity (max throughput – data rate). What data throughput does the technology support in toughest environments.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? 5: Fault tolerance, and what happens when desired level of comms break down – fallback modes.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? No radio-based communication technology in existence has complete solution for land seismic. • Certainly nothing based on 2.4 or 5.6/5.8 GHz.

Typical WiFi Access Point (2.4 GHz). Similar permitted power to seismic equipment (< 100 mW).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Even in free space (e.g. no vegetation) range quickly drops off. To assure some communications:

• WiFi signal automatically changes attempted transfer rate and modulation scheme to try to make at least some contact.

Data rate/bandwidth Percentage of maximum

WiFi reduces data rate and automatically adopts different data modulation scheme to try to make communication. Eventually becomes intermittent and then non-existent.

Quality of reception - range

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Even in free space (e.g. no vegetation) range quickly drops off. • Simple test to illustrate limitations of 2.4 GHz.

<100m, no trees, zero signal WiFi antenna 4m elevation

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Even in free space (e.g. no vegetation) range quickly drops off. In most seismic acquisition topologies, highest required data rate is less than maximum available from modern (domestic type) WiFI. So already range reduced is being traded for reliable data rate. Ultra high WiFi transfer rates not usually needed for most seismic system topologies. This is used to permit longer range.

Quality of reception - range

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Even in free space (e.g. no vegetation) range quickly drops off. But is this enough for seismic?

Ultra high WiFi transfer rates not usually needed for most seismic system topologies. This is used to permit longer range.

Quality of reception - range

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? iSeis has its own test site in/around Ponca City, Oklahoma. Consists of: • Flat fields, rolling meadows, sudden elevation changes, gulleys, small valleys, forests, varying vegetation, strong seasonal differences, water bodies etc. • An excellent test site for cableless systems!

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Requires necessary test equipment or capability within system to provide necessary readings. • Some antennas output RSS indication.

Ethernet connection on Sigma ground unit permits attachment of varying antenna types and comms systems.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Testing various antenna, protocols, comms links etc.

Checking that antenna elevation really does make a difference.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Setting a baseline?

Directional antenna (no absorption) @ 0.5m managed 1000m. Small change in height or vegetation produces SIGNIFICANT differences.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Testing various antenna, protocols, comms links etc.

Much reduced transmission since radio path takes in more vegetation.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Weather and season dependence. During dry season or winter (when water frozen) transmission possible through dry grass even on lowest power setting.

After rain, transmission almost impossible even at max. power setting.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Testing various antenna, protocols, comms links etc. Successful transmission through pile of dead wood, even when wet (due to large air spaces).

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Effect of metallic obstructions.

Simulating obstructions, interference from metallic objects etc.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Testing various antenna, protocols, comms links etc. Low elevation directional antenna, even after increasing power to 750 mW, range very poor – no visual line of sight.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Importance of (visual) line of sight to 2.4 GHz propagation.

Courtesy Sercel Inc.

Radio waves at GHz frequencies: “quasi line of sight” Raise antenna (where possible) above bulk of green vegetation, range increases. Courtesy Wireless Seismic Inc

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Testing various antenna, protocols, comms links etc. Very anisotropic. High bandwidth propagation entirely dependent on direction.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Chose test sites to try to simulate variety of seismic environments. Testing various antenna, protocols, comms links etc. Visual line of sight is less important as transfer rate requirement is reduced (more absorption acceptable). Often the most successful transmission path may not a straight line.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Results summary:

• Absorption SERIOUSLY compromises 2.4 GHz range/data rate. • Many real environments are anisotropic for 2.4 GHz. • Directional antenna better than omni. • Elevation – the more the better. • Data type B works MUCH better than type A.

Courtesy SRD Canada. Courtesy Wireless Seismic Inc

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Results summary: Can this be quantified from basic theory?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Transmit power Pt, in milliwatts or dBm (power relative to 1mW). 100mW is max permitted power in most countries, i.e. 20 dBm. USA permits 1W = 30 dBm.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Some definitions:

Free space path loss is representation of the reduction of radio strength as it propagates.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Some definitions:

Receive and transmit antenna may have gain Gt and Gr (measured in dBi, dB relative to isotropic radiator). Sensitivity of receiver (power at receiver) is Pr. This may include losses in antenna cable and connector (the latter of which can become important).

Theoretical operational range is relationship between FSPL and transmit power, antenna gains and sensitivity of receiver.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Some definitions:

Fade Margin – allowance for environmental factors. Examples:

• 15 dB is reasonable amount allowed in metropolitan areas for 2.4 GHz transmissions. • 6 dB is a good figure to take care of average short term atmosphere/weather variations.

• Both may be variable and unpredictable. • In LoS operations, 3dB loss = 40% range reduction.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Some definitions:

Given large degree of absorption (2.4 GHz, 5.6/5.8 GHz) by water molecules found in various types of vegetation, every individual absorber should have separate loss term.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Effect of single tree: loss of ~18dB - fixed installation in Germany. (Dresden Michler et al). A 3dB loss = halving of data rate – single tree may make factor of 50-100 difference in data rate.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Conclusions:

In most seismic environments the Σ loss term totally dominates. The magnitude of Σ loss term varies anisotropically and with time of day, year etc. (Dew on leaves!) In simple environments (desert, flat/cold areas) Σ loss is (almost) zero.

Everywhere else it determines what you can expect from the seismic recorder.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Conclusions.

Some typical maximum theoretical values in different cableless systems show huge range variation (if keeping data rate fixed). • Real life values are usually much less.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Solution? Do not try to exceed laws of physics.

• Main variable under our control is how hardware uses 2.4 GHz (i.e. viable deployment options – how does the system force operations to be undertaken).

• Rule No 1: Each seismic box should be deployed to achieve same range and transfer rate as all other boxes (or minimise differences). • Rule No 2: Build in fallback modes.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Cellular approach (point to multipoint).

Same transfer rate usually required from all boxes but there are greatly differing ranges. (Breaks 1st rule). WiFi tower

Assured comms

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Cellular approach (point to multipoint):

Range of assured comms can be increased (for example) by raising ground units. But as distance between transmitter and receiver increases, even this is not enough. Assured comms

Σ more important at range

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Cellular approach (point to multipoint):

Can be made to work for land seismic by planning only on reliable reception of low data rates from all spread (“Type B” data). • Fallback modes exist for when even this does not work.

Sigma cableless system being used in jungle and swamps sending back type B data. Observer can monitor (and control if nec) transmission pathing.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Cellular approach (Point to multipoint).

Can be made to work for higher data rate permanent installations by use of raised directional antenna.

Sigma cableless system being used as part of permanent real time/full data rate monitoring array over 800 sq/km. Courtesy MicroSeismic Inc.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment.

Point-to-single-point approach. Also breaks 1st rule.

Generally box-box range remains constant, but data rate increases along the line. Problem of serial dependence (i.e. cable system), though more complex as susceptibility to problems may relate to position in line and level of absorption (which may vary unpredictably).

Σ less important here.

Psf = 1 – (1-Pef)n

Σ more important here.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Basic theory and rules of thumb when using 2.4 GHz in the seismic environment. Point-to-single-point approach.

Can be made to work even in tougher areas by use of directional antenna. Very long seismic lines (high no. of channels per line), with long box-tobox range, and high transfer rates then possible.

Sigma cableless system in point-to-point mode, using directional antenna.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Given these limitations what is least problematic way to use 2.4 GHz ?

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Milan Polytechnico (Comms Dept) conclude best way to overcome limitations of 2.4/5.6/5.8 GHz is:

• Two levels of communications: • Short range between ground units in a “cluster”, long range directional between clusters. • Both permit mesh topology. • Self-healing and self-routing. • Helps minimise problems of anisotropy and allows greater flexibility in placement of seismic channels. • Capacity for 100’s thousand channels, high bandwidth, full real time. • Ground units should also have local storage and/or local collecting hubs.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Milan Polytechnico (Comms Dept) conclude best way to overcome limitations of 2.4/5.6/5.8 GHz is: • Mesh copes better with the Σ loss term by finding its own best paths from (possibly) multiple choices.

• Mesh copes better with serial dependence term as transmission not inherently serial and multiple fall back modes are provided.

Psf = 1 – (1-Pef)n

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Milan Polytechnico (Comms Dept) conclude best way to overcome limitations of 2.4/5.6/5.8 GHz is:

• Mesh copes better with the Σ term by finding its own best paths from (possibly) multiple choices. • In real life mesh systems, the routes “chosen” by mesh signals can be very surprising. (One tree = 20dB loss, whereas increase in range of ~1.4 produces only ~3dB loss). • Mesh routes rarely unbroken straight lines unless in flat, dry, unvegatated areas.

Sigma cableless system observer’s screen showing routes chosen for data paths by mesh.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Milan Polytechnico (Comms Dept) conclude best way to overcome limitations of 2.4/5.6/5.8 GHz is:

Ultra-Wide Band sensor networks in oil and gas explorations, IEEE Communications Magazine. Savazzi, U. Spagnolini, L. Goratti, D. Molteni, M. Latva-aho, M. Nicoli, , vol.51, n.4, pp. 142-153, April 2013.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? SRD Developments (Calgary) already came to similar conclusion (owners of important WiFi and other relevant patents). • Developed necessary seismic comms protocol using OTS 2.4 GHz radios. • Worked with iSeis Sigma system (Ethernet port already available) to turn into working system.

Ethernet port for attachment of high level mesh (SRD HyMesh). Data type A

Low level mesh (data type B) included in base unit).

Cluster re-use combined with mesh topology essentially allows unlimited outreach and channel count.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? SRD Developments (Calgary) already came to similar conclusion (owners of important WiFi and other relevant patents). • Developed necessary seismic comms protocol using OTS 2.4 GHz radios. • Worked with iSeis Sigma system (Ethernet port already available) to turn into working system. High capacity local storage in ground units. Data collectable by local collecting hub.

HyMesh antenna chosen according to requirements of survey, connected through Ethernet port.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? SRD Developments (Calgary) already came to similar conclusion (owners of certain WiFi and other relevant patents). • Developed necessary seismic comms protocol using OTS 2.4 GHz radios.

• Worked with iSeis Sigma system (Ethernet port already available) to turn into working system. Suited to any type of active and passive monitoring in almost all environments. Equipment/protocol adjustable to local environment to maximise range and data transfer rates.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? SRD Developments (Calgary) already came to similar conclusion (owners of certain WiFi and other relevant patents). • Example: Antenna/comms unit chosen according to position/requirement.

SRD Sigma-HyMesh. Snow depth – 1m. Range between connecting traces within cluster up to 400m. Coniferous and deciduous trees, winter, winds and snow.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation?

Unlikely that seismic systems will standardise products from competing manufacturers. • But first step is to use standardised connection protocols. • Allows maximum use of developments in field of wireless comms. •>$1bn spent annually.

Ethernet port. USB port.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation?

Other standard wireless comms protocols can be employed by connection through Ethernet/USB ports.

Sigma cableless system using cellphone connection. Full data transfer and remote contol enabled.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation?

3C data from powered and non-powered sensors • Sensor remotely controllable – USB port.

Sigma cableless system, 3C acquisition for active and passive surveys. Courtesy Spectraseis and GSL.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation?

USB standardisation allows local memory based harvesting, local hubs etc, where 2.4 GHz comms is problematic.

Locally stored data can be transmitted in real time via Ethernet port and/or copied to USB memory port.

Internal memory, max 2 TB.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation?

Standardised comms protocols permits cabling together of ground units if required (requirement of “System 2000”). Multiple means of communication permitted on each “spread”.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation?

Wireless comms protocols can be employed by connection through Ethernet/USB ports.

Sigma cableless system shallow marine operations, mesh-WiFi.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation? Today’s seismic reality.

• This takes the concept of intelligent auto-networking/remote storage/using-fewer-telemetry-cables approach started 18 years ago into the cableless/hybrid domain.

VHF/UHF or Microwave link

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? System 2000 – Standardisation? Today’s seismic reality. System 2000 – 14 years late.

• Cableless/hybrid systems are a reality with possibility to use multiple comms and storage methods to cope with differing environments on a single survey.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Conclusions

• Original ideals of System 2000 and ENI doc, 18 years later, turn out to be close to the mark of (one of) today’s cableless system. (Foresight!??) • Open architecture/hybrid systems are what can take industry forward – maximise the ability to use any piece of equipment from Manufacturer A with that from Manufacturer B (C and D) to reduce cost of surveys. • Such “System 2000-like” systems also can be used to: • Add sight to cableless systems which can’t communicate.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate?

Conclusions

• While physics sets the ultimate limits on what hardware can do, knowledge (or ignorance) of hardware limitations may often be the bigger hurdle. • Richard Feynman:"For a successful technology, reality must take precedence over public relations for nature cannot be fooled“. •Nullius in verba.

Finding Petroleum, London, 6th February 2014. Advances in Seismic Technology.

What does it take to communicate? Thanks and recognition to:David Bamford and Ian Jack. Michel Fattouche, Professor Emeritus, Dept of Electrical and Computer Engineering, University of Calgary. John Giles, President, iSeis Inc. Sisso el-Hammasy of SRD Innovations. Scott Burkholder, Chief Geophysicist, iSeis Inc. S. Savvazi & U. Spagnolini, University of Milan. Rory Clark, RTC Company. Oliver King, Cambridge University. Google and Wikipedia.