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In Brunei, Shell has an ongoing programme drilling into the reservoir from below. Drilling, completing and producing an upside-down well, however, poses a number of interesting questions.
One of the major challenges in understanding the nature of the subsurface is to accurately depict geology when data is sparse. By combining well logs and seismic data, seismic inversion can be used to visualize subsurface geostructures in a realistic form.
A new spin-off from HRT Petroleum, South America’s largest service company, HRT Oil & Gas, is staking their fortunes deep in Brazil’s Amazon Jungle.
Deep-reading technologies image the interwell space at higher resolution and provide a new scale of characterization that was previously not possible.
Electromagnetic surveying can be done using both horizontal and vertical transmitters/receivers. To understand the physics it pays off to use an analogy with heat waves.
Reducing errors in geological modelling and flow simulation needs a new way of representing the subsurface.
Lowered risk, increased rate of penetration and reduced down-time when drilling is all the ultimate outcome of using the new software DrillEdge that was launched in Europe last month.
The use of geophysical methods in petroleum exploration continues to expand and is an integral discipline in the discovery and production of oil and gas deposits.
The main purpose of applying EM data is to improve exploration decision making.
Over the last decade we have experienced several step-changes in marine seismic acquisition technologies. Because acquisition and seismic imaging are inextricably linked, these changes have impacted positively on the seismic image of subsurface geology. But have we found the ultimate acquisition technique? In this article, we speculate what the future may bring.
Polarcus is a new seismic company with an unusual agenda - to pioneer the acquisition of high quality towed streamer seismic data while causing minimal impact on the environment.
Ocean bottom seismic (OBS) produces superior seismic images compared to those from conventional 3D streamer seismic. OBS acquisition offers the prospect of full illumination and high multiplicity of signals from the same subsurface points (high data fold).
Natural fractures in rocks cause drilling mud losses and wellbore stability problems. A recently developed "double porosity model" can make drilling safer and less expensive.
The need to maximise recovery has spelt success for a seismic technique which hugely increases reservoir knowledge.
Seismic imaging is considered key to reducing risk and cost in exploratory
as well as development drilling. Seismic acquisition geometry impacts the seismic image, so in this article we show how advances in imaging deepwater subsalt plays in the deep water Gulf of Mexico is a result of the way the industry has embraced the wide azimuth streamer survey technique.
In 1828, Johann Gauss developed his theorema egregium, Latin for remarkable, to deal with curvature in 3-dimensional space. Now, through the use of volumetric curvature
attributes, geoscientists apply this remarkable tool to seismic interpretation without the need of a picked horizon.
Risks to hydrocarbon exploration and production as a result of geohazards on and below the seafloor can be reduced through the application of modern methods of high resolution surveying.
Conventional amplitude seismic interpretation may not delineate thin sands. However,
through the use of horizon
attributes, various seismic attributes, and the spectral decomposition of the seismic volume, it is possible
to visualize what may be the valley fill complexes
of a reservoir in Colorado.
Proper detection and analysis of hydrocarbon seepage can narrow the search for oil and gas and reduce the drilling risk in deep water plays.
Passive low-frequency seismic is an area of active research and development, and
is rapidly being taken up as a new direct hydrocarbon indicator (DHI) technique for
exploration.
Seismic monitoring is an important technology in the effectiveexploitation
of reservoirs in existing fields. The successful furtheruptake
of 4D technology requires extensive training of dedicatedpersonnel,
while the biggest challenge in 4D technology developmentis
to produce high vertical resolution 4D images of production.
In today’s digital oilfield, bringing geologists into the workflow with geophysicists
and reservoir engineers is vital to maximise the potential of every well.
A team from Aberdeen University have developed a method of generating
simulatedwireline
logs with the potential to produce real-time wellsite data,
reducing costs and supplementing conventional data.
While seismic is still seismic, Controlled Source ElectroMagnetic (CSEM) diversifies into
several types of competing technologies.
Producing energy from rock that burns is entering into a new research and development
phase. Can these processes now in the experimental stages unlock some of oil
shale’s enormous potential?
Geothermal energy is a clean, readily available, and renewable natural resource.
Yet the near limitless potential remains largely untapped accounting for only a very
small percentage of the total amount of energy we use today.
Time-lapse seismic is now a proven technology for monitoring fluid
movements and identifying undrained compartments in thick offshore
clastic reservoirs. Several challenges still exist, however, in
particular the use of the technology for carbonate and thin-bedded
clastic reservoirs.
Cable-free hardware is not new but there is something new in cable-free!
Ascend Geo have shown that cable-free technology can revolutionise
land seismic acquisition.
Optical sensing technology, originally developed for cold-war anti-submarine warfare,
is promising to be a reliable and cost-effective method of monitoring and improving
reservoir performance.
New modelling package SeisRoX uses rapid simulation of PSDM to aid seismic reservoir characterisation and monitoring. A principle goal within seismic modelling today is to incorporate more quantitative interpretation.
PgS claims to have built a marine seismic streamer that is capable
of removing receiver ghosts, thereby enhancing frequency bandwidth
and seismic resolution. if proven by full-scale field tests, this
could be a major break-through in seismic acquisition.
This case study from the Luva gas field in the Norwegian Sea clearly demonstrates
the potential of controlled-source electromagnetic (CSEM) technology for hydrocarbon
exploration purposes. The example also illustrates the complexity associated with
the processing of such data.
Shedding burdensome and restrictive cables, seismic sensors are now free to roam
the land reducing cost, health, safety, and environmental concerns in
obtaining quality full-wave, 3-D data.
The use of aeromagnetic data is an important tool in modern geological mapping and petroleum exploration. The advantages of recent advances in technology can be compared to the advancement from 2D to 3D seismic imaging.
As global interest in the hydrocarbon potenital of the Circum-Arctic increases, it is
becoming vital to unravel the complex geological history of the region.
Reprocessing of several seismic data sets acquired offshore Norway in the 1980’s have
demonstrated significant improvements in both resolution and structural imaging.
The improvements were gained mainly through more accurate velocity modelling and
effective multiple attenuation.
A rock as tight as a table top, the Barnett Shale has become the most prolific
gas reservoirin
Texas and the largest active natural gas play in the United States.
Explorationin
this play is truly cutting edge, pioneering stimulation technology
that will undoubtedly lead to new shale gas productionthroughout
the world
"Improved resolution and clarity in remote sensing satellite imagery helps
geoscientiststo
build models in hostile terranes, not only of the surface of the
earth, but also the subsurface."
Recent electromagnetic surveys carried out offshore the Falkland Islands demonstrateonce again the value of this new innovative technology that is now about to be accepted by the conservative oil industry.
Measuring the properties of geological formations and reservoir fluids has traditionally been performed with logging tools run on an electric wireline, a technique that was developed in the 1920’s. For a long time this was the only method of acquiring accurate subsurface data in boreholes.
Throughout the world, sub-salt imaging remains a major issue. Service and oil companies are striving to meet this challenge.
Sea Bed Logging is a new technology that offers the opportunity to detect trapped hydrocarbons in the subsurface prior to drilling. Shell EP has recently conducted a number of very successful data acquisition campaigns throughout the world based on this technology, leading it to substantially expand its use of this technique in the future.
Over the years remote sensing has developed from an obscure and expensive experiment to an essential and cost effective tool in the search for hydrocarbons, particularly in remote and inaccessible parts of the world.We talk to Infoterra, one of the leading exponents of this complex and fascinating discipline.
The introduction of Q-Marine* technology a few years ago has given WesternGeco a competitive edge, the company claims. In the Oslo Technology Centre they are proud of having been crucial in the development of seismic technology that, beyond any doubt, has given some oil companies value for money.
The advent of the individually steerable streamer has lead to the development of WesternGeco's 'Over/Under' seismic recording technique, resulting in a dramatic improvement in seismic quality and the ability to visualise sub-salt and sub-basalt.
AVO analysis provides the geologists with a powerful tool that give information about pore fluids, lithologies and reservoir pressures. However, AVO signatures can easily be sinterpreted without a proper feasibility study.
The installation of a permanent seismic array in the Norwegian Valhall field enables the operator to run frequent 4D re-shoots, and the amount of oil to be recovered may increase substantially by managing the reservoir better.
Errors in fault interpretation can have significant negative impact on reservoir models, facility plans, and field economics. By using integrated software applications and workflows that cross disciplines, asset teams can understand complex reservoirs better and faster.
Just two years after the very first commercial investigation we can confirm that the technology functions as planned. Sea bed logging seems to have come up to expectations achieving what was hoped for but thought by many to be too good to be true. The oil companies have, therefore, got a new means of determining whether oil or gas are present before they decide to drill.
Reservoir rocks have much poorer electrical conductivity if they are saturated with oil rather than salt water. This is the principle, well known from borehole logging, which is exploited in Sea Bed Logging.
A deep, structurally complex carbonate reservoir offshore Philippines has been imaged with great clarity and resolution, despite the severely rugose water bottom and stratigraphically complex overburden. This has been accomplished applying High-Density 3D (HD3DTM) marine streamer acquisition.
New seismic streamer methodology has facilitated resolution of complex sand bodies called injecties.
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