A TECHNOLOGICAL INNOVATION WHICH CHANGES THE FUTURE OF GEOTHERMAL ENERGY PRODUCTION AND ENABLES NOVEL EFFICIENT APPLICATIONS USING OIL AND GAS EXPLORATION AND PRODUCTION TECHNOLOGY IN GEOTHERMAL ENERGY DEVELOPMENT.
By
Angelo Piasentin (GeoNeurale, Munich/Germany)
and
Dr. Stephan Klauer (SK-Patent Law Office, Munich/Germany)
“Using these technologies, according to DDS concepts, it becomes possible to
circulate water within predefined flow lines, in continuous flow and in a closed
system, for more than 100 kilometers, while keeping most of or all the flow line
system below a predefined depth.
This depth could be, for example 3000 m and more, so that the water flow is for
most of the flow path length in a formation, the temperature of which is above
110 degrees Celsius, which is an ideal minimum temperature level enabling
the production of electrical power.”
DDS (Deep Directivity Systems) is an innovation in the field of geothermal exploration and production. It was originally presented a few months ago by GeoNeurale as a technology to be operative developed by Petrophysic-Consultants, but it appears that up to now few people really recognized
the enormous potential thereof for the deep geothermal and oil and gas exploration and production.
DDS comprises a set of state of the art reservoir development techniques adapted for use in deep geothermal energy development projects. In other words, DDS comprises combinations of existing technologies from the oil and gas exploration and production field, which are transferred to the
development of deep geothermal energy projects, enabling boosting the flexibility and efficiency of deep geothermal projects.
In this article, a few visionary example applications are presented and DDS main technological aspects are conceptually explained before the background of the state of the art of technology used in deep geothermal projects.
The technology base for DDS (or: What are its roots and bases ?)
A first main technology basis of DDS is horizontal drilling, an application that has been developed in the past to improve recovery in oil and gas reservoirs.
The first horizontal well was drilled in 1929 and at that time the potential of this technology was not fully encompassed. At present, it is possible to drill boreholes into the earth subsurface with lengths greater than 12000 m using horizontal drilling technology. Horizontal drilling creates a continuous borehole, and hence a regular flow-line from the surface to the well shoe.
A second main technology basis of DDS comprises reservoir stimulation techniques including hydraulic fracturing, suitably adapted to make permeable the rock formations found at the typical depths, ca. 3000 meters or more, of deep geothermal reservoirs.
DDS is a system of concepts using horizontal drilling and hydraulic reservoir fracturing for creating virtually indefinite lengths of downhole flow line connectivity.
The significance of DDS will be described together with a few examples of the potential thereof.
Using these technologies, according to DDS concepts, it becomes
possible to circulate water within predefined flow lines, in continuous
flow and in a closed system, for more than 100 kilometers, while keeping
most of or all the flow line system below a predefined depth.
This depth could be, for example 3000 m and more, so that the water flow
is for most of the flow path length in a formation, the temperature of
which is above 110 degrees Celsius, which is an ideal minimum
temperature level enabling the production of electrical power.
What can DDS make possible?
Envisage a futuristic mind game to describe the potential of our DDS technology and see the advantages which this could bring in the future.
Imagine that new drilling methods have become available for drilling a well in a few, possibly only one day.
With such drilling efficiency (ROP) and using the concepts of DDS technology, it would be possible to drill, within a few years, a deep flow-line system connecting Europe to America and/or Europe to China with flow lines running steadily below 3000 m or more of depth and back to Europe to the same point, where the hole was started to be drilled as an injection well (initial spud-point).
In this way, it would be possible to create an intercity system of geothermal power plants, deployed for instance along a highway for supplying electricity-driven cars with electric energy.
This is only one example of how a deep geothermal project could be indefinitely extended using DDS technology.
Between theory and technical realization, the following challenging factors need to be solved resp. overcome:
1. Hydraulic pressure loss would be directly proportional to the thermal efficiency and their ratio would need to be optimized.
2. In this respect, the positioning of downhole pumps would be a critical issue.
The above is only an example of extreme (and expensive) solutions that would require further technological innovations to achieve faster drilling.
However the concept and technology of DDS systems are available already now.
Smaller projects employing DDS technology at the city scale are already
now an economically feasible and technically realistic solution for
intercity geothermal power-plants having zero CO2 emissions, producing
enough energy to supply the energy need of two small towns.
DDS technology results from the scientific challenge of the firstly mentioned author and from many years of study and experience in the oil and geothermal exploration industry.
Bringing DDS technology to application will require a comparable level of creativity based on an attitude of scientific integrity and the integration of a specific scientific and technological philosophy.
STATE OF THE ART IN GEOTHERMAL ENERGY PRODUCTION
Up to now, deep geothermal energy was mainly exploited using the following two methods:
- Hydrogeothermal systems
and
- Hot Dry Rock (HDR) systems.
Hydrogeothermal systems are confined, however, to special areas,
corresponding to a relatively small part of the earth surface. Their utility is therefore very limited.
Hydrogeothermal systems are mostly associated with the presence of factured and karsted carbonate formations, which are scarcely distributed. Moreover, the risk of project failure in hydrothermal reservoirs is not negligible due to the high costs of required efficient seismic investigations and the uncertainty of geophysical methods to identify the presence of water
and the water flow lines in deep formations.
In Hot Dry Rock (HDR) projects, water is circulated through an injection well, the respective HDR formation and a production well, from which the water is, after extraction of heat energy using heat exchangers at the surface, re-injected into the injection well. In particular, the water is pumped into the injection well and down to the shoe. Between the shoe of the injection well and the shoe of the production well, a system of natural fractures is required to provide a natural flow stream for the water circulating from the injection well and the production well. Upon flowing through the rock porosity / permeability system, the water is heated due to its contact with the hot rock matrix/fluid interface and
transports the according heat energy to the surface.
Generally, the overall heath energy extraction at depth must be compensated by the natural geothermal heat flow, which radiates principally from the earth mantle outwards to the earth crust.
If a natural system of fractures does not exist or is inefficient to provide the required flow rate in order to run the geothermal energy extraction and production process, then an artificial fracture system must be provided through downhole fracturing operations.
In the producer well, downhole pumps provide the flow, in order to pump the hot water from the shoe to the surface. Proper downhole filters have to be installed for sand and solid control.
The hot water flowing to the surface passes through a heat exchange system,e.g. of a Kalina cycle or other type of power plant. At higher temperatures, e.g. above 150 degree Celsius, the water will
partially flow in the vapor phase, which increases its concentration at increasing temperatures.
In reservoirs with temperatures around about 300 to 400 degree Celsius, the flowing phase is only vapor. This vapor can directly flow through the turbines of the power plant.
The water/vapor flowing out of the power plant is re-injected into the thermal reservoir through the injection well and the circulation cycle starts again.
The difficulty of a HDR project is to manage and provide downhole an essentially horizontal system of fractures which are hermetically confined in order to avoid a dispersive flow.The flow directivity must be confined from the injector to the producer well. If there is not a natural reservoir directly providing high pressure steam and the necessary permeability, then fracture or stimulation operations must be applied in order to provide a suitable connectivity flow system in the geothermal reservoir.
In a fracture stimulation operation, water is pressed at high pressure cycles downhole and further injected through perforations in the well casing into the surrounding reservoir rock formation in order to overcome the minimum horizontal stress field (Sigma-3). This will generally produce a fracture that is perpendicular to Sigma-3 and in the Sigma-1/Sigma-2 plane, i.e. in a sub-vertical fracture.
A difficult task in controlling a fracture process relates to the difficulty of identifying with the required precision suitable geomechanical parameters allowing determining the heterogeneity of the rock
matrix/porosity system and the direction of the closure stress.
If the fracture stimulation process is not properly planned and the parameters influencing such process are not sufficiently determined in detail, control on the fracture directivity, especially in the far-field region with respect to the downhole center of the fracturing operation water injection might be lost. As a consequence, in the production phase the flow might not be focused in the desired direction and this might strongly reduce the geothermal energy recovery at the producer well.
The artificial fracture system might also intercept natural fractures, which might lead to water dispersive flow, fluid losses and system inefficiency.
In the absence of effective stress confinement, (barrier) layers above and below the fracture horizon, the vertical fracture propagation might reach permeable layers above with lower temperature or high permeability layers, which in turn might lead to flow dispersion.
For running an efficient geothermal cycle, a flow rate of more than 100 liter/second at temperatures possibly above 110 degree Celsius are needed to this aim, dispersive flow is a serious thread in geothermal production.
DDS SYSTEMS: A STEP AHEAD IN GEOTHERMAL SOLUTIONS
Deep Directivity Systems (DDS) can be defined as a combination of (latest and/or future) drilling, directional drilling control, reservoir stimulation, extensive fracture generation and well completion technologies.
The drilling technologies are for drilling multi-directional wells and/or systems of mutually interconnected wells and/or well systems, which are planned and directed to reach, from possibly only one or more spud points, interconnect and optimally permeate a plurality of deep geothermal reservoirs (formations) from which the geothermal energy will produced to the possibly only one spud point at the earth surface, where sufficient geothermal power is supplied from the plurality of reservoirs so that an electric power plant can be operated continuously.
The directional drilling control technologies are for controlling the complex subsurface path of the drill head. The reservoir stimulation and new fracture generation technologies are for permeably connecting respective large volumes of a deep geothermal reservoir formation to the plurality of respective wells which permeate the reservoir formation.
The well completion technologies are for completing the casings which are introduced into the wells and for providing in a casing wall the apertures required to provide the water flow communication from the interior of the respective well (injector) to the surrounding geothermal reservoir and further another well (producer) penetrating the same reservoir, thus closing a water flow loop for extracting geothermal energy from the respective reservoir and comprising the respective injector well, said reservoir and the respective producer well.
Having examined case studies of some failed geothermal projects, the DDS concept has been invented and developed conceptually with the aim to optimally control the flow directivity in the geothermal reservoir at the maximum possible resolution scale and efficiently and hermetically close
and interconnect respective water flow circulation systems reaching one or plural geothermal reservoirs, thereby avoiding dispersion by waterflooding.
A special workflow of reservoir characterization studies has been setup, as a specific program for the planning and implementation of DDS projects.
This comprises 3D seismic multi-component acquisition for the target identification and drilling program planning, specific suites of LWD and wireline petrophysical logs measurements for the construction of a static geological structural and electrofacies model.
One of the relevant advantageous features of DDS is that the water flow circulation system can be designed, re-designed and extended such that the energy conversion system provided at the earth surface can be adapted to virtually any desired scale in terms of power and efficiency.
For example, if initially a small scale project comprising a 2 Megawatt electrical power plant unit has been realized, this project can be virtually indefinitely extended, e.g. by adding new component units at the earth surface location for increasing the total power to 10, 100 or 1000Megawatt and by developing new deep geothermal reservoirs and flow-connecting these to the respective earth surface location.
Using the concepts of DDS, a deep geothermal project can be planned conceptually as a predefinable, locally optimized, turn-key system, in which the dimension and efficiency can be designed already in the pre-planning phase, thereby reducing the uncertainty and project risk to a
minimum level.
Compared to hydrothermal projects, which are limited to only a few areas in the world, and to Hot Dry Rock projects, which generally bear a considerable risk, projects designed using DDS system concepts can be realized in more than 95% of the earth's surface, which renders to such projects the maximum possible design flexibility and a vast spectrum of applications.
In result, the novel DDS concept for designing deep geothermal projects will bring increased project efficiency and lower risk with respect to any other kind of geothermal projects.
The novel DDS concept invented by GeoNeurale represents a great evolution in geothermal technology and in the renewable energy sector.
About the authors:
Angelo Piasentin holds a university degree (Laurea in geological sciences / internato in geophysics) and
is a senior geoscientist consultant and trainer.
He has worked for many years in the oil and gas service industry, oil and geothermal research and consultancy.
Currently, he is the head of GeoNeurale, a firm based in Munich (Germany) offering training and consultancy
in both oil and gas exploration and production and geothermal energy development.
Contact details:
Angelo Piasentin, GeoNeurale, Lichtenbergstr. 8, 85748 Munich-Garching, Germany,
Tel.: +49 - 89 - 89691118, piasentin@GeoNeurale.com, www.GeoNeurale.com.
Dr. Stephan Klauer holds a university degree (Master and Ph.D.) in physics, has worked for many years as a
researcher in the oil and gas exploration and production technology development, before he became a patent
professional and coaching consultant.
He is qualified as a European Patent Attorney and is the head of SK-Patent, a Munich-based patent law firm
dedicated to prosecute patents in Europe and world-wide.
Contact details:
Dr. Stephan Klauer, SK-Patent, Eduard-Schenk-Str. 64, 80807 Munich, Germany,
Tel.: +49 - 89 - 9901 9790,
E-Mail: info@skpatent.com, Internet: www.skpatent.com.
www.geoneurale.com
www.petrophysic-consultants.com
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DDS
" DEEP DIRECTIVITY SYSTEMS "
The Revolution on the Geothermal Exploration
Geoneurale / Petrophysic-Consultants developed a new technology,the key for the future of the renewable energy.
DDS is a new scientific innovation. Thanks to this technology containing the last developments in the Geophysics, Petrophysics and Drilling Technology every town in the world can develop its own deep geothermal projects, power plants and heating systems.
A method for the universal development of geothermal projects not only in high geothermal gradient and favourable areas but in every part of the world.
With DDS the door to the future of the clean renewable energies is open.
Petrophysic-Consultants develops and supervises the operative phase of DDS projects.
www.Petrophysic-Consultants.com
Advantages of the DDS technology :
1. DDS is a standard method and a final turnkey product.
2. DDS is a final product and standard for every kind of formation.
3. DDS can be applied to old oil wells in depleted reservoirs to develop a
geothermal project, saving drilling costs, adding value to old projects.
4. DDS can be applied to reactivate failed geothermal projects using the old wells
and saving the drilling costs to produce a new successful geothermal project.
5. DDS can be theoretically planned for the desired efficiency and electrical power
There is no theoretical limit to the maximal efficiency and output of the method.
6. DDS can be planned to for a working cycles of 10, 100, or more years. There is no theoretical limit for the
efficiency and life time of a project.
7. DDS is ideal for the joint development in a cooperation between 2 , 3 or more bordering towns.
8. DDS can be applied in every formation except the exceptional presence of evaporites.
9. DDS can be applied in every region of the world.
10. DDS can be expecially applied in volcanic areas defining the target and well path
within a safety area from the volcanic system, reaching the maximum efficiency in the power production.
11. DDS can be both used for power production or for hot water/heathing systems.
12. DDS ensure the maximal efficiency compared with other geothermal projects.
13. DDS ensure the minimum risk compared with other geothermal methods.
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The Oil Exploration Industry needs more Intellectual Workforce
With the catastrophe of the 22 April 2010 became evident that the conditions how the oil industry operates need a urgent and radical change. This series of significant mistakes shows that the oil exploration industry is faced with enormous problems.
Too little personnel have to solve too many problems in the minimum amount of time.
Engineers and scientists work steadily under pressure to take decisions and to take actions.
As geoscientists we know that small mistakes belong to the daily routine. In the geophysical sciences we directly experience everyday the statistical uncertainty which is intrinsic in the interaction between man and nature.
It is common practice in the remote sensing measurements, seismic acquisition and petrophysical log measurements to try and quantify parallel with each measurement its error variance both in the measurement magnitude and in its spatial definition.
All this reminds us that we are far from perfection.
Just a small parallelism to show that this catastrophe could have been avoided.
Any drilling engineer would recognize that good sense has been lost. Saving time for profit this time has been fatal.
On the best hypothesis that the oil pollution will remain localized and not be transported through the Atlantic currents to West Europe, Africa and Greenland, this tragedy will cost billions and billions and billions of dollars.
Millions of times more than increasing one hundred times the intellectual workforce in each oil company worldwide: Geophysicists, Petrophysicists, Geostatistical Analysts, Modeling Specialists, Reservoir Engineers Drilling Engineers, Safety Specialists and so on.
Decisions can not be left to a single person, they have to be a collegial event.
Knowledge must be shared and integrated and finally society must be aware of the cost of energy.
The cost of Safety has to be included.
The events in the earth´s history are unique and unrepeatable and there is no price for a lost nature.
Society´s sensitivity towards energy costs has to be upgraded.
IT IS THE ENERGY THAT WE PRODUCE THAT DRIVES AND SUSTAINS THE HUMAN CIVILIZATION IN ALL ITS SECTORS.
Chronicle of a catastrophe: Fotos and Comments
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GeoNeurale and in2earthm cooperation
Geostatistical Applications for the Carbonate Petrophysics and Stochastic Modeling.
GeoNeurale announces the partnership between GeoNeurale and in2earthm of Zurich for Research and Training.
GeoNeurale and Crienterprises
On the way to the excellence in Carbonate Petrophysics and Carbonate Research services GeoNeurale announces the partnership between GeoNeurale and Crienterprises for Research and Training.
www.Crienterprises.com
GeoNeurale and Neuronics : Strategical Partnership for Training and Research
Neuronics Inc. Switzerland develops and produces intelligent robots, which are being widely used in industry and research. Neuronics was being established as a spin-off venture of the Artificial Intelligence Laboratory at the Institut für Informatik of the University Zürich.
www.Neuronics.ch
GeoNeurale and Geovariances partnership
GEOVARIANCES is a French Independent Software Vendor, world Leader in GEOSTATISTICS.
GEOVARIANCES publishes ISATIS, integrated geostatistical software Solution, used by the majors
and independent companies.
GEOVARIANCES expertise lays in seismic QC and filtering, time-to-depth conversion, reservoir
characterization, risk assessment.
GeoNeurale and Geovariances
GeoNeurale and Geovariances are now partner for Training. The joint presentation that Geovariances of Fontainebleau and GeoNeurale of Munich made at the UTG " Umwelt Technologisches Gründerzentrum " - Augsburg - , described the fundamental role that Geostatistics can play in the Reservoir Characterization for Geothermal Exploration.
PRESENTATION REPORT
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NEW RELEASE OF FRACA 4.1 2006
Beicip-Franlab, Beicip Inc. and IFPmec are pleased to announce the imminent release of FRACA 4.1
NEW IN 4.1
- Deterministic fracture sets: for creating fractures/faults with specific properties at wells or anywhere
in the field
- Single-media scale-up and output for use in single-media dynamic simulation with a single phase
This even more powerful FRACA version provides users with the ability to handle all the fractures present in a reservoir:
natural, stimulation and induced.
The software will be available for Linux, Windows and Sun Microsystems Operating systems.
GeoNeurale
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