Difference between revisions of "Offshore exploration and exploitation"

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==Exploration==
 
==Exploration==
 +
Exploration first consists of the indirect searching for the resources using geophysical methods: Magnetic survey or register, gravimetric survey, and seismic survey.
  
[[File:Figura 1.jpeg|300px|thumbnail|right|{{figure number|1}}Gravimetric survey]]
 
 
At first, consist in the indirect searching of the resources using geophysics methods: Magnetic survey or register, gravimetric survey and seismic survey.
 
 
=== Magnetic survey or register ===
 
=== Magnetic survey or register ===
 
Consist in the register of the magnetic fields of the rocks, having the Earth magnetic field as reference. These fields are registered by a magnetometer installed in a plane that flies over the interest zone. Sedimentary formations with hydrocarbons don't manifest [[magnetics]] properties.
 
Consist in the register of the magnetic fields of the rocks, having the Earth magnetic field as reference. These fields are registered by a magnetometer installed in a plane that flies over the interest zone. Sedimentary formations with hydrocarbons don't manifest [[magnetics]] properties.
  
 
=== Gravimetric survey ===
 
=== Gravimetric survey ===
Registers the variation of the rocks density, taking as reference the Earth gravitational field (Figure 1).
+
[[File:Figura 1.jpeg|300px|thumbnail|right|{{figure number|1}}Gravimetric survey]]
=== Seismic survey ===
 
Is the most used and complete method of all. Register the reflection and refraction  variation of induced waves into the surface, where the different formations will act in opposite ways, according their characteristics. These waves are captured in surface or, in the offshore exploration, in a ship, by seismographers, who gaugethe transit time and the intensity of the reflected waves for the subgrade rocks. The method objective is that we be allowed to know how the geology in the prospected area is.
 
There are three kinds of seismic models, one more complete and detail than the other one: 2D, 3D and 4D Seismic.
 
  
[[File:2D Seismic.jpeg|300px|thumbnail|right|Figure 2: 2D Seismic]]
+
Registers the variation of rock density, taking as reference the Earth gravitational field ([[:File:Figura 1.jpeg|Figure 1]).
  
==== 2D Seismic ====
+
===Seismic survey===
In two dimensions (Figure 2). The sources and receptors of the induced waves are ubicated in a line, having as result a seismic line that cover the structure that we wish to know. The separation of these lines areuicated according to the objective and detail level.
+
Seismic surveys are the most used and complete method of all. Register the reflection and refraction variation of induced waves into the surface, where the different formations will act in opposite ways, according their characteristics. These waves are captured in surface or, in the offshore exploration, in a ship, by seismographers, who gauge the transit time and the intensity of the reflected waves for the subgrade rocks. There are three kinds of seismic models: one more complete and detail than the other one: 2-D, 3-D, and 4-D seismic.
  
[[File:3D Seismic.jpeg|300px|thumbnail|left|Figure 3: 3D Seismic]]
+
====2-D Seismic====
 +
[[File:2D Seismic.jpeg|300px|thumbnail|right|{{figure number|2}}2-D Seismic]]
 +
In two dimensions ([[:File:2D Seismic.jpeg|Figure 2]]), the sources and receptors of the induced waves are ubicated in a line, as a result the seismic line covers the structure. The separation of these lines are ubicated according to the objective and detail level.
 
   
 
   
==== 3D Seismic ====
+
==== 3-D Seismic ====
In three dimensions (Figure 3). For his register the sources and receptors ubicates across perpendicular lines each in the interest area, having as result a seismic data volume, with bigger density respect 2D seismic, and provide better ubication of the structures. This method generates seismic cubes according to the deep, the length of the seismic line and the hydrophones arrangement wide.  
+
[[File:3D Seismic.jpeg|300px|thumbnail|left|{{figure number|3}}3-D Seismic]]
+
Surveying in three dimensions ([[:File:3D Seismic.jpeg|Figure 3]]), registers the sources and receptors ubicates across perpendicular lines in each interest area, which results in a seismic data volume, with bigger density than r2-D seismic, and provides better ubication of the structures. This method generates seismic cubes according to the depth and length of the seismic line and the width of the hydrophones arrangement.
==== 4D Seismic ====
+
 
Consist in the repetition of a 3D seismic survey in exactly the same original area, after a determinated time. In consequence, the time function is added to a 3d cube.
+
====4-D Seismic====
Once that the seismic shows successful results, is necessary bring anocean bed survey for knowing his topography, in an area of 30 km2, having as objective establish the substrate conditions for the anchorage or support of the perforation unit. This is realized by bathymetry and cursory seismic. Also it’s has to make a wind, currents and waves study.
+
4-D seismic consists of the repetition of a 3-D seismic survey in exactly the same original area, after a determined time. In consequence, the time function is added to a 3-D cube. Once that the seismic shows successful results, it is necessary bring an ocean bed survey to look at topography, in an area of 30 km<sup>2</sup>, having as objective establish the substrate conditions for the anchorage or support of the perforation unit. This is realized by bathymetry and cursory seismic. There must also be a wind, current, and wave study.
  
 
==Exploitation Instance==
 
==Exploitation Instance==
 +
[[File:Different kinds of platforms.png|framed|{{figure number|4}}Different kinds of platforms: 1, 2) conventional fixed platforms; 3) compliant tower; 4, 5) vertically moored tension leg and mini-tension leg platform; 6) spar; 7, 8) semi-submersibles; 9) floating production, storage, and offloading facility; 10) sub-sea completion and tie-back to host facility. Courtesy Ocean Explorer<ref>[https://oceanexplorer.noaa.gov/explorations/06mexico/background/oil/media/types_600.html Ocean Explorer]</ref>]]
  
[[File:Different kinds of platforms.png|400|thumbnail|default|Figure 4: Different kinds of platforms: 1, 2) conventional fixed platforms; 3) compliant tower; 4, 5) vertically moored tension leg and mini-tension leg platform; 6) spar; 7,8) semi-submersibles; 9) floating production, storage, and offloading facility; 10) sub-sea completion and tie-back to host facility.]]
+
After a successful exploration, next comes the offshore platforms installation. These platforms extract oil and gas, and are used as a home for the workers and communication towers. Depending the circumstances, the platform can be fixed at the seafloor, float, or be an artificial island. There different kinds of platforms ([[:File:Different kinds of platforms.png|Figure 4]]), each one with different especial characteristic according to the deposit and ocean bed kind.
  
After a successful result in the exploration instance, it must to proceed to the offshore platforms installation. These platforms consists in large dimensions structures,  that besides extract oil and gas, are used like home for the workers and communication towers. Depending the circumstances, the platform can be fixed at the seafloor, float or be an artificial island. There different kinds of platforms (Figure 4), each one with different especial characteristic according to the deposit and ocean bed kind.
+
==References==
 +
{{reflist}}
  
 
==Bibliography==
 
==Bibliography==
 
+
* Michaud, F., and G. Ratzoud, G., et al., 2005, Métodos e Instrumentación acústica para la exploración en Geofísica Marina.
* Michaud, F., Ratzoud, G., et al. Métodos e Instrumentación acústica para la exploración en Geofísica Marina, 2005.
+
* Alvarez, C., and C. Lupo, 2014, [http://oilproduction.net/perforacion/item/1803-evaluacion-de-localizaciones-para-la-perforacion-costa-afuera Evaluación de Localizaciones para la perforación costa afuera]: Sclumberger.
* Alvarez, C., Lupo, C.. “Evaluación de Localizaciones para la perforación costa afuera”. Pemex, Sclumberger.
+
* Garcia Arboix, N., and J. A. Roca Maideu, Investigación de los materiales de una plataforma offshore: Universitat Politecnica de Catalunya Barcelonatech.
* Garcia Arboix, N., Roca Maideu, J. A. “Investigación de los materiales de una plataforma offshore”, Universitat Politecnica de Catalunya Barcelonatech.
 
  
 
==External Links==
 
==External Links==
 
 
* http://oceanexplorer.noaa.gov/explorations/06mexico/background/oil/media/types_600.html
 
* http://oceanexplorer.noaa.gov/explorations/06mexico/background/oil/media/types_600.html

Latest revision as of 22:00, 10 April 2019

Wiki Write-Off Entry
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Student Chapter UNLP: La Plata
Competition June 2015

Offshore drilling is the searching for hydrocarbon resources off of the continental platform. The exploration and exploitation are complex because of the difficulty for the transport of the necessary machinery. As a first step, it is necessary make indirect exploration, which, if it is successful, goes to a direct exploration, and if that is also successful, ends finally in an exploitation.

Exploration

Exploration first consists of the indirect searching for the resources using geophysical methods: Magnetic survey or register, gravimetric survey, and seismic survey.

Magnetic survey or register

Consist in the register of the magnetic fields of the rocks, having the Earth magnetic field as reference. These fields are registered by a magnetometer installed in a plane that flies over the interest zone. Sedimentary formations with hydrocarbons don't manifest magnetics properties.

Gravimetric survey

Figure 1 Gravimetric survey

Registers the variation of rock density, taking as reference the Earth gravitational field ([[:File:Figura 1.jpeg|Figure 1]).

Seismic survey

Seismic surveys are the most used and complete method of all. Register the reflection and refraction variation of induced waves into the surface, where the different formations will act in opposite ways, according their characteristics. These waves are captured in surface or, in the offshore exploration, in a ship, by seismographers, who gauge the transit time and the intensity of the reflected waves for the subgrade rocks. There are three kinds of seismic models: one more complete and detail than the other one: 2-D, 3-D, and 4-D seismic.

2-D Seismic

Figure 2 2-D Seismic

In two dimensions (Figure 2), the sources and receptors of the induced waves are ubicated in a line, as a result the seismic line covers the structure. The separation of these lines are ubicated according to the objective and detail level.

3-D Seismic

Figure 3 3-D Seismic

Surveying in three dimensions (Figure 3), registers the sources and receptors ubicates across perpendicular lines in each interest area, which results in a seismic data volume, with bigger density than r2-D seismic, and provides better ubication of the structures. This method generates seismic cubes according to the depth and length of the seismic line and the width of the hydrophones arrangement.

4-D Seismic

4-D seismic consists of the repetition of a 3-D seismic survey in exactly the same original area, after a determined time. In consequence, the time function is added to a 3-D cube. Once that the seismic shows successful results, it is necessary bring an ocean bed survey to look at topography, in an area of 30 km2, having as objective establish the substrate conditions for the anchorage or support of the perforation unit. This is realized by bathymetry and cursory seismic. There must also be a wind, current, and wave study.

Exploitation Instance

Figure 4 Different kinds of platforms: 1, 2) conventional fixed platforms; 3) compliant tower; 4, 5) vertically moored tension leg and mini-tension leg platform; 6) spar; 7, 8) semi-submersibles; 9) floating production, storage, and offloading facility; 10) sub-sea completion and tie-back to host facility. Courtesy Ocean Explorer[1]

After a successful exploration, next comes the offshore platforms installation. These platforms extract oil and gas, and are used as a home for the workers and communication towers. Depending the circumstances, the platform can be fixed at the seafloor, float, or be an artificial island. There different kinds of platforms (Figure 4), each one with different especial characteristic according to the deposit and ocean bed kind.

References

Bibliography

  • Michaud, F., and G. Ratzoud, G., et al., 2005, Métodos e Instrumentación acústica para la exploración en Geofísica Marina.
  • Alvarez, C., and C. Lupo, 2014, Evaluación de Localizaciones para la perforación costa afuera: Sclumberger.
  • Garcia Arboix, N., and J. A. Roca Maideu, Investigación de los materiales de una plataforma offshore: Universitat Politecnica de Catalunya Barcelonatech.

External Links