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Chapter 2 (Part 1). Petroleum Exploration. Petroleum Exploration (Part 1). Areas Covered: Surface Geographical Studies Collecting Data. Surface Geographical Studies. Historically exploration took place at or near oil seeps, where oil was actually present on the surface.
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Chapter 2 (Part 1) Petroleum Exploration
Petroleum Exploration (Part 1) • Areas Covered: • Surface Geographical Studies • Collecting Data
Surface Geographical Studies • Historically exploration took place at or near oil seeps, where oil was actually present on the surface. • Now: Scientist use several techniques to explore for hydrocarbons: • Topography • Aerial Photographs • Satellite Images • Radar • Oil and Gas Seeps
Topography • Topography: • The study and mapping of natural and man made features on the surface of the land.
Aerial Photographs • Used to narrow vast regions down to areas small enough for surface and subsurface analyses. • The past drawback: photos were shot at varying angles thus causing unequal quality making interpretation difficult. • Current Technology: Remote Sensing – Using infrared or other means to map an area.
Aerial Photographs Difficult to distinguish surface characteristics Varying camera angle produces unequal quality
Landsat • Landsat: Satellites that map the earth’s surface. • Primary Function: Map vegetation and observe long term changes to the earth’s surface • Provides visible, thermal, and infrared images of all land masses and coastal areas. • Exploration Companies can buy landsat images and satellite data from the government. • http://www.youtube.com/watch?v=LqM12r7UIxU
Radar • Bounces high frequency radio waves off land features to a satellite or an airplane. • Return “Echoes” are recorded to form a low-resolution relief map. • This helps discern large scale terrain features at a glance. • Aids in searching large unexplored areas for potential oil-traps
Radar (Image) Florence, Italy as provided from NASA.
Oil and Gas Seeps • Obvious signs of a subsurface petroleum source. • Typically so slow it is hard to detect due to weathering and bacteria decomposition. • Chemical testing can be done to detect traces of Hydrocarbons. • Plumes of gas seeping out of the ocean floor have led to offshore exploration.
Oil and Gas Seeps • Where they occur: • Typically along fractures that pierce the reservoir or at areas where the formations reach the surface. • They are also found at anticline crests.
Oil and Gas Seeps • http://www.youtube.com/watch?v=7g96FMoBFXw • http://www.youtube.com/watch?v=Hp6kendr0m4&feature=related
Collecting Data • Most of the information Exploration / Petroleum Geologist work with come from three resources: • Private Company Databases • Public Agency Records • Databases
Private Company Libraries • Companies typically maintain large collections of drilling and production data, maps, and or well logs. • It is built from the companies own exploration, drilling, and production projects as well as information gathered from public agencies and members contributions.
Public Agency Records • Governing Agencies that regulate the oil and gas industry collect and file data on all types of drilling and production projects. • Files are typically open to the public and accessible to anyone who knows the name of a well, the site of a well, who drilled it, and when it was drilled. • Information can also be found through public universities that have a core sample library or well logs.
Databases • Used by both public and private organizations the access and share a variety of information. • Typically classified by region, field and reservoir. • Most major oil companies subscribe to petroleum databases. • Non Subscribers can make requests on a per-search basis. • Many government agencies and universities have made or are making their data publicly available through the internet.
Questions • List the five main areas of surface geographical studies used in petroleum exploration. • Define topography. • What is the drawback to traditional aerial photography when used for exploration purposes? • What is Landsat? • How does radar map the earths surface? • What are the two locations oil and gas seeps occur the most? • What are the three resources for collecting petroleum exploration data?