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Use of Georeferenced Maps in Exploration

By

Jingyao Gong1 and Larry D. Gerken2

Search and Discovery Article #40039 (2002)

1AAPG, Tulsa, Ok 74101 ([email protected])

2Newfield Exploration Mid-Continent, Tulsa, OK 74102 ([email protected])

Summary

Spatial information, which is the core of data essential to petroleum geoscientists, now can be efficiently arranged and managed by use of geographic information system (GIS), such as ESRI’s ArcView and ERDAS’ Imagine. One of the functions of GIS software is to georeference maps, and thereby allow direct comparison of a suite of maps with different scales and projection. Once maps are scanned, or vectorized, and georeferenced, they are easily arranged in a desired order for viewing and analysis.

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uSummary

uFigure Captions

uMethodology

uExample

tArabian Plate

tBu Hasa Field

uReferences

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

uSummary

uFigure Captions

uMethodology

uExample

tArabian Plate

tBu Hasa Field

uReferences

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

uSummary

uFigure Captions

uMethodology

uExample

tArabian Plate

tBu Hasa Field

uReferences

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

uSummary

uFigure Captions

uMethodology

uExample

tArabian Plate

tBu Hasa Field

uReferences

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

uSummary

uFigure Captions

uMethodology

uExample

tArabian Plate

tBu Hasa Field

uReferences

 

 

 

 

 

Figure Captions

Figure 1. Vectorized Previous HitmapNext Hit of sedimentary provinces of Middle East and Europe, along with parts of Asia and Africa (from Previous HitmapNext Hit of St. John, Bally, and Klemme, 1984), with productivity or potential shown by color (red or pink with giant field(s), green with subgiant field(s), yellow nonproductive).

Figure 2. Vectorized Previous HitmapNext Hit of oil and gas fields of the Arabian Plate, with outcrops of basement rocks and ophiolites (from Beydoun, 1991), as overlay to Previous HitmapNext Hit of sedimentary provinces. Click on inset Previous HitmapNext Hit for enlargement.

Figure 3. Georeferenced structure Previous HitmapNext Hit (Previous HitbaseNext Hit of Mesozoic) of the Arabian Plate (Alexander, 1986), as overlay to Previous HitmapNext Hit of sedimentary provinces. Click on inset Previous HitmapNext Hit for enlargement.

Figure 4. Georeferenced Previous HitmapNext Hit of Upper Jurassic source rocks in Arabian Plate (Alexander, 1986), as overlay to Previous HitmapNext Hit of sedimentary provinces. Click on inset Previous HitmapNext Hit for enlargement.

Figure 5. Georeferenced bouguer gravity anomaly Previous HitmapNext Hit for southern Iran and contiguous areas (Bushara, 1995), as overlay to oil and gas Previous HitmapNext Hit. Click on inset Previous HitmapNext Hit for enlargement.

 

Figure 6. Georeferenced structure Previous HitmapNext Hit, Shuaiba Formation, in part of U.A.E. (Alsharhan, 1993), as inset to oil and gas Previous HitmapNext Hit. Click on inset Previous HitmapNext Hit for enlargement.

 

Figure 7. Georeferenced structure Previous HitmapNext Hit of Bu Hasa oil field (Alsharhan, 1993), as inset to structure Previous HitmapNext Hit of U.A.E. Click on inset Previous HitmapNext Hit for enlargement.

 

Figure 8. Georeferenced isopach Previous HitmapNext Hit of Cretaceous Shuaiba Formation, Bu Hasa field (Alsharhan, 1993), as an overlay to structure Previous HitmapNext Hit.

 

 

 

 

Figure 9. Databases and illustrations of Bu Hasa features, linked to structure Previous HitmapNext Hit of U.A.E. (Alsharhan, 1993). Database for Burial History prepared by M.K. Horn.. Click on burial history plot to view database in Excel; click on database of field parameters to view it in Excel; click on illustration for view in PDF.

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Methodology

Maps are generally scanned with resolution of 300 dpi and are saved in tif format. The scanned Previous HitmapNext Hit is opened in the “View” window of ERDAS Imagine in order to perform the following:

1. Go to the “Raster” menu and choose “Geometric corrections”; a dialogue box of “Set Geometric Model” opens.

2. Choose “Polynomial” and click OK; the “Polynomial Model Properties” window opens; the scanned Previous HitmapNext Hit is to be matched to its spatially corresponding points on a reference Previous HitmapNext Hit, one that is in digital and geographic coordinate system. A “polynomial order” of 3 is satisfactory in most cases. After ”Close” is clicked, the GCP Tool Reference Setup window opens.

3. Choose “Vector Layer” option and click “OK” button.

4. A selection window is opened for users to select a vectorized Previous HitmapNext Hit as a reference. Themes from ESRI data, such as boundaries of counties or states, are commonly used. After the reference Previous HitmapNext Hit is selected, it is shown on a second view window that is automatically opened after the selection.

5. Find and click the corresponding points in pairs in the two views, such as the marks of latitude/longitude, if they are present, selected geographic boundaries, etc. on the scanned Previous HitmapNext Hit. After 10 pairs are selected, go to step 6.

6. Click on the Resample icon in the “Geo Correction Tools” window that has been automatically opened at the top of the computer screen. The resample option dialogue box will be displayed. Choose tif format in the “Output File” drop-down menu, select a folder and name the Previous HitmapNext Hit that will be generated after resampling; click the box of “Ignore Zero in Statistics,” and click OK. The newly generated Previous HitmapNext Hit is georeferenced.

7. Open a blank project in ArcView and add the newly generated Previous HitmapNext Hit to a view. Technically, this tif Previous HitmapNext Hit can be used for overlay comparisons, but the defaulted black background of the edge of the Previous HitmapNext Hit is not pleasant. In order to convert the edge’s color from black to white, use a free extension from ESRI website called “quick and dirty georeferencing.” First, turn on the extension and click on the associated “Write World File” icon to write tifw file for the Previous HitmapNext Hit. Delete the Previous HitmapNext Hit from the view. Afterwards, open the Previous HitmapNext Hit using Adobe Photoshop and delete black background from the edge. It should be noted that the size of the Previous HitmapNext Hit cannot be changed; otherwise the tifw file is invalid and the Previous HitmapNext Hit is no longer georeferenced. However, color and text can be edited. An ERDAS-generated tif Previous HitmapNext Hit has three files; one with .aux extension, one with .rrd extension and the other one with .tif extension. If this type of Previous HitmapNext Hit is edited in Adobe Photoshop, the special information is absent, and the edited Previous HitmapNext Hit is not georeferenced. This is the reason why we use software to write a tifw file before the color of a georeferenced Previous HitmapNext Hit is edited because a tifw file can still recognize the edited Previous HitmapNext Hit. Once the tifw file is written, the .aux and .rrd files can be deleted.

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Example

Presented herein is an atlas of selected georeferenced maps of the Middle East derived from AAPG publications. The vectorized maps of Sedimentary Provinces of the World (St. John, Bally, and Klemme, 1984) and fields of the Arabian Plate (Beydoun, 1991) are the bases for the following georeferenced maps:

1. Structure Previous HitmapNext Hit of Arabian Plate

2. Previous HitMapNext Hit of Upper Jurassic source rocks, Arabian Plate

3. Bouguer gravity anomaly mmap of southern Iran and contiguous area

4. Structure Previous HitmapNext Hit of part of United Arab Emirates (U.A.E.)

5. Structure and isopach maps of Bu Hasa oil field

Two databases and illustrations of Bu Hasa features are linked to the structure Previous HitmapNext Hit of the field.

 

Arabian Plate

Figures 1, 2, 3, and 4 show several aspects of the rich hydrocarbon Arabian province--its areal extent, fields, foredeep nature, and the extent and thickness of one of the important sequences of source rocks.

 The gravity Previous HitmapNext Hit in Figure 5 extends from the eastern edge of the Zagros foldbelt of southern Iran to U.A.E.; the area includes two gravity-anomaly highs, represented by the Qatar Arch and Marazouk-Dhafra trend, which contain draping folds Bushara (1995) hosting giant fields, such as North field, the world’s largest gas field.

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Bu Hasa Field, United Arab Emirates

U.A.E. on the eastern shelf of the Arabian platform contains northeast-southwest folds at the Cretaceous Thamama level (Figure 6). Major fields are present on two prominent structure-highs (Shah-Asab on the east and Huwaila - Bu Hasa axis on the west. 

Bu Hasa field (Figure 7) is an north-trending anticline, about 22 mi (35 km) long. The anticline, shaped as a tear drop, tapers in width to the south. The structural relief of about 800 ft (250 m) and an areal closure is about 205 mi2 (535 km2) at the top of the Cretaceous Shuaiba carbonate (Alsharhan, 1993). The multiple pays are Upper Cretaceous limestones. Its estimated reserves, as of 1993, was 20 billion bbl of oil.

The isopach Previous HitmapNext Hit of the Shuaiba Formation (Figure 8) shows that the thickest part of the is about 2 to 3 mi (1.2 to 2 km) wide and trends northwest-southeast for more than 14mi (9 km) across the structural crest. Variations in thickness are due to the changes of depositional environments and erosion.

ArcView® can link a feature (oil/gas field, fault, anticline, well, seismic line, etc.) on a Previous HitmapNext Hit to different kinds of data, such as images and databases. Figure 9 shows that Bu Hasa field is linked to three databases. The first one is the burial history case-study, with nine different properties, in Microsoft Excel format. The second one, also in Excel, is the comprehensive database of field parameters. The third data consists of images of illustrations of field features.

References

Alsharhan, A.S., 1993, Bu Hasa Field--United Arab Emirates, Rub al Khali Basin, Abu Dhabi in AAPG Treatise: Structural Traps VIII, p. 99-127.

Alexander, R. G., 1986, California and Saudi Arabia Geologic Contrasts in AAPG Memoir 40: Future Petroleum Provinces of the World, p. 291 –315

Beydoun, Z. R., 1991, The Arabian Plate Hydrocarbon Geology and Potential--A Plate Tectonic Approach: AAPG Studies in Geology No. 33, 77p.

Bushara, Mohamed N., 1995, Subsurface Structure of the Eastern edge of the Zagros Basin as Inferred from Gravity and Satellite data: AAPG Bulletin, p. 1259-1273.

St. John, Bill, A.W. Bally, and H.D. Klemme, 1984, Sedimentary Provinces of the World--Hydrocarbon Productive and Nonproductive: Previous HitmapNext Hit and booklet: AAPG.

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