Aplikasi Satellite GEOSAT dan ERS sebagai Metode Alternatif Pengukuran Gravity Ground pada Cekungan Hidrokarbon di Pulau Timur

Muhammad Yanis; Marwan Marwan; Nuzul Kamalia

doi:10.22146/mgi.50782

Aplikasi Satellite GEOSAT dan ERS sebagai Metode Alternatif Pengukuran Gravity Ground pada Cekungan Hidrokarbon di Pulau Timur

https://doi.org/10.22146/mgi.50782

Muhammad Yanis^(1*), Marwan Marwan⁽²⁾, Nuzul Kamalia⁽³⁾

(1) Teknik Geofisika, Universitas Syiah Kuala, Darussalam, Banda Aceh, Indonesia
(2) Teknik Geofisika, Universitas Syiah Kuala, Darussalam, Banda Aceh, Indonesia and Jurusan Fisika, Universitas Syiah Kuala, Darussalam, Banda Aceh, Indonesia
(3) Teknik Geofisika, Universitas Syiah Kuala, Darussalam, Banda Aceh, Indonesia
(*) Corresponding Author

Abstract

Graviti merupakan metode awal yang digunakan untuk mempelajari basement pada area potensial hidrokarbon. Pada umumnya metode graviti diukur melalui darat dengan peralatan Scientrex maupun LaCoste & Romberg, teknik ini membutuhkan waktu dan financial yang relative banyak. Padahal secara prinsip pengukuran, metode ini tidak membutuhkan kontak langsung dengan tanah, sehingga dimungkinkan untuk diukur melalui airborne dan satelit. Oleh karena itu untuk mempelajari akurasi data graviti satelit, maka pada penelitian ini data satelit akan dibandingkan dengan pengukuran darat yang telah diakuisisi pada area hidrokarbon di Pulau Timor. Data graviti pengukuran darat telah diakuisisi sejak tahun 1948-1989 oleh beberapa perusahaan minyak, sedangkan graviti satelit yang digunakan berupa Geodetic Satelit (GeoSat) dan European Remote Sensing (ERS) tahun 2011 dengan resolusi 1.85 km/px. Perbedaan waktu pengukuran yang relative jauh dari kedua data tersebut, maka data graviti darat ditransformasikan ke model standar ellipsoid baru dari International Terrestrial Reference Frame ITRF (WGS84). Data bouger anomali dari kedua data tersebut menunjukkan pola yang relative sama, disisi utara didominasi oleh anomali yang tinggi (90 s/d 185 mGal), sedangkan sisi selatan anomali yang rendah (-75 s/d 90 mGal). Pada beberapa tempat yang diduga terdapat hidrokarbon; ditunjukkan oleh syncline, anticline, rembesan oil dan gas maka data graviti satelit dapat menunjukkan anomali yang kontras dibandingkan dengan graviti pengukuran didarat. Hal ini diakibatkan oleh resolusi data satelit yang bersifat regional dibandingkan dengan graviti darat

Gravity is the frontier method used for mapping the basements in hidrokarbon areas. In general, the method is measured from the ground surface using the Scintrex or LaCoste & Romberg instrument, but for a large area the ground gravity is highly cost and financial resources in data observation. In principle, the gravity method does not require direct contact with the ground that will be possible to measure from airborne and satellite. Therefore, we study the accuracy of satellite data that potential used for hidrokarbon investigation. In this research, we compare the satellite data with the ground surveys that have been acquired on the island of Timor. The Ground survey data was acquired from 1948-1989 by several oil companies, while the satellites used is Geodetic Satellites (GeoSat) and European Remote Sensing in 2011 with a resolution of 1.85 km/px. The Ground survey data is transformed into a new ellipsoid standard model from the International Terrestrial Reference Frame ITRF (WGS84), this is due to the difference in measurement time that is relatively far from the two data. Based on the results, it can be shown that the anomaly bouger from both data shows a very similar pattern, where the north side is dominated by high anomalies (90 to 185 mGal) while the southern side of the anomaly is low (-75 to 90 mGal). In some places that are suspected to have hidrokarbons; indicated by syncline, anticline, oil and gas seepage, satellite gravity data can show contrast anomalies compared to ground surveys. This is caused by satellite data resolution which is regional compared to ground survey.

Keywords

graviti satelit, cekungan minyak, graviti permukaan

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DOI: https://doi.org/10.22146/mgi.50782