ANALISIS STRUKTUR GEOLOGI UNTUK PENENTUAN PERANGKAP HIDROKARBON HORISON ZUBAIR-RATAWI BERDASARKAN DATA SEISMIK 2-D DI DAERAH BASRA, IRAK SELATAN

Abstract

Regionaly, Iraq is a part of Arabian concavity, located in Northwest Arabian Peninsula which popular as the largest oil producer in the world. In current physiographic location, Arabian concavity is foreland concavity located between Arabian Shield in Arabian northwest Peninsula and Zagros Orogen with the direction of northwest to southeast in Iraq Southwest. The Arabian concavity divided into Zagros Foldbelt, Mesopotamia Foredeep, and Arabian plateform. Geophysical data, especially seismic reflective are 13 line, which has used in the research. Research was more emphasize on assessment process and more examine the technical stages, so that research uses more hardcopy data. It should note that regional tectonically pattern, which used to predict pattern and direction of local structure distribution based on existing structure complexity. As for the research aim is to identify the bellow surface geology in Basra area, South Iraq, includes function structure as oil trap and ground gaseous through the interpretation, also to identify the structure configuration of formation potential as oil and ground gaseous reservoir, especially Zubair and Ratawi Formation. In final exam the writer use 2 metode, they are descriptive metode and analysis metode. Analysis metode using TDC (Time Depth Curve) and calculation of RMS (Root Mean Square). The geology structure formed in Basra area, especially Zubair and Ratawi horizon consists of anticline, stike-slip fault, and normal fault. Zubair and Ratawi Horizon formed during Mesozoic term. Based on contour map of time structure, the common research area has joint structure and stike-slip fault with direction of northwest – east west, and down Cesar with northwest - east west as it orientation. Strike-slip fault in research area has dextral movement and flow structure seem on seismic section is positive flower structure, so that it likely that research is a part of regional restraining bend. Hydrocarbon trap formed on Zubair and Ratawi formation that is incorporate of anticline with stike-slip fault with direction of northwest – eastwest. Sort of anticline that become hydrocarbon trap are asymmetric 4 direction joint. The total accumulation cover of Zubair formation hydrocarbon in Basra, that is 27,323,82 acre, while the Ratawi Formation is 32,219,12 acre.