Deep geological structure of An Chau trough base on new study data

Abstract

An Chau trough with an area of ​​​​about 10,000 km2 located in the Northeast of Vietnam is the southwest tail of the Mesozoic Thap Van Dai Son basin and has a complex geological structure. The geological structure of An Chau trough has been studied since the 70s of the last century, however, previous studies were mainly surface geological studies. Deep structure studies only based on measurement gravity data at the scale of 1/200.000 with outdated machinery, equipment and processing technology. With the goal of re-searching, investigating and surveying oil and gas resources, from 2013 to 2017, Vietnam National Oil and Gas Group has deployed measuring over 9,000 km of the Airbone high-resolution Mag-Gravity survey with the resolution of measuring points on the measure-line from 6 m to 7 m/point, more than 450 ground gravimetric points and acquiring over 1,000 km 2D seismic survey. All magnetic-gravity and seismic data collected in the field is then processed at processing centers with modern technology such as Sander Geophysics - Canada, Institute of Geophysics - VAST, CGG Veritas Singapore. The results of interpretation and integration of these new documents together with the previous geological documents have initially allowed to identify and construct a deep geological model of An Chau trough. The results of this study will help clarify the history of geological development of the study area based on evidences that can only be observed on seismic data. Inaddition, these results also help to make orientation for explorating mineral resources in general and oil and gas resources in particular.