Utilization of Bathymetry Data and Backscatter in Geohazard Identification Process at Drilling Stage

¹ Geomatics Engineering Department, Institut Teknologi Sepuluh Nopember, 60111 Surabaya, Indonesia
² Pertamina Hulu Energi Offshore Southeast Sumatera (PHE OSES), Indonesia

^* Corresponding author: irena@its.ac.id

Abstract

The Indonesian people’s need for energy supply has increased in recent years, and hydrocarbon production has been intensified to meet these needs. Exploration on land or at sea is not an obstacle to obtaining the hydrocarbons sought; both are subject to the presence of geohazards. This study was conducted to determine the seabed features conditions that potentially become geohazards and to provide recommendations for the jack-up rig line selection. The purpose of this research is, in line with the Sustainable Development Goals, to prevent and significantly reduce marine pollution of all kinds. The acoustic instruments used were Single Beam Echosounder, Multibeam Echosounder, and Side Scan Sonar. The seabed depth varied from 22-23.9 m with a nearly flat morphology and local slope of 0°-2°. The main features identified include exposed pipes, jack-up rig footprints, a spud-can drag scar, and a seabed scar. The sediment distribution showed a predominance of soft-textured clay. Using the weighting combined with the slope value and the presence of geohazard potential features, it is recommended that the jack-up rig enter through the Northeast-East side of the platform to improve operational safety and reduce potential accidents such as exposed pipelines and subsea cables and clusters of seabed scars.