Unveiling the petroleum potential of one of the world’s last frontier petroleum provinces: the Bengal Fan, offshore Bangladesh

First Published: First Break, Vol. 42, May 2024 by Elisabeth Gillbard TGS

Elisabeth Gillbard, TGS, presents high-resolution seismic imaging illustrating the extensive
petroleum potential of the Bengal Fan, from shelf and slope to the deep water domain.

Abstract

The Bay of Bengal contains the world’s largest deep marine fan and yet remains almost entirely unexplored for petroleum. Evaluation of more than 12,600 line km of 2D seismic, gravity and magnetics data acquired by TGS and their partners SLB in 2023 (Figure 1), alongside historic well data, has provided a regional framework for understanding the evolution of the whole geological history of the basin and insight into the extensive petroleum potential of this highly frontier region. In this paper, we will present high-resolution seismic imaging, characterising the facies and reservoir architecture within the fan and illustrating the extensive petroleum potential of the Bengal Fan, from shelf and slope to the deep water domain.

Introduction

The discovery of several large gas fields within the Bengal Fan between 2004 and 2016 (e.g., Shwe, Shwe-Phyu, Mya, Thalin gas fields) has proven the vast potential within this highly active petroleum system. In March 2024 the Government of the People’s Republic of Bangladesh and The Bangladesh Oil, Gas and Mineral Corporation (Petrobangla) announced an offshore bidding round for oil and gas exploration, the first since 2012. This highly anticipated licensing round offers 24 blocks extending from the shelf and slope to the deep water, a significant area of which is covered by 2D seismic data, which is the subject of this paper (Figure 1).

The 2D seismic data spanning the shelf, slope and deep water offshore Bangladesh were acquired with long offsets (10 km) and have been processed with modern preprocessing workflows (including deghosting, surface-related multiple-elimination (SRME), shallow-water demultiple) with particular emphasis on the shallow-water area on the platform. For the velocity model building, an integrated tomography and full-waveform inversion (FWI) workflow was implemented alongside geological interpretation to refine and improve the imaging of discrete features such as channel bodies and gas pockets and to constrain anisotropy.

Read the full article here.