Subsurface Modeling using Gravity and TDEM in Jiken, Blora Regency
Eko Januari Wahyudi, Warsa, Waskito Aji
Institut Teknologi Bandung
Abstract
Gravity survey using Scintrex CG5 relative gravimeter were conducted on proposed location for CO2 injection. Survey area covers 5x5 km2 surounding Jepon well that proposed as CO2 injection well. Gravity data were obtained at 402 stations on regular grid with 250 m interval spacing. The gravity survey is aimed at providing information of baseline density structure for Carbon Capture and Storage (CCS) pilot project in that area. In this work, we use Second Vertical Derivatives (SVD) of gravity data and describe the design of gravity inverse modeling using iterative calculation. Iterative calculation using gravity data aims to provide interface between density contrasts in the subsurface. Based on our study of gravity data in Gundih field, we can show correlation of SVD results with reverse fault as interpreted with seismic data. We also provide estimation of top structure in study area for Ngrayong Formation and Tawun Formation. At the end of this study, we integrate the interpretation using inverse model of TDEM data.
Keywords: inversion, gravity, TDEM
Topic: Sub surface modelling and computation