The Development Scheme in the Oilfield with Subtle Stratigraphic Trap, a Key to Extent Mature Field Life-span in Sangasanga Field, East Kalimantan, Indonesia

Abstract

The fluvio-deltaic sand of Balikpapan Group in Sangasanga field is one of the most prolific hydrocarbons bearing reservoirs in the East Kalimantan with a cumulative production of 359.25 MMSTB. Most of the past oil production is derived from the structural traps along the Sangasanga anticline axial. However, the likelihood to discover new pools in this area is immense over previously unprognoses stratigraphic trap in the structurally “non-attractive” area. This study was a part of a reservoir management effort aimed to extent the mature field life-span. The pilot projects is consist in two major stages, (1) is to execute “semi-exploratory” grid-based drilling program to appraise the subtle stratigraphic trap in the previously untapped area, followed by (2) integrated reservoir characterization scheme dedicated to every individual layer discovered in stage 1. The major task of the study is included paleomorphological reconstruction for each identified depositional elements, multi-attribute and neural network analysis of 3D seismic data, and 3D static and dynamic model building, constrained by various reservoir diagnostic data such as SCAL, PVT, IPR and phase envelope studies. This program has proven successful with the discovery of several new significant oil and gas producing sand pools. The paleomorphological based geological modelling offers a high improvement to both of thin layer identification and lateral sand net to gross prediction to the outer extent. This integrated study could be used to assist the interpretation of the geometry and dispersal pattern of the reservoir sand (e.g. distributary channel-fill, tidal channel-fill, crevasse splay, mouth-bar or other depositional elements) for the infill and out-step drilling planning purpose.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014