Every Step of the Way: A Full Cycle Basin Modeling Case Study from Deepwater Sabah, Malaysia

Abstract

Northwest Borneo is an acknowledged petroleum province with numerous discovered oil and gas fields, notwithstanding the prolific Brunei Basin wedged between the Malaysian states of Sabah and Sarawak. As a results of continuous exploration since the late 1800's, hydrocarbon exploration in these areas have become more challenging, whereby efforts are now forced to focus towards the less explored frontier areas where water depths reach more than 1km. The full cycle of 1D, 2D and 3D basin modelling techniques has been employed to facilitate the investigation of possible petroleum systems elements development in the deepwater Sabah area. It presents the application of basin modeling methods during the different stages of exploration activities, i.e. before, during and after drilling. This includes the reconnaissance study stage where available data and maps provide the initial model framework, followed by model refinement with the availability of new maps and the improved understanding of sediment depositional concepts. The final calibrated 3D model is subsequently used to facilitate the delineation of potential hydrocarbon charge and entrapment areas, to postulate pre-drill predictions of temperature-depth profiles of selected prospects for well planning purposes and, most importantly, to perform the assessment of hydrocarbon charge, migration and accumulation risks of the area. Upon the completion of prospect drilling, the 3D model is subjected to a validation process by comparing the predicted versus actual well data. In deepwater Sabah, the source rock, reservoir and seal facies distributions pose as the main challenges in developing the petroleum system model. A good understanding of the sedimentary deposition mechanisms is crucial for the model building stage. Past publications have reported the terrigenous origin of the Sabah oils despite the deepwater environment, leading to the ambiguity in the prediction of source rock occurrence, while reservoirs are represented by the elusive turbidite sands. This is where the flexibility in basin modelling lends itself to the quick investigations of numerous petroleum systems elements scenario options. It also underscores the importance of keeping the model evergreen through continuous model updates with newly acquired information, thus leading to a better understanding of the petroleum systems elements, especially in challenging exploration areas such as this.

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