Monday, March 14, 2016

Motivation

"you can do everything if your motivation is to help people." (Dalai Llama , 2013)




Wednesday, March 2, 2016

Nuclear Magnetic Resonance (NMR) Wireline Logging

Nuclear Magnetic Resonance (NMR) tools offer a new and advance physical principal. It refers to the response of atomic nuclei to external magnetic field. Hydrogen proton behaves like a small bar magnet with magnetic moment and angular momentum (spin) which can be aligned and measure its frequency and amplitude signal in the presence of external static field. The signal is proportional to amount of hydrogen in the sensitive volume which can then be calibrated for rock porosity.

NMR logs differ from density and resistivity logs because the NMR measurements provide information only on saturating fluids and are generally lithology independent. The effect of lithology, hydrocarbon, and formation heterogeneity increases the uncertainty in density derived porosities. The technique of using combined NMR and bulk density data  significantly reduces uncertainty in derived logging parameters through elimination of the neutron log. This removes the need to characterize and correcting work for flushed zone fluid densities. (Hamada, 2008).

Reference: Hamada, G.M., Abushanab. 2008. Better Porosity Estimate of Gas Sandstone Reservoirs Using Density and NMR Logging Data. Emirates Journal for Engineering Research.



Tuesday, March 1, 2016

Transgressive Phase

The most important product of the transgressive phase is the deposition of the regional seal. This seal is most effective in certain basin where it is not offset by later faulting. In certain basin, migration related to later faulting has disrupted the seal.

Sunday, February 28, 2016

Tectonic History and Stratigraphic Framework In Biliton Basin

Five major tectonic events effected the structural development of the Biliton Basin. In order from the oldest to most recent: (Atkinson et al, 2004).


  • Late Cretaceous to Early Eocene (100-56 Ma)
 Regional metamorphism generated by subduction and evolution of the Meratus arc. Deformation, uplift, erosion and cooling occured in the Paleocene.


  • Eocene (50-40 Ma)
Indian plate collides with Eurasian coupled with change in relative plate motions of the Pacific Plate. This gives rise to dextral wrenching of the southern margin of the Sunda craton.


  • Mid Oligocene (34-30 Ma)
South China Sea rifting and accretion in Northern Kalimantan. The New Guinea margin of the Australian plate collides with several arc complexes.


  • Mid Miocene (17-10 Ma)
South China Sea rifting ceases with the collision of continental derived Gondwana fragments (Northern Australia/ Western Papua) against the eastern Sunda Margin.


  • Late Miocene (7-5 Ma)
Northwest Australia collides with the Sunda Craton with development of the Sunda Trench and Indonesian Arc.


reference: Atkinson, C., Renolds, M., Clarke, A., Sampurno, 2004, Why Look In Deepwater When Elephants Prefer The Shallows, The Biliton Basin Revisited, Indonesia Petroleum Association Symposium.

Wednesday, February 3, 2016

Channel-lobe complex

The channel-lobe complex as the dominant depositional system indicates a dynamic fluidized current as the agent of deposition. The presence of relatively parallel layers suggests deposition by turbulent flows. The ability of the current to transport abundant sediment that create a very broad channel-lobe system (up to several kilometers) indicates that this current is high density and possibly high velocity.

Tuesday, January 19, 2016

Basin Thermal History

The thermal history of sedimentary basins is of great interest to petroleum geologists because the hydrocarbon maturation process is controlled primarily by the temperature the source rock has experienced since its deposition.

Researchers mathematically constrain the sedimentary thermal history by building a physical model that simulates the process whereby the sediments become gradually heated by geothermal heat as they are deposited, buried and compacted over time. The researcher must have detailed knowledge of the sedimentation history, the thermal properties of the sediments, and the regional geothermal heat flux in order to reconustruct the thermal history of the basin of interest.

To determine maturity of potential source-rock intervals, 1-D, 2-D or 3-D models are constructed and calibrated. To calibrate these models, corrected bottom-hole temperatures or sediment surface heat flow measurements are needed.