2D NMR and Restricted Diffusion Applications in Unconventional Reservoirs

PRESENTER: Lukasz Zielinski
Schlumberger

DATE: Wednesday, February 13th, 2013

TIME:12:00 AM
(Cocktails at 11:30)

PLACE: Fairmont Palliser
Alberta Room

Abstract:

: In conventional reservoirs, 2D-NMR fluids evaluation targets the free fluid part of the total porosity with the assumption that the bound fluid is irreducible water. As such, pulse sequences are designed for long relaxing fluids, and the interpretation commonly assumes free diffusion of hydrocarbon molecules in water-wet pores. This is clearly not appropriate for unconventional reservoirs such as shale gas and shale oil where the fast-relaxing fluids of interest reside in the bound fluid region.

We propose a revised 2D NMR model that includes the effects of geometric restriction on the hydrocarbon phase. The model takes rigorously into account both restricted diffusion and the shift in relaxation times due to increased surface interactions. In the presentation I will explain the basic principles underlying the model and show applications to both gas shale and oil shale reservoirs. 2D-NMR log examples will be compared with lab results, showing how adding diffusion and T1 information to standard T2 relaxation logs improves the understanding and evaluation of unconventional reservoirs.

Biography:

Lukasz Zielinski joined Schlumberger in 2003 as a research scientist at Schlumberger-Doll Research (SDR) in Ridgefield, CT. Subsequently, he worked for two years as Wireline field engineer in Mexico and then returned to SDR for five more years. His research there focused on developing new NMR applications for both petrophysics and engineering. Currently, he is Principal Physicist at Schlumberger’s Sugar Land, TX, engineering facility, where he leads the development of a next-generation LWD tool.