Vahid Bolandi

Petrophysics

Pasargad Energy Development Company (PEDC)

Vahid Bolandi is a petrophysicist and petroleum geologist specializing in advanced well-log interpretation, reservoir characterization, and geochemical analysis. He holds an M.Sc. in Petroleum Geology from Shahid Chamran University of Ahvaz, graduating with distinction, and a B.Sc. in Geology from the University of Tabriz.


With more than a decade of professional experience, Vahid has worked across major Iranian oilfields, conducting NMR interpretation, DSI and dipole sonic analysis, cement evaluation (CBL–VDL, SBT), PLT, Pressure analysis, and full-set petrophysical evaluation. He is proficient in industry software such as Geolog, Techlog, Kappa Emeraude, IP, and Petrel.


Vahid has published multiple peer-reviewed articles in international journals, focusing on NMR-based reservoir characterization, permeability estimation, TOC prediction, and machine-learning applications in petrophysics. He also serves as a reviewer for the Journal of Petroleum Science and Engineering.


In addition to industry work, he has delivered several specialized training courses , covering NMR interpretation, conventional logging, and PLT theory. His interests include advanced petrophysics, reservoir modeling, production logging, geomechanics, and data-driven subsurface analysis.

Participates in

TECHNICAL PROGRAMME | Primary Energy Supply

Advances in Geoscience
Forum 05 | Digital Poster Plaza 1
30
April
10:00 12:00
UTC+3
Accurate permeability estimation is vital step to reservoir analysis and management. However, it is very challenging in carbonate reservoirs because of their intrinsic heterogeneity, dual porosity systems, and complex pore geometries. The conventional approaches, including empirical porosity–permeability transforms or log-based correlations, typically do not describe the degree of variability in flow units. By advent of advanced Nuclear Magnetic Resonance (NMR) logs, valuable pore-size distribution data provided by means of transverse relaxation times (T2), and permeability is usually determined from models such as the Schlumberger-Doll Research (SDR) and Timur–Coates equations. Despite their proven effectiveness, NMR logs are costly and not always available. In contrast, Dipole Sonic Imager (DSI) tools are routinely logged in comparison with NMR log data, generating monopole, dipole, and Stoneley waveform data. Although Stoneley slowness and attenuation have been studied as permeability indicators, the richness of data within the full DSI waveform has not yet been tapped. In this paper, we propose a new signal-derived property for permeability prediction from the Hilbert envelope under-curve area (UEA) of DSI waveforms.

The workflow includes:


  1. DSI monopole, dipole, and Stoneley waveforms extraction; 

  2. Hilbert transform envelope calculation for each waveform; 

  3. Computation of UEA as a proxy of waveform energy dissipation;

  4. Extraction of logarithmic mean relaxation time (T2-lm) from NMR logs; (5) scaling of UEA versus T2-lm to derive a semi–T2-lm hybrid parameter; and (6) application of a modified SDR equation to calculate permeability values.


Application to a carbonate oil reservoir demonstrates that the above-described methodology correlates core permeability higher than NMR-SDR prediction. This hybrid approach bridges acoustic and NMR physics and demonstrates the untapped potential of DSI waveform attributes for petrophysical applications in wells where NMR measurements are unavailable.

Keywords: Permeability, Carbonate reservoir, Dipole Sonic Imager (DSI), Acoustic Waveform, Hilbert transform, Envelope under-curve area (UEA), NMR T2-lm, SDR model.

Co-author/s:

D. Hasanvand, Pasargad Energy Development Company (PEDC).

A. Heravi, Pasargad Energy Development Company (PEDC).
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