John Warren
Hello
I am an expert in evaporites at SaltWork Consultancy in Adelaide. I divide my time between the coastal region of Adelaide and out-of-town consultancy. With over 30 years of experience, I have consulted for the petroleum and minerals industries and have trained numerous individuals who are now working in these fields. I hold a doctorate from Flinders University of South Australia and am also a graduate of the University of Adelaide.
SaltWork Consultants
Senior executive: 2012 - present
I am a senior executive at SaltWork Consultancy, focusing on training and mentoring in the various but interrelated technical aspects of saline geosystems. I also work as an on-site consultant, dealing directly with various evaporites, saline geosystems, reservoirs, and mine geology.
The home base for SaltWork is Kingston Park, where the sunsets can be spectacular.
Chulalongkorn University
Professor, Petroleum Geoscience
2008-2021
Most of my time at Chula was spent in postgraduate teaching or research in the rock-based analysis of well-logs and seismic, rock property geology, and applied aspects of modern and ancient carbonate and evaporite geosystems.
The rest of my time in Thailand was spent enjoying the traffic in Bangkok.
Sultan Qaboos University, Oman
Professor, Shell Chair
2006-2008
I spent a delightful two years helping design a Petroleum Geology program for the university. In my spare time, I enjoyed experiencing Oman's geology and rich culture.
Earlier in my career
1980-2005
Before 2006, I was a contract Professor at Universiti Brunei Darussalam. In the mid-1990s, in a former life as a full-time bureaucrat, I was Professor of Petroleum Geology and Director of the Key Centre for Resource Exploration in the School of Applied Geology at Curtin University in Perth, Western Australia. In the 1980s and early 90s, I was a faculty member of the University of Texas at Austin and the National Centre of Petroleum Geology and Geophysics in Adelaide.
Downtown Perth, Australia
Technical expertise
Interwoven associations of fluid crossflows, salt alteration, and carbonate porosity evolution characterise saline hydrocarbon and metal systems. These subsurface overprints are generally less intense in siliciclastic sediments. Still, productive geometries in a sandstone reservoir can be complicated, especially if they are tied to the coming and going of saline cements. Much reservoir or ore quality in these systems is not a response to depositional geometries but to the timing of multistage diagenetic overprints.
Skills
Rock properties
Saline hydrocarbon and metal systems are characterised by interwoven associations of fluid crossflows, salt alteration, and carbonate porosity evolution. These subsurface overprints are generally less intense in siliciclastic sediments. Still, productive geometries in a sandstone reservoir can be complicated, especially if they are tied to the coming and going of saline cements.
Much reservoir or ore quality in these systems is not a response to depositional geometries but to the timing of multistage diagenetic overprints. Understanding this complexity requires more than a basic knowledge of the depositional setting, sequence stratigraphy, or primary geometries.
Wireline
We mainly deal with mono- or bimineralic intervals in a sealing salt unit, so interpreting wireline response in evaporite seals is relatively straightforward. A porosity effect is rare in the log signatures of salt masses, but analysing the impact of the evolving porosities in the associated carbonate reservoir is much less straightforward. Total gamma values are often poor differentiators of rock type in saline geosystems.
Interpreting a density, neutron, or sonic log reliably for porosity (storage) prediction, understanding the volumetrics of fluid distribution responses in electric logs, and reliably applying Archies Law requires an understanding of the interwoven associations of fluid crossflows, salt alteration, and carbonate porosity evolution.
Seismic
The unique nature of thick evaporite deposits, characterised by a set of drawdown processes, necessitates hydrology without any surface connection to the ocean. This requirement alters many of the fundamental assumptions associated with seismic stratigraphic interpretation.
Once these salt masses are deposited in a tectonically defined position within the Earth, they can flow and create a predictable series of evolving stratigraphic and structural traps.
A crucial skill in this context is understanding aquifer evolution over time, particularly as sediment exists in the subsurface and its structural characteristics change.
Fear of large cats
In the photo, notice that I am not positioned near the business end of this beautiful two-year-old male tiger.
"Fear is excitement without breath."
Robert Heller
Trainer
Evaporite systems
Download a course catalog
All course modules are designed to help participants understand how variations in subsurface salts, carbonates, and brines serve as valuable predictive tools that, when applied correctly, enhance exploration and development efforts.
Carbonate Reservoir Systems