B.A.S.S. DIVISION
Division Profile

Our meeting schedule is to have at least one informal brown-bag talk every month, except during the summer. Talks normally start at 12:00 noon and finish before 1:00 p.m. Each talk consists of a 40 minute technical presentation followed by a 10 minute question period. 

Involvement of our CSPG members is the key to the success of the Division. Individuals are encouraged to take part in all activities. Service companies are also encouraged to attend Division meetings and be involved in all Division activities.
Basin Analysis and Sequence Stratigraphy Technical Division Talks are free to CSPG members. Please bring your lunch. For further information about the division, joining our mailing list, a list of upcoming talks, or if you wish to present a talk or lead a field trip, please contact either Steve Donaldson at (403) 808-8641 or Mark Caplan at (403) 975-7701. 

BASS would like to thank AGAT Laboratories for supplying refreshments.
 

Upcoming Division Talk

Montney – From the Rock to the Log II

SPEAKER: Godfried Wasser, Dana Kinnaird, and Shpetim Cobaj | Eucalyptus Consulting Inc.

LOCATION: geoLOGIC Room (2nd Floor), Aquitaine Tower, 540-5th Avenue S.W., Calgary
DATE: 12:00 Noon Monday, October 30th, 2017

Abstract
Our work method follows our motto: From the Rock to the Log. We examine core and cuttings to learn what a reservoir is about. What makes it tick? Then we extrapolate our learnings using wireline logs.

We presented Phase 1 of our Montney Evaluation at the 2017 CSPG Core Conference.  Following the stratigraphic nomenclature proposed by Graham Davis and Tom Moslow in 1997, the Montney of Alberta’s Deep Basin was subdivided into 6 unconformity bounded cycles (Montney A through D; we expanded with E and F) and many sub cycles. Also, a Middle Montney interval was recognized.

Core work indicated that the Montney comprises deep water shales with abundant quartz (30-35%) and dolomite (20-30%); minor to no bioturbation and 30% average clay content. They are also associated deep water turbidite deposits comprising very fine siltstones (30-50 microns); with moderate clay content (Vclay 16-29%), quartz (20-35%), dolomites (20-40%), and porosities ranging from 3 to 13%. Although very fine grained, the turbidites have conventional, low permeability reservoir characteristics. These deposits occur together with interbedded very fine-grained siltstones and shales of similar composition as described above. They contain little bioturbation but have common wavy laminations and small-scale wave ripples. We interpreted the depositional environment as proximal shelf to transition zone.

A second group of facies range from deep water shales to shallow marine deposits and carbonate rich soils. The soils occur as a dolomitic siltstone facies characterized by intense chaotic structures often resulting from synsedimentary deformation. Thin section analysis showed the presence of some early expansive anhydrite cementation replaced by calcite, and the abundant occurrence of dolomite sedimentary rock fragments. The latter commonly recrystallized into blocky dolomite cement (22-30%). Porosities are often 12 to 22% with particle sizes typically being coarse silt. 

Above these soil deposits are some coquina debris beds also rich in primary dolomite fragments that are often recrystallized into blocky dolomite cement with leached vuggy porosity. The porosity of the coquina can be up to 25% and permeabilities reach the darcy level. We interpreted these coquina beds as berm like deposits washed during storm onto the soils. The soils grade down into highly porous, medium to coarse siltstones comprised of quartz with dolomite (particles and replacement cement) and some calcite cement interbedded with shale. The clay content of both the shale and siltstone was found to be 30 to 9%. Sedimentary structures are mostly small-scale ripples and wave ripples with some synsedimentary deformation as well as some indications of tidal influences. It is imported to distinguish between clay volume and the shale/rock ratio. In this interbedded facies, the latter ranges from 20 to 75%. We interpret these deposits as tidally influenced mudflats that grade down into the aforementioned deep water shales.  

Intercalated with the mudflat sediments is a facies that has thin to massive bedded siltstones with sharp contacts and some Bouma-like successions of sedimentary structures. Top bed contacts are often gradational into shale. Bed thickness varies from 20cm to 2 meters. Vclay is typically 5% or less in the siltstones and up to 35% in the shales. Porosities are as high as 26% and permeabilities may be up to 10s of millidarcies. In some rare cases, the ‘siltstone’ beds increase in grain size to very fine sand (60-70 microns) and permeability as high as a darcy.  We interpret this facies as shallow marine storm beds. 

The subsequent petrography and petrophysics focused on defining algorithms of clay volume (Vclay) rather than the more traditional shale volume (Vsh), grain size distribution, porosity, formation water distribution, etc. Wireline logs of close to 1400 wells were normalized and the algorithms derived from the rock work were applied during petrophysical analysis to determine porosity, Vclay, water saturation and OOIP distributions within the Montney overall and its subdivisions. 

The results were used to generate a wide variety of maps for the Montney and its cycles throughout the study area (Twp 70 to 80, Rge 19W5 to 13W6). Several clay volume, porosity, water saturation and OOIP distribution trends were identified. 

At the presentation, we will also introduce our Detailed Horizontal Well Reviews which integrate our petrophysical knowledge, rock data such as cuttings, mapping combined with MWD data to place the wellbore more precisely in the producing zone, as well as calculate porosity, grain size, composition, water saturation and brittleness along the wellbore. This should help with completion planning; remedial work; explanation of production performance. This method is a very affordable alternative to running a full wireline logging suite to measure a well’s potential.

The Montney in the study area comprises mostly low permeability conventional reservoirs that produce from pool to pool a variety of hydrocarbons ranging from condensate and gas liquids to light oil. Some reservoirs also produce large volumes of water. Eucalyptus has just launched a regional Montney Phase II evaluation which covers Twp 58 to 69, Rge 16W5 to the Alberta Border.

Biography
Godfried Wasser studied at the State University of Utrecht in the Netherlands. He has a B.Sc. in geology and an M.Sc. in Sedimentology. He has worked in the Canadian oil patch since 1979 for companies such a PanCanadian Petroleum (now Encana), Canadian Natural Resources, PennWest Exploration and as owner/president of Eucalyptus Consulting Inc. He specializes in clastic reservoir geology working both on the pool level and on regional evaluations. His working experience ranges from conventional oil and gas, heavy oil, secondary and enhanced recovery and on low permeability (unconventional) reservoirs such as the Viking in Saskatchewan and Alberta, the Nikanassin (Minnes Gp) in N.E. B.C.; Cardium oil and gas in the Deep Basin and south of Keystone as well as the Spearfish (Lower Amaranth) in Manitoba.  Godfried also has worked in Indonesia and taught various courses through the CSPG ranging from Belly River field school to Reservoir Geology in Sandstones. He has also taught reservoir geology internationally. 
Godfried has won a CSPG Tracks Award and several service awards. He has published on various topics at conferences, the CSPG Core Conference and various CSPG Divisions. Currently Godfried is President of Eucalyptus Consulting which does reservoir geological evaluations integrating geology, sedimentology, petrography, petrophysics, reservoir engineering and operations geology. Eucalyptus is currently working for small clients and on Phase II of a multi-client Montney regional reservoir geological evaluation. The company’s motto is: “From the Rock to the Log”
 

Past Presentations

April 27th, 2016
Sequence Stratigraphic Analysis of Mixed,
Reefal 
Carbonate and Siliciclastic Systems
Ashton Embry
Download Slides (.PDF) 
March 11th, 2015
Geological Risk
Kirk Osadetz
Download Slides (.PDF) 
March 14th, 2014
The Future of Gas Hyrdates as a Fuel 
Kirk Osadetz 
Download Slides (.PDF)  


 February 11th, 2014

Alberta Hydrocarbon - Bearing Shales & Siltstones
Steve Lyster & Dean Rokosh
Download Slides (.PDF)
 
Division Information

Our meeting schedule is to have at least one informal brown-bag talk every month, except during the summer. Talks normally start at 12:00 noon and finish before 1:00 p.m. Each talk consists of a 40 minute technical presentation followed by a 10 minute question period. 

Involvement of our CSPG members is the key to the success of the Division. Individuals are encouraged to take part in all activities. Service companies are also encouraged to attend Division meetings and be involved in all Division activities.

Basin Analysis and Sequence Stratigraphy Technical Division Talks are free. Please bring your lunch. For further information about the division, joining our mailing list, a list of upcoming talks, or if you wish to present a talk or lead a field trip, please contact either Steve Donaldson at (403) 808-8641 or Mark Caplan at (403) 975-7701. 

Talk space generously provided by: 

March 14th, 2014
The Future of Gas Hyrdates as a Fuel
Krik Osadetz
February 11th, 2014
Alberta Hydrocarbon - Bearing Shales & Siltstones
Steve Lyster & Dean Rokosh
Tal