Cronkwright, David (University of Calgary) | Ghanizadeh, Amin (University of Calgary) | DeBuhr, Chris (University of Calgary) | Song, Chengyao (University of Calgary) | Deglint, Hanford (University of Calgary) | Clarkson, Chris (University of Calgary) | Ardakani, Omid (Geological Survey of Canada)
This paper was prepared for presentation at the Unconventional Resources Technology Conference held in Denver, Colorado, USA, 22-24 July 2019. The URTeC Technical Program Committee accepted this presentation on the basis of information contained in an abstract submitted by the author(s). The contents of this paper have not been reviewed by URTeC and URTeC does not warrant the accuracy, reliability, or timeliness of any information herein. All information is the responsibility of, and, is subject to corrections by the author(s). Any person or entity that relies on any information obtained from this paper does so at their own risk. The information herein does not necessarily reflect any position of URTeC. Any reproduction, distribution, or storage of any part of this paper by anyone other than the author without the written consent of URTeC is prohibited. Abstract Fluid distribution and fluid-rock interactions within the nano-/macro-porous pore network of tight oil reservoirs will affect both primary and enhanced oil recovery (EOR) processes. Focusing on selected samples obtained from the liquids-rich reservoirs within the Montney Formation (Canada), the primary objective of this work is to evaluate the impact of mineralogical composition on micro-scale fluid distribution at different saturation states: 1) "partially-preserved" and 2) after a series of core-flooding experiments using reservoir fluids (oil, brine) under "in-situ" stress conditions. Small rock chips (cm-sized), sub-sampled from "partially-preserved" (using dry ice) core plugs, were cryogenically frozen and analyzed using an environmental field emission scanning electron microscope (E-FESEM) equipped with X-ray mapping capability (EDS).
Euzen, Tristan (IFP Technologies (Canada) Inc.) | Watson, Neil (Enlighten Geoscience Ltd.) | Chatellier, Jean-Yves (Tecto-Sedi Integrated Inc.) | Mort, Andy (Geological Survey of Canada) | Mangenot, Xavier (Caltech)
With the development of unconventional resources, the large number and high density of well data in the deep/distal part of sedimentary basins offer new avenues for petroleum system analysis. Gas geochemistry is a widespread and inexpensive data that can provide invaluable information to better understand unconventional plays. This paper illustrates the use of early production gas composition as a proxy for in-situ hydrocarbon phase distribution in the Montney play of westernmost Alberta and northeastern British Colombia. We demonstrate that a careful stratigraphic allocation of the landing zone of horizontal wells is a key step to a meaningful interpretation and mapping of gas geochemical data. The regional mapping of the dryness of early production gas from the Montney formation clearly delineate thermal maturity windows that are consistent with available carbon isotopic data from produced and mud gas. Integrating this mapping with pressure and temperature data also highlights gas migration fairways that are likely influenced by major structural elements and compartmentalization of the basin. In the wet gas window, reported condensate-gas ratios show that the liquid recovery from multi-stage fractured horizontal wells is highly variable and strongly influenced by variations in reservoir quality and stimulation design. Understanding in-situ fluid distribution can help narrow down the number of variables and identifying key controls on liquid recovery. Several examples combining produced and mud gas data illustrate the use of geochemistry to better constrain geological and operational controls on productivity and liquids recovery in the Montney play.
With the rapid development of unconventional resources, a wealth of new data has been released from historically undrilled or poorly documented portions of sedimentary basins. The large number and high density of well data over extended areas of deep/distal parts of these basins offer invaluable information and new perspectives for petroleum system analysis. In the Montney play of Western Canada, the distal unconventional part of the basin covers an area of approximately 65,000 square kilometers and has been penetrated by over 7,000 horizontal wells. Due to sustained low gas price in North America over the past decade, most of the industry activity has been focused on the liquids-rich gas and light oil fairways of this resource play. Production data show that although a broad liquids-rich fairway can be defined at the basin scale, local variations of fluid distribution and reservoir quality strongly affect the liquid recovery from horizontal wells. The geochemical compositions of both produced gas and mud gas provide a powerful tool to investigate those variations, their geological controls and their impact on well performance. While this paper focuses on the fluid distribution, numerous studies have documented the influence of reservoir quality on the liquid recovery in the Montney play (Chatellier and Perez, 2016; Kato et al., 2018; Akihisia et al., 2018; Iwuoha et al., 2018).
Nakatsukasa, Masashi (Japan Oil, Gas, and Metals National Corporation) | Ban, Hideaki (Japan Oil, Gas, and Metals National Corporation) | Kato, Ayato (Japan Oil, Gas, and Metals National Corporation) | Shimoda, Naoyuki (Japan Oil, Gas, and Metals National Corporation) | White, Don (Geological Survey of Canada) | Nickel, Erik (Petroleum Technology Research Centre)
We analyzed the ACROSS - DAS VSP baseline data with offsets to ∼770 m acquired in the Aquistore CO2 storage site in Canada to demonstrate its potential for permanent reservoir monitoring (PRM). The data was recorded for 8 hours. Stacking data improved S/N in accordance with the square root of the stacking number. The data quality was comparable with dynamite – DAS VSP data in the same field. Reservoir reflectors at ∼3250 m depth between the source and the DAS well were imaged by applying reverse time migration (RTM). The resulting image has high correlation with a synthetic seismogram at the injection well ∼150 m away from the DAS well. These results demonstrate the high potential of ACROSS – DAS combination in permanent reservoir monitoring to continuously monitor small changes in seismic properties in the reservoir.
Presentation Date: Monday, October 15, 2018
Start Time: 1:50:00 PM
Location: 204C (Anaheim Convention Center)
Presentation Type: Oral
We present the results of two surveys showing that shear wave seismic reflection can image a sewage tunnel buried at 17 m in marine clay, and coalmine tunnels close to the bedrock surface beneath about 30 m of recent fluvial sediments. The SH shear wave seismic reflection method provides outstanding diffraction features only visible with transverse horizontal sources and recording capacities (H2,H2). These data were acquired using an impulsive or a broader band vibrating source coupled with a landstreamer. The use of SV vertical shear and PP compressive waves extracted from data acquired with vertical vibrating source and receiver mode (V,V) did not give satisfying results for locating tunnels in these environments.
Presentation Date: Thursday, October 18, 2018
Start Time: 8:30:00 AM
Location: 204A (Anaheim Convention Center)
Presentation Type: Oral
Knapp, Levi J. (Japan Oil, Gas and Metals National Corporation (JOGMEC)) | Nanjo, Takashi (Japan Oil, Gas and Metals National Corporation (JOGMEC)) | Uchida, Shinnosuke (Japan Oil, Gas and Metals National Corporation (JOGMEC)) | Haeri-Ardakani, Omid (Geological Survey of Canada) | Sanei, Hamed (Aarhus University)
This paper was selected for presentation by a JFES program committee following review of an abstract submitted by the author(s). The complexities of these relationships are not well defined however and may be influenced by a variety of factors including organic matter richness, thermal maturity, kerogen type, original kerogen structure and primary organic-hosted porosity, compositional fractionation, interaction with mineral catalysts, compaction, and occlusion by generated products such as solid bitumen. This abstract presents preliminary results from the first of three wells analyzed in the play fairway of the Duvernay Formation of western Canada - a prolific source rock and rising star as an unconventional reservoir. Distinct porosity morphology groups have been observed in SEM and ongoing work has shown that organic matter porosity morphology may be influenced by organic matter composition and degree of isolation from nearby macerals. Integration of porosity calculated from image analysis of focused ion beam scanning electron microscopy (FIB-SEM) images with results from nuclear magnetic resonance (NMR), mercury injection capillary pressure (MICP), and helium porosimetry has demonstrated that a significant portion of the porosity is below typical SEM imaging resolution and that even methods such as He-porosimetry are challenged to access nanometer-scale pores. Variations in sample preparation and analysis procedures can significantly alter porosity results.
Kurz, Bethany A. (Energy & Environmental Research Center) | Sorensen, James A. (Energy & Environmental Research Center) | Hawthorne, Steven B. (Energy & Environmental Research Center) | Smith, Steven (Energy & Environmental Research Center) | Sanei, Hamed (Aarhus University) | Ardakani, Omid (Geological Survey of Canada) | Walls, Joel D. (Ingrain - Halliburton) | Jin, Lu (Energy & Environmental Research Center) | Butler, Shane (Energy & Environmental Research Center) | Beddoe, Christopher (Energy & Environmental Research Center) | Mibeck, Blaise (Energy & Environmental Research Center)
Kerogen is functionally defined as the portion of OM in a sample that is insoluble using organic solvents (Tissot and Welte, 1984). Primary kerogen consists of OM deposited in the sedimentary basins from which hydrocarbons form during the catagenesis process in the sedimentary rocks (Vandenbroucke and Largeau, 2007). Depending on the depositional environment of the rock, kerogens can be composed of algae, spores, pollen, and woody or herbaceous material (Tissot and Welte, 1984). Solid bitumen is also an important component of kerogen in organic-rich mudrocks (Sanei and others, 2015). Solid bitumen is generally defined as a secondary kerogen formed because of cracking of retained hydrocarbon (Jacob, 1984; Curiale, 1986, Sanei and others, 2015). Curiale (1986) also identified a preoil bitumen formed from the earlygeneration (immature) products of rich source rocks, probably extruded as very viscous fluids, which migrated minimal distances to fractures. Some components of solid bitumen, depending on their composition, are generally considered extractable using organic solvents, although at later stages of thermal maturity, solid bitumen becomes a carbon-rich, unextractable solid referred to as pyrobitumen (Jacob, 1984; Curiale, 1986; Sanei and others, 2015).
This paper was prepared for presentation at the Unconventional Resources Technology Conference held in Houston, Texas, USA, 23-25 July 2018. The contents of this paper have not been reviewed by URTeC and URTeC does not warrant the accuracy, reliability, or timeliness of any information herein. All information is the responsibility of, and, is subject to corrections by the author(s). Any person or entity that relies on any information obtained from this paper does so at their own risk. The information herein does not necessarily reflect any position of URTeC.
Ghanizadeh, A. (University of Calgary) | Clarkson, C. R. (University of Calgary) | Clarke, K. M. (University of Calgary) | Yang, Z. (University of Calgary) | Rashidi, B. (University of Calgary) | Vahedian, A. (University of Calgary) | Song, C. (University of Calgary) | DeBuhr, C. (University of Calgary) | Haghshenas, B. (University of Calgary) | Ardakani, O. H. (Geological Survey of Canada) | Sanei, H. (Aarhus University) | Royer, D. P. (Encana Corporation)
Hydrocarbon storage capacity of organic-rich shales depends upon porosity and surface area, whereas pore (throat) size distribution and pore (throat) network connectivity control permeability. The pores within organic matter (OM) of organic-rich shales develop during thermal maturation as different hydrocarbon phases are generated and expelled from the OM. Organic-rich shales can potentially retain a large proportion of the hydrocarbons generated during the diagenesis process. Commercial hydrocarbon production from liquid-rich shale reservoirs can be achieved using completion technologies such as multi-stage-fractured horizontal wells (MFHWs). However, the ability of industry to identify "sweet spots" along MFHWs is still hampered by insufficient understanding of the effect of type/content of entrained hydrocarbon/OM components on reservoir quality. The primary objective of the current study is therefore to investigate the impact of entrained hydrocarbon/OM on storage and transport properties of the organic-rich shales.
To accomplish this goal, a comprehensive suite of petrophysical analyses are performed on a diverse sample suite from the Duvernay Formation (a prolific Canadian shale oil reservoir) differing in organic matter content (2.8-5 wt.%; n = 5), before and after sequential pyrolysis by a revised Rock-Eval analysis (extended slow heating (ESH) Rock-Eval analysis;
Compared to the "as-received" state, porosity, permeability, modal pore size distribution and surface area increase with sequential pyrolysis stages, associated with expulsion and devolatilization of free light oil and fluid-like hydrocarbon residue (S2a; up to 380 °C). However, the change in petrophysical properties associated with the degradation of solid bitumen/residual carbon (S2b; up to 650 °C) is variable and unpredictable. The observed reduction in porosity/permeability values after the S2b stage are likely attributed to 1) occlusion of pore volume with solid bitumen/residual carbon degradation (i.e. coking) and/or 2) sample swelling due to water loss from lattice structure of clay minerals (i.e. illite) and 3) sample compaction as a result of OM removal from the rock matrix.
The present study is a continuation of previous works (
Nakatsukasa, M. (Japan Oil, Gas and Metals National Corporation) | Ban, H. (Japan Oil, Gas and Metals National Corporation) | Kato, A. (Japan Oil, Gas and Metals National Corporation) | Worth, K. (Petroleum Technical Research Centre) | White, D. J. (Geological Survey of Canada)
Time-lapse seismic is often used for reservoir monitoring. Although some case studies have been reported, especially for offshore oil fields, similar onshore Abu Dhabi studies have been limited. Onshore monitoring challenges are mainly due to hard carbonate reservoir rock, in which fluid displacement invokes only minor changes in rock properties. Moreover, complex near-surface structures create strong surface-related noises such as surface waves and elastic scattering. These noises significantly degrade the repeatability if repeat data are recorded with positioning error of 1 meter. To address the problems above, permanent reservoir monitoring has been spotlighted recently. Although permanent receivers are widely used for seismology, few studies of permanent seismic sources have been reported. In this study, we demonstrate a permanent source, Accurately Controlled Rotational Operated Signal System (ACROSS), which has a fixed position and excites highly repeatable seismic waves by rotating an accurately controlled eccentric mass. We deployed ACROSS at the Aquistore CCS test field onshore in Canada and recorded the wavefield with permanent receivers buried underground. The ACROSS system was operated several times throughout one year. The data acquired in a continuous 45 day operation were analyzed to calculate variation of amplitudes. The result indicated that we had obtained very stable waveforms with less than 3% variation if the data is stacked sufficiently. We also compared the two datasets acquired at different times of the year by calculating the normalized root mean square (NRMS) as a repeatability index. The histogram showed that the peak of NRMS distribution approached ~15% with only front and back mute processing. These results support our conclusion that an ACROSS system has potential to be used for reservoir monitoring in onshore fields by providing highly repeatable data for an extended time period.
Nakatsukasa, Masashi (Japan Oil, Gas and Metals National Corp) | Ban, Hideaki (Japan Oil, Gas and Metals National Corp) | Takanashi, Mamoru (Japan Oil, Gas and Metals National Corp) | Kato, Ayato (Japan Oil, Gas and Metals National Corp) | Worth, Kyle (Petroleum Technology Research Centre) | White, Donald (Geological Survey of Canada)
Repeatable seismic source positioning and coupling are important for successful onshore time-lapse monitoring. Consistent coupling is difficult to achieve due to variable near-surface conditions. Use of a permanent rotary vibrator source is a potential solution to this problem as it is fixed and continuously excites seismic wave. This technology is still at the research stage with few field examples having been previously reported. We deployed a rotary source called “ACROSS” at the Aquistore CCS field site and acquired data with a permanent surface array of geophones over the course of a year. This study evaluated hourly and seasonal repeatability of the ACROSS by calculating normalized rms difference (NRMS) and time shifts for correlated shot gathers as indices of repeatability. Most of the data for 47 days of recording have NRMS<20% and time shift <1ms. Comparison of data for different seasons showed that NRMS and time shift in a similar season is smaller than 30% and 1ms, respectively, while these values are higher in March. These results indicate high repeatability of the ACROSS and in spite of some challenging issues, suggest the potential to detect time-lapse signals due to CO2 injection in this area.
Presentation Date: Wednesday, September 27, 2017
Start Time: 9:45 AM
Location: Exhibit Hall C, E-P Station 1
Presentation Type: EPOSTER