Overview


This natural gas atlas creates an inventory of the molecular and stable isotope signatures of natural gases from the relevant geologic units and locations in BC


These natural gas fingerprints will:


  1. 1.Assemble a catalogue of unique natural gas compositional IDs for active 

          gas operations in BC with a focuson northeast BC)

  1. 2.Characterize the geochemical conditions of BC’s major ongoing and future regions of petroleum exploration and production

  2. 3.Contribute to understanding the geologic framework of natural gas deposits at scales of fields to basin levels

  3. 4.Assist petroleum system models to de-risk plays

          - understanding and predicting generation occurrences, histories and

          potential productivity of natural gas in BC

  1. 5.Provide robust baseline of gas signatures to identify and track fugitive emissions of natural gas (groundwaters and atmosphere), e.g., distinguish microbial gas from thermogenic gases (associated gas, shale gas, coal seam gas and coal bed methane, etc.)

  2. 6.Offer a “geochemical DNA” catalogue for different gas sources for provenance work in production, well completions, processing and transport

  3. 7.Establish the database of fugitive emissions in surface waters and the atmosphere

 

Detailed goal description   


    Natural gas development in northeast British Columbia has a history of over 60 years. With the advent of new drilling and completion techniques to access previously uneconomic deposits, British Columbia is experiencing somewhat of a natural gas development renaissance. The nascent LNG industry on the west coast of British Columbia, which will be sourced primarily from NE B.C., will require extensive new exploration, drilling and production to realize any of the projected goals.


    As these new (and previous) wells and oil and gas reservoirs are drilled and tested, natural gas samples are collected. By routinely measuring the molecular and isotopic composition of these gases, we learn important details about the character of the gases present, their habitat, origin (e.g., microbial or thermogenic), type of organic source material (kerogen), maturity or rank levels. We can also identify secondary processes, such as degradation, oxidation, mixing and commingling.


   This detailed geochemical characterization of natural gases, which must include the stable isotope information of the gases, has exploitation benefits to the operator, potentially allowing them to optimize the gas revenue stream by understanding where certain gas-types occur. The systematic cataloguing of B.C. natural gases in this BC-NGA project will reveal information about the development, migration, segregation and compartmentalization within petroleum systems. It will also define the distribution of natural gas liquids, which help gas producers target higher value targets and natural gas streams.


    Additional information may be gained on the effectiveness of regional seals and the impact of geologic structuring on seal integrity. This information is critical to ensure shallow aquifers are not being compromised during hydraulic fracturing operations. Also communication between wells, e.g., during hydraulic fracturing, can be tested with gas geochemical tracers.


    Although new wells are generally drilled with state-of-the-art completion methods and production equipment, there are concerns that the associated drilling, production and transmission activities allow gases to fugitively escape into the atmosphere or shallow groundwaters. This includes release of natural gas from poor well completions, compromised surface casing cements and from pressure cycling during hydraulic fracturing. There are also additional concerns regarding fugitive gas emissions from older, sometimes abandoned, well bores where cementing practices were less rigorous than today.


    The ability to identify a leaking gas source has many benefits for the public and industry. In the case of a leaking wellbore, operators can lower remediation costs, by having a higher level of certainty as to the gas source (e.g., depth and location), thereby allowing the operator to quickly and efficiently plan remediation of leaking wellbore. This same methodology can remediate old and abandoned wellbores – the methodology would allow the service company to pinpoint the horizon(s) which is (are) leaking, thereby reducing fugitive gas emissions (and lost product).


    The detection of fugitive emissions from natural gas upstream activities (exploration, production and transmission) is critical for the responsible development of the resource, and for the health and safety of the adjacent communities, including the First Nations. Cataloguing the fingerprint of the different types and sources of natural gas in the subsurface is a critical first step in the development of this comprehensive air monitoring network for air quality.



Value proposition


    This study has value for public, local communities, First Nations, the BCOGC, the natural gas sector, and Governments.


Some of the value-adds include:


  1. Identification of thermogenic vs. biogenic natural gas sources


  1. Provide initial critical step in the evaluation of potential  fugitive gas emissions


  1. Identification of fugitive gas sources in  abandoned and producing wellbores


  1. Optimization of gas revenue stream by predicting and mapping gas content

      and quality


  1. Lower remediation costs by providing  a high level of certainty as to the location

      in the subsurface of the gas release


  1. Provide the technical framework for air monitoring programs


  1. Provide information that aids regulatory agencies with aquifer protection

    - integrates with ongoing activities and plans to monitor groundwater and analyze

       dissolved hydrocarbons in B.C.


  1. Increase understanding of petroleum systems, seal integrity, NGL distribution, to   

      help natural gas producers target higher value gas reservoirs


  1. Petition for access to legacy isotope data and archived gas samples,

      Produced Gas Samples and Gas Samples from Exploratory Wildcat (EW)

      and Exploratory Outpost (EO) wells


    In order for this initiative to be successful, the project requires representative natural gas samples from all producing pools/fields throughout the geological column in BC, focusing on N.E. BC. In addition, temporal gas samples from the same well/pool/field can provide important information with respect to the gas stream and optimization of production practices.


    The needed data for the project will come from three potential sources:


  1. 1.legacy isotope data (and standard molecular analyses) from older archived conventional gas production and mud gas analyses


  1. 2.Produced gas samples from existing producing wells will help infill data gaps from the legacy isotope data


  1. 3.New gas samples from Exploratory Wildcat (EW) and Exploratory Outpost (EO)

        wells will update knowledge in new exploration regions and fairways




Tasks of BC-NGA


1. Acquire and catalogue existing and ongoing data 


  1. Compilation and integration of existing and new geochemical and metadata

    from exploration and production wells in northeast British Columbia

    - identify and catalogue all available molecular and isotope compositional data

       from previous petroleum wells in northeast British Columbia that are available

       from regulatory agencies (e.g., OGC, Minister of Energy and Mines), service

       companies and industry


  1. Collate molecular and isotope compositional data from new and ongoing

    petroleum wells in northeast British Columbia


• Request and collect proprietary gas data from the energy sector



2. Gas geochemical analyses on archived well samples


• Make routine measurements on gas samples from past petroleum wells in            

    northeast B.C. (e.g., shut-in or abandoned wells)

    - measure molecular and isotope compositions of gas on archived samples from

      petroleum wells in northeast British Columbia, e.g., gas composition of

      hydrocarbon and permanent gases, e.g., methane - pentane, δ13CH4, δ13C2H6 ,

         δ13C3H8, δ13CO2 and δ2H-CH4


  1. Assemble geochemical data with related metadata from exploration and

    production wells from NE B.C.


  1. Extend the archived sample study to other exploration regions in B.C.

    e.g., Netchako basin, Elk Valley and Crowsnest, Hat Creek, Comox

    and Nanaimo, etc.


  1. Explore using archived cuttings samples to make ‘sorbed gas’ compositional

    measurements instead of traditional ‘free gas’ data, when the latter are unavailable



3. Gas geochemical analyses on current well samples


  1. Make routine measurements on gas samples from current petroleum wells in

    northeast British Columbia


  1. Measure molecular and isotope compositional data from new and ongoing

    petroleum exploration and production wells in NE B.C. at the Biogeochemistry    

    Facility (UVic), e.g., gas composition of hydrocarbon and permanent gases


  1. Assemble geochemical data with metadata from exploration and production

    wells from NE B.C.


  1. Extend the study to current unconventional exploration in other regions of B.C.

    e.g., Netchako basin, Elk Valley and Crowsnest, Hat Creek, and Comox

    and Nanaimo, etc.


  1. Identify critical gaps in data and seek to obtain infill samples



4. Water geochemical analyses on current well samples 

    Northeast BC Aquifer Characterization Study


  1. Make complimentary gas geochemical measurements on fluid (water) samples

     collected from current petroleum wells in northeast British Columbia


  1. Sampling and analyses in conjunction with joint water project ‘Northeast BC

    Aquifer Characterization Study’ with OGC, BCMFLNRO, BCMoE, and

    SFU (contacts: C. van Geloven D. Wilford and D. Kirste)


  1. Measure dissolve gas molecular and isotope compositions, i.e., hydrocarbon

    and permanent gas concentrations


  1. Currently the NE B.C. water sampling program coordinated through D. Wilford

    and C van Geloven (OGC) has access to over 95 water and monitor wells in the

    region for measurement and cross referencing in the BC-NGA


  1. Approximately 100 water gas samples will be collected and analysed during the

    project for detailed lab-based gas molecular ad isotope measurements at the

    Biogeochemistry Facility (UVic).



  1. 5.Gas geochemical measurements on fugitive emissions from well sites in

    NE B.C. - Fugitive Gas Emission Characterization Study


Collaboration in the joint OGC/UBC project (PI: U. Mayer) to analyze surface gas samples collected from oil and gas well sites in NE. B.C.


  1. Our part in this project analyses the stable carbon and hydrogen isotope

    compositions of free gases fluxing out the soil at well sites and dissolved gases

    in the waters in the well bores


  1. Similar to the NBCACS, this study will interpret the origin of the gases,

    i.e., allochthonous vs. autochthonous, or microbial vs. thermogenic, etc.


  1. In the case of thermogenic gases, the project will establish any links of shallow

    gas occurrences with potential sources in the subsurface using the detailed

    BC-NGA signature inventory


  1. At the outset of the project approximately 25 well sites in NE B.C. will be

    visited by the team. Flux measurements will be made on site at ca. 20 - 30

    locations on and around well sites by optical spectroscopy.

    Gas samples will be collected for detailed lab-based gas molecular and isotope

    measurements at the Biogeochemistry Facility (UVic)

• Overview
• Detailed goal description
• Value Proposition
• Initial Tasks