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  • Dalhousie University Petroleum Geoscience Field Methods Trinidad

    Summary Report

    Submitted to:

    Offshore Energy Research Association of Nova Scotia (OERA)

    to fulfill requirements of the Graduate Student Research Travel Program

    Submitted by:

    April 2013

    Darragh OConnor

    Basin and Reservoir Laboratory

    Department of Earth Sciences

    Dalhousie University

    Alex Hurley

    Department of Oceanography

    Dalhousie University

  • 1

    Table of Contents

    Introduction 2

    Benefits and Outcomes of Travel and Significance to Nova Scotia 4

    Benefits 4

    Outcomes Darragh OConnor 8

    Significance to Nova Scotia Darragh OConnor 8

    Outcomes Alex Hurley 10

    Significance to Nova Scotia Alex Hurley 12

    Trip Itinerary 14

    *Front cover image: sketch of a scarlet ibis, the national bird of Trinidad and Tobago

  • 2

    Introduction

    The Petroleum Geology Field Methods course at Dalhousie University is a collaborative course with

    students from Atlantic Canadian Universities, the University of the West Indies (UWI), and professionals

    from both Trinity Exploration & Production and Petrotrin. The course focuses on collaboration between

    students and professionals in order to define associations between offshore and onshore geology

    through field-based and laboratory outcrop, core, and log analyses (Fig. 1). The course is comprised of

    three sections: pre-trip literature review of Caribbean geology involving reports on relevant petroleum

    systems elements, field and laboratory exercises on the Island of Trinidad, and a presentation post trip.

    Students are encouraged to work collaboratively with Trinidadian professionals in order to learn the

    application methods of classroom taught concepts.

    The course emphasizes the importance of onshore analogues for offshore petroleum systems that are

    relevant for offshore Nova Scotia. Trinidad provides an overview of the effects of compressional and

    extensional tectonics in the development of petroleum systems. This is best viewed through fluvial-

    estuarine, shelf margin delta, and deepwater depositional system outcrops, along with the occurrence

    Figure 1: Left A group of Dalhousie University students, UWI students, Trinity E&P employees, and trip organizer Grant

    Wach along the beach at Cedros Bay. At this location deltaic sequences and abandonment deltaic lobes were described.

    Right Dalhousie University students with Petrotrin employees outside the Petrotrin core laboratory. Students described

    and interpreted offshore core to gain insight on the similarities between offshore and onshore geology

  • 3

    of mud volcanoes and oil seeps (Fig. 2). Subsurface data from offshore Trinidad, provided by Trinity

    Exploration & Production and Petrotrin, allows students to build a framework for understanding

    subsurface geology. Overall, the combined teams and new datasets provide opportunities for students

    to conduct petroleum geosciences research on analogues relevant to offshore Nova Scotia geology.

    The following topics are introduced in both the laboratory and field:

    Basin tectonics and structural setting

    Caribbean tectonics and seismicity

    Trinidad structural evolution

    Source rock, maturation, and overpressure

    Source rock, fluid migration, and trap formation

    Petroleum biodegradation

    Mud volcanoes, shale tectonics, petroleum migration

    Oil and gas generation in the northern and southern basins

    Depositional systems and modern day analogues

    Figure 2: Left Active petroleum seeps in the city of San Franado, found near the backyard of a family residence. These

    oil seeps appear as hydrocarbons travel from depth to surface through interconnected fault systems.

    Right An active mud volcano near Piparo, located in central Trinidad. The mud volcano demonstrates the overpressure

    of a petroleum system, often associated with active tectonism.

  • 4

    Accommodation space and basin fill

    Mechanisms for sediment transport and settling rates

    Micropaleontology

    Modern fluvial and deltaic systems

    Margin delta and slope reservoir characterization

    Outcrop and core descriptions, gamma ray and permeability readings

    Resource evolution of modern oil sand open pits

    Health, safety, and environmental lectures

    A unique component to the course is the addition of industry instructors (e.g. Petrotrin, BP, and Trinity

    E&P) who assist in field and laboratory exercises. Their expertise in Trinidadian geology gave us and

    Dalhousie and other students from Atlantic Canadian universities an excellent opportunity to develop

    the necessary training for future careers in the petroleum industry.

    Benefits and Outcomes of Travel and Significance to Nova Scotia

    Benefits

    Trinidad is an exceptional location for the study of petroleum geoscience. The island offers remarkable

    outcrop which clearly demonstrates petroleum system elements of source, seal, reservoir, trap, and

    migration; all of which are required in forming an effective petroleum system. The thick reservoir and

    seal packages of deltaic deposits (Fig. 3); the active overpressure shown through mud-volcanoes; the

    over mature Northern Range organic rich source rock; the large number of faults indicating tectonic

    activity; and the many oil seeps are examples of petroleum systems elements on the island of Trinidad.

    In order to better understand the formation of petroleum system elements, the trip involved studying

    modern wetlands and deltaic systems. Researching modern depositional systems, we were able to use

    present day deposition models as keys to decipher and understand the formation of outcrop.

  • 5

    Aside from containing world-class outcrops and modern depositional analogues, Trinidad has a number

    of other benefits in the study of petroleum geoscience. These benefits are:

    1. The island is approximately 4700 km2, or about half the size of Cape Breton Island. This allows

    for daily trips to be completed from the lodge to points of interest, all within reasonable time.

    The longest period spend travelling from point to point was approximately two hours.

    2. The island is a current hydrocarbon producing nation. Many of the rock formations seen on the

    coast extend far into the subsurface of offshore Trinidad. The Trinidadians have learned to

    exploit their well exposed onshore geology to aid in understanding and producing of offshore

    subsurface reservoirs. This connection between onshore and offshore geology is a vital point of

    proof when teaching and learning about petroleum system elements. Observations are made on

    outcrop, then interpretations on how they formed, theories are conceived on how these would

    produce hydrocarbons, and then offshore platforms are seen producing from these same

    Figure 3: A collaborative effort amongst

    Dalhousie students and Trinity E&P and

    Petrotrin employees to try and piece

    together the depositional history of this

    outcrop. The outcrop is part of a known

    deltaic sequence which often forms

    both reservoir and sealing units. Both

    of these petroleum system elements

    are seen here: gray sediments are fine

    grained silts and sand producing sealing

    units and yellow sediments are clean

    sands which produce hydrocarbon

    reservoirs. A fault also highlights the

    past tectonic influence on this system.

    This deltaic system is an analogue for

    the depositional systems of the sable

    field offshore Nova Scotia.

    Fault trace

    Reservoir

    Seal

    Seal

  • 6

    reservoirs. These same procedures are being used to aid in describing reservoirs offshore Nova

    Scotia.

    3. There is a strong connection between academic, industrial, and governmental groups in Trinidad

    with Dalhousie University, in part to close ties between Grant Wach and geologists of Trinidad.

    This connection gives students the opportunity to meet and learn from Trinidadian geologic

    professionals. The University of West Indies is a current member of the Atlantic Association of

    Universities, again connecting Dalhousie University to UWI. Trinity Exploration & Production

    often collaborates in field participation by sending a number of young geologists, engineers, and

    chemists, as well as experienced managers, to both learn from and teach us. Petrotrin, the

    petroleum company of Trinidad and Tobago, invited all Dalhousie University course participants

    to study offshore core and to learn from some of the Worlds top biostratigraphers. Trinidad is

    known to be one of the founding nations in biostratigraphy, giving students a unique

    opportunity to meet the founding fathers of modern petroleum geoscience biostratigraphers.

    4. Hydrocarbon production is clearly integrated into the Trinidadian culture. The mesh of

    hydrocarbons and culture is shown in political relations, national monuments, employment and

    the economy, and day to day life. A national monument in Trinidad is Naparima Hill, located in

    the city of San Fernando. Culture and petroleum are tied together once again as the hill is the

    only outcrop of the petroleum systems source rock, known as the Naparima Hill Formation.

    The economy also s