The OETR Association (Offshore Energy Technical Research) has initiated an industry standard Play Fairway Analysis and Geoscience Data Package program. This program is intended to serve a pivotal role in stimulating industry interest in exploration of Nova Scotia’s offshore petroleum resources by providing explorers with critical information about prospectivity and resource potential to aid in decision making.

A Play Fairway is the present day area of a potential reservoir unit, with the possibility of having a complete working petroleum system (seal, charge and trap). The Play Fairway Analysis examines relative risks and total volume potential and the four play components (reservoir, seal, charge, trap). It also provides prospect ranking across basins, identifies work program and data acquisition issues and helps in assignment of exploration budgets.

FIGURE 2: Diagram of the Play Fairway Concept

Background: Nova Scotia's Offshore and the Play Fairway Analysis

The history of petroleum exploration of offshore Nova Scotia began more than 40 years ago with the first well drilled in 1967 and the first discovery in 1969. During this period more than 200 exploration, delineation and production wells have been drilled with discovered reserves in the range of 2.1 billion barrels of oil equivalent (boe). However, it was not until 1992 that the first oil production took place at the Cohasset Panuke development, and the first natural gas production in 1999 from the Sable Offshore Energy Project. More recently the discovery of commercial quantities of natural gas at Deep Panuke has resulted in the development of that field, with first gas expected in mid 2011 with a capacity for 300 million cubic feet per day.

The remaining resource potential of Nova Scotia’s offshore has been estimated by the Canada-Nova Scotia Offshore Petroleum Board (CNSOPB) to range from 12 to 39 trillion cubic feet (tcf) of natural gas and between 1.3 and 4.5 billion barrels of oil. In spite of what appears to be an attractive resource base, exploration activity has declined sharply over the last decade, with only one commercial discovery, Deep Panuke in 1998. The lack of exploration drilling success is reflected in the decline in exploration licenses from a high of 59 in 2002 to only 10 by the end of summer 2009.

This history shows that although there is a proven petroleum system, past exploration efforts have failed to unlock its potential. Each of the current proven plays has exploration risks that are unacceptable to the industry. The OETR Play Fairway Analysis and Geoscience Data Package Program is designed to examine the hydrocarbon potential and to demonstrate reduced risk to the industry so that  the remaining hydrocarbon potential can be economically explored.

The Play Fairway Analysis and Geoscience Data Package Program comes in response to previous studies by various levels of government. The results of past studies have increased the interest in taking action to investigate and explain the positive aspects of exploring offshore Nova Scotia prompting the Government of Nova Scotia to commission the OETR Association to co-ordinate a number of subsequent geoscience studies. These studies are intended to fill research gaps and to better understand the current body of knowledge surrounding the geoscience of offshore Nova Scotia.

Play Fairway Program: Providing Explorers with the Means to Make Informed Decisions

In April 2009, after an extensive Request for Proposals process, the OETR Association awarded an 18-month contract to RPS Energy of the United Kingdom for program management services to co-ordinate an industry standard Play Fairway Analysis project for offshore Nova Scotia. The objective of the project is to promote Nova Scotia’s hydrocarbon prospectivity to the oil and gas industry in order to attract maximum participation in forthcoming licensing rounds.
 
The Exploration history has shown the complex geological problems that need to be solved in order to demonstrate to the industry that there is a viable, attractive hydrocarbon region in offshore Nova Scotia.  Several leading oil companies have determined that there is limited potential value in the shelf and have pulled out. The standard approaches to unlocking the hydrocarbon potential have failed.

The geoscience story is crucial. The key issues that will be addressed through the geoscience work include the following:

• Showing that there is a route to reducing risk to acceptable levels with the fault seal capacity on the shelf to exploit the Sable Island play fairway.
• Developing a model that can be used to predict reservoir presence on the slope, which will require understanding the interrelationship between salt movement and sediment transport and ponding.
• Understanding the source rock story.  There appears to be multiple source rock horizons with differing maturation timing and migration routes. 

This work will help evaluate the large undrilled features / structures that exist in the area and could be hydrocarbon bearing and have substantial volumes.  An understanding of the associated issues will be gained through innovative thinking based on a rigorous systematic approach to understanding the petroleum system.

FIGURE 2: Current onshore and offshore rights for petroleum exploration and production in Nova Scotia

The creation of a data package to accompany this Play Fairway Analysis is an important component to the OETR program. The provision of a data package will enable interested companies to test the proposed hydrocarbon models on real data and also to go some way toward evaluating prospects. There are two data issues that must be addressed:

1. The Data: OETR has commissioned a set of activities in which approaches are being made to data owners to explore commercial terms under which digital data can be licensed to interested companies.
2. Data Quality: Although for the most part the seismic data quality is good in the area, improved imaging is neccessary to improve the predictive quality of the data, particularly sub-salt.

The Play Fairway Program was initiated in May 2009 with a workshop attended by leading academic thinkers from Canada, Europe and Morocco.  The workshop concluded that three important issues needed to be addressed as part of the overall play fairway program:

Plate Tectonic Reconstruction:
Improve the understanding the relationship between rifting and salt deposition is critical in developing models for potential syn-rift and early post rift depositional environment. A critical issue is to establish the degree to which volcanism was involved in the rift history of the margin. This has a profound impact on the possibility of encountering extensive restricted marine source rock systems.

Forensic Geochemistry:
Although much geochemical data exists on the margin through the many hydrocarbon shows and discoveries, the source rock story is not well understood.   The program will undertake a systematic evaluation of geochemical source rock and hydrocarbon typing data.  An important component of this work will include fluid inclusion studies from hydrocarbon traces found in the salt.  An indication of lacustrine or restricted marine early Jurassic source rocks would considerably enhance the hydrocarbon potential of the area.

Sequence Stratigraphic Framework:
There is a need to develop a systematic public domaine sequence stratigraphic framwork for the margin. The program of work includes a re-evaluation of the biostratigraphy of several key wells which will be integrated with a seismic interpretation, and tectonic models, to build a comprehensive sequence framework.

Program Components

As a result of the May 2009 workshop and conversations with the academic and geoscience community in Halifax, the Play Fairway Program has evolved into a number of proposed individual projects. These include:

• Plate Tectonics Modeling
• Biostratigraphy
• Geochemistry
• Petroleum Systems Modeling
• Seismic database preparation / Synthetics
• Reprocessing of seismic lines” of around 6,300km data
• Seismic Rock Physics Review
• Salt Structural Interpretation
• Reservoir Quality
• Play Fairway Evaluation

As part of the Plate Tectonics project,  the OETR Association contracted GeoPro to use 100 Ocean Bottom Seismographs (OBS) to acquire a 400 km long refraction line offshore eastern Nova Scotia. The processing of this refraction data will allow the geoscience community to better understand the formation history of the basin, and to make more accurate assumptions concerning source rock and reservoir distribution.

The projects are designed to incorporate leading academic research being undertaken in Halifax into the overall Play Fairway Analysis.  Of particular note are the plate tectonic, salt modelling, biostratigraphy and reservoir quality projects underway at local research institutions. All projects will build on the existing expertise in the region. 

The Play Fairway Analysis and Geoscience Data Package Program integrates the results of these individual projects to build an industry standard evaluation of the remaining resource in the basin. This will include the creation of Gross Depositional Environment (GDE), and Common Risk Segment (CRS) maps on each key sequence leading to estimate of the ultimate Yet to Find in the basin.

OETR has selected and contracted Beicip-Franlab of France to carry out the Play Fairway Analysis. In addition, a number of special projects such as Biostratigraphy are also underway. The Play Fairway Program is expected to be completed in the first quarter of 2011 with the publication of a Play Fairway Analysis and sample Geoscience Data Package for use by explorers. 

Dr. Kevin Vessey, President and Director of OETR Association, is optimistic that the results of this program will make Nova Scotia’s offshore an attractive area for development by industry companies. “The goal of this work is to renew industry interest in developing Nova Scotia’s offshore resources, increasing benefit to Nova Scotians through offshore royalty payments. The Play Fairway Analysis and Geoscience Data Package produced by this program will help to identify potential prospective areas.”

As part of the Government of Nova Scotia’s commitment to reducing barriers for exploration in Nova Scotia’s offshore, the Province has invested over $15 million in the OETR Association to coordinate research activities to make this work possible.