HGS Virtual General Lunch – Reality Check: Life Cycle of Geophysical Data Utilized in the Exploration and Development of Deepwater Stratigraphic Traps

Wednesday, May 25, 2022

Virtual Event
12:00pm – 1:00pm

Member- $15 Non-Member- $30 Students – $10

A confirmation email will be sent upon registration with meeting links.

To guarantee a spot, you must pre-register on the HGS website and pay with a credit card.  Please cancel by phone or email within 24 hours before the event for a refund.  Online & pre-registration closes Wednesday, May 25 at 12:00 p.m.

**Non-Members can submit an application and pay their dues before registering to get the member price. Please call the HGS office at 713-463-9476 to be registered only AFTER your application and dues are submitted.**

Speaker: Joseph Reilly

Joseph Reilly started his oil & gas career with Mobil in 1980 and has over 41 years of industry experience in addressing Exploration, Development and Production geoscience challenges throughout the world.  In his early career he sat wells as both geologist and geophysicist offshore USA East Coast, Morocco, UK and Equatorial Guinea. Similarly, he has been directly involved in countless seismic campaigns throughout the world and has had the good fortune during his career of experiencing numerous exploration successes, as well as failures.  He has a BSc in Geology from University of Rochester and an MSc in Geology/Geophysics from Virginia Tech.  He has authored/coauthored hundreds of papers and presentations on geophysical applications.  He is a long-standing member of AAPG, SEG and EAGE.  He has held both technical and management positions and recently retired as ExxonMobil Chief Research Geoscientist. He is currently serving as Second Vice President, SEG Board of Directors.

Reality Check: Life Cycle of Geophysical Data Utlized in the Exploration and Development of Deepwater Stratigraphic Traps

Geoscientists have been successfully exploring for, and developing, stratigraphic traps for decades. Deepwater clastic “play opening” examples within the greater Atlantic region include Brazil – Marlim (1985), Equatorial Guinea – Zafiro (1995), Angola – Girassol (1996), Ghana – Jubilee (2007), Guyana – Liza (2015) and now Namibia – Graff & Venus (2021 & 2022).

Most of these clastic reservoirs are multi-cycle with varying rock physics responses.  Individual reservoir thicknesses challenge the seismic methods ability to separate individual units and not be misled by tuning, overburden and focusing effects.  This is particularly difficult in the pre-capture phase of the exploration cycle when 2D seismic, gravity and magnetic data might be the only geophysical data available to support the geologic concepts and models leading to identification, and initial assessment of an opportunity.  Accurate DHI/AVO prediction becomes particularly challenging in this situation.  Even when 3D seismic is available it will rarely, if ever, be optimized for a specific reservoir interval and calibration to rock physics will likely be poor.  It is especially important to emphasize that the most critical decisions (Exploration acreage capture and wildcat drill) are made with significantly lower quality and quantity of data than that typically available during the Appraisal and Development phases. Analogs from these more mature settings are useful but need to be utilized in the context of the data actually available.  Good geologic concepts, analogs, integration of all data types, experience, judgement, and good luck all are in play for true frontier exploration ventures. 

All the above being true, recent advances in acquisition and processing technology are clearly an enabler for improving the resolution of our seismic images; hence improved identification and characterization of stratigraphic traps whether it be in the Exploration, Appraisal or Development stage.  However, care must be taken to ensure these imaging enhancements retain the amplitude fidelity necessary to allow for detailed AVO/DHI analysis.  Acquisition, processing, and interpretation all play important and interrelated roles in obtaining the maximum utility from the seismic data. The challenge is to maximize the bandwidth of the seismic data while retaining amplitude fidelity across all offsets/angle ranges with specific attention to what constitutes the irreducible seismic noise floor. 

The primary focus of this presentation will be stratigraphic traps in the marine deepwater environment.  We will discuss the challenges of data availability and confidence, where resolution and data fidelity can be gained or lost, what factors primarily determine bandwidth recovery, and what decisions still need to be made in a somewhat subjective, target oriented manner.  In addition, the importance of visual resolution for interpretation, regardless of the actual data fidelity, will be highlighted.  Data from deepwater Guyana is used to demonstrate fundamental principles and the evolution of acquisition, processing, and interpretation workflows over the history of this project. 

 
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