4D Time-Lapse Seismic - Still on Plateau after 30 years

Course Description

The course shows explores the reasons that Dedicated 4D Time-Lapse Seismic is alive and kicking, about 30-odd years after its first applications in the North Sea. Why is it that this technology is so widely used (at least in the offshore) without signs of tapering off, while at the same time the business challenges keep increasing in the form of deeper reservoirs, lower porosity, more complicated overburdens? 

We will investigate the 4D signal magnitudes in hard rocks, and indicate the challenges associated with some selected cases such as carbonates, Land 4D seismic, and Steam floods. Thanks to the immense progress in seismic acquisition and processing, we see 4D noise levels dropping to very low levels, enabling deployment of the technology in areas previously seen as unfeasible. We will discuss current trends and directions that promise to maintain the momentum of progress. Finally, we present a number of difficult or anomalous 4D cases that illustrate some remarkable features in rocks, fluids, or otherwise, and the learnings drawn from these, sometimes a little speculative.

Course Outline

Day 1

 1. Today's "hard" 4D problems and challenges:

- Hard rock 4D

- Estimating small signals & role of porosity

- Carbonates versus clastics

- CCS, depleted gas fields versus saline aquifer; resolution limitations

- Land and its seismic challenges

 - EOR/complex reservoir dynamics

2. Technology and innovation: reducing noise, reducing cost, increasing temporal frequency

- Seismic Acquisition: spatial densification versus sparsification

- Seismic Processing

-Trends and directions. 

3. Selected case studies & learnings

- Hard Rocks

- Complicated Fluids

- Geomechanics through time

- HSSE/safety examples

Participants’ Profile

The Course should appeal to Subsurface staff involved in Field Development of "difficult" Assets who are interested in understanding how modern 4D Time-Lapse Seismic methods can perhaps address monitoring requirements previously thought unsolvable. This Course aims to be of interest to those with a strong technical focus as well as those developing today's challenging Assets.

Prerequisites

This course builds on Participant's basic understanding of Rock Physics, Fluid Properties, and Seismic Modeling. It also assumes familiarity with standard Seismic Acquisition and Processing methods and workflows.

About the Instructor

After joining Shell in 1991, Jan started as Research Geophysicist in Seismic Processing. This was followed by an assignment as Quantitative Interpretation Geophysicist with emphasis on Rock Physics. This made him "tick all the boxes" when Shell UK sought a focal point to coordinate this "new technology" called 4D seismic in the late 1990's. He grabbed this opportunity with both hands, and has never regretted it.

4D seismic was here to stay. From the initial breakthrough results and extensive deployment efforts in the various diverse geologic provinces of the North Sea, he moved to the USA in the early 2010's just when the OBN revolution was starting to take place in Deepwater. This technology unlocked 4D in that setting as evidenced by a major deployment cycle within Shell. This was followed by a more general Geophysical assignment to the Middle East and its associated challenges of dealing with Land seismic. 
After returning to the USA in the early 2020's he oversaw Shell's efforts to deploy 4D in hard-rock settings - with success. 

A constant throughout his whole career has been a fascination for Technological Progress and Innovation, such that 4D Data Quality kept improving just as Business Requirements grew ever more demanding. As a result, 4D seismic is as valuable today in deep/tight/hard rock reservoirs as it was 25-odd years ago in shallow/soft/high porosity reservoirs, an enormous achievement by Industry as a whole.