User Story

Using Microscopy to Understand Reservoir Characteristics

byZEISS Microscopy 29 September 2023 2 min read

Introduction

Eneva is one of the largest integrated energy generators in Brazil. They operate not only in the exploration and production of natural gas but also in the supply of energy solutions. Currently, they run eleven natural gas fields.

Lilian Souza has been with Eneva for the past 12 years. As a geologist, she takes care of rock and oil analysis. Souza spends most of her time coordinating and managing the cooperation partners who assist with different analyses of the rocks.

Analysis of cores extracted from the wells involves the preparation of many thin sections. For a standard analysis of 200 wells, this means 4000 thin sections.

Well Core Analysis

As part of the petrographical analysis, Souza is assessing porosity as this gives an indication of deposit quality. E.g., 10% of porosity indicates good reservoir potential. Permeability, density, and rock composition (mineralogy) are also important markers. With these analyses, she is identifying not only the best areas for exploration but also optimizing the process of exploration and the development of wells. For oil exploration, analyzing the quality and transportation paths is crucial. For gas deposits, composition is the key to identifying the quality of the deposit and possible dangerous elements that would disturb the production, high concentrations of sulfur or CO², for example.

Microscopic Imaging of Sandstone

Observing Porosity, Grain Size, Fabric and Texture

Sandstone in brightfield, imaged with ZEISS Axioscan 7

Sandstone in polarization (xPol), imaged with ZEISS Axioscan 7

Digitizing Petrography Data

With ZEISS Axioscan 7 Geo, data are made available to the various departments of Eneva simultaneously, stored in a cloud and accessible by different areas and specialists within the company. 36 geologists use the data of the slide scanner plus automated petrography platform on a regular basis.

They do scans every day. Until now, the team could only test eight thin sections at the same time.

With ZEISS Axioscan 7 we can scan up to 100 images in a single run, digitizing 50 images per second in various polarization modes to give us the full picture of a sample. We can generate so much more data and the whole team can access the information from everywhere. This makes our work much easier and faster.

Lilian Souza | Eneva