Formation Evaluation with Pre-Digital Well Logs

By Richard M. Bateman

Formation Evaluation with Pre-Digital Well Logs covers the practical use of legacy materials for formation evaluation using wireline logging equipment from 1927 until the introduction of digital logging in the 1960s and ‘70s. The book provides powerful interpretation techniques that can be applied today when an analyst is faced with a drawer full of old “E logs." It arms the engineer, geologist and petrophysicist with the tools needed to profitably plan re-completions or in-fill drilling in old fields that may have been acquired for modern deeper and/or horizontal drilling.

• Includes more than 150 figures, log examples, charts and graphs
• Provides work exercises for the reader to practice log analysis and formation evaluation
• Presents an important source for academia, oil and gas professionals, service company personnel and the banking and asset evaluation teams at consultancies involved in reserve and other property evaluation

• Language: English
• Publisher: Elsevier Science
• Release date: Feb 8, 2020
• ISBN: 9780128202333

Richard M. Bateman

Richard M. Bateman was educated in the UK obtaining his M.A. in Natural Science, Physics from Oxford University. He began his career in the oil industry in South America as a field engineer for Schlumberger. He worked in many North and South American field locations and later spent three years at the Schlumberger Doll Research Centre in Ridgefield, Connecticut. He subsequently joined Amoco International Oil Company (now BP) and travelled extensively throughout the world from their Chicago headquarters finding oil and gas and teaching others how to do so. Richard has also held posts as Chief Petrophysicist of Halliburton Logging Services, Engineering Manager for Bridas (now Pan American Energy), Manager for Gaffney Cline and Associates’ Latin American operations, based in Buenos Aires, and as a well log interpretation and petrophysics instructor for PetroSkills/OGCI. Richard has authored four books and multiple patents and technical papers. He is a Senior and Life Member of the SPE and is also active with the SPWLA and the SCA. Richard recently retired as a member of the faculty of Texas Tech University as an Associate Professor in the Petroleum Engineering Department.

Book preview

possible.

Section I

The mechanics of reading old E-Log paper prints

Outline

Chapter 1 Introduction

Chapter 2 Applications

Chapter 1

Introduction

Abstract

This chapter sets out the purpose of this work and provides a guide to the way the material has been structured. It is not a requirement that the reader necessarily progress through the different chapters in chronological order. In all, there are 18 chapters that have been grouped into seven sections as documented in this first chapter under the paragraph designated Organization.

Keywords

Pre-Digital Log Analysis Road Map; Log Analysis Methods; Logging Tool History; Reading Analog Prints; Depth Coding; Resistivity Scaling; Genealogy of Wireline Service Companies

Early wireline logging operations. Reproduced from The Schlumberger Adventure by Anne Gruner Schlumberger. Published by Arco Publishing, Inc., New York, 1982. ISBN 0-668-05644-4 (pp. 60-61).

1.1 Purpose

This work is intended as a practical vade mecum for the working energy professional faced with the problem of making profitable use of well logs recorded as paper prints (analog) in the pre-digital era from the 1930s to the 1970s. Many such well logs are today archived in back room filing cabinets and/or on microfiche. The lost art of extracting vital petrophysical answers from single point readings taken off wavy curved lines on a paper print can be quite daunting to those schooled in modern digital well-log recordings and continuous data processing. The purpose here, then, is to equip the working geoscientist with the necessary skills to determine the type of device used to record any legacy materials available, understand the units of measurement, and translate such data into terms that can be used as input to modern log analysis and formation evaluation methods.

This is not yet another book on log analysis and formation evaluation. It is assumed that the reader already has some familiarity with log analysis and petrophysics having completed an undergraduate, or industry, course covering the subject. If that is not the case, then the reader is encouraged to obtain a copy of my exhaustive textbook on the subject.¹

Along the way, the reader will be introduced to the pioneering thinking of the original log analysts who were faced with very limited tools for the job in hand and yet came up with some remarkable methods of making do with very limited raw measurements. They were able to arrive at many very useful and practical results on which current analysis methods are based. In many cases, these pioneers found subtle ways of eliminating unknown quantities (e.g., by taking ratios) and were able to provide perfectly usable numbers for porosity and fluid saturations without the benefits of multiple porosity devices, spectroscopy, high-speed data processing or nuclear magnetic resonance.

It is the aim, therefore, to equip the reader with the skills needed to pluck paper prints, recorded 50 plus years ago, from the archives and identify the logging tools used to make the recordings, the units in which they were recorded and then use the data to calculate porosity, permeability, saturation, hydrocarbon type, and lithology.

1.2 Road map

The simple road map shown below will help readers to get their bearings. Log analysis objectives for the workers in the analog era were no different from what they are today. The basic answers required included: porosity, permeability, water saturation, hydrocarbon type, and rock