The Practice of Reservoir Engineering [Hardcover]

It is the long awaited update Laurie Dake's 1978 book Fundamentals of Reservoir Engineering and whereas that book was dry as dust, this new book is written with a wit and style as befits a man at the top of his profession. Does anybody else have an OBE for services to reservoir engineering?

It's a practical book with special emphasis on the offshore, concerned with processes on the scale of hillsides not coreplugs. It begins with an introduction inspired by the absence of the word reservoir in Daniel Yergin's history of the oil industry, The Prize. Armed only with Occam's Razor, Laurie tackles the observations, assumptions and calculations that underpin the subject while offering career advice en route - the best time to move jobs is when appraisal has finished and before development begins!

Relax, 90% of reservoir engineering is concerned with the application of 4 physical principles:

The conservation of mass

Darcy's Law

Isothermal compressibility

Newton's laws of motion

The second chapter is concerned with appraisal with useful advice on the use of the RFT to define contacts and a section on unitisation, the first time I can remember seeing this covered in a textbook. On the testing of appraisal wells Laurie's sound advice is:

Appraisal wells should be perforated just as if they were development wells.

He goes on to show how this advice wasn't followed in the testing of an exploration well which any ex-Britoiler will recognise as 30/17b-2, the Clyde discovery well. Since he was Chief Reservoir Engineer at the time, this is a thinly disguised exercise in self-flagellation!

Laurie's one-man mission to put material balance alongside reservoir simulation as the key techniques in reservoir engineering, is covered in chapter 3. Since there can be 8 unknowns in the material balance equation, great care must be exercised in any assumptions made in its application.

Oilwell testing is covered in chapter 4 and the need for long pressure build-up is questioned. If this is the case the time taken to test wells could be considerably reduced with consequent savings in rig-time and well costs.

Chapter 5 is Laurie's masterpiece, 150 pages on waterdrive which could be published as a book in its own right. Drawing on examples from the North Sea, the biggest laboratory ever for the study of waterdrive it demolishes the misconceptions that have grown up over relative permeability curves and stresses the importance of the fractional flow equation in understanding fluid displacement. The section on the effects of vertical permeability distributions on waterflooding should be required reading for every oil company geologist.

The last chapter tackles gas reservoir engineering, a timely read for those who have ignored the possibility of an active aquifer in their gas fields. Gas injection and recycling are also covered with the critical effect reservoir heterogeneity can have on recycling stressed.

Finally, a thought-provoking quote from chapter 1:

Even now, in a mature producing area like the North Sea, the fact that some entrepreneurial outfit has found a minor oil accumulation grabs the newspaper headlines whereas the fact that an operator may have peformed a series of successful, innovative workovers or modified a water injection project, which receovers twice as much oil as contained in the minor discovery, is a dull statistic that remains buried in the filing cabinet.

Not a sentiment I can recall ever hearing outside the Guinea. -- Malcolm Pye, PESGB --This text refers to the Paperback edition.