I have a long-standing preference for document formats that are system-independent, and do not require the purchase of commercial software merely to view the contents of the document. Having just returned from a scientific meeting in Beijing that required all presentations to be prepared using PowerPoint, and having watched several authors attempt to explain how their equations should have appeared, I have become familiar with the problem of font replacement that sometimes occurs when documents are transferred from one operating system (e.g., Macintosh or Linux) to another (e.g., Windows).

LaTeX (pronouced "lah-tek") is a freely distributed, system independent, high-quality document  preparation system that is the de facto standard for the publication of scientific documents. It is typically used to generate PDF or PS files. Because SPE Journal includes fundamental research papers that sometimes contain a considerable number of equations, the option for authors to use LaTeX is a welcome development.

The biggest advantages of LaTeX for authors include consistency of appearance and attractive mathematics. LaTeX lets authors worry about writing the paper and designers worry about the appearance. I have a habit of scanning papers that were prepared using commercial word-processing software to check for additional white space between words, for paragraph indentations and margins that are not consistent, mathematical symbols that do not sit on the text baseline, and citations in text that do not correspond to the proper citation in the bibliography. It is common to find errors in most documents prepared using commercial word-processing software.

While it is possible to generate ugly documents using using LaTeX, it is rather difficult, and requires either relatively advanced knowledge and intent, or the creation of a style file with ugliness designed in. The high-quality, but now defunct, journal In Situ had one of the least attractive styles ever used for a reputable technical journal, yet it was possible to use LaTeX to prepare camera-ready manuscripts for the journal simply by inserting a command to use the style file for In Situ.

Other than creating a truly ugly paper, one of the most difficult things for an author to do using LaTeX is to make a paper fit the particular style requirements of a journal. Note, for example, that tables in SPEJ have horizontal lines that do not connect, and equations have a series of dots to the right margin. Fortunately, for almost anything that a rational author might like to do, someone will have written a style file or package to make the process easy. There are packages for putting multiple graphics each with its own subcaption and label into a single figure, for using an extended set of mathematical symbols, and even to make the text region to be shaped like a heart. The most important package for SPEJ authors is the one named "spej.sty." A second bibliography style file, "spej.bst," specifies the format for citations and references, although this is currently under revision in accordance with recent changes to the journal’s reference style.

The number of people using LaTeX for manuscript preparation is quite small in the general SPE population, but there has always been a substantial minority of SPEJ authors for whom LaTeX was the preferred system. These authors now have the option to publish their LaTeX-prepared papers in SPEJ. The paper "An Improved Implementation of the LBFGS Algorithm for Automatic History Matching" by Gao and Reynolds in the March issue, for instance, was the second to be prepared using the LaTeX template system.

BibTeX is a complimentary application that works with LaTeX to produce bibliographies in LaTeX documents. I presently maintain a BibTeX database with approximately 2,000 entries. To include a reference to any of the papers in my database, it is only necessary for me to specify the keyword for the reference using the cite command, so \cite{gao:06} in a LaTeX document would produce a reference to the recent SPEJ paper by Gao and Reynolds, as long as my database included the following entry:

@ARTICLE{gao:06,
    author = "Guohua Gao and Albert C. Reynolds",
    journal = "SPE Journal",
    title = "An Improved Implementation of the LBFGS Algorithm for Automatic History Matching",
    year = 2006,
    pages = "5—17",
    volume = 11,
    number = 1 }

The syntax is simple and the advantages of using BibTeX are significant.

The papers appearing in this issue represent a wide variety of topics, covering aspects of production engineering, reservoir simulation, formation evaluation, well testing, and geostatistics. The final two papers cover somewhat unconventional topics for SPEJ: subsidence mapping and coal swelling in response to CO₂ sequestration. Perhaps not surprisingly, both were unsolicited manuscripts (i.e., they were never presented at an SPE meeting). I hope you find several interesting papers in this issue.