Development and Application of an Integrated Petroleum Engineering and Geologic Information System in the Giddings Austin Chalk Field

Abstract

Abstract This paper relates the success of applying microcomputers to quickly and accurately analyze a large mature field. The objective of this study was to combine historical and ongoing activity with geologic information to locate restimulation, recompletion and horizontal drilling potential in the Giddings Austin Chalk field. The project was divided into four segments: system design, software development, data analysis and project implementation. The end product was a custom analysis system which allowed the operator to economically add reserves through restimulation and recompletion projects. Introduction This project came about as part of an effort to evaluate a small independent's interest in 200 wells and 24,000 acres [971 ha] in the Giddings Austin Chalk Field, as well as an ongoing effort to add reserves through workovers, restimulations and recompletion projects. Specifically, the technical staff was requested by management to evaluate the "water-frac" restimulation phenomenon in the field. Although the water-frac process had been applied with success by the company in the past, the scope of the project was to be greatly expanded, demanding a more rigorous evaluation. The company sought to refine the existing water-frac theory, evaluate the success rate of the process, identify "sweet spots" and establish a field-wide candidate selection criteria. In addition, the Buda and Georgetown formations required evaluation for recompletion potential. An ancillary project which benefitted from this work was the evaluation of, and participation in, horizontal drilling in the field. Due to the high level of horizontal drilling and water-frac activity it was necessary to continuously update the study with new information. The large volume of data involved and limited staffing demanded automaton to accomplish the project. Three functional areas were identified: performance evaluation, mapping and candidate screening. After a brief examination of the off-the-shelf systems available it was determined that a custom system would be required to meet the specific objectives of the project. The heart of the system is a series of related databases. The databases required included a stimulation database, digital well location database, lease database, production history database and a lease I.D./A.P.I. number cross reference. A horizontal well database and digital formation tops were linked to the system at a later date. This system, which runs on the Apple Macintosh II platform, requires 2 megabytes (Mb) RAM and occupies 20 Mb of hard drive space. Specific software functions include: data import/export, database maintenance, computer mapping, offset well analysis, data review/statistical analysis, candidate screening and report formatting. FoxBase/+Mac, a high level relational database engine which utilizes a Dbase IV compatible language and file structure, was utilized to develop the system over a period of three months. FoxBase/+Mac was chosen for its speed, graphical user interface, data importation capabilities and compatibility with FoxPro for MS-DOS. The system was installed on a Novell Netware 2.15 network with Novell for Macintosh drivers using Arc-net topology for both the Macintosh computers and PC-compatibles. The network allowed for the transparent interchange of data between MS-DOS based data providers and the Macintosh software that was developed. Production and geologic mapping was accomplished through an interface with MacGridzo, a geologic mapping and contouring package. Statistical analysis and plotting of production parameters was performed by exporting data to Exstatix, an advanced statistics package with a variety of curve fitting and statistical analysis functions. As a result of the application of this system the company experienced a high success rate in adding economical reserves through restimulation and recompletion projects. P. 199^