SPWLA Twenty-First Annual Logging Symposium, JULY 8-11, 1980        PAPER A

PAPER A

ECONOMICS OF LOG EVALUATION FOR LARGE PROJECTS

 

E. R. Crain, P. Eng.

E. R. Crain and Associates Ltd.

Calgary, Alberta

 

ABSTRACT

Log evaluation of multi-zone, multi-well projects is done for three basic purposes:

 

1.  Identification of potential reserves to be drilled during exploratory projects

2. Evaluation of probable reserves, for development now or in the future

3. Evaluation of proven reserves for use in cash flow analyses, for secondary recovery studies, and for reporting to regulatory agencies

 

Such evaluations usually require a large expenditure in professional staff and possibly computer time, as well as a large organizational effort by supervisory staff to keep the project on-track and on-time. This paper describes the job performance of a self-contained, portable, micro-computer based log evaluation system, which minimizes the direct cost and organizational overhead needed for effective and timely results. The average performance for a typical system provides analyses for about 500 zones averaging 200 feet in length in 378 working days (18 months), for an average cost of $0.86 per foot of well-bore.  A permanent database is established during the initial evaluation, which can

be reviewed or revised as prospect knowledge or economic conditions change.