Stephen Chudy
Dresser Atlas, Dresser Industries, Inc.
Tolbert, The Netherlands
ABSTRACT
Gravel packing has been used in the Schoonebeek Oil Field of The Netherlands in recent years to allow sand-free production. With increased thermal activity in the field, i.e., steam injection, the success of gravel packing operations becomes more important. Well completion problems are exaggerated by high temperature and deviation.
The Nederlandse Aarodolie Maatschappij B.V., which operates this field, aims to gravel pack up to a minimum of 10 meters inside the casing shoe with the top of the slotted liner or wire wrap screen also inside the casing. The Photon Log is now being used to indicate the quality of the gravel packing operation, particularly the gravel top, thus aiding decision-making on whether or not corrective action is needed.
Since rig time is costly, the objective is to obtain all the information from one logging trip into the hole after the gravel pack operation, without needing a base log run beforehand. If the Photon Log could aid in evaluation of the gravel pack, then it would only be required when problems were suspected. Ten logs were initially run in wells with different completion types and the results from these logs allowed the author to produce a transparency with which the wellsite engineer could interpret the log. Since then an additional 10 logs have been run. Of these 20 wells, 5 wells needed corrective action which was undertaken on the basis of the logs.
This paper will discuss briefly the theory of operation and calibration technique, results of logs with field examples, and plans for the future.