1963 Paper G

A LOGGING PROGRAM FOR CASED-HOLE RECOMPLETION by

L. L. Raymer and R. L. Morris Schlumberger Well Surveying Corporation Houston, Texas

ABSTRACT

For the cased well, a logging program consisting of Gamma Ray - Neutron - Chlorine Log, Cement Bond Log, and Formation Tester is presented. This program provides a rapid and economical method of finding and evaluating possibly productive horizons behind casing.

The Gamma Ray provides lithology data. Through a measurement of the average salinity of the formation fluids, the Chlorine Log can distinguish hydrocarbons from saline waters. Gas detection and porosity index are contributed by the Neutron Log. Comparisons of these data permit estimations of porosity and saturations and thereby the location of interesting zones.

Confirmation of these results and resolution of questionable zones are provided by the Formation Tester. In addition, the tester provides important reservoir data. From this flow test, fluid type and characteristics, formation pressures, gas-oil ratio, and water cut can be determined. When equipped with the Cement Squeeze Adapter, the tester not only perforates and tests in one simple operation, but also, if desired, cements the perforations at the conclusion of the test.

Successful operation of the Cement Squeeze Adapter requires a good primary cement job. Also, channeling of nonreservoir fluids between the casing and formation may cause erroneous Chlorine Log and Formation Tester interpretation. Therefore, the effectiveness and reliability of this program may be enhanced through use of the Cement Bond Log to provide information regarding quality of the cement job. It is also of value in selecting the optimum completion procedure once a productive horizon is found.

The use and interpretation of these logging devices will be discussed and illustrated with examples from actual field situations.