Abstract

Procedures used by ARCO for shaly-sand analysis in the B-field and other areas of the offshore Northwest Java sea of Indonesia are described. Merged overlays with sidewall core data has been used in over 500 wells out of 900 total for "quick-look" qualitative analysis.

Quantitiative shaly-sand analysis is in the stage of development and is being cross-checked using core data. An integrated approach by Schlumberger uses computer enhanced high sampling rate, Electromagnetic Propagation Tool* (EPT) results, Formation Microscanner* (FMS) information, Geochemical Logging Tool* (GLT) data and a "Textural" parameter derived from the compressional modulus to provide an improved estimate of water saturation. This integrated approach gives an estimate of variable "m" to be used in shaly-sand saturation equations.

Analysis is complicated because the shaly-sands consist of both laminar and dipersed clays. Glauconite, siderite and ankerite are also present, and in some areas the sands also contain potassium rich feldspar.

A procedure is also shown for correcting Compensated Neutron Log* (CNL) data for stand-off distance.