Improved Formation Evaluation Through Use of Rotary Sidewall Coring Tool and Well-Site Core Analysis

R. A. Skopec

The rotary sidewall coring tool (RSCT) is a new wireline coring device that cuts undamaged core samples in virtually all reservoirs. Prior to the introduction of RSCT, only conventional coring techniques could obtain samples suitable for accurate measurement of petrophysical parameters. Percussion sidewall cores are not representative of the formation due to compaction and alteration of the true rock fabric. RSCT is a unique hydraulic and electric tool equipped with a diamond core bit to drill sidewall plugs perpendicular to the tool axis. Exact depth correlation is maintained using a gamma-ray section in the tool. The reservoir can be cored after running wireline logs to identify productive zones.

The mobile petrophysics laboratory (MPL) is also being introduced to provide the log analyst with data necessary to evaluate formations. Well-site core analysis allows the operator to integrate core data with all other information in the most expedient manner. Decisions concerning well testing and completion practices can be aided through knowledge of rock properties. Data that can be provided at the well site include porosity, permeability, mineralogy (from x-ray diffraction and scanning electron microscopy), and fluid saturations.

AAPG Search and Discovery Article #91037©1987 AAPG Southwest Section, Dallas, Texas, March 22-24, 1987.