Optimal Design and Application of Two-Dimensional NMR Logging in Chuanxi Tight Gas Reservoir

Abstract

Two-dimensional nuclear magnetic resonance (2D NMR) logging has been increasingly used in the reservoir modeling and fluid identification. A series of problems were encountered when applying the technique in the Chuanxi gas field, including poor efficiency in logging data collection and mismatch between the logging evaluation and reservoir properties. By comparing two commonly-used 2D NMR logging intersection methods and analyzing in-field results, we optimized the design. It was found the T2-T1 method was more suitable than the T2-D method for tight reservoir evaluation. The activation set TGR01 (tight gas reservoir 01) derived from the optimized method, was shown to be superior to the existing method for the tight gas reservoir. At the same time, the T2-T1 intersection method was found to be able to identify different fluids effectively, and applicable to the evaluation of tight gas reservoir.

Keywords

• low-field NMR
• activation sets design
• 2D NMR logging
• tight gas reservoir
• logging evaluation