Advance Nuclear Magnetic Resonance and Image Logs Application for Predicting Particle Sand Distribution

Abstract

The complexities of designing an effective sand control for unconsolidated gas reservoirs in a deepwater environment is exacerbated when the targeted formation sands are characterized by particle size distributions with poorly sorted and non uniform coeficients, and high fine concentrations. Managing these intricacies requires comprehensive sand retention studies developed to ascertain the effectiveness of the sand control performance of gravel and screen gauge opening combinations in the presence of selected formation sand ratios. To build a representative testing program, actual core samples from the targeted studied zones are desirable. However, for economical, technical or logistic contrains the availability of these cores is not always feasible. This paper covers a workflow to determine a synthetic Particle Size Distribution (PSD) of a targeted well in a development block where no core data is available. The data feeding the workflow is derived from wireline bore hole imagers and Non-Magnetic Resonance (NMR) logs obtained from six wells drilled in the exploration phase of the studied gas block. Results are calibrated with localized PSD from available side wall cores. Furthermore, data obtained from the process is used to interrogate sand retention testing Mastercurves built with formation samples from one of the fields in the studied block (Field I). The interrogation process takes the synthetic PSD from the targeted well and creates normalized formation testing ratios which are then compared to the results documented on the sand retention Mastercurves. This paper is intends to discuss the worklflow and results of its field application.