Utilizing Simultaneous Capture of T1 and T2 NMR Data to Solve Reservoir Evaluation Issues

Abstract

Abstract Deep basin drilling along the Wichita Mountain front in the Anadarko basin of western Oklahoma poses one of the most difficult log interpretation issues. Advances in the acquisition and processing of 3D seismic have enabled the drilling and production of targets that previously could not be imaged. Although the increased abilities to identify and target the desired objective horizon in the well have enhanced prospect economics, the petrophysical evaluation of prospective zones has never been straightforward. Well-to-well correlations are difficult because of rapid facies changes in the Pennsylvanian Granite Wash, along with complex folding and faulting in deeper horizons along the Wichita Mountain Front. Nearby wells are often not connected because of the rapid facies changes and the intense faulting and folding. High density/neutron porosities do not relate directly to permeability, nor does high resistivity relate directly to hydrocarbon production. Advances in the analysis of nuclear magnetic resonance (NMR) T2 data have enabled producibility (permeability) information to be extracted from this data. The measurements of NMR T1 data have provided an excellent approximation of fluid typing. We worked together in order to arrive at a useful solution that would provide these data sets in a continuous logging pass. An algorithm was developed that greatly enhances the economics of drilling and completion by simultaneously measuring these data (T1 and T2) in a usable form and enabling the correct evaluation of these reservoirs.