12 research outputs found
Recommended from our members
Reservoir Characterization of North Buck Draw Field Based on Tracer Response and Production/Injection Analysis
A major goal in reservoir characterization is to develop methods to describe the spatial distribution of properties that incorporate observed heterogeneity and variability due to the geologic complexities. Among these, reservoir continuity is one of the properties that significantly affects production strategies and ultimate oil recovery. Furthermore, proper quantification of the spatial distribution of properties and associated uncertainties is important for most reservoir engineering applications. But, before applying any reservoir characterization technique, some factors have to be analyzed, including the type of problem to be tackled and the information avail-able. With this research project, a practical and theoretically based technique was developed to determine preferential flow trends in the reservoir by integrating tracer response, Spearman rank correlation coefficient results and reservoir geology. The basic data required are tracer response information and production and injection rates that make the technique suitable for implementation in all types of reservoirs including ones with scarce information. The Spearman rank correlation coefficient, being a quick, simple and power-ful test of the existence of association of variables regardless of the shape of the population distribution from which the samples are drawn, provides a potential tool for investigating the correlation between production and injection rates in reservoirs. It was successfully applied to the flow rates of injector/producer pairs of wells in the North Buck Draw field to establish dominant communication trends in the reservoir. The major contribution of this work is to provide guidelines to assess infor-mation about variability of reservoir continuity in interwell regions from the widely available measurements of production and injection rates at existing wells. The in-formation gained from the application of this technique can contribute to both the daily reservoir management, and the future design, control and interpretation of sub-sequent projects in the reservoir, without the need of additional data.Petroleum and Geosystems Engineerin
Fluid Discrimination Using De-Trended Seismic Impedance
Compaction effects can obscure the impedance separation between hydrocarbon-bearing and fully brine-saturated sandstones. Discrimination can be improved by removing depth-related trends from inverted seismic impedance. Although the ratio of compressional-to-shear wave velocity versus seismic compressional-wave impedance cross plots show differences between pay, brine sand, and shale trends, using absolute inverted impedances only imperfectly distinguishes hydrocarbon sands from brine sands due to outliers. In a given locality, statistical comparison of well log and seismic-derived impedances enables a shale impedance model to be obtained and used as a lithology baseline to de-trend the impedance from the effects of burial and overburden. This has the effect of unmasking anomalies associated with hydrocarbon-bearing sands and serves as a reliable fluid discriminator. For an offshore Gulf of Mexico dataset on the flank of a salt dome, with pay occurring over a wide range of depths, we find that hydrocarbon-bearing sands are identified with a greater success rate after de-trending the absolute seismic impedance.Earth and Atmospheric Sciences, Department o