Reservoir characterization This paper gives an overview of the activities in geostatistics for the Petroleum industry in the domain of reservoir characterization. This description has been simplified in order to emphasize the original techniques involved. The main steps of a study consist in successively building: • the reservoir architecture where the geometry of the units is established, • th...

Proper determination of bed boundaries in layered reservoirs is vital ‎for accurate petrophysical interpretation of conventional logs. In the ‎wellbore, logs continuously measure physical properties of reservoir ‎while the properties change stepwise. This continuous representation ‎of logs may lead to ignorance of some high potential reservoir zones. ‎The main reasons for continuous nature of l...

[1] Direct estimation of groundwater solute concentrations from geophysical tomograms has been only moderately successful because (1) reconstructed tomograms are often highly uncertain and subject to inversion artifacts, (2) the range of subsurface conditions represented in data sets is incomplete because of the paucity of colocated well or core data and aquifer heterogeneity, and (3) geophysic...

Tight reservoir means reservoir of low porosity and low permeability. Many tight formations are extremely complex, produced from multiple layers with different permeability that is often enhanced by natural fracturing. The complicity of these reservoirs is attributed to a) Low porosity and low permeability reservoir, b) The presence of clay minerals like illite, kaolin and micas in pores, c) Th...

Porosity is one of the fundamental petrophysical properties that should be evaluated for hydrocarbon bearing reservoirs. It is a vital factor in precise understanding of reservoir quality in a hydrocarbon field. Log data are exceedingly crucial information in petroleum industries, for many of hydrocarbon parameters are obtained by virtue of petrophysical data. There are three main petrophysical...

We discuss petrophysical analysis of wireline logs, methods for formation evaluation and issues in evaluating tight sandstone formations. The main concerns of log interpretation in tight gas sandstones include porosity interpretation, understanding the effect of clay on the log responses, accurate computation of water saturation, and permeability determination (Kukal et al., 1985). Moreover, va...

NMR is a popular logging technique used to estimate pore size information, formation permeability, wettability and irreducible water saturation. Quantitative interpretation of NMR data is based on a set of fundamental assumptions (e.g., pore isolation and fast diffusion). These assumptions establish the quantitative link between NMR response and petrophysical predictions. While there is a need ...

[1] Geophysical imaging has traditionally provided qualitative information about geologic structure; however, there is increasing interest in using petrophysical models to convert tomograms to quantitative estimates of hydrogeologic, mechanical, or geochemical parameters of interest (e.g., permeability, porosity, water content, and salinity). Unfortunately, petrophysical estimation based on tom...

Biyad Formation is mainly made up of clastic sediments that contain substantial amount of proven crude oil in the eastern Yemen. The Byiad clastic is divided into Upper and Lower Biyad clastic units. Several vertical wells have been drilled and penetrated this formation. This study is concerned with the petrophysical evaluation by means of well log data of the Lower Cretaceous rocks at the East...

[1] We have investigated the potential of combining cross-hole georadar velocity and attenuation tomography as a method for characterizing heterogeneous alluvial aquifers. A multivariate statistical technique, known as k-means cluster analysis, is used to correlate and integrate information contained in velocity and attenuation tomograms. Cluster analysis allows us to identify objectively the m...