Porosity is one of the key parameters associated with oil reservoirs. Determination of this petrophysical parameter is an essential step in reservoir characterization. Among different linear and nonlinear prediction tools such as multi-regression and polynomial curve fitting, artificial neural network has gained the attention of researchers over the past years. In the present study, two-dimensi...

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 ...

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...

Colmenar Limestone is one of the traditional materials most commonly used in monuments in Madrid, Spain. The petrophysical properties of this stone determine its high resistance to decay. Its low water absorption and pore size distribution favour good hydraulic behaviour, which is likewise furthered by its high ultrasound velocity and low anisotropy. The durability findings pursuant to the 280 ...

Surface geological and geochemical mapping have been key technical contributors to many gold discoveries over the past 25 years. However, in the last ten years there has been a growing emphasis on using geophysical techniques to compliment them in covered terrains. As the search for gold deposits under covered areas expands, there will be increasing emphasis on integrating the geoscientific dis...

estimation of reservoir water saturation (sw) is one of the main tasks in well logging. many empirical equations are available, which are, more or less, based on archie equation. the present study is an application of radial basis function neural network (rbfnn) modeling for estimation of water saturation responses in a carbonate reservoir. four conventional petrophysical logs (pls) including d...

Two-dimensional (2D) NMR techniques have been proposed as efficient methods to infer a variety of petrophysical parameters, including mixed fluid saturation, in-situ oil viscosity, wettability, and pore structure. However, no study has been presented to quantify the petrophysical limitations of such methods. We address this problem by introducing a pore-scale framework to accurately simulate su...