Effective porosity

About: Effective porosity is a research topic. Over the lifetime, 1199 publications have been published within this topic receiving 26511 citations.

Best tracer selection for hydrogeological investigations: preliminary results from laboratory test

Abstract: Tracers techniques are a good tool to investigate groundwater dynamics; they are essential to perform measurement of hydrogeological parameters of aquifers. This study was aimed at characterizing adsorption, effective porosity and pore water velocity in soil samples collected in a hydrographic basin of Marche Region (Italy). This basin has the typical geologic and hydrogeological features of many basins in Central Italy. Therefore. the principal aim is to evaluate the best tracer to be used for hydrogeological purpose (i.e. groundwater tracer test and aquifer parameter estimation). Adsorption has been investigated by means of laboratory batch tests using different tracers and involving different soils. In literature some application of tracers both to laboratory scale and to field scale can be found. Column tests have been performed also to test the effectiveness of different test equipment and to investigate the influence of some test parameters on the calculation of effective porosity and pore water velocity. These considerations and test results are very useful to advise the choice of the best tracer to be used in tracer field tests.

Reservoir Characterization with Acoustic Impedance Inversion and Multi attribute Method on "essen" Field, Talang Akar Formation, Sub-Ciputat Basin, North West Java

Abstract: Acoustic impedance and multi-attribute seismic inversion seismic are a number of seismic methods that can be used to map sandstone reservoir distribution Using this method, we can separate the sandstone and shale in the Talang Akar Formation found on the "Essen" Field, Ciputat Sub-Basin Both of these methods will be compared with each other in order to get more valid results in sandstone reservoir mapping The inversion method used in this study is a model-based method While the multi-attribute method used is the neural network in mapping gamma-ray volume, shale volume, and porosity The inversion results are not able to image the sandstone distribution good enough because the range is too large and there is overlapping on the acoustic impedance values of sandstones with ranges (8000-12000) (m/s)*(g/cc) The results of the gamma-ray multi-attribute, shale volume and porosity, have been shown to consistently show the distribution of sandstones that have a trend in the distribution of NW-SE reservoir zones From the results of the analysis there are several potential areas that have the potential to become the next development area, namely the distribution of sandstones in the northern part with high effective porosity, and good seals; In the south with a large volume of sandstones; as well as the distribution formed on the channel surrounding the fault

Method of determining porosity

Abstract: This invention relates to the art of determining the porosity of solid, non-compressible, permeable bodies, and more particularly to the determination of the porosity of rock samples taken during the drilling of oil wells. Such rock samples are commonly referred too as cores, and the rock strata...

Effective porosity determination for tight gas formations

Abstract: A disclosed effective porosity determination method for tight gas formations includes: obtaining a core sample sealed in a pressure-maintaining core vault during transport out of the borehole; coupling the core vault to a collection chamber; based at least in part on measured pressure, temperature, and fluid volumes in the collection chamber, deriving the number of moles of gas retrieved with the core sample; and combining the number of moles with a downhole pressure, a downhole temperature, and a downhole core sample volume to determine an effective porosity of the tight gas formation. A system embodiment includes: a coring tool having a core vault with a seal to provide pressure-preserved transport of a core sample from a tight gas formation; a collection chamber that attaches to the core vault to measure volumes of fluids and gas; and a processing unit that responsively determines an effective porosity of the tight gas formation.

Log-Analysis Problems Associated with Bimodal Pore System, Interlake Formation, North Dakota: ABSTRACT

Abstract: The Interlake Formation is a Silurian-age sequence of dolostones, which produces hydrocarbons in the Williston basin. Log analysis of numerous Interlake wells from the Nesson anticline reveals that both water-productive and hydrocarbon-productive zones commonly have calculated water saturations in excess of 60%. These high calculated water saturations, in zones that produce water-free hydrocarbons, appear to be the result of a bimodal pore system. Non-fabric selective vugular pores are the major type of porosity seen in visual examination of Interlake cores. These vugs have been interconnected by fracturing and are responsible for most of the hydrocarbon production. The matrix that separates the vugs is composed of small equant dolomite crystals and also contains large am unts of intercrystalline microporosity, which is interconnected by pore throats less than 0.5 µm across. These small pore throats result in low permeability and high capillary pressures; thus the microporosity is capable of holding 100% irreducible water, whereas the vugular pores produce water-free hydrocarbons. Because it composes up to 50% of the total porosity, this microporosity drastically reduces the resistivity of the formation. Recognition that a formation contains a significant amount of microporosity is important not only in preventing bypassed production, but also in determining reserves and exploration economics. Determination of the percentage of effective porosity cannot be made using electric log or conventional core analysis. A combination of special core analysis and petrographic techniques is needed to better define the amount of effective porosity. End_of_Article - Last_Page 296------------