Saturated hydrocarbon

Laminae of clay and clay drapes act as vertical or horizontal baffles or barriers to fluid flow and pressure communication. Dispersed days occupy pore space-which in a clean sand would be available for hydrocarbons. They may also obstruct pore throats, thus impeding fluid flow. Reservoir evaluation, is often complicated by the presence of clays. This is particularly true for the estimation of hydrocarbon saturation. 

Data gathering in the water column should not be overlooked at the appraisal stage of the field life. Assessing the size and flow properties of the aquifer are essential in predicting the pressure support which may be provided. Sampling of the formation water is necessary to assess the salinity of the water for use in the determination of hydrocarbon saturations. 

A vast variety of logging tools are In existence and Section 5.4 will cover only those which enable the evaluation of essential reservoir parameters, specifically net reservoir thickness, lithology, porosity and hydrocarbon saturation. 

The most oommon method for measuring formation resistivity and henoe determining hydrocarbon saturation is by logging with a resistivity tool such as the Laterolog. The tool is designed to force electrical current through the formation adjacent to the borehole... 

The data gathered from the logs and cores of the development wells are used to refine the correlation, and better understand areal and vertical changes in the reservoir quality. Core material may also be used to support log data in determining the residual hydrocarbon saturation left behind in a swept zone (e.g. the residual oil saturation to water flooding). 

Low reactivity contaminants halogenated hydrocarbons, saturated aliphatics, benzene. 

The analyses of gases in the oil industry comprises the determination of the inert gases (He, Hj, O2, Ar and N2), low-boiling compounds (CO, CO2, H2S, COS) and the lower hydrocarbons, saturated and unsaturated, up to hexane. Some special samples. Such as natural gas, have to be analysed for low concentrations of higher-boiling compounds (up to CiqS) since such compounds have an important influence on the calorific value and dew point. 

The true porosity <1> is determined with the neutron-density Pe logs. R is generally given by the deep investigation resistivity curve. R equals R, in the water formations. It increases rapidly in hydrocarbon saturated formations. 

C. E. Morriss, R. Freedman, C. Straley, M. Johnston, H. J. Vinegar, P. N. Tu-tunjian 1997, (Hydrocarbon saturation and viscosity estimation from NMR logging in the Belridge diatomite), Log Analyst 38 (2), 44-59. 

No, aromatic hydrocarbons cannot be saturated hydrocarbons. Saturated hydrocarbons, like hexane (C6H14), have only single bonds between the sp3 hybridized carbon atoms. 

Residual hydrocarbon saturation will exist within both the unsaturated and capillary zone through which the LNAPL phase migrated. As might be expected, residual hydrocarbon saturation tends to be higher as the grain size decreases and... 

Since hydrocarbon and water are immiscible fluids, free-phase recoverable LNAPL can simplistically be viewed as being perched on the capillary fringe above the actual water table with the understanding that what is being referred to as actual NAPL thickness is what one could perceive as being equivalent to the approximate thickness of that portion of the zone of hydrocarbon saturation that is considered mobile. The physical relationships that exist are illustrated in Figure 6.5. This discrepancy can be a result of one or a combination of factors or phenomena. Some of the more common factors or phenomena are schematically shown in Figure 6.6 and include ... 

More sophisticated methods for estimating LNAPL volumes have recently been proposed and are based on the general approach that the specific volume of LNAPL can be determined by integrating the hydrocarbon saturation over the vertical distance of its occurrence ... 

Graphs of relative permeability are generally similar in pattern to that shown in Figure 5.10. As shown, some residual water remains in the pore spaces, but water does not begin to flow until its water saturation reaches 20% or greater. Water at the low saturation is interstitial or pore water, which preferentially wets the material and fills the finer pores. As water saturation increases from 5 to 20%, hydrocarbon saturation decreases from 95 to 80% where, to this point, the formation permits only hydrocarbon to flow, not water. Where the curves cross (at a saturation... 

Baildown tests have been used for decades during the initial or preliminary phases of LNAPL recovery system design to determine adequate locations for recovery wells and to evaluate recovery rates. Baildown tests involve the rapid removal of fluids from a well with subsequent monitoring of fluid levels, both the LNAPL-water (or oil-water) interface and LNAPL-air (or oil-air) interface, in the well with time. Hydrocarbon saturation is typically less than 1, and commonly below 0.5, due to the presence of other phases in the formation (i.e., air and water). Since the relative permeability decreases as hydrocarbon saturation decreases, the effective conductivity and mobility of the LNAPL is much less than that of water, regardless of the effects induced by increased viscosity and decreased density of the LNAPL. 

Huntley, D., Hawk, R. N., and Corley, H. P., 1992, Non-Aqueous Phase Hydrocarbon Saturations and Mobility in a Fine-Grained, Poorly Consolidated Sandstone In Proceedings of the 1992 Petroleum Hydrocarbons and Organic Chemicals in Groundwater Prevention, Detection, and Restoration, National Ground Water Association, Columbus, OH, pp. 223-237. 

The site is a carwash facility located in the city of Escondido, in southern California. A sequence of investigative and remedial activities has been performed since 1987 that established the presence, nature, and extent of subsurface hydrocarbons derived from former USTs. Since conducting these activities, the former USTs have been removed and the hydrocarbon-affected soil surrounding the USTs has been excavated. Additionally, all potentially recoverable LNAPL (i.e., gasoline) has been removed, leaving only residual hydrocarbon saturation (i.e., smear zone) in place at the water table. Subsequent pump-and-treat activities have reduced dissolved BTEX concentrations to asymptotic levels (Figure 13.9). 

The solubilities of organic compounds such as alkanes, cycloalkanes, alkenes, aromatic hydrocarbons, saturated alkylamines, and N- and S-containing aromatic compounds in several ionic liquids were reported recently (86). The solubilities in the ionic liquid [TMAC]Al2Cl7 are listed in Table IV. 

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