Actual Saturation Research Articles

Oxygen affinity independent action of cyanate and 2,3 DPG on sickling.

Since the Hb S oxygen dissociation curve is shifted to lower partial pressures by carbamylation, it seems important to know whether the cyanate induced in vitro inhibition of sickling is completely or partially due to this increase in oxygen affinity. In order to detect a possible direct interference of carbamyl groups with the aggregation of deoxy-hemoglobin S molecules, sickling was compared in carbamylated and noncarbamylated sickle cells, and the number of sickled forms and the actual oxygen saturations of the hemoglobin were determined simultaneously. These studies have shown that the cyanate effect on sickling is partially independent of the effect of cyanate on oxygen affinity.

14C‐Studies on Apple Trees. IV. Photosynthate Consumption in Fruits in Relation to the Leaf‐Fruit Ratio and to the Leaf‐Fruit Position

AbstractThe photosynthate consumption in apple fruits in relation to the leaf/fruit ratio was studied in sections of branches of the Graasten and Golden Delicious varieties by exposure to 14CO2during July and August. A significant, negative correlation was found between the fixation of 14C in the fruits in terms of percent of the total amount of 14C absorbed and the leaf/fruit ratio of the branch sections. The leaf area required for the saturation of one fruit was found to be ca. 190 and 230 cm2 (14 and 17 leaves) in the case of Golden Delicious, and ca. 400 and 670 cm2 (25 and 42 leaves) for Graasten in July and August, respectively, calculated under conditions of large leaf areas per fruit. In such cases a fairly good, reverse proportionality exists between the 14C fixation in the fruit in terms of percent and the leaf area expressed in multiples of saturation area. At low leaf/fruit ratios, however, the actual saturation area is found to be lower than the theoretically computed one.The translocation of the 14C assimilated in the leaves of the extension shoots or of spurs without fruits to fruits on other spurs was on the whole promoted by a decreasing leaf/fruit ratio in the parts in question; similarly the greatest transport took place on the side where the leaf/fruit ratio was lowest. The fixation was often greatest in the fruit closest to the treated leaves, hut in a number of cases the value was higher for the second closest or even further removed fruits. In this connection the importance of the size of the fruit and the vascular connections is discussed.

Logging Observation Wells in Gas Storage

Abstract The underground storage of gas is relatively new in certain parts of the country, and the problems involved are unique. Some of these problems can be solved through use of electrical wireline logging services. Information concerning the actual gas saturation, growth of the gas bubble, and leakage into thief zones can be obtained with a logging program of formation density logs and gamma ray-neutron logs. The selection of logging services for observation is governed by the completion method. If the hole through the storage zone is uncased, a formation density log can be used to determine gas saturation. If casing is set through the storage zone, the neutron log is employed. Field examples of projects located in Illinois, Indiana and Kentucky are used to illustrate the interpretation techniques. Introduction Gas is stored in permeable and porous formations which have a suitable cap rock and sufficient closure, caused either by structure or stratigraphy. The storage zones are of two main types:those that were originally aquifers, containing only water, andthose that contained gas or oil as well as water. The well logs recorded in a gas storage observation well are, in many cases, the same as those used by the oil industry. There is, however, a significant difference in the interpretation and application of the logs. In a storage field the gas saturation is quite often changing daily as gas is injected or withdrawn, and occasionally gas moves from the storage zone to a different permeable and porous horizon and builds up there in considerable quantities. It is important to know how much gas is available in the storage zone and what quantity has migrated to another horizon. At the present time there are two tools used to determine gas saturations in the storage zone:the formation density log, when casing is set on top of the zone, andthe neutron log, when the casing has been set through the storage zone. Formation Density Logging of Observation Wells The formation density log measures the average bulk density of the formation investigated by the tool. The bulk density p, of a formation having a grain density pa and a porosity filled with fluid of density p, is given by: (1) The fluids of interest in gas storage reservoirs are formation water and gas. Formation water density p. ranges from about 1 to 1.15 gm/cc depending upon its temperature, pressure and salinity. The density of gas p, in these relatively shallow low-pressure reservoirs is negligible and may be considered to be zero. Thus, p, in Eq. 1 may be written as: In a reservoir containing only water and gas, Eq. 1 for the bulk density may therefore be written: where Sw is that fraction of pore volume filled with-water of density p. (the remaining fraction of pore volume, 1 - Sw, or Sg, being filled with gas whose density, pg is assumed to be zero).Solving the last equation for Sw and setting pw equal to 1: Since(2) Eq. 2 gives the gas saturation when, phi and p are known. may be taken as 2.65 gm/cc for most sandstones, as 2.71 gm/cc for most limestones and as 2.87 gm/cc for dolomites. The value of phi is known from core analysis or the density log or sonic log responses when the reservoir contained only water (prior to gas injection).The value p is the true bulk density of the zone when it contains some gas. Eq. 2 may be used when the true p is known. JPT P. 745ˆ

Improved Interpretation of Formation Productivity by Combined Use of Core Analysis and Electric Log Data: ABSTRACT

ABSTRACT Reservoir properties, such as permeability, porosity, residual fluid saturations, and capillary pressure characteristics are obtained by direct measurement of core samples. Electric logging devices provide information for computing approximate values for the formation factor or porosity, formation water resistivity, and formation water saturation. In the past, these two formation evaluation tools have been used more or less independently of each other. This paper presents a method of combining core analysis and electric log information to obtain more reliable interpretations of fluid productivity. The porosity and the immobile interstitial water saturation derived from core analysis may be used to compute a value which is called productive resistivity, or (Rp). Productive resistivity is defined to be the resistivity of a hydrocarbon-productive formation with an interstitial water saturation equal to or less than the immobile value. The deep investigation electric logging devices, such as the induction log, approach in measurement the true resistivity or (Rt), from which the formation water saturation can be calculated. If the true formation resistivity measured by the electric or induction log is less than the calculated productive resistivity, it may be concluded that or induction log is less than the calculated productive resistivity, it may be concluded that the actual water saturation is greater than the immobile interstitial water, and the formation interval may be either partially or wholly water-productive. On the other hand, if the measured resistivity equals or exceeds the productive resistivity calculated from core analysis, it may be concluded that the actual formation water saturation is no greater than the immobile interstitial water and the sand is probably wholly hydrocarbon-productive. A similar calculation may be made using a higher water saturation value taken from the transitional zone to determine a value called the minimum productive resistivity, or Rmp.