This paper presents a general review of gas hydrate knowledge, the utilization of such knowledge in the natural gas industry, some contemplated uses of gas hydrates in sea water desalinization, and discusses the existence of natural gas hydrates under the permafrost of the Northern Hemisphere. The theory of how gases enter the water phase and cause premature crystallization of water into an ice-like hydrate structure is presented. With this background, hydrate formation in ocean sediments is considered.

In the present investigation, we have carried out power spectrum analysis of sunspot number and great hard X-ray (GHXR) burst (equal to or greater than i0,000 counts per second) for a period of about 6 years. The GHXR bursts show a periodicity of about 155 days. On the other hand, sunspot numbers do not show any periodicity. The GHXR burst periodicity confirms the existence of a 152-158 days periodicity in the occurrence of solar energetic events. Further, the GHXR bursts are showing periodicity independently indicating that the GHXR bursts are a separate class of X-ray flares.

No abstract

No abstract

No abstract

Here we have carried out a power-spectrum analysis of solar nuclear gamma-ray (NGR) flares observed by SMM and HINOTORI satellites. The solar NGR flares show a periodicity of 152 days, confirming the existence of a 152-158 days periodicity in the occurrence of solar activity phenomena and also indicating that the NGR flares are a separate class of solar flares . The power-spectrum analysis of the daily sunspot areas on the Sun for the period 1980-1982 shows a peak around 159 days while sunspot number data do not show any periodicity (Verma and Joshi, 1987). Therefore, only sunspot area data should be treated as an indicator of solar activity and not the daily sunspot number data. l.IntroductionDuring the solar cycle 21, 152-158 day periodicity was detected in the rate of occurrence of energetic solar flares. This periodicity was first pointed out by Rieger et al. (1984) from the occurrence rate of solar gamma-ray (GR) bursts detected above 300 keY . Rieger et al. (1984) found that soft X-ray bursts also show a 152 day periodicity in the rate of GOES events with classification > M 2.5. Kiplinger et al. (1984) studied larger sample of 6775 solar hard X-ray (HXR) bursts above 30 key and found a 158 day periodicity. Ichimoto et al. (1985) found similar periodicity from H-alpha flare data observed during solar cycles 20 and 21.Bogart and Bai (1985) carried out a power-spectrum study of microwave (MW) emission bursts observed on 1 GHz for the period 1966-1983 and found a 152 day periodicity. Verma and Joshi (1987) analysed strong HXRbursts and sunspot number data for the period 1980-1984 and found a 155 day periodicity in case of strong HXR events and no periodicity in case of sunspot number data. Wolff (1983) carried out Fourier analysis of the variation of the mean monthly sunspot numbers for the period 1799-1979 and found that the most prominent peak below 200 days is 155.4 days, remarkbly close to the period for flares in cycle 21.In the present work, we have carried out a power-spectrumanalysis of daily solar NGR flares, sunspot area data and umbral area data. Observational Data, Analysis and ResultsIn the present investigation we have used data of flares observed by SMM satellite during the period 1980-1985 and HINOTORI satellite during 1981 -1982 The SMM satellite recorded 92 NGR flares (Cliver et ai.,1989).

Hydrate formation from gases dissolved in hydrocarbon liquids partially strips lighter components from the liquid phase. Experiments demonstrate why Alaskan North Slope crude oils found below the permafrost can be expected to be denuded of a substantial portion of their dissolved gases. Introduction Gas hydrates are crystalline, ice-like solids formed when certain light hydrocarbons and other low-molecular-weight, nonpolar substances are contacted with water. Previous work in this field, which has been extensively reviewed, bad the major thrust of defining conditions that allow industrial gas-processing units to operate free from deposition of solid hydrates. Gas hydrates are known to exist in natural gas fields in colder climates, and it is believed that they also can exist in oil fields, under permafrost, if suitable pressure-temperature permafrost, if suitable pressure-temperature conditions prevail. The majority of previous studies considered conditions for hydrate formation from pure gases and gas mixtures, although it is now known that a gas phase need not be present to form hydrates. That is, gas hydrates can be formed from liquids containing dissolved hydrate-forming gases. It follows that if hydrate-forming conditions exist in oil fields, the lighter hydrocarbons can be removed from crude oils, rendering the denuded crudes that are low in methane to isobutane constituents. Such denuded crudes will have no dissolved gases to expel the oil and will have high viscosity, making them difficult to displace. This problem can be further complicated by the blockage problem can be further complicated by the blockage of reservoir rock pores, which can reduce flow of oil to the recovery well. This study shows the denuding effect of hydrate formation on two condensates and one crude oil containing dissolved methane and propane gases, and is a continuation of our recent study on hydrate formation from methane-propane and methane-propane-decane liquid mixtures. Experimental Apparatus and Procedure The experimental apparatus, shown schematically in Fig. 1, consisted of an instrumented, high-pressure, glass-windowed cell immersed in a controlled temperature bath. In a typical run, each hydrocarbon component was charged quantitatively to the cell and the resulting mixture was pressurized by injecting water. After mixing by rocking the cell, the bubble-point curve was determined by a method described by Katz et al. Next, the four-phase (vapor, liquid hydrocarbon, liquid water, and hydrate) equilibrium point was measured by subcooling the system to initiate hydrate formation, bringing the cell to equilibrium conditions, and holding for 6 to 8 hours. Only a few hydrate crystals and a very small gas bubble were allowed to exist in equilibrium with the large hydrocarbon phase to insure small changes from the initial measured composition. To demonstrate denuding, all hydrate crystals were melted and the system was pressurized well above the bubble point at a temperature below the quadruple point. Large amounts of hydrates were formed. point. Large amounts of hydrates were formed. JPT P. 223

In this investigation, we have studied the latitudinal, longitudinal (northern and southern hemispheric) distributions based on 1737 major flares observed during solar cycles 19 and 20 (see subsequent paragraphs) and have arrrived at some interesting results which go to show that as far major flares are concerned latitudewise 1'1-20 ~ belts, and longitudewise 5-8 places are most prolific in producing major flares in each hemisphere. During the above cycles at least 5 flare zones are present in each hemisphere. In fact these zones seem to produce more than 50 % of the total number of energetic flares investigated by us and occupy only < 4% area of the Sun.