For the first time the features of regional and local hydrogeochemical background and hydrogeochemical anomalies was identified in the contiguous zones of hydrocarbon deposits. It was established the statistical patterns of behaviour of the main macro and micro components, water-dissolved gases and gas saturation at the distance from water-oil and gas-water contacts. The hydrogeological model of 37reference hydrocarbon fields are made and in the first variant schemes of their water halos of dispersion are proposed. It has been established that a comprehensive interpretation of the available hydrogeochemical materials, based on statistical analysis methods, allows to substantiate the direction of prospecting for oil and gas with a high degree of reliability. The most reliable hydrogeological criteria are gas, since they are the most active components of the "water-rock-gas-organic matter" system.