Methodology of experimental filtration studies (releases) from high-pressure inter-salt productive deposits of industrial lithium-bearing brines of the hydrogeological halogen-carbonate formation of the Siberian platform

Abstract

It is known that all our knowledge about the industrial brines of the Siberian platform was obtained while drilling wells for oil and gas whereas targeted studies of brine-bearing horizons in deep wells for hydrocarbons are hardly conducted. One of the reasons is the high daily rate in the drilling cycle resulting in carrying out strictly limited additional works not related to drilling. Meanwhile, the geological results including the forecast, the estimation of the calculated parameters of the section productive intervals, the exploration and development methodology of deposits of industrial metal-bearing brines with abnormally high reservoir pressure directly depend on the data of the hydrodynamic studies. Today, large companies – subsurface users of the south of the Irkutsk region are tasked to determine the methodology of short-term pilot releases, which provides correct input data for reserve calculation of industrial brines of natural inter-salt carbonate fractured reservoirs of the hydrogeological halogen-carbonate formation. To determine a reliable permeability coefficient under the experimental filtration work, it is necessary to achieve a quasi-stationary filtration mode. The optimal mode is an intermittent one of brine release with a constant flow rate at the same time intervals with a continuous recording of pressure changes by the telemetry system. The results of pilot releases implemented at the Znamenskiy site of the Angara-Lena deposit of industrial lithium-bearing brines have been considered. The release methods enabling the performance of experimental filtration work in a short time, and applicable in well construction for hydrocarbon production have been proposed. Surface users can carry out the research using the proposed methodology in the case when the well bottom unexpectedly opens a brine formation with an abnormally high reservoir pressure of the fluid system. The implementation of experimental filtration work employing the described methods allows the subsoil users to substantiate the resource base of industrial brines and the elements in them including lithium, rubidium, cesium, bromine, iodine and other rare, trace elements and mineral salts.