FEATURES OF DRY MIXTURES FOR OIL AND GAS WELLS CEMENTING

Abstract

The article describes a relatively new and promising direction – the usage of dry cement mixtures in oil and gas wells construction. The key to the success of the cementing quality and is correctly selected for the specific conditions of tampon mixture. Until recently, the grouting mixture was made to cook directly in the field using mobile workshops, equipped, usually pneumatic supply and mixing of the components and then loads of ready mix in cement. In recent years, the method of producing cement mixtures in the factory, where the mixture is prepared in areas with better infrastructure and then delivered to the field, well established itself. The authors substantiate the possibility of dry cement mixtures at various downhole conditions using a mixture of appropriate additives, and describe the effect of additives on the parameters of the cement slurry. Despite a number of features that distinguish grouting mixture of traditional building, in their formulations, mainly used similar additives: water retention, pla-stifitsiruyuschie, accelerators, retarders, fiber, polymer powders. Widespread additives with special properties (materials, to prevent fluid loss, weights, oblegchiteli) due to the specific nature of downhole conditions. Special conditions of application of cement slurries and imply specific requirements applicable to the oil and gas industry in the traditional additives for dry construction mixtures. So, for polymer powders backfill material should consist of polymers with short chains and to be thermally stable when used at elevated temperatures. Many of the used oil and gas additives have complex effects on the backfill solution. Competent selection of additives, based on data about the geotechnical conditions at a specific field, provide qualitative dry grouting mixture, the use of which is the key to successful cementing operations.