ANALYSIS AND SELECTION OF A GROUTING MIXTURE, RESISTANT TO DYNAMIC LOADS, IN ORDER TO IMPROVE THE SUPPORT TIGHTNESS QUALITY IN THE ANNULUS

Abstract

The quality of well anchoring is a very urgent problem in the field of well cementing. During the development of the field, the well is subjected to both static and dynamic loads, while it is worth noting that the influence of the dynamic component is more significant, since when the cement stone is destroyed, complications associated with premature watering of the well may occur, and overflows may occur. The paper considers the analysis of the causes of the well support tightness breach during operation and selects a composition that increases cement stone strength characteristics. Relevance. The quality of well cementing is an urgent problem today. Due to the high complexity of predicting the behavior of rocks with various types of cements, situations related to the leakiness of the borehole often arise. Tthey lead to complications and accidents, and this in its turn increases the cost of work and the cost of their elimination. There are many works aimed at solving the problem of tightness quality, but despite this, the problem has not been solved and remains relevant and important in this field of research. Purpose: to develop the composition of a grouting mixture with high resistance to various loads to increase the strength characteristics of cement stone, in addition, it is necessary to consider the most promising additives, in particular, elastomers; to investigate their influence on the basic properties of cement mortar and stone. Methods. To achieve this goal, a literary review of foreign and domestic researchers was conducted. Laboratory tests of grouting mortar and cement stone with the addition of various concentrations of elastomer additives were carried out. The methods of determining the Young's modulus and the Poisson's ratio of the grouting stone are considered and applied. All studies were conducted in accordance with SS 34532-19 «Grouting cements. Test methods», SS 28985-91 «Mountain rocks. Method for determining deformation characteristics under uniaxial compression», SS 21153.3-85 «Mountain rocks. Methods for determining the tensile strength at uniaxial tension». Results. During the experiment, cement mortars with additives: latex and rubber crumb of different fractions (concentrations differ), were obtained. It was found that at the concentrations under consideration, the density of the solution decreases, the spreadability value increases, except for the concentration of 4 % latex, and the water separation of the solution with the addition of latex decreases. There was an increase in flexural and tensile strength for all samples. The composition of the cement mixture with the best indicators of the content of 3 % latex and 3 % rubber crumb fractions of 1–2 mm was determined. Conclusions. The developed composition of the grouting mixture with the addition of elastomers improves the quality of the support and has high resistance to dynamic loads during well operation.

Keywords

• fastening quality
• dynamic loads
• latex
• rubber crumb
• cement stone strength