Investigation of the fluids influence on change of sandstones collectors mechanical properties during saturation and degassing

Serhii Tynyna,Vasyl Babenko,A Bulat,V Heyets,B Liu,Y Kryzhanivskyi,O Voloshyn

doi:10.1051/e3sconf/201910900103

Abstract

The article discusses the effect of fluids on the properties of rocks. It is known that surface active environments, including gas, can significantly change the mechanical characteristics of solids. To establish the dependence of the effect of methane on the strength characteristics of rocks, the results of full-scale and laboratory studies are considered. The experiments were carried out on samples of outburst sandstone formation m3, taken at a depth of 915 m. Analysis of research results allowed to establish the effect of changes in gas saturation of rocks on their mechanical properties before and after degassing and partial discharge of experimental areas after they have been worked by lavas along m3 formation. It has been established that the reason for the increase in drillability and strength of sandstones was their degassing, and not a change in the stress state of the environment. This led to a change in the deformation properties of rocks in gas-saturated and degassed states.

Highlights

In oil, gas, chemical industries, much attention is paid to the search for surface active agents that can change the strength properties of solid environments and materials [1]
By drillability, the strength of outburst sandstones can be determined in those parts of the massif in which the core was divided into disks during the drilling of wells
The mechanical characteristics of outburst and outburst-safe sandstones differ noticeably among themselves. These differences are clearly seen in the gas-saturated state of the rocks and are largely smoothed out when they are degassed

Summary

Introduction

Gas, chemical industries, much attention is paid to the search for surface active agents (surfactants) that can change the strength properties of solid environments and materials [1]. Aqueous solutions of surfactants are used to reduce the strength when drilling oil and gas wells. It is known that surface-active environments, including gas, can significantly change the mechanical characteristics of solid bodies [2]. The bottomhole and marginal part of coal seams is strengthened during degassing [2, 3]. A change in the strength of coal by 25–30 % with saturation with methane was confirmed under laboratory conditions [4, 5]. The injection of water with surfactant additives into coal seams is one of the ways to control emissions [6]

Methods

Results

Conclusion